Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Proteins isolated from the outer membrane of Gram-negative bacteria.
Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.
The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.
Glycoproteins found on the membrane or surface of cells.
Proteins found in any species of bacterium.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Established cell cultures that have the potential to propagate indefinitely.
A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)
Transport proteins that carry specific substances in the blood or across cell membranes.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
The sum of the weight of all the atoms in a molecule.
Proteins associated with the inner surface of the lipid bilayer of the viral envelope. These proteins have been implicated in control of viral transcription and may possibly serve as the "glue" that binds the nucleocapsid to the appropriate membrane site during viral budding from the host cell.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Proteins obtained from ESCHERICHIA COLI.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Cell membranes associated with synapses. Both presynaptic and postsynaptic membranes are included along with their integral or tightly associated specializations for the release or reception of transmitters.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Proteins prepared by recombinant DNA technology.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Ubiquitously expressed integral membrane glycoproteins found in the LYSOSOME.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.
The rate dynamics in chemical or physical systems.
Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.
The thermodynamic interaction between a substance and WATER.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.
Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.
Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Rhodopsins found in the PURPLE MEMBRANE of halophilic archaea such as HALOBACTERIUM HALOBIUM. Bacteriorhodopsins function as an energy transducers, converting light energy into electrochemical energy via PROTON PUMPS.
Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
Minute projections of cell membranes which greatly increase the surface area of the cell.
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.
A major integral transmembrane protein of the ERYTHROCYTE MEMBRANE. It is the anion exchanger responsible for electroneutral transporting in CHLORIDE IONS in exchange of BICARBONATE IONS allowing CO2 uptake and transport from tissues to lungs by the red blood cells. Genetic mutations that result in a loss of the protein function have been associated with type 4 HEREDITARY SPHEROCYTOSIS.
A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured. Such rupture is supposed to be under metabolic (hormonal) control. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Elements of limited time intervals, contributing to particular results or situations.
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).
Functionally and structurally differentiated, purple-pigmented regions of the cytoplasmic membrane of some strains of Halobacterium halobium. The membrane develops under anaerobic conditions and is made almost entirely of the purple pigment BACTERIORHODOPSINS. (From Singleton & Sainsbury Dictionary of Microbiology and Molecular Biology, 2d ed)
The thin layers of tissue that surround the developing embryo. There are four extra-embryonic membranes commonly found in VERTEBRATES, such as REPTILES; BIRDS; and MAMMALS. They are the YOLK SAC, the ALLANTOIS, the AMNION, and the CHORION. These membranes provide protection and means to transport nutrients and wastes.
Antibodies produced by a single clone of cells.
Structures which are part of the CELL MEMBRANE or have cell membrane as a major part of their structure.
The functional hereditary units of BACTERIA.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
An abundant lysosomal-associated membrane protein that has been found to shuttle between LYSOSOMES; ENDOSOMES; and the PLASMA MEMBRANE. Loss of expression of lysosomal-associated membrane protein 2 is associated with GLYCOGEN STORAGE DISEASE TYPE IIB.
Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.
Proteins found in any species of fungus.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
Compounds containing carbohydrate or glycosyl groups linked to phosphatidylinositols. They anchor GPI-LINKED PROTEINS or polysaccharides to cell membranes.
Substances elaborated by bacteria that have antigenic activity.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
A synaptic membrane protein involved in MEMBRANE FUSION of SYNAPTIC VESICLES with the presynaptic membranes. It is the prototype member of the R-SNARE PROTEINS.
The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.
A high molecular weight (220-250 kDa) water-soluble protein which can be extracted from erythrocyte ghosts in low ionic strength buffers. The protein contains no lipids or carbohydrates, is the predominant species of peripheral erythrocyte membrane proteins, and exists as a fibrous coating on the inner, cytoplasmic surface of the membrane.
Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
The space between the inner and outer membranes of a cell that is shared with the cell wall.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
Vesicles that are involved in shuttling cargo from the interior of the cell to the cell surface, from the cell surface to the interior, across the cell or around the cell to various locations.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.
A subfamily of Q-SNARE PROTEINS which occupy the same position as syntaxin 1A in the SNARE complex and which also are most similar to syntaxin 1A in their AMINO ACID SEQUENCE. This subfamily is also known as the syntaxins, although a few so called syntaxins are Qc-SNARES.
A large group of membrane transport proteins that shuttle MONOSACCHARIDES across CELL MEMBRANES.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
SNARE proteins where the central amino acid residue of the SNARE motif is an ARGININE. They are classified separately from the Q-SNARE PROTEINS where the central amino acid residue of the SNARE motif is a GLUTAMINE. This subfamily contains the vesicle associated membrane proteins (VAMPs) based on similarity to the prototype for the R-SNAREs, VAMP2 (synaptobrevin 2).
The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC
Measurement of the intensity and quality of fluorescence.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The ability of a substrate to allow the passage of ELECTRONS.
Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.
Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.
Sites on an antigen that interact with specific antibodies.
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.
The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
Condensed areas of cellular material that may be bounded by a membrane.
Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
The major sialoglycoprotein of the human erythrocyte membrane. It consists of at least two sialoglycopeptides and is composed of 60% carbohydrate including sialic acid and 40% protein. It is involved in a number of different biological activities including the binding of MN blood groups, influenza viruses, kidney bean phytohemagglutinin, and wheat germ agglutinin.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a serine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and serine and 2 moles of fatty acids.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
Single membrane vesicles, generally made of PHOSPHOLIPIDS.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
A fungal metabolite which is a macrocyclic lactone exhibiting a wide range of antibiotic activity.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
An anionic surfactant, usually a mixture of sodium alkyl sulfates, mainly the lauryl; lowers surface tension of aqueous solutions; used as fat emulsifier, wetting agent, detergent in cosmetics, pharmaceuticals and toothpastes; also as research tool in protein biochemistry.
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. They play a role in the intracellular transport of molecules contained within membrane vesicles. Vesicular transport proteins are distinguished from MEMBRANE TRANSPORT PROTEINS, which move molecules across membranes, by the mode in which the molecules are transported.
A family of membrane-associated proteins responsible for the attachment of the cytoskeleton. Erythrocyte-related isoforms of ankyrin attach the SPECTRIN cytoskeleton to a transmembrane protein (ANION EXCHANGE PROTEIN 1, ERYTHROCYTE) in the erythrocyte plasma membrane. Brain-related isoforms of ankyrin also exist.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A fold of the mucous membrane of the CONJUNCTIVA in many animals. At rest, it is hidden in the medial canthus. It can extend to cover part or all of the cornea to help clean the CORNEA.
The inner layer of CHOROID, also called the lamina basalis choroideae, located adjacent to the RETINAL PIGMENT EPITHELIUM; (RPE) of the EYE. It is a membrane composed of the basement membranes of the choriocapillaris ENDOTHELIUM and that of the RPE. The membrane stops at the OPTIC NERVE, as does the RPE.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.

Membrane-tethered Drosophila Armadillo cannot transduce Wingless signal on its own. (1/57141)

Drosophila Armadillo and its vertebrate homolog beta-catenin are key effectors of Wingless/Wnt signaling. In the current model, Wingless/Wnt signal stabilizes Armadillo/beta-catenin, which then accumulates in nuclei and binds TCF/LEF family proteins, forming bipartite transcription factors which activate transcription of Wingless/Wnt responsive genes. This model was recently challenged. Overexpression in Xenopus of membrane-tethered beta-catenin or its paralog plakoglobin activates Wnt signaling, suggesting that nuclear localization of Armadillo/beta-catenin is not essential for signaling. Tethered plakoglobin or beta-catenin might signal on their own or might act indirectly by elevating levels of endogenous beta-catenin. We tested these hypotheses in Drosophila by removing endogenous Armadillo. We generated a series of mutant Armadillo proteins with altered intracellular localizations, and expressed these in wild-type and armadillo mutant backgrounds. We found that membrane-tethered Armadillo cannot signal on its own; however it can function in adherens junctions. We also created mutant forms of Armadillo carrying heterologous nuclear localization or nuclear export signals. Although these signals alter the subcellular localization of Arm when overexpressed in Xenopus, in Drosophila they have little effect on localization and only subtle effects on signaling. This supports a model in which Armadillo's nuclear localization is key for signaling, but in which Armadillo intracellular localization is controlled by the availability and affinity of its binding partners.  (+info)

Membrane fusion: structure snared at last. (2/57141)

The structure of the core of the neuronal 'SNARE complex', involved in neurotransmitter release, has been determined recently. Its topological similarity to viral fusion proteins suggests how the SNARE complex might facilitate membrane fusion.  (+info)

The hematopoietic-specific adaptor protein gads functions in T-cell signaling via interactions with the SLP-76 and LAT adaptors. (3/57141)

BACKGROUND: The adaptor protein Gads is a Grb2-related protein originally identified on the basis of its interaction with the tyrosine-phosphorylated form of the docking protein Shc. Gads protein expression is restricted to hematopoietic tissues and cell lines. Gads contains a Src homology 2 (SH2) domain, which has previously been shown to have a similar binding specificity to that of Grb2. Gads also possesses two SH3 domains, but these have a distinct binding specificity to those of Grb2, as Gads does not bind to known Grb2 SH3 domain targets. Here, we investigated whether Gads is involved in T-cell signaling. RESULTS: We found that Gads is highly expressed in T cells and that the SLP-76 adaptor protein is a major Gads-associated protein in vivo. The constitutive interaction between Gads and SLP-76 was mediated by the carboxy-terminal SH3 domain of Gads and a 20 amino-acid proline-rich region in SLP-76. Gads also coimmunoprecipitated the tyrosine-phosphorylated form of the linker for activated T cells (LAT) adaptor protein following cross-linking of the T-cell receptor; this interaction was mediated by the Gads SH2 domain. Overexpression of Gads and SLP-76 resulted in a synergistic augmentation of T-cell signaling, as measured by activation of nuclear factor of activated T cells (NFAT), and this cooperation required a functional Gads SH2 domain. CONCLUSIONS: These results demonstrate that Gads plays an important role in T-cell signaling via its association with SLP-76 and LAT. Gads may promote cross-talk between the LAT and SLP-76 signaling complexes, thereby coupling membrane-proximal events to downstream signaling pathways.  (+info)

Sonic hedgehog signaling by the patched-smoothened receptor complex. (4/57141)

BACKGROUND: The Hedgehog (Hh) family of secreted proteins is involved in a number of developmental processes as well as in cancer. Genetic and biochemical data suggest that the Sonic hedgehog (Shh) receptor is composed of at least two proteins: the tumor suppressor protein Patched (Ptc) and the seven-transmembrane protein Smoothened (Smo). RESULTS: Using a biochemical assay for activation of the transcription factor Gli, a downstream component of the Hh pathway, we show here that Smo functions as the signaling component of the Shh receptor, and that this activity can be blocked by Ptc. The inhibition of Smo by Ptc can be relieved by the addition of Shh. Furthermore, oncogenic forms of Smo are insensitive to Ptc repression in this assay. Mapping of the Smo domains required for binding to Ptc and for signaling revealed that the Smo-Ptc interaction involves mainly the amino terminus of Smo, and that the third intracellular loop and the seventh transmembrane domain are required for signaling. CONCLUSIONS: These data demonstrate that Smo is the signaling component of a multicomponent Hh receptor complex and that Ptc is a ligand-regulated inhibitor of Smo. Different domains of Smo are involved in Ptc binding and activation of a Gli reporter construct. The latter requires the third intracellular loop and the seventh transmembrane domain of Smo, regions often involved in coupling to G proteins. No changes in the levels of cyclic AMP or calcium associated with such pathways could be detected following receptor activation, however.  (+info)

Alzheimer's disease: clues from flies and worms. (5/57141)

Presenilin mutations give rise to familial Alzheimer's disease and result in elevated production of amyloid beta peptide. Recent evidence that presenilins act in developmental signalling pathways may be the key to understanding how senile plaques, neurofibrillary tangles and apoptosis are all biochemically linked.  (+info)

Vac1p coordinates Rab and phosphatidylinositol 3-kinase signaling in Vps45p-dependent vesicle docking/fusion at the endosome. (6/57141)

The vacuolar protein sorting (VPS) pathway of Saccharomyces cerevisiae mediates transport of vacuolar protein precursors from the late Golgi to the lysosome-like vacuole. Sorting of some vacuolar proteins occurs via a prevacuolar endosomal compartment and mutations in a subset of VPS genes (the class D VPS genes) interfere with the Golgi-to-endosome transport step. Several of the encoded proteins, including Pep12p/Vps6p (an endosomal target (t) SNARE) and Vps45p (a Sec1p homologue), bind each other directly [1]. Another of these proteins, Vac1p/Pep7p/Vps19p, associates with Pep12p and binds phosphatidylinositol 3-phosphate (PI(3)P), the product of the Vps34 phosphatidylinositol 3-kinase (PI 3-kinase) [1] [2]. Here, we demonstrate that Vac1p genetically and physically interacts with the activated, GTP-bound form of Vps21p, a Rab GTPase that functions in Golgi-to-endosome transport, and with Vps45p. These results implicate Vac1p as an effector of Vps21p and as a novel Sec1p-family-binding protein. We suggest that Vac1p functions as a multivalent adaptor protein that ensures the high fidelity of vesicle docking and fusion by integrating both phosphoinositide (Vps34p) and GTPase (Vps21p) signals, which are essential for Pep12p- and Vps45p-dependent targeting of Golgi-derived vesicles to the prevacuolar endosome.  (+info)

Role of alphavbeta3 integrin in the activation of vascular endothelial growth factor receptor-2. (7/57141)

Interaction between integrin alphavbeta3 and extracellular matrix is crucial for endothelial cells sprouting from capillaries and for angiogenesis. Furthermore, integrin-mediated outside-in signals co-operate with growth factor receptors to promote cell proliferation and motility. To determine a potential regulation of angiogenic inducer receptors by the integrin system, we investigated the interaction between alphavbeta3 integrin and tyrosine kinase vascular endothelial growth factor receptor-2 (VEGFR-2) in human endothelial cells. We report that tyrosine-phosphorylated VEGFR-2 co-immunoprecipitated with beta3 integrin subunit, but not with beta1 or beta5, from cells stimulated with VEGF-A165. VEGFR-2 phosphorylation and mitogenicity induced by VEGF-A165 were enhanced in cells plated on the alphavbeta3 ligand, vitronectin, compared with cells plated on the alpha5beta1 ligand, fibronectin or the alpha2beta1 ligand, collagen. BV4 anti-beta3 integrin mAb, which does not interfere with endothelial cell adhesion to vitronectin, reduced (i) the tyrosine phosphorylation of VEGFR-2; (ii) the activation of downstream transductor phosphoinositide 3-OH kinase; and (iii) biological effects triggered by VEGF-A165. These results indicate a new role for alphavbeta3 integrin in the activation of an in vitro angiogenic program in endothelial cells. Besides being the most important survival system for nascent vessels by regulating cell adhesion to matrix, alphavbeta3 integrin participates in the full activation of VEGFR-2 triggered by VEGF-A, which is an important angiogenic inducer in tumors, inflammation and tissue regeneration.  (+info)

Cell growth inhibition by farnesyltransferase inhibitors is mediated by gain of geranylgeranylated RhoB. (8/57141)

Recent results have shown that the ability of farnesyltransferase inhibitors (FTIs) to inhibit malignant cell transformation and Ras prenylation can be separated. We proposed previously that farnesylated Rho proteins are important targets for alternation by FTIs, based on studies of RhoB (the FTI-Rho hypothesis). Cells treated with FTIs exhibit a loss of farnesylated RhoB but a gain of geranylgeranylated RhoB (RhoB-GG), which is associated with loss of growth-promoting activity. In this study, we tested whether the gain of RhoB-GG elicited by FTI treatment was sufficient to mediate FTI-induced cell growth inhibition. In support of this hypothesis, when expressed in Ras-transformed cells RhoB-GG induced phenotypic reversion, cell growth inhibition, and activation of the cell cycle kinase inhibitor p21WAF1. RhoB-GG did not affect the phenotype or growth of normal cells. These effects were similar to FTI treatment insofar as they were all induced in transformed cells but not in normal cells. RhoB-GG did not promote anoikis of Ras-transformed cells, implying that this response to FTIs involves loss-of-function effects. Our findings corroborate the FTI-Rho hypothesis and demonstrate that gain-of-function effects on Rho are part of the drug mechanism. Gain of RhoB-GG may explain how FTIs inhibit the growth of human tumor cells that lack Ras mutations.  (+info)

TY - JOUR. T1 - Structural genomics target selection for the New York consortium on membrane protein structure. AU - Punta, Marco. AU - Love, James. AU - Handelman, Samuel. AU - Hunt, John F.. AU - Shapiro, Lawrence. AU - Hendrickson, Wayne A.. AU - Rost, Burkhard. PY - 2009/12. Y1 - 2009/12. N2 - The New York Consortium on Membrane Protein Structure (NYCOMPS), a part of the Protein Structure Initiative (PSI) in the USA, has as its mission to establish a high-throughput pipeline for determination of novel integral membrane protein structures. Here we describe our current target selection protocol, which applies structural genomics approaches informed by the collective experience of our team of investigators. We first extract all annotated proteins from our reagent genomes, i.e. the 96 fully sequenced prokaryotic genomes from which we clone DNA. We filter this initial pool of sequences and obtain a list of valid targets. NYCOMPS defines valid targets as those that, among other features, have at ...
TY - CHAP. T1 - The hybrid solution/solid-state NMR method for membrane protein structure determination. AU - Veglia, G.. AU - Traaseth, N. J.. AU - Shi, L.. AU - Verardi, R.. AU - Gopinath, T.. AU - Gustavsson, M.. PY - 2012. Y1 - 2012. N2 - This chapter describes a hybrid nuclear magnetic resonance (NMR) method for the structure determination of membrane proteins. The method consists in combining distance and orientational restraints derived from both solution and solid-state NMR techniques into a hybrid energy function that is minimized using simulated annealing calculations. Using this approach, we are able to determine the structural ensemble, topological orientation, and depth of insertion of membrane proteins in lipid environments. The feasibility of this method is demonstrated for three different single-pass membrane proteins ranging from 3 to 30. kDa in molecular weight. Finally, this chapter provides an overview of the most recent NMR pulse sequences with enhanced sensitivity and ...
Purchase Recombinant Human NKG2-D type II integral membrane protein(KLRK1),partial (Active). It is produced in Mammalian cell. High purity. Good price.
Membrane proteins are proteins that interact with, or are part of, biological membranes. They include integral membrane proteins that are permanently anchored or part of the membrane and peripheral membrane proteins that are only temporarily attached to the lipid bilayer or to other integral proteins.[1][2] The integral membrane proteins are classified as transmembrane proteins that span across the membrane and integral monotopic proteins that are attached to only one side of the membrane. Membrane proteins are a common type of proteins along with soluble globular proteins, fibrous proteins, and disordered proteins.[3] They are targets of over 50% of all modern medicinal drugs.[4] It is estimated that 20-30% of all genes in most genomes encode membrane proteins.[5][6]. Compared to other classes of proteins, the determination of membrane protein structures has remained a challenge in large part due to the difficulty in establishing experimental conditions where the correct conformation of the ...
The topology of the integral membrane protein MalF, which is required for maltose transport in Escherichia coli, has been analyzed using fusions of alkaline phosphatase (EC The properties of such fusion strains support a MalF structure previously proposed on theoretical grounds. Several transmembrane segments within MalF can act as signal sequences in exporting alkaline phosphatase. Other transmembrane sequences, in conjunction with cytoplasmic domains, can stably anchor alkaline phosphatase in the cytoplasm. Our results suggest that features of the amino acid sequence (possibly the positively charged amino acids) of the cytoplasmic domains of membrane proteins are important in anchoring these domains in the cytoplasm. These studies in conjunction with our earlier results show that alkaline phosphatase fusions to membrane proteins can be an important aid in analyzing membrane topology and its determinants.. ...
The overexpression and purification of membrane proteins is a bottleneck in biotechnology and structural biology. E. coli remains the host of choice for membrane protein production. To date, most of the efforts have focused on genetically tuning of expression systems and shaping membrane composition to improve membrane protein production remained largely unexplored. In E. coli C41(DE3) strain, we deleted two transporters involved in fatty acid metabolism (OmpF and AcrB), which are also recalcitrant contaminants crystallizing even at low concentration. Engineered expression hosts presented an enhanced fitness and improved folding of target membrane proteins, which correlated with an altered membrane fluidity. We demonstrated the scope of this approach by overproducing several membrane proteins (4 different ABC transporters, YidC and SecYEG). In summary, E. coli membrane engineering unprecedentedly increases the quality and yield of membrane protein preparations. This strategy opens a new field for
Reliable prediction of structures could have a major impact on our understanding of membrane protein function. This is underscored by the fact that less than 1% of the structures in the Protein Data Bank are of integral membrane proteins despite these comprising over 20% of all genes in mammalian genomes. Membrane proteins are physiologically crucial given their function as a vital communication interface between the intracellular and extracellular environments, and between the cytosol and diverse membrane-bound organelles. Hence, many membrane proteins are pharmacologically important and are potential drug targets. While efforts in structural genomics have led to the elucidation of structures of numerous soluble proteins, determining the structure of membrane proteins remains challenging due to difficulties involved in their expression, purification and crystallization. Thus, any approach that provides insights into structures of membrane proteins will be very useful in explaining their ...
α-helical membrane proteins constitute 20-30% of all proteins in a cell and are involved in many essential cellular functions. The structure is only known for a few hundred of them, which makes structural models important. The most common structural model of a membrane protein is the topology which is a two-dimensional representation of the structure.. This thesis is focused on three different aspects of membrane protein structure: improving structural predictions of membrane proteins, improving the level of detail of structural models and the concept of dual topology.. It is possible to improve topology models of membrane proteins by including experimental information in computer predictions. This was first performed in Escherichia coli and, by using homology, it was possible to extend the results to 225 prokaryotic organisms. The improved models covered ~80% of the membrane proteins in E. coli and ~30% of other prokaryotic organisms.. However, the traditional topology concept is sometimes too ...
From the moment of cotranslational insertion into the lipid bilayer of the endoplasmic reticulum (ER), newly synthesized integral membrane proteins are subject to a complex series of sorting, trafficking, quality control, and quality maintenance systems. Many of these processes are intimately controlled by ubiquitination, a posttranslational modification that directs trafficking decisions related to both the biosynthetic delivery of proteins to the plasma membrane (PM) via the secretory pathway and the removal of proteins from the PM via the endocytic pathway. Ubiquitin modification of integral membrane proteins (or cargoes) generally acts as a sorting signal, which is recognized, captured, and delivered to a specific cellular destination via specialized trafficking events. By affecting the quality, quantity, and localization of integral membrane proteins in the cell, defects in these processes contribute to human diseases, including cystic fibrosis, circulatory diseases, and various ...
Our understanding of the events and cellular components required for the intracellular trafficking, targeting, and degradation of complex multispanning membrane proteins is in its infancy. The study of the life cycle of polytopic membrane proteins has become increasingly important, since improper intracellular trafficking has been implicated in a number of genetic diseases, such as cystic fibrosis, in which the misfolded cystic fibrosis conductance transmembrane regulator (CFTR) chloride channel is retained in the endoplasmic reticulum (ER) or certain forms of hypercholesterolemia in which the mutant low-density lipoprotein receptor is either ER retained or not internalized from the cell surface (1, 24, 52).. This study focuses on the intracellular trafficking of Ste6p, thea-factor mating pheromone transporter in Saccharomyces cerevisiae. Studies on yeast membrane proteins provide excellent model systems for studying general aspects of the trafficking and degradation of distinct classes of ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class=publication>Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href=>Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
Proteins of the p24 family form a rather unique family of abundant, small (20-24 kDa) type I trans-membrane proteins in the early biosynthetic pathway. They can be sub-divided by sequence homology into 4 sub-families (p23 or delta, p24 or beta, p25 or alpha, and p26 or gamma) (Dominguez et al., 1998; Emery et al., 1999). Mammalian cells contain at least one member of each p23, p24 and p25 subfamily, and three members of the p26 sub-family (Emery et al., 1999). All seem to cycle in the early secretory pathway (Blum et al., 1999; Fullekrug et al., 1999; Rojo et al., 2000), and to localize primarily to the cis-Golgi network (CGN) or the cis side of the Golgi complex (Emery et al., 2000; Fullekrug et al., 1999; Rojo et al., 1997; Stamnes et al., 1995), except p25 (GP25L) which is also abundant in the endoplasmic reticulum (ER) (Dominguez et al., 1998; Wada et al., 1991). They share a predicted exoplasmic coiled-coil domain and a small (12-18 amino acids) cytoplasmically oriented C terminus that ...
Creative Biostructure, featured as a leader in the structural biology field, now provides a comprehensive list of custom membrane protein services from gene to structure with an emphasis on protein purification, crystallization, structure determination and analysis.. Although membrane proteins play an important role in all organisms, their purification has historically, and continues to be, a huge challenge for protein scientists. In 2008, 150 unique structures of membrane proteins were available, and by 2019 only 50 human membrane proteins had their structures elucidated. For the important roles they play in cell functions, membrane proteins are now considered to be perfect drug targets. Investigating membrane protein structure and function can provide valuable information for drug characterization and optimization, however, such proteins are inherently difficult to purify and characterize. Even when expressed at high levels, the purification can still be challenging.. Owing to years of devoted ...
My research is on membrane protein structure, dynamics, and function with a focus on membrane proteins involved in bacterial pathogenesis. I teach CHEM4411 and CHEM4421, the Biological Chemistry Laboratory courses at UVa. With my colleagues, Carol Price and Cameron Mura, I have developed a year long inquiry- and research-based biochemistry laboratory. We have created BioLEd to share and enable faculty to more easily develop their undergraduate biochemistry laboratories and research.. ...
The ERM family members, ezrin, radixin, and moesin, localizing just beneath the plasma membranes, are thought to be involved in the actin filament/plasma membrane association. To identify the integral membrane protein directly associated with ERM family members, we performed immunoprecipitation studies using antimoesin mAb and cultured baby hamster kidney (BHK) cells metabolically labeled with [35S]methionine or surface-labeled with biotin. The results indicated that moesin is directly associated with a 140-kD integral membrane protein. Using BHK cells as antigens, we obtained a mAb that recognized the 140-kD membrane protein. We next cloned a cDNA encoding the 140-kD membrane protein and identified it as CD44, a broadly distributed cell surface glycoprotein. Immunoprecipitation with various anti-CD44 mAbs showed that ezrin and radixin, as well as moesin, are associated with CD44, not only in BHK cells, but also in mouse L fibroblasts. Furthermore, immunofluorescence microscopy revealed that in ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Creative Biostructure provides custom gene-to-structure services for membrane protein families, unveiling the structures, functions and pharmaceutical properties.
peripheral membrane protein (Science: protein) membrane proteins that are bound to the surface of the membrane and not integrated into the hydrophobic region. Usually soluble and were originally thought to bind to integral proteins by ionic and other weak forces (and could therefore be removed by high ionic strength, for example). However, it is now clear that some peripheral membrane proteins are covalently linked to molecules that are part of the membrane bilayer (see acylated proteins and glypiation) and that there are others that fit the original definition but are perhps more appropriately considered proteins of the cytoskeleton (e.g. Band 4.1 and spectrin) or extracellular matrix (e.g. Fibronectin). ...
The module will cover the structure and function of biological membranes. There will be a general introduction to membrane structure and a discussion of the biosynthesis of membrane proteins. The insertion of membrane proteins into bio-membranes is introduced by matching physic-chemical properties and investigated for spontaneous membrane protein insertion. Protein complexes involved in membrane protein insertion and in transport across the membrane will be introduced. The electron transport chain and its relation to energy transduction will be covered together with an introduction to Mitchells chemi-osmotic hypothesis. The structure and function of specific membrane proteins involved in electron transport, proton translocation and phosphorylation in mitochondria and photosynthesis will be described and discussed in terms of our present understanding of how oxidation reactions or light energy are coupled to the synthesis of ATP. The role of multi-domain cell surface proteins in cell recognition ...
Protein that is physically associated with a membrane, via interactions with lipid headgroups at the membrane surface or with another membrane protein. Peripheral membrane proteins are typically bound to the membrane surface, but may dip slightly into the lipid bilayer. Peripheral membrane protein ...
Despite many high-profile successes, recombinant membrane protein production remains a technical challenge; it is still the case that many fewer membrane protein structures have been published than those of soluble proteins. However, progress is being made because empirical methods have been developed to produce the required quantity and quality of these challenging targets. This review focuses on the microbial expression systems that are a key source of recombinant prokaryotic and eukaryotic membrane proteins for structural studies. We provide an overview of the host strains, tags and promoters that, in our experience, are most likely to yield protein suitable for structural and functional characterization. We also catalogue the detergents used for solubilization and crystallization studies of these proteins. Here, we emphasize a combination of practical methods, not necessarily high-throughput, which can be implemented in any laboratory equipped for recombinant DNA technology and microbial ...
The great majority of helical membrane proteins are inserted co-translationally into the ER membrane through a continuous ribosome-translocon channel. The efficiency of membrane insertion depends on transmembrane (TM) helix amino acid composition, the helix length and the position of the amino acids within the helix. In this work, we conducted a computational analysis of the composition and location of amino acids in transmembrane helices found in membrane proteins of known structure to obtain an extensive set of designed polypeptide segments with naturally occurring amino acid distributions. Then, using an in vitro translation system in the presence of biological membranes, we experimentally validated our predictions by analyzing its membrane integration capacity. Coupled with known strategies to control membrane protein topology, these findings may pave the way to de novo membrane protein design. PubMed: 26987712. Doi: 10.1038/srep23397.. ...
The LPSM works at deciphering the mechanism of membrane-related processes, with a specific emphasis on the molecular mechanism of active transport across biological membranes, as well as the study of protein-protein and protein-lipid interactions and significance. We use a combination of complementary experimental and in silico approaches: biochemistry, spectroscopies, molecular dynamics simulations and structural methods. The laboratory works on flippase-type membrane proteins, on caveolin and on membrane proteins associated with pathologies.
Membrane proteins are of great biomedical importance. They account for ~25% of all genes and are involved in diseases ranging from diabetes to cancer. Membrane proteins play a key role in the biology of infection by pathogens, including both bacteria and viruses. They also play an important role in signalling within and between cells. It is therefore not surprising that membrane proteins are major targets for a wide range of drugs and other therapeutic agents. Recently, the number of known structures of membrane proteins has started to increase. Large scale computer simulations allow researchers to study the movements of these proteins in their native membrane environments. 
A: The fluid mosaic model of membrane structure. The membrane consists of a phospholipid double layer with proteins inserted in it (integral proteins) or bound to the cytoplasmic surface (peripheral proteins). Integral membrane proteins are firmly embedded in the lipid layers. Some of these proteins completely span the bilayer and are called transmembrane proteins, whereas others are embedded in either the outer or inner leaflet of the lipid bilayer. The dotted line in the integral membrane protein is the region where hydrophobic amino acids interact with the hydrophobic portions of the membrane. Many of the proteins and lipids have externally exposed oligosaccharide chains. B: Membrane cleavage occurs when a cell is frozen and fractured (cryofracture). Most of the membrane particles (1) are proteins or aggregates of proteins that remain attached to the half of the membrane adjacent to the cytoplasm (P, or protoplasmic, face of the membrane). Fewer particles are found attached to the outer half ...
Recent increases in the number of deposited membrane protein crystal structures necessitate the use of automated computational tools to position them within the lipid bilayer. Identifying the correct orientation allows us to study the complex relationship between sequence, structure and the lipid environment, which is otherwise challenging to investigate using experimental techniques due to the difficulty in crystallising membrane proteins embedded within intact membranes. We have developed a knowledge-based membrane potential, calculated by the statistical analysis of transmembrane protein structures, coupled with a combination of genetic and direct search algorithms, and demonstrate its use in positioning proteins in membranes, refinement of membrane protein models and in decoy discrimination. Our method is able to quickly and accurately orientate both alpha-helical and beta-barrel membrane proteins within the lipid bilayer, showing closer agreement with experimentally determined values than existing
This project seeks to determine the mechanisms, structures, and structure change of integral transmembrane proteins that govern critical transmembrane processes, at the level that can lead to improved therapeutics for human disease. The premise is that alterations in molecular structures are necessary for the function of transmembrane transporters and gated channels, and are coordinated by regulatory functions. The hypothesis is that understanding the linkage between structure change and function provides a roadmap for therapeutic intervention by organic compounds or Fab fragments generated to stabilize conformational states. A major innovation is the technology and ability to determine atomic structures of membrane proteins and eukaryotic, or human membrane proteins at a resolution sufficient to instruct in the development of therapeutic development of compounds. Principal technologies include X-ray diffraction, electron cryomicroscopy, transport assays, electrophysiology. Three aims focus on ...
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Membrane proteins fulfil a number of tasks in cells, including signalling, cell-cell interaction, and the transportation of molecules. The prominence of these tasks makes membrane proteins an important target for clinical drugs. Because of the decreasing price of sequencing, the number of sequences known is increasing at such a rate that manual annotations cannot compete. Here, topology prediction is a way to provide additional information. It predicts the location and number of transmembrane helices in the protein and the orientation inside the membrane. An important factor to detect transmembrane helices is their hydrophobicity, which can be calculated using dedicated scales. In the first paper, we studied the difference between several hydrophobicity scales and evaluated their performance. We showed that while they appear to be similar, their performance for topology prediction differs significantly. The better performing scales appear to measure the probability of amino acids to be within a ...
Integral membrane proteins (SCAMPs), tetraspan vesicle membrane proteins) that act as carriers, recycling proteins to the cell surface. At least three members of the family have been identified in humans: SCAMP1 (338 aa), SCAMP2 (329 aa), and SCAMP3 (347 aa). ...
TY - JOUR. T1 - Mimicking multipass transmembrane proteins. T2 - Synthesis, assembly and folding of alternating amphiphilic multiblock molecules in liposomal membranes. AU - Muraoka, Takahiro. AU - Shima, Tatsuya. AU - Hamada, Tsutomu. AU - Morita, Masamune. AU - Takagi, Masahiro. AU - Kinbara, Kazushi. PY - 2011/12/6. Y1 - 2011/12/6. N2 - Alternating amphiphilic multiblock molecules 1-4, involving fluorescent hydrophobic units, were designed as mimics for multipass transmembrane proteins. Fluorescence spectroscopy of 1-4 in liposomal membranes suggested the face-to-face stacking of the hydrophobic units to give folded structures as well as intermolecular assemblies.. AB - Alternating amphiphilic multiblock molecules 1-4, involving fluorescent hydrophobic units, were designed as mimics for multipass transmembrane proteins. Fluorescence spectroscopy of 1-4 in liposomal membranes suggested the face-to-face stacking of the hydrophobic units to give folded structures as well as intermolecular ...
To understand the partnership between conformational maturation and quality controlCmediated proteolysis in the secretory pathway, we engineered the well-characterized degron from your -subunit from the T-cell antigen receptor (TCR) in to the -helical transmembrane domain name of homotrimeric type I integral membrane proteins, influenza hemagglutinin (HA). antibodies show that membrane-integrated HA++ substances have the ability to mature towards the plasma membrane having a conformation indistinguishable from that of HAwt. These evidently indigenous HA++ substances are, nevertheless, quickly degraded by an activity thats insensitive to proteasome inhibitors but clogged by lysosomotropic amines. These data recommend the presence in the secretory pathway of at least two sequential quality control checkpoints that identify the same transmembrane degron, therefore making sure the fidelity of proteins deployment towards the plasma membrane. Intro Biogenesis of essential membrane proteins in ...
Proteins and channels , Hydrophobicity , Self-assembly ,,. Hydrophobicity literally means fear of water. The opposite of this is hydrophilicity which means love of water. These two terms denote the properties of molecules or parts of molecules to bond with water (hydrophilicity) or reject water (hydrophobicity). This effect is seen when one puts a drop of oil on water. The oil (hydrophobic) remains on the surface and sticks together in stead of mixing with the water (hydrophilic). In cells these properties are essential. Most of the cell is hydrophilic but there are hydrophobic borders (membranes) which compartmentalize the cell into different spaces and hereby separate reactions. Of course there must be some sort of interaction between compartments and this is facilitated by membrane proteins (look here to read up on membrane proteins).. These membranes are formed with molecules with hydrophobic properties, such as phospholipids, cholesterol and membrane proteins. The phospholipids and ...
Junctional complexes between the plasma membrane (PM) and endoplasmic/sarcoplasmic reticulum (ER/SR) are a common feature of all excitable cell types and mediate cross talk between cell surface and intracellular ion channels. Junctophilins (JPs) are important components of the junctional complexes. JPs are composed of a carboxy-terminal hydrophobic segment spanning the ER/SR membrane and a remaining cytoplasmic domain that shows specific affinity for the PM. Four JPs have been identified as tissue-specific subtypes derived from different genes: JPH1 is expressed in skeletal muscle, JPH2 is detected throughout all muscle cell types, and JPH3 and JPH4 are predominantly expressed in the brain. In the CNS, both JPH3 and JPH4 are expressed throughout neural sites and contribute to the subsurface cistern formation in neurons. Mice lacking both JPH3 and JPH4 subtypes exhibit serious symptoms such as impaired learning and memory and are accompanied by abnormal nervous functions. A repeat expansion in ...
Voltage gated potassium channels are transmembrane protein complexes that form a pore specifically allowing the passage of potassium ions. One method to determine the structure of these and other membrane proteins is electron crystallography. For this, purified membrane proteins are mixed with lipids and induced to form two-dimensional crystals. These flat crystal sheets are then imaged by cryo-EM and analysed. There is no potential gradient across them as the protein is surrounded by the same buffer. The gradient required for voltage gated channel proteins to function can be created if they are embedded in a spherical lipid bilayer that encloses liquid, i.e., if they are embedded in the membrane of a liposome. The buffer conditions inside and outside the liposomes dictate whether they are in an open or a closed conformation ...
Membrane proteins are critical components of all cells, controlling, e.g., signaling, nutrient exchange, and energy production, and are the target of over half of all drugs currently in production. At an early stage of their synthesis, nearly all membrane proteins are directed to a protein-conducting channel, the SecY/Sec61 complex, which permits access to the membrane via its lateral gate.
Within this framework, we focus on several membrane proteins whose function is to transport copper ions for one, chloride ions for another, and whose dysfunctionings are responsible for serious diseases in humans, such as Wilsons disease and cystic fibrosis. Our work focuses also on other membrane proteins responsible for transporting metals (TRP channels as TPRC6 and TRPM7 and P-type ATPases). Another concern of ours is the regulation of metal homeostasis by bacterial transcriptional regulators and eukaryotic translational regulators involved in the homeostatic control of iron and nickel. Studies of these regulatory systems, especially in stress conditions (metallic, oxidative or, for example associated with exposure to nanoparticles or other chemical molecules) is of particular interest to understand the metabolic disturbances caused ...
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Integral membrane proteins are found within the plasma membrane and span the whole length across. The inside of the membrane is very hydrophobic due to the long carbon chains. Extensive hydrophobic interactions between the protein side chain and the lipid tails will help anchor the protein in the membrane.. ...
Presented in this section is an adherent culture of Swiss mouse embryo fibroblasts that was immunofluorescently labeled with Rhodamine Red conjugated to antibodies directed against peroxisomal membrane protein 70 (PMP 70), an abundant and integral membrane component of peroxisomes.
Presented in the digital image in this section is a culture of Swiss mouse embryo fibroblasts that was immunofluorescently labeled with Rhodamine Red conjugated to antibodies directed against peroxisomal membrane protein 70 (PMP 70), an abundant and integral membrane component of peroxisomes.
Membrane Protein Structure and Dynamics - This Methods in Molecular Biology TM book details approaches to the structure dynamics and interactions of membrane (EAN:9781627030229)
JC just returned from two back-to-back meetings in Snowmass, CO. He presented work on small-helix partitioning in membranes at the first meeting on Free Energy Methods and structures of BamA and a new complex between SecY and a nascent chain at the second meeting on Membrane Proteins. Not all the time was spent in front of a screen though, as the picture to the right clearly shows!. ...
The Valiyaveetil lab studies potassium channels, which are integral membrane proteins that catalyze the selective conduction of K+ ions across biological membranes. While a great deal of research has been focused on these channels, fundamental questions regarding the mechanism of ionic selectivity and gating remain. Valiyaveetils team has developed a unique combination of methods to address these questions. Their methods include the use of chemical synthesis to introduce precise chemical changes in the channels, x-ray crystallography to determine the structural effects and electrophysiology to determine the functional effects of these changes. Using this multidisciplinary approach they hope to explain the mechanism of ion selectivity and channel gating.. ...
Membrane proteins play an essential role in controlling the movement of material and information in and out of the cell, in determining the flow and use of energy, as well as in triggering the initiation of numerous signaling pathways. To fulfill these roles, conformational and interaction dynamics exert a dominant influence on their functional behavior, for it is the interplay between structure and dynamics what ultimately defines their function.. The Membrane Protein Structural Dynamics Consortium (MPSDC) has been designed as a highly interactive, tightly integrated and multidisciplinary effort focused on elucidating the relationship between structure, dynamics and function in a variety of membrane proteins. This website serves as a gateway both to the Consortiums activities and resources, and to the scientific field at large. Read the directors statement ». ...
Separation of integral membrane proteins by 2-DE. The integral proteins were separated using 18-cm IPG strips covering pH ranges 3-10 (nonlinear), and 4-7 f
Coll, J M.; Luborsky, S W.; and Mora, P T., Metabolically labeled cell membrane proteins in spontaneously and in sv40 virus transformed mouse fibroblasts. (1977). Subject Strain Bibliography 1977. 1406 ...
Integrins are heterodimers formed by the noncovalent bonding of two transmembrane glycoproteins,ref,You TJ, Maxwell DS, Kogan TP, et al. A 3D structure model of integrin alpha 4 beta 1 complex: I. Construction of a homology model of beta 1 and ligand binding analysis. Biophysical Journal. 2002;82(1 Pt 1):447-457.,/ref,; an alpha and beta subunit. As they are transmembrane proteins, they consist of both a relatively large extracellular component and a short cytoplasmic component. The extracellular component consists of approximately 1000 amino acids for the α (alpha) subunit and 700 amino acids for the β (beta) subunit. About half of the α subunits possess an I-domain region at the β-propeller which is an important binding site for ligands. Ligand protein binding is essential because it is the way integrins interact with actin cytoskeleton organization and initiate the transduction of intracelluar signals. Like the α subunit, the β also possesses an I-domain which functions essentially the ...
Slmap - mouse gene knockout kit via CRISPR, 1 kit. |dl||dt|Kit Component:|/dt||dd|- |strong|KN316256G1|/strong|, Slmap gRNA vector 1 in |a href=
4.5 Protein targeting and import *4.5.1 Transport proteins and membrane translocons ... Outer chloroplast membrane. Main article: Chloroplast membrane. The outer chloroplast membrane is a semi-porous membrane that ... Inner chloroplast membrane. Main article: Chloroplast membrane. The inner chloroplast membrane borders the stroma and regulates ... All chloroplasts have at least three membrane systems-the outer chloroplast membrane, the inner chloroplast membrane, and the ...
... s are a family of highly conserved membrane proteins that are important in creating membrane curvature. Epsins contribute ... Epsins may be the major membrane curvature-driving proteins in many clathrin-coated vesicle budding events. In addition to its ... "Sequence analysis of Arabidopsis thaliana E/ANTH-domain-containing proteins: membrane tethers of the clathrin-dependent vesicle ... Epsin contains various protein domains that aid in function. Starting at the N-terminus is the ENTH domain. ENTH stands for ...
Hsieh, CL; Kumar, NM; Gilula, NB; Francke, U (Mar 1991). "Distribution of genes for gap junction membrane channel proteins on ... One hemichannel proteins have four transmembrane domains[6][19]. *6 hemichannel proteins create one hemichannel. When different ... The membrane from each cell is the dark line with the whiter narrow gap between the two darkly stained membranes. In such ... "Identification of a 70,000-D protein in lens membrane junctional domains". The Journal of Cell Biology. 101 (1): 28-35. doi: ...
Membrane proteins are a large component of the genome, and include many proteins of great physiological importance, such as ion ... Lundstrom K (November 2006). "Structural genomics for membrane proteins". Cellular and Molecular Life Sciences. 63 (22): 2597- ... Lundstrom K (August 2004). "Structural genomics on membrane proteins: mini review". Combinatorial Chemistry & High Throughput ... When a new protein structure is solved by X-ray crystallography and deposited in the Protein Data Bank, its authors are ...
Cell membrane protein disorders (other than Cell surface receptor, enzymes, and cytoskeleton) ... Several different proteins can be affected, and the specific protein that is absent or defective identifies the specific type ... Among the proteins affected in LGMD are α, β, γ and δ sarcoglycans. The sarcoglycanopathies could be possibly amenable to gene ... Protein MYOT (also known as TTID one of the many genes whose mutations are responsible for this condition). ...
Ghosh, Raja (2002). "Protein separation using membrane chromatography: opportunities and challenges". Journal of Chromatography ... Membranes can be prepared through isolation of the membrane itself, where membranes are cut into squares and immobilized. A ... Membrane exchange chromatography[edit]. A type of ion exchange chromatography, membrane exchange[34][35] is a relatively new ... Thömmes, J., & Kula, M. R. (1995). Membrane chromatography-an integrative concept in the downstream processing of proteins. ...
Cell membrane protein disorders (other than Cell surface receptor, enzymes, and cytoskeleton) ... The mutation can appear in GJB1 coding for connexin 32, a gap junction protein expressed in Schwann cells. Because this protein ... Some mutations affect the gene MFN2, on chromosome 1, which codes for a mitochondrial protein. Mutated MFN2 causes the ... Charcot-Marie-Tooth disease is caused by genetic mutations that cause defects in neuronal proteins. Nerve signals are conducted ...
... falciparum erythrocyte membrane protein-1 (PfMP-1).[12] This protein is the parasite's main cytoadherence ligand and virulence ... receptor (cellular surface) - specialized integral membrane proteins that take part in communication between the cell and the ... The Gerbich antigen system is an integral membrane protein of the erythrocyte and plays a functionally important role in ... Hempelmann E, Götze O (1984). "Characterization of membrane proteins by polychromatic silver staining". Hoppe-Seyler's Z ...
Cell membrane protein disorders (other than Cell surface receptor, enzymes, and cytoskeleton) ... Dejerine-Sottas neuropathy is caused by a genetic defect either in the proteins found in axons or the proteins found in myelin. ... "Dejerine-Sottas syndrome associated with point mutation in the peripheral myelin protein 22 (PMP22) gene". Nat. Genet. 5 (3): ...
Membrane transport proteins such as the sodium-potassium pump within the membrane are equivalent to turbines that convert the ... "Membrane Physiology and Membrane Biophysics. 6: 29. doi:10.3389/fphys.2015.00029. PMC 4319557 . PMID 25705194.. ... Structural biochemistry and biophysics of membrane proteins. 1850 (3): 536-553. doi:10.1016/j.bbagen.2014.05.021.. ... When there are unequal concentrations of an ion across a permeable membrane, the ion will move across the membrane from the ...
EMP2: Epithelial membrane protein 2. *ENKD1: Enkurin domain-containing protein 1. *ERAF: Alpha-hemoglobin-stabilizing protein ... UNKL: encoding protein RING finger protein unkempt-like. *VAT1L: encoding protein Vesicle amine transport protein 1 homolog (T ... LINC00273 encoding protein Long intergenic non-protein coding RNA 273. *LOC124220: encoding protein Zymogen granule protein 16 ... SHCBP1: encoding protein SHC SH2 domain-binding protein 1. *SLZ1: encoding protein SLX1 structure-specific endonuclease subunit ...
... which help the protein bind more tightly to the membrane by contributing to protein hydrophobicity and membrane association, is ... Most commonly found in the plasma membrane and endoplasmic reticulum (ER), SLC46A3 is a multi-pass membrane protein with 11 α- ... Lengths shown are for the precursor proteins. SLC46A3 is an integral membrane protein 461 amino acids (aa) of length with a ... Reithmeier RA (1996). "Assembly of proteins into membranes". Biochemistry of Lipids, Lipoproteins and Membranes. New ...
In purple bacteria, such as Rhodospirillum rubrum, the light-harvesting proteins are intrinsic to the chromatophore membranes. ... Salton, MR (1987). "Bacterial membrane proteins". Microbiological sciences. 4 (4): 100-5. PMID 3153178. Frigaard, NU; Bryant, ... In some forms of photosynthetic bacteria, a chromatophore is a coloured, membrane-associated vesicle used to perform ...
Member 5, also known as SLC17A5 or sialin is a lysosomal membrane sialic acid transport protein which in humans is encoded by ... 2002). "Identification of a novel membrane protein, HP59, with therapeutic potential as a target of tumor angiogenesis". Clin. ... Winchester BG (2001). "Lysosomal membrane proteins". Eur. J. Paediatr. Neurol. 5 Suppl A: 11-9. doi:10.1053/ejpn.2000.0428. ... Sialin, also known as H(+)/nitrate cotransporter and H(+)/sialic acid cotransporter, is a protein which in humans is encoded by ...
Nanodisc - water-soluble protein-stabilized lipid discs that can trap and stabilize membrane proteins. Bowie, J (2001). " ... Amphipol-trapped membrane proteins are, as a rule, much more stable than detergent-solubilized ones, which facilitates their ... Amphipols can be used to fold denatured membrane proteins to their native form and have proven particularly precious in the ... Popot, J.-L. (2018) Membrane proteins in aqueous solutions. From detergents to amphipols. Springer, New York, xxv + 708 p. v t ...
Palmitoylation is important for membrane localisation of many proteins. Applications[edit]. Palmitic acid is used to produce a ... some proteins are modified by the addition of a palmitoyl group in a process known as palmitoylation. ...
In molecular biology caveolins are a family of integral membrane proteins that are the principal components of caveolae ... All three members are membrane proteins with similar structure. Caveolin forms oligomers and associates with cholesterol and ... Caveolins may act as scaffolding proteins within caveolar membranes by compartmentalizing and concentrating signaling molecules ... Both the C-terminus and the N-terminus face the cytoplasmic side of the membrane. There are two isoforms of caveolin-1: ...
... performs this function by specifically binding to ergosterol and inhibiting membrane transport proteins.[14] ... Polyene antibiotic that inhibits membrane transport proteins. Proc. Natl. Acad. Sci. U. S. A. 2012, 109, 11156-11159. ... Natamcyin is able to inhibit growth of fungi by inhibiting transport of amino acids and glucose across the plasma membrane. ... It results in fungal death by altering the cell membrane.[1] ...
... 1, Lysosomal-associated membrane protein 1. *LAMP2, Lysosomal-associated membrane protein 2 ... Lysosome-associated membrane glycoprotein. Organisations[edit]. *Lutheran Association of Missionaries and Pilots, a cross- ... LAMP3, Lysosomal-associated membrane glycoprotein 3. *All pages with a title containing lamp, includes many other forms of lamp ...
Orientations of Proteins in Membranes database. *Opportunistic Mesh, a wireless networking technology ...
"Electrostatic binding of proteins to membranes. Theoretical predictions and experimental results with charybdotoxin and ...
VAPB: VAMP (vesicle-associated membrane protein)-associated protein B and C. *YTHDF1: encoding protein YTH domain family, ... encoding protein Transmembrane prostate androgen-induced protein. *TTPAL: encoding protein Tocopherol (alpha) transfer protein- ... FASTKD5: encoding protein FAST kinase domain-containing protein 5 (FASTKD5). *FITM2: encoding protein Fat storage-inducing ... BPIFB4: encoding protein BPI fold containing family B, member 4. *C20orf132: encoding protein Uncharacterized protein C20orf132 ...
protein transporter activity. Cellular component. • integral component of membrane. • mitochondrial inner membrane. • membrane ... protein transport. • protein folding. • visual perception. • genitalia development. • protein targeting to mitochondrion. • ... "Mitochondrial import inner membrane translocase subunit TIM14". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB).. ... CL is a key phospholipid in mitochondrial membranes that modulates the fusion and fission of mitochondrial membranes, as well ...
Organization of membrane proteins". Biochimica et Biophysica Acta (BBA) - Biomembranes. 426 (4): 647-58. doi:10.1016/0005-2736( ... Until recently, camel milk could not be made into camel cheese because rennet was unable to coagulate the milk proteins to ... On the other hand, camel milk and meat are rich in protein, vitamins, glycogen, and other nutrients making them essential in ... and other arid regions where alternative forms of protein may be limited or where camel meat has had a long cultural history. ...
1991). Crystallization of membrane proteins. CRC Press. M Caffrey (2003). "Membrane protein crystallization". J. Struct. Biol. ... For membrane proteins, the situation is more complicated because the system that is being crystallized is not the membrane ... protein itself but the micellar system in which the membrane protein is embedded. The size of the protein-detergent mixed ... Misquitta Y.; Caffrey M. (2003). "Detergents Destabilize the Cubic Phase of Monoolein: Implications for Membrane Protein ...
Protein: cell membrane proteins (other than Cell surface receptor, enzymes, and cytoskeleton) ... Hemolysins or haemolysins are lipids and proteins that cause lysis of red blood cells by disrupting the cell membrane. Although ... "Membrane Association of α-Hemolysin: Proteins Functionally Reconstituted in tBLMs". Carnegie Mellon University.. ... TDH induces Ca2+ influx from an extracellular environment accompanied by protein kinase C phosphorylation. Activated protein ...
Kir channels are formed from as homotetrameric membrane proteins. Each of the four identical protein subunits is composed of ... UMich Orientation of Proteins in Membranes families/family-85 - Spatial positions of inward rectifier potassium channels in ... By mediating a small depolarizing K+ current at negative membrane potentials, they help establish resting membrane potential, ... pushing the membrane potential back to the resting potential. This can be seen in figure 1: when the membrane potential is ...
In addition to serving as a primary component of cellular membranes and binding sites for intra- and intercellular proteins, ... as the cellular plasma membrane and the intracellular membranes of organelles; in animal cells, the plasma membrane physically ... Membranes[edit]. Eukaryotic cells feature the compartmentalized membrane-bound organelles that carry out different biological ... Molecular Computer Simulations - Modeling of Lipid Membranes. *Lipids, Membranes and Vesicle Trafficking - The Virtual Library ...
FTIR is used to investigate proteins in hydrophobic membrane environments. Studies show the ability of FTIR to directly ... Brielle, Esther S.; Arkin, Isaiah T. (2018). "Site-Specific Hydrogen Exchange in a Membrane Environment Analyzed by Infrared ... single viruses and protein complexes) and with 10 to 20 nm spatial resolution.[13] ... "Environment Polarity in Proteins Mapped Noninvasively by FTIR Spectroscopy". The Journal of Physical Chemistry Letters. 3 (7 ...
Proteins that have a greater hydrophobic content - for instance, many membrane proteins, and those that interact with ... For proteins, sodium dodecyl sulfate (SDS) is an anionic detergent applied to protein samples to coat proteins in order to ... 2-Dimensional Protein Gelelectrophoresis. *[1] Hempelmann E. SDS-Protein PAGE and Proteindetection by Silverstaining and ... Separating gels allow for the separation of proteins and have a relatively lower porosity. Here, the proteins are separated ...
... from membrane currents, proteins, and chemical coupling to network oscillations, columnar and topographic architecture, and ... "A quantitative description of membrane current and its application to conduction and excitation in nerve". J. Physiol. 117 (4 ...
Another bile acid receptor is the cell membrane receptor known as G protein-coupled bile acid receptor 1 or TGR5. Many of their ... Among these protein targets, the enzyme N-acyl phosphatidylethanolamine-specific phospholipase D (NAPE-PLD) generates bioactive ... Bile acids bind to some other proteins in addition to their hormone receptors (FXR and TGR5) and their transporters. ... the farnesoid X receptor and G protein-coupled bile acid receptor/TGR5.[7][10] They bind less specifically to some other ...
Zhou W, Resh MD (1997). "Differential membrane binding of the human immunodeficiency virus type 1 matrix protein". J. Virol. 70 ... Mumby SM, Heukeroth RO, Gordon JI, Gilman AG (1990). "G-protein alpha-subunit expression, myristoylation, and membrane ... 1985). "Amino terminal myristylation of the protein kinase p60src, a retroviral transforming protein". Science. 227 (4685): 427 ... "Identification of a membrane-binding domain within the amino-terminal region of human immunodeficiency virus type 1 Gag protein ...
It stays associated with the membrane through protein-protein interactions of itself and other membrane associated proteins, ... endoplasmic reticulum unfolded protein response. · protein localization to nucleus. · sterol regulatory element binding protein ... 核纖層是真核生物细胞核中附于内核膜(英语:inner nuclear membrane)内侧的网络片层结构。其核纤层蛋白家族在进化中高度保守。在有絲分裂过程中,核纤层蛋
VEGF-B treatment of hepatoma carcinoma cells can cause α-catenin to move from its normal location on the membrane into the ... Catenins are a family of proteins found in complexes with cadherin cell adhesion molecules of animal cells. The first two ... Mutations in genes encoding these proteins can lead to inactivation of cadherin cell adhesions and elimination of contact ... "Adjuvant immunochemotherapy with protein-bound polysaccharide K for colon cancer in relation to oncogenic β-catenin activation ...
... proteins, and viruses. Ultracentrifuges can also be used in the study of membrane fractionation. This occurs because ... Sedimentation Velocity Analysis of Heterogeneous Protein-Protein Interactions: Lamm Equation Modeling and Sedimentation ... By 1900, it had been generally accepted that proteins were composed of amino acids; however, whether proteins were colloids or ... Howlett, G.J., Minton, A.P., Rivas, G. Analytical Ultracentrifugation for the Study of Protein Association and Assembly. ...
Proteins in the membraneEdit. Main article: Membrane protein. Proteins within the membrane are key to its working. These ... may be membrane proteins.[5] Some of these proteins are linked to the exterior of the cell membrane. An example of this is the ... Some proteins are always stuck into it, these are called integral membrane proteins. It also has some which are only sometimes ... The membrane contains many proteins. The surface proteins can act as gates. They let some chemicals into the cell and let other ...
protein binding. •extracellular matrix constituent conferring elasticity. •extracellular matrix binding. Componente celular. • ... maternal single nucleotide polymorphisms in candidate genes that predispose to spontaneous preterm labor with intact membranes ... Rosenbloom J (1984). «Elastin: relation of protein and gene structure to disease». Lab. Invest. 51 (6): 605-23. PMID 6150137. ... 2010). «Functional consequences of homocysteinylation of the elastic fiber proteins fibrillin-1 and tropoelastin». J. Biol. ...
Newly synthesised structural proteins and genomes self-assemble and accumulate near the inside of the cell membrane. Virions ... which code for proteins with antiviral properties.[51] EBOV's V24 protein blocks the production of these antiviral proteins by ... This processing appears to allow the virus to bind to cellular proteins enabling it to fuse with internal cellular membranes ... which are then translated into structural and nonstructural proteins. The most abundant protein produced is the nucleoprotein, ...
... is a membrane protein complex that transfers a 14-sugar oligosaccharide from dolichol to nascent protein. It is a type of ... the newly synthesized protein is transported across the membrane (gray) into the interior of the ER. Sec61 is the protein- ... Yeast OST is composed of eight different membrane-spanning proteins in three subcomplexes (one of them is OST4).[7][8] These ... ER Translocon complex.[2] Many protein complexes are involved in protein synthesis. The actual production takes place in the ...
The channels are regulated by G protein-coupled receptors that can activate or inhibit the NALCN channels depending on the ... Unlike the fast and transient sodium current, the persistent sodium current (INaP) is activated at very low membrane potentials ... Since NALCN sodium leak channels appear to contribute to the depolarization of neurons, their regulation by G-protein coupled ... Rhythmogenesis, the generation of rhythm, is modulated by membrane properties and synaptic interactions occurring in ...
Conjugated polyene fatty acids as membrane probes: preliminary characterization. Proc. Natl. Acad. Sci. U.S.A., 1975, 72. vsk, ... Role of beer lipid-binding proteins in preventing lipid destabilization of foam. J. Agric. Food Chem., 2002, 50. vsk, nro 26, s ... Townsend A-A, Nakai S. (1983). Relationships between hydrophobicity and foaming characteristics of food proteins. Journal of ... Zhu H, Damodaran S. (1994). Heat-induced conformational changes in whey protein isolate and its relation to foaming properties ...
This membrane protein-related article is a stub. You can help Wikipedia by expanding it.. *v ... membrane. • synapse. • integral component of plasma membrane. • chloride channel complex. • cell junction. • plasma membrane. • ... integral component of membrane. • GABA-A receptor complex. • postsynaptic membrane. • ... integral component of postsynaptic specialization membrane. • dendrite membrane. • neuron projection. • postsynapse. Biological ...
A protein kinase drifting around on the outer chloroplast membrane can use ATP to add a phosphate group to the Toc34 protein, ... it is known that for about every five Toc75 proteins in the outer chloroplast membrane, there are two Tic20 I proteins (the ... which anchors the protein to the outer chloroplast membrane.[48]. Toc159 probably works a lot like Toc34, recognizing proteins ... The TIC translocon, or translocon on the inner chloroplast membrane translocon[38] is another protein complex that imports ...
... protein.[45] PPARα increases the activity of activator protein 1 (AP-1) and NF-κB, thereby leading to the recruitment of ... membrane. *Aphthous stomatitis. *oral candidiasis. *lichen planus. *leukoplakia. *pemphigus vulgaris. *mucous membrane ... These free radicals likely interfere with the bacterium's metabolism and ability to make proteins.[79][80] Additionally, ... Squalene oxidation activates NF-κB (a protein complex) and consequently increases IL-1α levels.[45] Additionally, squalene ...
The CD20 proteins are sticking out of the cell membrane, and rituximab, the Y-shaped antibody, is binding to the CD20 proteins. ... The antibody binds to the cell surface protein CD20. CD20 is widely expressed on B cells, from early pre-B cells to later in ... In contrast, when the B cell lacked this asymmetric protein cluster, it was killed only 40% of the time.[36][37] ... Rituximab tends to stick to one side of B cells, where CD20 is, forming a cap and drawing proteins over to that side. The ...
The lacey membranes of the endoplasmic reticulum were first seen in 1945 by scientists using an electron microscope.[2] ... Rough endoplasmic reticulum (RER), so called because it is studded with ribosomes, and secretes proteins into the cytoplasm. ... Smooth endoplasmic reticulum (SER). Among its functions is the production of proteins and steroids, the maintenance of plasma ... 5 Ribosome on the rough ER 6 Proteins that are transported 7 Transport vesicle 8 Golgi apparatus 9 Cis face of the Golgi ...
integral component of membrane. • membrane. • GO:0005578 extracellular matrix. • plasma membrane. • extracellular region. • ... GO:0001948 protein binding. • carbohydrate binding. • identical protein binding. • receptor ligand activity. • extracellular ... Zona pellucida sperm-binding protein 3, also known as zona pellucida glycoprotein 3 (Zp-3) or the sperm receptor, is a ZP ... The protein encoded by this gene is a major structural component of the ZP and functions in primary binding and stimulation of ...
That is, oral candidiasis is a mycosis (yeast/fungal infection) of Candida species on the mucous membranes of the mouth. ... This adhesion involves adhesins (e.g., hyphal wall protein 1), and extracellular polymeric materials (e.g., mannoprotein). ... It may precede the formation of a pseudomembrane, be left when the membrane is removed, or arise without prior pseudomembranes ... in the mouth and on other mucous membranes (i.e., a secondary oral candidiasis). These include Localized chronic mucocutaneous ...
Its receptor - the neurokinin type 1 - is distributed over cytoplasmic and nuclear membranes of many cell types (neurons, glia ... "The neuropeptide substance P activates p38 mitogen-activated protein kinase resulting in IL-6 expression independently from NF- ... "Metalloproteinases and transforming growth factor-alpha mediate substance P-induced mitogen-activated protein kinase activation ... "Substance P induces rapid and transient membrane blebbing in U373MG cells in a p21-activated kinase-dependent manner". PLOS ...
Editing is concentrated in the nervous system and affects proteins involved in neural excitability and neuronal morphology. ... which is mostly suspended from the roof of the mantle cavity by numerous membranes. The tract consists of a crop, where the ... the proteins that guide the connections neurons make with each other. The California two-spot octopus has had its genome ... Octopus blood contains the copper-rich protein haemocyanin to transport oxygen. This makes the blood very viscous and it ...
Cell development involves many such proteins working together. Fig#1 shows how TipN interact with two other polar proteins : ... Included are those involved in chemotaxis, outer membrane channel function, degradation of aromatic ring compounds, and the ... The DnaA protein acts at the origin of replication to initiate the replication of the chromosome. The CtrA protein, in contrast ... These five proteins directly control the timing of expression of over 200 genes. The five master regulatory proteins are ...
This results in a series of unstable intermediates, the last of which binds stronger to a G protein in the membrane, called ... Stacks of membrane-enclosed disks are unattached to cell membrane directly Disks are attached to outer membrane ... To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential. ... The pigment, called iodopsin or rhodopsin, consists of large proteins called opsin (situated in the plasma membrane), attached ...
This form of motility has been shown to be regulated by the cAMP receptor protein. Hedger 11:30, 14 2007. The mechanism for ... have a common outer membrane. Basa 16:31, 19 January 2007 (UTC) ... the nitrogen-fixing protein complex may be packaged into ... However it is a somewhat ineffective method as it causes the organism to degrade protein, a very metabolically expensive method ...
The B. natans genome contains 293 genes that code for proteins as compared to the 465 genes in G. theta. B. natans also only ... Having two sets of membranes indicate that the plastid, a prokaryote, was engulfed by a eukaryote, an alga, which was then ... Most of the genes that moved to the host cell involved protein synthesis, leaving behind a compact genome with mostly single- ... Nucleomorphs are small, vestigial eukaryotic nuclei found between the inner and outer pairs of membranes in certain plastids. ...
A hexavalent (OspA) protein subunit-based vaccine candidate VLA15 was granted fast track designation by the U.S. Food and Drug ... Because of their double-membrane envelope, Borrelia bacteria are often mistakenly described as Gram negative despite the ... Within the tick midgut, the Borrelia's outer surface protein A (OspA) binds to the tick receptor for OspA, known as TROSPA. ... A recombinant vaccine against Lyme disease, based on the outer surface protein A (ospA) of B. burgdorferi, was developed by ...
Mijelin protein nula • Osteonektin • Protein C • Protein S • Proteoglikan • Serum amiloid P komponenta • Sialoglikoprotein ( ... Transmembranska forma može biti odvojena od membrane, čime se generiše rastvorni proteinski fragment. BAFF je prirodni ligand ... Faktor aktivacije B-ćelija, (BAFF) koji je takođe poznat kao faktor nekroze tumora ligand superfamilija član 13B, je protein ... On je izražen kao transmembranski protein na različitim ćelijskim tipovima, kao što su monociti, dendritske ćelije i ćelije ...
Lang F, Alevizopoulos K, Stournaras C (2013). "Targeting membrane androgen receptors in tumors". Expert Opin. Ther. Targets. 17 ... "G protein-coupled receptors: extranuclear mediators for the non-genomic actions of steroids". Int J Mol Sci. 15 (9): 15412-25 ... Androgens have also been found to signal through membrane androgen receptors, which are distinct from the classical nuclear ...
The balance between potassium and sodium is maintained by ion transporter proteins in the cell membrane.[231] The cell membrane ...
... s are antimicrobial proteins found in saliva.[1] Function[edit]. Histatins are antimicrobial and antifungal proteins, ... Salivary proteins as a defense against dietary tannins. Shimada T. Journal of Chemical Ecology 2006 Jun;32(6):1149-63. ... "Histatins, a novel family of histidine-rich proteins in human parotid secretion. Isolation, characterization, primary ...
... tethering proteins are responsible for the initial recognition and attachment of the fusing membranes, whereas SNARE protein ... It emerges that proteins that tether fusing structures together also decrease the energy needed for the final fusion step. See ... Specifically, these proteins play a mechanical part by increasing the volume of SNARE complexes and deforming the site of ... They find that, in yeast cells, tether proteins are also essential for the transition from the hemifused state to the fusion ...
integral membrane protein type of membrane protein that is permanently attached to the biological membrane ... Media in category "Integral membrane proteins". The following 15 files are in this category, out of 15 total. ... Dynamic-Organization-of-SecA-and-SecY-Secretion-Complexes-in-the-B.-subtilis-Membrane-pone.0157899.s010.ogv 1 min 59 s, 120 × ... Retrieved from "" ...
Shedding of plasma membrane proteins.. Arribas J1, Merlos-Suárez A.. Author information. 1. Laboratori de Recerca Oncològica, ...
... in many integral membrane proteins they comprise a significantly higher proportion of the amino acid composition. Now that... ... While tryptophans are generally found in low abundance in soluble proteins, ... While tryptophans are generally found in low abundance in soluble proteins, in many integral membrane proteins they comprise a ... Oligopeptide biases in protein sequences and their use in predicting protein coding regions in nucleotide-sequences, Proteins: ...
Crystallizing membrane proteins using lipidic mesophases.. Caffrey M1, Cherezov V.. Author information. 1. Membrane Structural ... A flow chart summarizing the steps involved in and time required for setting up an in meso membrane protein crystallization ... Crystals of membrane proteins growing in the lipidic mesophase. A, bacteriorhodopsin; B, light harvesting complex II; C, the ... Cartoon representation of the events proposed to take place during the crystallization of an integral membrane protein from the ...
Membrane proteins represent about one third of the proteins encoded in a cells genome, and, because of their key physiological ... Amphipols Reviewed Membrane Protein Folding Membrane Protein Stability Membrane Protein Structural Studies Membrane Protein ... Membrane proteins represent about one third of the proteins encoded in a cells genome, and, because of their key physiological ... Topical chapters cover in vitro folding, cell-free synthesis and stabilization of membrane proteins, and such biophysical and ...
Although the concept of membrane-protein topology dates back at least 30 years, recent advances in the field of translocon- ... In the world of membrane proteins, topology defines an important halfway house between the amino-acid sequence and the fully ... recent advances in the field of translocon-mediated membrane-protein assembly, proteome-wide studies of membrane-protein ... Membrane-protein topology Nat Rev Mol Cell Biol. 2006 Dec;7(12):909-18. doi: 10.1038/nrm2063. ...
Membrane Protein Labeling, Imaging and Functional Characterization, with Howard Hughes Medical Institute (HHMI). Apply Today. ... Research Specialist - Membrane Protein Labeling, Imaging and Functional Characterization. Howard Hughes Medical Institute (HHMI ... Optimize high-throughput genome-editing methods to tag and label endogenous membrane proteins in the brain (mouse). ... super-resolution and electron microscopy pipeline to map and annotate the sub-cellular localization of membrane proteins in the ...
Orientations of Proteins in Membranes (OPM) database provides spatial positions of membrane protein structures with respect to ... membrane topology, quaternary structure of proteins in membrane-bound state, and the type of a destination membrane for each ... Orientations of Proteins in Membranes. Content. Description. The database provides spatial arrangement of proteins in the lipid ... Proteins structures are taken from the Protein Data Bank. OPM also provides structural classification of membrane-associated ...
Postdoctoral position in Membrane Protein Structure / Protein NMR. *Postdoctoral position in Molecular Biophysics / NMR-based ... Postdoctoral position in Membrane Protein Structure / Protein NMR. *Postdoctoral position in Molecular Biophysics / NMR-based ... Postdoctoral Position in Membrane Protein NMR at TUM / Helmholtz Center Munich. *Postdoctoral Position in Metabolic MRI - ... Postdoctoral Position in Membrane Protein NMR at TUM / Helmholtz Center Munich. *Postdoctoral Position in Metabolic MRI - ...
Determinants of membrane protein topology. D Boyd, C Manoil, and J Beckwith ... The topology of the integral membrane protein MalF, which is required for maltose transport in Escherichia coli, has been ... These studies in conjunction with our earlier results show that alkaline phosphatase fusions to membrane proteins can be an ... of the cytoplasmic domains of membrane proteins are important in anchoring these domains in the cytoplasm. ...
... latent membrane protein 2 (LMP2) are two viral proteins of the Epstein-Barr virus. LMP2A/LMP2B are transmembrane proteins that ... "The Epstein-Barr virus latent membrane protein 2A PY motif recruits WW domain-containing ubiquitin-protein ligases". Virology. ... Twelve membrane spanning segments ending with a short 28 residue COOH tail are common to both proteins in residue 379. The 119 ... Latent Membrane Protein 2 (LMP2) is a rightward transcribing gene. LMP2s transcript originates across the fused terminal ...
Centre of Membrane Proteins and Receptors. The Centre of Membrane Proteins and Receptors (COMPARE) is a unique collaboration ... COMPARE works to develop novel methods for visualising single membrane proteins, as well as identifying new approaches for the ... New algorithms and mathematical models of signalling by G Protein-Coupled Receptors (GPCR) and Tyrosine Kinase-linked Receptors ... development of a new generation of drugs with reduced side effects by virtue of targeting receptors in their unique membrane ...
... stabilization and structural analysis techniques of membrane proteins Explores the structural ... Membrane Proteins Production for Structural Analysis. Editors. * Isabelle Mus-Veteau Copyright. 2014. Publisher. Springer- ... Overexpression of Membrane Proteins in Saccharomyces cerevisiae for Structural and Functional Studies: A Focus on the Rabbit ... Isabelle Mus-Veteau is a biochemist and biophysicist specialist in membrane protein characterization. She obtained her PhD in ...
Intrinsically curved proteins or protein oligomers can provide "scaffolding" that leads to membrane bending; partially membrane ... The peripheral membrane protein M1 is considered not to have membrane subdomain specificity. In the next paragraphs, we ... The matrix protein M1 (red in Figure 1) binds to membranes, but does not have a transmembrane span [9-11]. M1 is most likely ... M1 can fulfill this function by being transported to the plasma membrane by the other viral membrane proteins (see above). Of ...
Delivery of non-native ER proteins to the proteasome requires retrograde transport across the ER membrane and depends on a ... ER-Associated Degradation of Membrane Proteins in Yeast. Cédric Pety de Thozée and Michel Ghislain ... Proteins destined for the secretory pathway are translocated into the endoplasmic reticulum (ER), where they are subjected to a ... Newly synthesized proteins that have defect in polypeptide folding or subunit assembly are recognized by quality control ...
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a disorder of the nervous system. Explore symptoms, ... Mitochondrial membrane protein- ... Mitochondrial membrane protein-associated neurodegeneration due to C19orf12 mutation. *Mitochondrial protein-associated ... The protein produced from this gene is found in the membrane of cellular structures called mitochondria. , which are the energy ...
"Discovery Links Proteins Necessary To Repair Membranes." Medical News Today. MediLexicon, Intl., 11 Jun. 2009. Web.. 20 Jan. ... Linking these proteins creates a mechanism that allows damaged membranes to be repaired, which may transform treatment for ... 2009, June 11). "Discovery Links Proteins Necessary To Repair Membranes." Medical News Today. Retrieved from. https://www. ... His research team announced in December 2008 that it had discovered MG53 as a key initiator of membrane repair in damaged ...
... Christian Ebeling cebelin at Fri Sep 19 22:23:47 EST 1997 *Previous message: First ... Hello, i need for my project membran proteins from any organism which forms a specific heterodimer with a strong affinity. This ...
... Dr E. Buxbaum EB15 at Mon Sep 22 16:47:30 EST 1997 *Previous message: membrane protein ... Christian Ebeling wrote: , , Hello, , i need for my project membran proteins from any organism which forms a , specific ... These proteins have definetly been expressed in Xenopus oocytes and in yeast, I am not sure about E. coli (the beta subunit is ...
Postdoctoral position in Membrane Protein Structure / Protein NMR. *Postdoctoral position in Molecular Biophysics / NMR-based ... Postdoctoral position in Membrane Protein Structure / Protein NMR. *Postdoctoral position in Molecular Biophysics / NMR-based ... Postdoctoral Position in Membrane Protein NMR at TUM / Helmholtz Center Munich. *Postdoctoral Position in NMR Methods ... Postdoctoral Position in Membrane Protein NMR at TUM / Helmholtz Center Munich. *Postdoctoral Position in NMR Methods ...
We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their ... InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites ... This family consists of putative outer membrane proteins, mainly from H. pylori. ... Potential targets for vaccine development are H. pylori-specific proteins that are surface-exposed and highly antigenic. ...
He and his team have now shed light on how these proteins assemble on the surface of a cell and reshape its membrane. ... The process involves EHD proteins -- a focus of research by Prof. Oliver Daumke of the MDC. ... frequently form on membranes of cells and are taken up into their interior. ... not bound to the membrane. Until now, scientists did not know how EHD proteins become activated, attach to the membrane and ...
Purchase Membrane Protein-Cytoskeleton Interactions, Volume 43 - 1st Edition. Print Book & E-Book. ISBN 9780121533434, ... and in regulating membrane protein, and ultimately, cell function. This volume reviews the regulation of membrane protein ... Membrane-Cytoskeleton Interactions with Cadherin Cell Adhesion Proteins; Roles of Catenins as Linker Proteins. ... G.G. Gayer, J.T. Campanelli, and R.H. Scheller, Regulation of Membrane Protein Organization at the Neuromuscular Junction. ...
How proteins fold is a fundamental problem in molecular biology and has been the subject of intense study. Membrane protein ... Methods to measure the thermodynamic stability of membrane proteins have largely followed methods developed for soluble protein ... the stability of other membrane proteins to see if high thermodynamic stability is common among helical membrane proteins, and ... helical membrane protein.. The steric trapping approach is outlined in Fig. 1. Two biotin tags are placed on the protein at ...
Fitting Periplasmic Membrane Fusion Proteins to Inner Membrane Transporters: Mutations That Enable Escherichia coli AcrA To ... A TolC-Like Protein Is Required for Heterocyst Development in Anabaena sp. Strain PCC 7120 Suncana Moslavac, Kerstin Nicolaisen ... Compromised Outer Membrane Integrity in Vibrio cholerae Type II Secretion Mutants Aleksandra E. Sikora, Suzanne R. Lybarger, ... Outer Membrane Components of the Tad (Tight Adherence) Secreton of Aggregatibacter actinomycetemcomitans Sarah A. Clock, Paul J ...
... expression of membrane proteins in heterologous systems is challenging. ... Due to unique physical properties and requirement for association with cellular membranes, ... Purification Expression of Difficult Proteins Membrane Protein Expression Membrane Protein Expression. Product Listing ... expression of membrane proteins in heterologous systems is often daunting.. Cellular expression of recombinant membrane protein ...
... while also spotting the subtle features of protein structure, which is important for future research and drug development. They ... offer an alternative to the conventionally used SONICC method of protein crystal detection. Their proposed CARS technique can ... MIPTs scientists that previously succeeded in growing protein microcrystals within just three weeks to make studying proteins ... microcrystals_of_membrane_proteins_no_longer_hiding_from_scientists?CODE=. microcrystals_of_membrane_proteins_no_longer_hiding_ ...
Membrane lipids, membrane proteins, anionic lipids, membrane remodeling, intracellular vesicles, model membrane systems, ... In this PhD thesis, the influence of lipids on the membrane protein function was studied using three different membrane protein ... The interplay between lipids and membrane proteins is known to affect membrane protein topology and thus have significant ... Lipid-protein interactions, fatty acid modeling, cyclopropanation, membrane fluidity, monotopic membrane proteins, ...
The second algorithm was that proteins were first selected to react and proteins which did not react were subjected to movement ... and simulation analyses of clustering of membrane proteins have been performed. It was claimed that a cluster is formed by the ... All proteins were subjected to movement in the first substep, followed by reaction in the second substep. ... In contrast to algorithms in previous simulations, our results suggest that it is more appropriate that proteins move to the ...
  • Cellular expression of recombinant membrane protein often results in protein aggregation and misfolding due to the hydrophobic nature of transmembrane segments. (
  • Peripheral membrane proteins are temporarily attached either to the lipid bilayer or to integral proteins by a combination of hydrophobic , electrostatic , and other non-covalent interactions. (
  • Schematic of a membrane-bound protein, which relies on the hydrophobic environment within the cell membrane. (
  • these protein segments are stable when embedded within the equally hydrophobic lipid-based cell membrane (Fig. 1), but tend to assemble into irregular, improperly folded clumps when prepared in solution. (
  • This reaction is performed in the presence of lipids and detergent, which protect hydrophobic protein segments and help initial folding along (middle). (
  • The part of the protein that is embedded in the hydrophobic regions of the bilayer are alpha helical and composed of predominantly hydrophobic amino acids. (
  • The outer edges of the membrane are hydrophilic (soluble in water ), while the interior area is hydrophobic (insoluble in water). (
  • However, molecules with high polarity, such as sodium, are not able to freely enter the cell membrane because the charged ion cannot pass through the hydrophobic core of the membrane. (
  • A hydrophobic domain of the protein resides in the oily core of the membrane, while hydrophilic domains protrude into the watery environment inside and outside the cell or compartment. (
  • This is because hydrophobic regions of the protein are protected within the phospholipid bilayer of the cell membrane. (
  • Domain I, consisting of the amino-terminal 47 amino acids, contains a 21-residue hydrophobic segment that anchors the protein in the inner membrane. (
  • One major obstacle in crystallizing membrane proteins was that they are actually membrane proteins and lipids together, meaning the membrane is partly hydrophobic and it is thus impossible to create an aqueous solution. (
  • Indeed, the hydrophobic protein equipment of plant plasma membrane still remains largely unknown, though several proteomic approaches have been reported. (
  • To identify new putative transport systems, we developed a new proteomic strategy based on mass spectrometry analyses of a plasma membrane fraction enriched in hydrophobic proteins. (
  • Using complementary methods for the extraction of hydrophobic proteins and mass spectrometry analyses on mono-dimensional gels, about 100 proteins have been identified, 95% of which had never been found in previous proteomic studies. (
  • Science: protein) membrane proteins that are bound to the surface of the membrane and not integrated into the hydrophobic region . (
  • The low natural expression and hydrophobic nature of membrane proteins complicates their study. (
  • Integral MPs span the entire phospholipid bilayer with one or more segments composed of hydrophobic residues that interact with the fatty acyl groups of the membrane phospholipids. (
  • With the earlier-generation Mem-PER Kit, extraction resulted in a viscous detergent-based hydrophobic fraction containing MPs, which required further processing before downstream procedures such as protein concentration determination, SDS-PAGE, and western blotting. (
  • For example, proteins involved in immune response The localization of proteins in membranes can be predicted reliably using hydrophobicity analyses of protein sequences, i.e. the localization of hydrophobic amino acid sequences. (
  • Transport proteins move molecules and ions across the membrane. (
  • Finally, transport proteins play an important role in the maintenance of concentrations of ions. (
  • These transport proteins come in two forms: carrier proteins and channel proteins. (
  • Finally, in the fourth session, we will hear about novel functional properties of known transport proteins and the newly discovered molecular identities behind the well-known cellular-transport phenomena. (
  • This GRS will be held in conjunction with the "Membrane Transport Proteins" Gordon Research Conference (GRC). (
  • Topics concerned with degradation and reconstruction of membrane and components and with transport proteins, excitable membranes, and transport adenosine triphosphatase. (
  • Embedded within and spanning the phospholipid bilayer are various transport proteins that serve as "gates," selectively allowing charged molecules and ions and larger molecules to pass through the membrane. (
  • These transport proteins channel molecules by a variety of methods, including facilitated diffusion (movement with the concentration gradient, using no ATP energy ) and active transport (movement against the concentration gradient, using ATP energy). (
  • The transport proteins that move solutes against a concentration gradient are called carrier proteins. (
  • The UhpA and UhpB proteins are related to the response-regulator and sensor-kinase proteins of two-component regulatory systems, whereas the UhpC protein is related to UhpT and homologous transport proteins. (
  • Its most recent successes are the human-engineered beta(2)-adrenergic and adenosine A(2A) G protein-coupled receptors. (
  • The Centre of Membrane Proteins and Receptors (COMPARE) is a unique collaboration between the Universities of Birmingham and Nottingham which aims to bring together leading researchers to generate innovative opportunities. (
  • Information from state-of-the-art imaging technology will enable development of a new generation of drugs with reduced side effects by virtue of targeting receptors in their unique membrane environment. (
  • New algorithms and mathematical models of signalling by G Protein-Coupled Receptors (GPCR) and Tyrosine Kinase-linked Receptors (TKLR). (
  • Important examples of this protein class include certain signal transduction receptors, cell adhesion molecules and ion channels. (
  • This procedure has been extensively used for ligand - G protein-coupled receptors (GPCR) and their complexes. (
  • IMPs include transporters , linkers, channels , receptors , enzymes , structural membrane-anchoring domains, proteins involved in accumulation and transduction of energy , and proteins responsible for cell adhesion . (
  • G protein coupled receptors (e.g. (
  • To get past the membrane, nutrients or hormones in the bloodstream, for example, bind to specific receptors on cells membranes. (
  • Some membrane proteins serve as receptors for hormones , transferring the signal to the interior of the cell (via G proteins) without allowing the "messenger" molecule to enter, thus protecting the integrity of the cell. (
  • Besides, chief amongst the cell membranes constituents are integral membrane proteins, which act as biological gatekeepers, controlling the flow of biomolecules through transporters and transmitting signals through receptors. (
  • Within the integral membrane protein class are several different categories of protein, many of which are receptors and other types of cell signaling molecules. (
  • Certain types of T cell receptors, the insulin receptor, and many other receptors and neurotransmitters, are all integral transmembrane proteins. (
  • In general, receptors, transmitters, and transporters tend to belong to this class of IMP because proteins that span the entire membrane are typically able to sense conditions both inside and outside of the cell simultaneously. (
  • They use an arsenal of membrane receptors, channels and pumps to control signal transduction that is unmatched by even the most powerful computers. (
  • This method is important for production and study of difficult to express proteins such as transporters and receptors. (
  • Signalling mechanisms of membrane receptors involve subtle conformational changes of these proteins [1]. (
  • Membrane proteins and receptors are the largest category of druggable targets studied in the pharmaceutical industry. (
  • They help to ensure that vesicles fuse with the correct target compartment through a lock-and-key-like process in which α-helical structural regions of SNAREs on different membranes intertwine and zipper together to form a structure called a trans -SNARE complex 2 . (
  • OPM also provides structural classification of membrane-associated proteins into families and superfamilies, membrane topology , quaternary structure of proteins in membrane-bound state, and the type of a destination membrane for each protein. (
  • The main objective of this project is to understand the function - and underlying structural properties - of these proteins and their interaction with the mitochondrial membrane environment. (
  • For this purpose we will use structural biological methods focusing on solid-state NMR spectroscopy of lipid-protein complexes. (
  • By applying advanced solid-state NMR approaches, we will be able to provide structural insight into the molecular mechanism by which the survival membrane protein Bcl-2 and its antagonist, the cell-killing Bax protein, interact with each other at the mitochondrial membrane and thereby determine the fate of the cell. (
  • This book is essential reading for all researchers, biochemists and crystallographers working with membrane proteins, who are interested by the structural characterization of their favorite protein and who wish to follow the expression, migration, modifications and recycling of a membrane protein. (
  • She organized two international summer schools on membrane protein production for structural analysis and two international congresses on membrane biophysics. (
  • 2017): "Structural insights into the activation mechanism of dynamin-like Eps15-homology domain proteins. (
  • The cytoskeleton plays essential roles in delineating membrane protein distributions, in defining structural and functional domains in the plasma membrane, and in regulating membrane protein, and ultimately, cell function. (
  • Discussions also include the roles of cytoskeleton in the structural and functional organization of membranes and membrane proteins with emphasis on key problems, the current status of understanding, experimental approaches, and future directions. (
  • The biochemical and structural characterization of this challenging class of protein represents an important frontier in both basic science and drug discovery research. (
  • Structural proteins are attached to microfilaments in the cytoskeleton which ensures stability of the cell. (
  • Ursell created a physical model which shows that the membrane itself can communicate structural and hence formational information between membrane proteins. (
  • Now, a research team led by Shigeyuki Yokoyama at the RIKEN Systems and Structural Biology Center in Yokoyama has developed an efficient preparation method that produces high yields of functional membrane proteins 1 . (
  • The Protein Structure Initiative (PSI), funded by the U.S. National Institute of General Medical Sciences (NIGMS), part of the National Institutes of Health (NIH), has among its aim to determine three-dimensional protein structures and to develop techniques for use in structural biology , including for membrane proteins. (
  • As part of the French Infrastructure for Integrated Structural Biology ( FRISBI ), our laboratory hosts the yeast expression technical platform MPEX ( M embrane P rotein EX pression) and therefore state-of-the-art equipment for membrane protein expression and purification. (
  • Many functions of the cell membrane are controlled by proteins that transduce signals across the lipid bilayer, either via molecular-transport reactions or structural rearrangements. (
  • Membrane proteins are one of the most challenging and attractive objects in modern structural biology, as they are targets for the majority of medicines. (
  • De novo design allows us to survey the full scope of protein sequence and structural space, and to see whether artificial constructs could replace natural proteins or have useful non-natural functions. (
  • Structural commonalities among integral membrane enzymes. (
  • Our technology, termed Salipro, may offer a wide range of potential applications, ranging from structural biology to the discovery of new pharmacological agents, as well as the therapeutic delivery of protein-based therapeutics and vaccines', says first author Jens Frauenfeld, who was working at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet when the study was performed. (
  • However, detergents are associated with protein instability and poor compatibility with structural and biophysical studies. (
  • Taken together, the researchers apply the method on three different membrane protein targets for structural and functional studies. (
  • Using bioinformatic tools we have previously shown that viral structural proteins are a rich source for new bioactive peptide sequences, namely antimicrobial and cell-penetrating peptides. (
  • Overall, the results show that structural viral proteins are an abundant source for membrane-active peptides sequences with strong antibacterial properties. (
  • This analysis also reveals 10 proteins that display structural properties compatible with transport functions and will constitute interesting targets for further functional studies. (
  • The plasma membrane (PM) 1 is an organized system serving as a structural and communication interface with the extracellular environment for exchanges of information and substances. (
  • This FOA solicits applications to establish Centers for Membrane Protein Structure Determination that will become a vital component in fulfilling the expanded goals of the NIGMS PSI:Biology network for high-throughput-enabled structural biology. (
  • These signalling components are delivered to the cell membrane through a pathway in which vesicles containing these molecules transit through different organelles by a series of vesicle budding and fusion events. (
  • This leads to phase separation wherein protein molecules diffuse from the continuous bilayered reservoir of the cubic phase by way of a sheet-like or lamellar portal to lock into the lattice of the advancing crystal face (mid-section of figure). (
  • This book, written by a specialist of membrane proteins and one of the creators of amphipols, describes the properties and uses of these novel molecules. (
  • Although its function is unknown, researchers suggest that the C19orf12 protein plays a role in the maintenance of fat (lipid) molecules, a process known as lipid homeostasis. (
  • Comparing the active and inactive protein structures, they discovered that EHD molecules flip open when they bind to the membrane, exposing specialized regions. (
  • To pretest the quality, scientists currently use the SONICC technique, which is based on imaging from the SHG method (which allows scientists to "see" ordered crystals through a disordered medium in which they are growing) and UV-TPEF (a special type of microscopy that can only see special amino acids present in protein molecules). (
  • Do membrane proteins cluster without binding between molecules? (
  • Understanding the interactions between proteins and soap molecules (surfactants) has long been important for the industry, particularly within detergents and cosmetics. (
  • Much of that success is the result of a seemingly mundane achievement - the development of techniques to purify and study these proteins in isolation, allowing us to barrage them with biophysical methods, some drawn from existing arsenals, others developed specifically for this class of molecules. (
  • Yokoyama and colleagues solved this problem by developing a hybrid technique that incorporates elements of both preparation methods, synthesizing their proteins in a bacteria-derived extract containing both detergent and lipid molecules. (
  • Antiporter , also called exchanger and counter-transporter , is an integral membrane protein that involves in a secondary active transporter of two or more different substrates (molecules or ions). (
  • The membrane then forms a pit around these bound molecules, which is squeezed into a pouch, or vesicle, that detaches from the rest of the cell membrane and carries its essential cargo into the cell. (
  • Initially, most scientists believed that many dynamin molecules assembled long spirals on cell membranes, and that in the presence of GTP these spirals tightened, lopping off a vesicle. (
  • The majority of the membrane is composed of two layers of phospholipid molecules lined up side by side with their fatty acid "tails" facing inward. (
  • Because of this dual chemical nature of the phospholipid bilayer, the entire membrane surface is permeable to gases (such as oxygen and carbon dioxide ), to small, uncharged polar molecules (such as water and ammonia ), and to nonpolar molecules (such as lipids). (
  • However, the membrane is impermeable to charged molecules (such as ions and proteins ) and to larger, uncharged polar molecules. (
  • The plasma membrane that forms the boundary of a cell has several other molecules in addition to the basic membrane structure. (
  • Other carbohydrate molecules attached to the exterior of the plasma membrane act as "markers," identifying the cell as a particular type. (
  • Transport of molecules across membrane is the movement of a molecule from inside the membrane to outside or vice versa. (
  • One process is the transport of molecules from one side of a membrane to the other. (
  • According to the results obtained by the researchers in Dortmund, many KRas molecules would still be lost on the available surface of the rest of the membrane systems in the cell, which is 200 times bigger than that of the cell membrane. (
  • After seven minutes, half of all KRas molecules are internalized from the cell membrane to be subjected to the cycle and sent back to the cell membrane. (
  • Examples of the functions that different integral membrane proteins serve include the identification of the cell for recognition by other cells, the anchoring of one cell to another or to surrounding media, the initiation of intracellular responses to external molecules and the transportation of molecules across the membrane. (
  • We have created lipid and polymer membranes with a high density of PSI molecules and have characterized their activity using time-resolved optical spectroscopy and photocurrent measurements. (
  • This protein, called clathrin, is known for its key role in the process of internalization of molecules from the extracellular space into the cell, called endocytosis. (
  • As they continue to manufacture different membrane proteins, the team is tackling the next step to creating a pathway to protein crystallization for membrane proteins by developing specialized molecules, or reagents. (
  • Molecules that mimic the lipid bi-layer, or membrane. (
  • Scientists at Lawrence Livermore National Laboratory took an important step in creating a nanobioelectronic device when they combined a silicon nanowire (shown in the picture in gray ), covered it with a lipid bilayer (blue), and incorporated bundles of alamethicin molecules (purple) to form pore channels in the membrane. (
  • These membranes form a stable, self-healing,and virtually impenetrable barrier to ions and small molecules. (
  • The biosensor takes advantage of recently developed fluorogen-activating proteins (FAPs) that display fluorescence only when bound to otherwise-nonfluorescent fluorogen molecules. (
  • Various membrane trafficking pathways transport molecules through the endosomal system of eukaryotic cells, where trafficking decisions control the localisation and activity of a diverse repertoire of membrane protein cargoes. (
  • However, it is now clear that some peripheral membrane proteins are covalently linked to molecules that are part of the membrane bilayer (see acylated proteins and glypiation ) and that there are others that fit the original definition but are perhps more appropriately considered proteins of the cytoskeleton (e.g. (
  • The cells from our body as well as intracellular organelles are surrounded by a thin sheet called the membrane, which is primarily made of lipids and proteins. (
  • However, the enormous complexity of cell membranes, being built up by numerous different lipids and proteins, combined with the fact that membrane proteins must reside in this environment to function, makes functional characterization of this class of protein extremely demanding. (
  • Cell membranes are comprised of a heterogeneous mixture of lipids and proteins. (
  • The 119 amino-terminal cytoplasmic domain of LMP2A has several motifs that mediate interactions between proteins, including eight tyrosine residues. (
  • Prior to this study, the underlying interactions that inhibited membrane repair in muscle tissue were unknown. (
  • The research will focus on supramolecular interactions of membrane proteins using a combined approach of modern solid-state NMR methods & modern MD simulations methods. (
  • T.A. Schroer and S.R. Gill , Interactions between Microtubules and Intracellular Membranes: The Roles of Microtubule-Based Motors and Accessory Proteins. (
  • A.S. Fanning, L.A. Lapierre, A.R. Brecher, and C.M. Van Italie , Protein Interactions in the Tight Junction: The Role of MAGUK Proteins in Regulating Tight Junction Organization and Function. (
  • L.Y.W. Bourguignon , Interactions between the Membrane-Cytoskeleton and CD44 during Lymphocyte Signal Transduction and Cell Adhesion. (
  • Luna, E.J. and Hitt, A.L. (1992) Cytoskeleton-plasma membrane interactions. (
  • CITATION: Ursell T, Huang K, Peterson E, Phillips R (2007) Cooperative gating and spatial organization of membrane proteins through elastic interactions. (
  • The Laboratory of Membrane Protein and Membrane Systems works at deciphering the mechanism of membrane-related processes, with a specific emphasis on the molecular mechanism of active transport across biological membranes, as well as the study of protein-protein and protein-lipid interactions and significance. (
  • How do helix-helix interactions help determine the folds of membrane proteins? (
  • Protein-lipid interactions (Ed. L.K. Tamm) Wiley, 2005. (
  • Mapping membrane protein interactions in cell signaling systems. (
  • Most other stains produce high backgrounds on nylon membranes due to strong charge interactions with the membrane. (
  • Thus, taking also advantage of modern hardware we may enhance our understanding of membrane protein functions and the role of specific lipid/protein interactions [5]. (
  • Where available, membrane protein crystal structures facilitate elucidation of their functions and discovery of mechanisms of MP-drug molecule interactions. (
  • The topology of the integral membrane protein MalF, which is required for maltose transport in Escherichia coli, has been analyzed using fusions of alkaline phosphatase (EC (
  • A monotopic membrane protein, monoglucosyldiacylglyecerol synthase (MGS) from Acholeplasma laidlawii is known to induce intracellular vesicles when expressed in Escherichia coli . (
  • The group A colicins and the DNA of many single-stranded filamentous bacteriophage are able to use combinations of the Tol proteins to gain entrance into or across the membrane of Escherichia coli. (
  • Expression of the Escherichia coli uhpT gene, encoding the sugar phosphate transport protein, is induced by extracellular glucose-6-phosphate and requires the function of the uhpABC regulatory genes. (
  • She developed a method to select for Escherichia coli strains that express (membrane) proteins at an elevated level and in a functional state. (
  • SNAREs are a group of membrane proteins present on the surface of vesicles and organelles. (
  • Then, through its interaction with Cav3, MG53 recruits intracellular vesicles to the injury site in the membrane, acting as a trafficking agent in the repair process. (
  • The vesicles interact with dysferlin to fuse with the membrane, thereby creating a repair patch and allowing for normal membrane function. (
  • EHD proteins are one type of molecular machine responsible for the creation of vesicles. (
  • X. Yao and J.G. Forte , Membrane-Cytoskeleton Interaction in Regulated Exocytosis and Apical Insertion of Vesicles in Epithelial Cells. (
  • X- and Y-enriched sperm-plasma-membrane vesicles. (
  • The structure of the protein, called dynamin, is helping to answer many longstanding questions about how vesicles form, advancing knowledge of a process critical to cell survival. (
  • That study did not reveal how the dynamin collars pinch off membrane vesicles, though. (
  • In order for it to be transported by special transport vesicles from the vicinity of the cell nucleus to the cell membrane, the solubilising factor PDEδ and its antagonist Arl2 must be active. (
  • KRas is now insoluble in water again and can be trapped on membranes and transported back to the cell membrane by vesicles. (
  • Up to now, however, the creation of planar supported cell-membrane mimics from compositionally complex cell-membrane derived vesicles has remained relatively elusive. (
  • In this process, the cell membrane folds creating vesicles with a cladded structure. (
  • [1] [2] The integral membrane proteins are classified as transmembrane proteins that span across the membrane and integral monotopic proteins that are attached to only one side of the membrane. (
  • Integral monotopic proteins are integral membrane proteins that are attached to only one side of the membrane and do not span the whole way across. (
  • Integral monotopic proteins are associated with the membrane from one side but do not span the lipid bilayer completely. (
  • These are integral transmembrane proteins, and integral monotopic proteins. (
  • Integral monotopic proteins do not span the entire biological membrane. (
  • Integral monotopic proteins are unable to sense conditions both inside and outside the cell, and are less likely to be involved in intercellular signaling. (
  • Integral monotopic proteins , are permanently attached to the membrane from one side. (
  • Once local enrichment of transmembrane proteins is successfully accomplished, it is our aim to employ surface analytical tools, such as SPR, TIRF microscopy, electrical impedance spectroscopy and QCM-D, for functional studies of membrane proteins in a near-native cell-membrane environment. (
  • However, studies of membrane proteins are hindered by several obstacles, including their low ability to crystallize, highly dynamic behavior of some of their domains, and need for membrane-like environment. (
  • The investigators demonstrate that the method facilitates high-resolution 3-dimensional studies of membrane proteins by single-particle electron cryo-microscopy, cryo-EM, an increasingly popular technique among scientists who want to study proteins at atomic resolution. (
  • Cells communicate with each other by releasing and taking up molecular 'messages', which are often proteins or hormones. (
  • The ultimate goal is to characterize the sub-cellular localization and dynamics of cell-type specific channel and receptor proteins in the brain and study how neural computation in single neuron units is regulated at the molecular level. (
  • This postdoctoral position is part of a research project where we will investigate the regulation of programmed cell death at the molecular level with focus on the structure of the proteins and biological membranes involved in this important process. (
  • Experience in molecular / cell biology techniques / protein expression is strongly desirable. (
  • Oliver Daumke of the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC) is investigating the function and spatial structure of these EHD proteins. (
  • Together with international colleagues, Daumke and his PhD student Arthur Alves de Melo have now published an article in the current issue of the scientific journal PNAS that describes the active form of this molecular EHD machine - that which occurs when it comes into contact with the membrane. (
  • Another region reorients toward the membrane and anchors the molecular machines on the cell surface. (
  • K.R. Fath and D.R. Burgess , The Role of the Cytoskeleton and Molecular Motors in Transport between the Golgi Complex and Plasma Membrane. (
  • R.R. Dubreuil , Molecular and Genetic Dissection of the Membrane Skeleton in Drosophila. (
  • How proteins fold is a fundamental problem in molecular biology and has been the subject of intense study. (
  • Proteins are important molecular machines that perform most of the functions in the human body. (
  • Membrane-embedded proteins execute many of the most important cellular functions, detecting external environmental cues, mediating communication and signaling, and facilitating molecular import and export. (
  • Molecular Membrane Biology, Vol. 32, Issue. (
  • In our group, we aim to decipher the mechanism by which membrane proteins catalyze their function, at a molecular level, with a specific emphasis in the interplay between lipids and membrane proteins, and in the role of membrane proteins in the dynamic organization of membrane lipids. (
  • Scientists at the Max Planck Institute of Molecular Physiology in Dortmund have now discovered why KRas is almost exclusively found at the cell membrane when observed under the microscope. (
  • The protein KRas acts as a molecular switch in relaying signals to the cell's interior. (
  • Instead, KRas constantly and unspecifically re-distributes to the various membrane systems of the cell and must then be concentrated on the inner leaflet of the cell membrane via a continuous cycle," explains Malte Schmick from the Max Planck Institute of Molecular Physiology. (
  • Continuous Lipid Bilayers Derived from Cell Membranes for Spatial Molecular Manipulation. (
  • Nuclear magnetic resonance spectroscopy of high-molecular-weight proteins. (
  • Cross-correlated relaxation enhanced 1H[bond]13C NMR spectroscopy of methyl groups in very high molecular weight proteins and protein complexes. (
  • It has recently been shown that a molecular wire can successfully tether a hydrogenase enzyme (H 2 ase) and a photosynthetic protein complex, Photosystem I (PSI) to integrate hydrogen generation with effective solar energy conversion. (
  • Specific recruitment of different proteins to distinct intracellular membranes is fundamental in the biology of eukaryotic cells, but the molecular basis for specificity is incompletely understood. (
  • Since x-ray crystallography was, and still is, the best way to reveal the molecular structure of proteins, neither their structure nor their function could be determined without crystallization. (
  • Though channel activities have been well characterized in plasma membrane by electrophysiology, the corresponding molecular entities are little documented. (
  • It is becoming increasingly clear that many of the molecular requirements to fulfil autophagy intersect with those of conventional and unconventional membrane trafficking pathways. (
  • Molecular view on protein sorting into liquid-ordered membrane domains mediated by gangliosides and lipid anchors. (
  • Integral and peripheral membrane proteins (MPs) are important for the maintenance of many cellular functions such as signal transduction, cell integrity, intracellular and extracellular transport of molecular solutes and cell-to-cell communication. (
  • Collaborate closely with imaging tool builders at Janelia to develop super-resolution and electron microscopy pipeline to map and annotate the sub-cellular localization of membrane proteins in the brain. (
  • There are a number of tools for predicting protein subcellular localization out there that can help. (
  • I'm actually unclear at the moment whether you want to find "known" membrane-localised proteins or predict localization (which is what psort and others do). (
  • If you want to predict localization based on signal peptides in the protein sequence, try signalP or SubLoc. (
  • The plasma membrane localization was confirmed for several proteins, therefore validating such proteomic strategy. (
  • The use of opr (for outer membrane protein) is proposed as the genetic designation for the P. aeruginosa outer membrane proteins and letters are assigned, in conjunction with this designation, to known outer membrane proteins. (
  • This review describes the current knowledge in the field of spirochetal outer membrane protein (OMP) biology. (
  • Our results suggest that integral membrane proteins can have different effects, and in the case of the bacterial outer membrane protein, BtuB, the greater the density of protein, the larger the reduction in stiffness. (
  • In addition, the presence of plasmid encoding antibiotic-resistant genes also alters the outer membrane protein profile in a similar manner. (
  • And more importantly, different outer membrane protein profiles were required to cope with different antibiotics. (
  • This type of specific pattern provides the rationale for the development of novel strategy to design outer membrane protein arrays to identify diverse multidrug resistance profiles as biomarkers for clinical medication. (
  • While tryptophans are generally found in low abundance in soluble proteins, in many integral membrane proteins they comprise a significantly higher proportion of the amino acid composition. (
  • However, although there is now considerable experimental and theoretical validation of this approach for soluble proteins ( 2 ⇓ - 4 ), the validity of these extrapolations is not clear for measuring stability of membrane proteins. (
  • The Lemo21(DE3) protein production strain was designed for tunable T7 expression to achieve optimal assembly of transmembrane proteins or the optimal folding of soluble proteins. (
  • Obtaining a crystal of a membrane protein is very difficult -- traditional methods of crystallization used to produce crystals of water-soluble proteins do not give the desired results. (
  • Most water-soluble proteins can readily be produced either within modified cell lines or through the use of cellular extracts that contain the full complement of machinery required for protein synthesis. (
  • The motivations for membrane protein design are much the same as those put forward for 'water-soluble' proteins, which have recently been discussed in several excellent reviews and perspectives [ 12 - 19 ]. (
  • Researchers studying water-soluble proteins often use commercial E. coli -based systems to express, or produce, copies of the protein. (
  • A major contribution of our study is the introduction of a fast computational tool to simulate a variety of forced-induced unfolding measurements of membrane and soluble proteins with a resolution comparable to the highest resolution measurements. (
  • The invention provides an in vitro method for producing proteins, membrane proteins, membrane-associated proteins, and soluble proteins that interact with membrane-associated proteins for assembly into an oligomeric complex or that require association with a membrane for proper folding. (
  • However, due to their unique physical properties and requirement for association with cellular membranes, expression of membrane proteins in heterologous systems is often daunting. (
  • Profilee Satyajit Mayor discusses his explorations of cell membranes, which are helping to update the classical fluid mosaic model of dynamic cellular boundaries. (
  • The investigators behind the new study worked around that problem by using the small cellular protein saposin. (
  • This proposal investigates the hypothesis that coincidence detection of proteins and lipids constitutes a major mechanism for specific recruitment of proteins to intracellular membranes in order to control cellular membrane dynamics. (
  • An in silico analysis shows a correlation between the putative functions of the identified proteins and the expected roles for plasma membrane in transport, signaling, cellular traffic, and metabolism. (
  • On the basis of two-dimensional (2-D) gel electrophoresis, Masson and Rossignol ( 5 ) estimated that 500 polypeptides were present in the PM, corresponding to about 3% of total cellular proteins identified at that time. (
  • Efforts to develop a safe and effective syphilis vaccine have been hindered by uncertainty about the relative importance of humoral and cellular mechanisms to protective immunity and the fact that T. pallidum outer membrane proteins have not been unambiguously identified. (
  • and mixing the intracytoplasmic membranes with the template and a transcription/translation-competent cellular extract to cause simultaneous production of the membrane proteins and encapsulation of the membrane proteins within the intracytoplasmic membranes. (
  • Autophagy (particularly macroautophagy) is a bulk degradation process used by eukaryotic cells in order to maintain adequate energy levels and cellular homeostasis through the delivery of long-lived proteins and organelles to the lysosome, resulting in their degradation. (
  • The heterogeneity of biological membranes plays an important role in cellular function. (
  • To understand the way a protein functions it is important to consider its cellular environment. (
  • However, despite the high abundance of MPs in the cell proteomes (20-30% of all cellular proteins), only 0.1% of MPs crystal structures have been determined to date. (
  • Protocols are provided for preparing and characterizing the lipidic mesophase, for reconstituting the protein into the monoolein-based mesophase, for functional assay of the protein in the mesophase and for setting up crystallizations in manual mode. (
  • Here, we summarize the experimental evidence for this model with emphasis on the raft-targeting features of HA, NA, and M2 and review the functional importance of raft domains for viral protein transport, assembly and budding, environmental stability, and membrane fusion. (
  • In the case of membrane proteins less expression often results in more functional protein. (
  • Simons, K. and Ikonen, E. (1997) Functional rafts in cell membranes. (
  • Rietveld, A. and Simons, K. (1998) The differential miscibility of lipids as the basis for the formation of functional membrane rafts. (
  • However, the yield of membrane proteins obtained from cultured cells is generally inadequate, and scientists have had to tinker extensively with extract-based production methods to obtain usable quantities of functional protein. (
  • Yokoyama and his colleagues' protein preparations also retained proper functional characteristics. (
  • Biomimetic membrane technology, based on the use of nano-scale functional additives in the form of channel proteins or artificially made channel structures, represents an attractive way of optimizing membrane separation technology. (
  • When dynamin assembles into short collars, the GTPase domains of neighboring tetramers form functional dimers that are necessary for GTPase activity and for membrane pinching. (
  • In addition, the membrane proteins of viruses are the key functional unit in commercial vaccines. (
  • To our knowledge, the HIV spike protein preparation presented in the study using the Salipro system represents the first approach that allows the stabilisation of the HIV-1 spike, including the important membrane domains, in a soluble and functional state', says Professor Pär Nordlund at the Department of Oncology-Pathology. (
  • Single-molecule force spectroscopies, including AFM and magnetic tweezers, are powerful methods for examining the folding process of proteins and other biomolecules as they adopt their functional shapes. (
  • Over the past three years, we have developed tailored experimental methods for all steps in the MS3D method for rhodopsin, including protein purification, a functional assay, cross-linking, proteolysis and mass spectrometry. (
  • Nadia Gul has focused on the production and functional analysis of membrane proteins. (
  • Gul also describes the purification and functional reconstitution of the ATP-binding cassette transporter ProU, an important membrane protein that plays in a role in the regulation of the volume of E. coli cells. (
  • Nevertheless, many functional mechanisms, such as ligand/protein binding/unbinding and large protein motion, remain inaccessible through standard calculations because of the limiting timescale of MD simulations. (
  • Polypeptide toxins and many antibacterial peptides , such as colicins or hemolysins , and certain proteins involved in apoptosis , are sometimes considered a separate category. (
  • Proteins are targeted to the Tat pathway by N-terminal signal peptides that contain an almost invariant twin-arginine motif. (
  • The antibacterial mechanism of action of the two most active viral protein-derived peptides, vAMP 059 and vCPP 2319, was studied in detail. (
  • Also, these peptides cause bacterial membrane permeabilization and damage of the bacterial envelope of P. aeruginosa cells. (
  • Without chemical modi-fication of peptides, over 75 % pure phosphopeptides were isolated from plasma membrane digests and de-tected and sequenced by mass spectrometry. (
  • However, this also anchors the protein to other intracellular membranes. (
  • Proteins that are not destined for degradation can be recycled to other intracellular compartments, such as the Golgi and the plasma membrane. (
  • Biological membranes consist of a phospholipid bilayer and a variety of proteins that accomplish vital biological functions. (
  • As an example of the relationship between the IMP (in this case the bacterial phototrapping pigment, bacteriorhodopsin) and the membrane formed by the phospholipid bilayer is illustrated below. (
  • In this case the integral membrane protein spans the phospholipid bilayer seven times. (
  • The phospholipid bilayer with its biochemical inclusions is known as the fluid mosaic model of membrane structure. (
  • For this reason, detergents, denaturing solvents, and nonpolar solvents must be used to disrupt the phospholipid bilayer and extract the integral membrane protein. (
  • These proteins may span the membrane once, or may span it several times, weaving through the phospholipid bilayer such that there are several pieces of the protein protruding through the cell wall. (
  • The physical nature of the association between integral or peripheral MPs and the membrane phospholipid bilayer is significantly different. (
  • As well as the practical benefits of miniaturisation and simplicity for understanding sequence-structure-function relationships, minimalism should also support the abstract conceptualisation of membrane proteins as modular components for synthetic biology. (
  • However, SNARE proteins have only a small cytoplasmic domain that is probably too short to bring a vesicle close to the organelle that is its fusion target (although SNARE proteins are sufficient to drive membrane fusion in reconstituted cell-free in vitro systems 3 ). (
  • Topical chapters cover in vitro folding, cell-free synthesis and stabilization of membrane proteins, and such biophysical and biochemical applications as electron microscopy, Xray diffraction, NMR, optical spectroscopy, mass spectrometry, the whole range of solutions studies, proteomics, and such practical applications as membrane protein immobilization and drug screening and the use of amphipols in vivo for vaccination and drug delivery. (
  • Important key players in the mitochondrial (intrinsic) cell death pathway are membrane-active proteins of the Bcl-2 family. (
  • Family members with opposite functions meet at the outer membrane of mitochondria, where they determine the fate of a cell, namely to live or to die. (
  • LMP2A is a transmembrane protein that inhibits normal B-cell signal transduction by mimicking an activated B-cell receptor (BCR). (
  • The viral envelope is a lipid bilayer derived from the apical plasma membrane of the infected cell. (
  • His research team announced in December 2008 that it had discovered MG53 as a key initiator of membrane repair in damaged tissue, making it the first group to specifically pinpoint a protein responsible for promoting cell repair. (
  • He and his team have now shed light on how these proteins assemble on the surface of a cell and reshape its membrane. (
  • These proteins bind themselves to the inside of a cell membrane, where they form long chains and ring-like structures. (
  • The rings then invaginate the membrane, contract like a drawstring, and, finally, detach the vesicle from the surface of the cell. (
  • P. Devarajan and J.S. Morrow , The Spectrin Cytoskeleton and Organization of Polarized Epithelial Cell Membranes. (
  • The plasma membrane acts as both a boundary and a site of exchange between the outside and the inside of a cell. (
  • When using E. coli as a host, it is advantageous to express membrane proteins in moderation to avoid saturation of the membrane protein biogenesis pathway, which may lead to cell death and/or inclusion body formation. (
  • Proteins whose primary functions involve pore formation, transport of specific substrates, cell structure determination and membrane stabilization are discussed. (
  • Of particular importance are membrane proteins, which "sit" on the membrane of every cell in our bodies -- they carry substances, energy, and signals, directly into a cell, enabling it to "communicate. (
  • Clustering is a basic event for the initiation of immune cell responses, and simulation analyses of clustering of membrane proteins have been performed. (
  • Horejsi, V. (2003) The roles of membrane microdomains (rafts) in T cell activation. (
  • Conserved Arabidopsis ECHIDNA protein mediates trans-Golgi-network trafficking and cell elongation. (
  • Researchers have used cryo-electron microscopy to elucidate for the first time the structure and function of a very small enzyme embedded in cell membranes. (
  • A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle. (
  • Cell recognition proteins allow cells to identify each other and interact. (
  • Membrane enzymes produce a variety of substances essential for cell function. (
  • A major part of this regulation and communication is performed by proteins within the membrane of a cell. (
  • Up until now, aggregation and misfolding of membrane proteins during cell-free protein synthesis have been avoided by adding either lipid-based liposomes or detergents," explains Yokoyama. (
  • Protein is produced in a tube via a cell-free transcription and translation reaction (left). (
  • When detergent is removed by dialysis, the properly folded proteins end up embedded within liposomes, replicating their normal integration into cell membranes (right). (
  • The C terminal end of the protein is in the cytosol while the N terminal region is in the outside of the cell. (
  • To study the effect of other T cell activators on these T cell membrane antigens, the authors incubated mononuclear cells for 0-3 days with lectins or pharmacologic agents and stained with monoclonal antibodies to their antigens. (
  • PMA induced a 2-3-fold increase in cell diameter concomitant with the alterations in membrane antigens. (
  • It is a channel that transports different types of substrates across a phospholipid membrane (one into the cell and one out of the cell) either simultaneously or sequentially. (
  • The cell membrane typically acts as a barrier around the cell, keeping out harmful materials. (
  • By watching vesicle transformation through a microscope, the scientists showed that dynamin proteins only form a short collar around the cell membrane. (
  • Cell membranes or plasma membranes surround cells, separating the cytoplasm and organelles on the inside from the extracellular fluid on the outside. (
  • Several cell organelles (mitochondria, endoplasmic reticulum, and Golgi bodies) are also bounded by membranes. (
  • The membrane allows a cell or organelle to maintain a constant internal environment, usually one that is quite different from the medium surrounding it. (
  • Color enhanced scanning transmission electron micrograph of cell membranes of adjoining cells separated by an intercellular cleft. (
  • The membranes found in all cells are crucial to life's processes as they partition the cell into different volumes and provide communication between them. (
  • Consequently, many of medicine's most important drug targets are to be found in cell membranes.All-over-the-world benefit Bruker's instrumentation helps scientist gaining a better understanding of the involved processes - faster. (
  • Membranes are much more than merely a barrier that insulates the outside medium from the inside of the cell. (
  • Membranes coordinate a number of cell signaling events, e.g. through the recruitment of peripheral proteins like small G proteins. (
  • As such, integral membrane proteins are involved in a host of different functions, ranging from cell signaling, membrane trafficking, ion/lipid transport, cell detoxication, cell energization, to the generation of membrane potential. (
  • In sum, damages to membranes can grossly alter most processes within the cell. (
  • It sits on the inner leaflet of the cell membrane and relays signals into the cell's interior. (
  • Apparently, the protein is not specifically sent to the cell membrane after it is formed, but is also located on other membrane systems within the cell for its entire life span. (
  • Without the two of them, KRas would spread to cell membranes. (
  • In order for KRas to be able to function correctly, it must remain on the inner leaflet of the cell membrane for a sufficient period of time. (
  • Similar to a polystyrene ball in a plastic bag, the electrostatic interaction of these positive charges with the negatively charged inner leaflet of the cell membrane reinforces the lipid anchoring. (
  • But even lipid anchor and positive charges are not enough to ensure that KRas is permanently enriched at the cell membrane. (
  • Our results show that the cell membrane is by no means the final destination of KRas, which must only be encountered once. (
  • When it gets close to the nucleus of the cell, the activity of the protein Arl2 removes this glove. (
  • The cell therefore does not have a unique targeting system for KRas, which sends it exclusively to the cell membrane. (
  • In total, each KRas molecule travels for approximately 20 minutes before it reaches the cell membrane again," says Schmick. (
  • We can now develop active agents that reduce the enrichment of mutated, permanently active KRas at the cell membrane," explains Philippe Bastiaens, Director at the Max Planck Institute in Dortmund. (
  • This demanding challenge has spurred intense activities directed towards membrane-protein separation and enrichment protocols applicable directly on natural cell-membranes, with the aim to bypass the destructive solubilization step. (
  • Supported lipid bilayers, which are continuous two dimensional cell-membrane mimics (originally developed for biosensor applications) have due to preserved lateral mobility emerged as a promising system for this type of membrane-protein separation. (
  • a) Schematic illustration of a continuous lipid bilayer derived from native cell membrane, (b) micrograph of the separation of two types of fluorescently labeled membrane-associated proteins, (c) microfluidic setup, (d) polymer-cushioned planar cell membrane, and (e) electrophoretic separation of transmembrane proteins. (
  • Quast RB, Sonnabend A, Stech M, Wüstenhagen DA, Kubick S. High-yield cell-free synthesis of human EGFR by IRES-mediated protein translation in a continuous exchange cell-free reaction format. (
  • An integral membrane protein , also known as an IMP, is one which spans the entire biological membrane of a cell. (
  • These proteins are attached permanently to the cell membrane , and their function typically relies on being present in the membrane. (
  • Structurally, the IMP is usually placed such that protein strands are woven throughout the structure of the cell membrane. (
  • Sections of protein protrude through the cell wall inside or outside the cell, or in both directions. (
  • Integral transmembrane proteins are those which span the entire cell membrane. (
  • Instead they are attached to the membrane from only one side, with one end of the protein protruding either inside or outside the cell. (
  • Researchers at the Bellvitge Biomedical Research Institute (IDIBELL) have just described for the first time the crucial involvement of a cell membrane protein in the development and progression of liver cancer, according to an article published in the Journal of Hepatology . (
  • TGF-β, which belongs to a large group of proteins called cytokines, has a dual role: in normal conditions, or in early stages of carcinogenesis, it plays a tumor suppressive role, promoting cell death and reducing tumor growth. (
  • The ease with which a cell membrane can bend and deform is important for a wide range of biological functions. (
  • The first step in studying most proteins is to dissolve them in water," Hanson said, "but that does not work with membrane proteins that live in the oily, lipid bi-layer that surrounds the cell. (
  • That's not to mention that these lipid membranes also can house an unlimited number of protein machines that perform a large number of critical recognition, transport and signal transduction functions in the cell," said Nipun Misra, a UC Berkeley graduate student and a co-author on the paper. (
  • We produced from Arabidopsis cell suspensions a highly purified plasma membrane fraction and characterized it in detail by immunological and enzymatic tests. (
  • We describe a novel biosensor system for reporting proximity between cell surface proteins in live cultured cells. (
  • Furthermore, increasing the size and complexity of the systems is necessary to obtain models which more closely resemble the in vivo cell membrane environment. (
  • Thus, today there is a tremendous need to accurately consider the complexity in size and composition of cell membranes in computational models and to reach with simulations the real-life timescale. (
  • Methods to characterize MPs are limited by the lack of extraction protocols and reagents that allow sufficient amounts of MPs to be obtained from various cell types without cross-contamination from other protein fractions. (
  • We evaluated membrane protein extraction efficiencies from various mammalian cell lines and several types of mouse tissues using various commercially-available extraction kits: Thermo Scientific Mem-PER Plus Membrane Protein Extraction Kit, Thermo Scientific Mem-PER Eukaryotic Membrane Protein Extraction Reagent Kit (the first generation kit), EMD Millipore ProteoExtract™ Native Membrane Protein Extraction Kit (Merck), and Bio-Rad ReadyPrep™ Protein Extraction Kit Membrane I (Bio-Rad). (
  • Integral membrane proteins are a permanent part of a cell membrane and can either penetrate the membrane (transmembrane) or associate with one or the other side of a membrane (integral monotopic). (
  • Peripheral membrane proteins are transiently associated with the cell membrane. (
  • Although the concept of membrane-protein topology dates back at least 30 years, recent advances in the field of translocon-mediated membrane-protein assembly, proteome-wide studies of membrane-protein topology and an exponentially growing number of high-resolution membrane-protein structures have given us a deeper understanding of how topology is determined and of how it evolves. (
  • Integral membrane proteins constitute a significant fraction of the proteome of all living cells. (
  • Mapping the human membrane proteome: a majority of the human membrane proteins can be classified according to function and evolutionary origin. (
  • While many studies have investigated the action of individual outer membrane proteins during antibiotic stress, a proteomic approach reveals the dynamic features of the entire outer membrane proteome. (
  • The inventory of the plasma membrane proteome generated by this approach contains numerous plasma membrane integral proteins, one-third displaying at least four transmembrane segments. (
  • The total number of ∼750 PM proteins can now be inferred from the entire Arabidopsis proteome ( 2 ). (
  • Detergents are traditionally used to extract proteins from membranes in order to make them amenable to the tools of biochemistry and biophysics. (
  • It opens with general introductions on membrane proteins and their natural environment, detergents, the current status of membrane protein in vitro studies, a broad panorama of non-conventional surfactants and a discussion of their respective advantages and limitations, and the preparation and properties of amphipols and membrane protein/amphipol complexes. (
  • Such proteins can be separated from the biological membranes only using detergents , nonpolar solvents , or sometimes denaturing agents. (
  • In initial experiments, they were able to demonstrate successful production of properly folded BR with a variety of detergents, and although the overall folding efficiency was somewhat lower than previously described preparations, the overall quantity of protein produced was significantly greater-as much as 80-fold greater, depending on the detergent. (
  • Most often, detergents are used to extract the membrane proteins. (
  • Moreover, detergents do not provide a lipid environment, which is important for membrane proteins. (
  • 1. Designer detergents that remove the membrane protein from the lipid bi-layer where it resides, 2. (
  • To solve this problem, detergents were needed, but they tend to form large micelles that can obscure the protein within. (
  • Detergents can be used to render membrane proteins water soluble, but these can also alter protein structure and function. (
  • Three-dimensional structures of ~160 different integral membrane proteins have been determined at atomic resolution by X-ray crystallography or nuclear magnetic resonance spectroscopy . (
  • Three-dimensional structures of only ~160 different integral membrane proteins are currently determined at atomic resolution by X-ray crystallography or Nuclear magnetic resonance spectroscopy due to the difficulties with extraction and crystallization. (
  • However, many questions remain about the mechanisms driving the regulation and execution of the membrane fusion (in which the lipid bilayers on two separate membranes fuse to form one bilayer) underlying this process. (
  • The tryptophan locations with respect to the lipid bilayer (along the direction normal to the membrane surface) are strikingly non-uniform in nearly all of the membrane proteins examined. (
  • Orientations of Proteins in Membranes ( OPM ) database provides spatial positions of membrane protein structures with respect to the lipid bilayer . (
  • The calculated spatial arrangements of the lower resolution protein structures in the lipid bilayer can be found in other resources, such as PDBTM. (
  • Membrane protein folding is a particularly thorny challenge because the proteins reside in a complex, nonhomogenous bilayer. (
  • They include integral membrane proteins that are permanently anchored or part of the membrane and peripheral membrane proteins that are only temporarily attached to the lipid bilayer or to other integral proteins. (
  • Integral and peripheral proteins may be post-translationally modified, with added fatty acid , diacylglycerol [13] or prenyl chains, or GPI (glycosylphosphatidylinositol), which may be anchored in the lipid bilayer. (
  • These proteins are water-soluble but can aggregate and associate irreversibly with the lipid bilayer and become reversibly or irreversibly membrane-associated. (
  • Type V proteins are anchored to the lipid bilayer through covalently linked lipids. (
  • The lipid-bilayer membrane that encloses all cells and their internal organelles has due to its important role in biology and medicine been subject to intense investigations. (
  • In running projects, the group is further developing these microfluidic-based (Fig. 1c) concepts with the aim to improve the spatial mobility also of membrane proteins that span across the entire lipid bilayer, which due to their close contact with the underlying support typically become immobile. (
  • For this reason, the membrane mimetic has to form particles of small size and simultaneously to properly simulate the bilayer membrane to be applicable for solution NMR spectroscopy. (
  • It is estimated that up to 30% of all proteins are integral membrane proteins [ 1 ], with at least one part of the protein sequence passing through a lipid bilayer membrane. (
  • The researchers incorporated lipid bilayer membranes into silicon nanowire transistors by covering the nanowire with a continuous lipid bilayer shell that forms a barrier between the nanowire surface and solution species. (
  • They can be classified according to their relationship with the bilayer: Integral polytopic proteins are transmembrane proteins that span across the membrane more than once. (
  • [4] It is estimated that 20-30% of all genes in most genomes encode membrane proteins. (
  • 20-30% of all genes in genomes code for membrane proteins. (
  • There are a number of inborn errors of glycogen metabolism that result from mutations in genes for virtually all of the proteins involved in glycogen synthesis, degradation, or regulation. (
  • About 25 % of genes encode membrane proteins, and furthermore membrane proteins are targets for ~50 % of marketed drugs. (
  • In the world of membrane proteins, topology defines an important halfway house between the amino-acid sequence and the fully folded three-dimensional structure. (
  • These studies in conjunction with our earlier results show that alkaline phosphatase fusions to membrane proteins can be an important aid in analyzing membrane topology and its determinants. (
  • The interplay between lipids and membrane proteins is known to affect membrane protein topology and thus have significant effect (control) on their functions. (
  • MgdA is an integral membrane protein with multiple transmembrane helices and a unique membrane topology. (
  • These proteins may have different transmembrane topology . (
  • Predicting transmembrane protein topology with a hidden markov model: application to complete genomes. (
  • The most common type of IMP is the transmembrane protein (TM), which spans the entire biological membrane . (
  • Design and perform electrophysiology experiments to validate the function of the tagged protein in cultured cells or in brain slices. (
  • HA assembles into a homotrimer in the ER and is transported via the secretory pathway to the plasma membrane, more specifically the apical plasma membrane in polarized (e.g., epithelial) cells, where virus assembly and budding take place [ 2 ]. (
  • Small "bubbles" frequently form on membranes of cells and are taken up into their interior. (
  • Zacharias, D.A., Violin, J.D., Newton, A.C. and Tsien, Y.R. (2002) Partitioning of lipid-modified monomeric GFPs into membrane microdomains of live cells. (
  • Proteins can be responsible for the fact that the active ingredients of drugs are simply released from the target cells. (
  • Newswise - A team of scientists at The Scripps Research Institute and the National Institutes of Health (NIH) has discovered the structure of a protein that pinches off tiny pouches from cells' outer membranes. (
  • One-third of all tumours contain cells with mutations of Ras proteins. (
  • Cells assemble integral membrane proteins in the endoplasmic reticulum . (
  • Both structurally and functionally, they are integral parts of the membranes of cells. (
  • Examples of integral transmembrane proteins include voltage-gated ion channels such as those which transport potassium ions in and out of cells. (
  • The research team, led by Dr. Isabel Fabregat, who is a professor at the Faculty of Medicine and Health Sciences of the University of Barcelona and a researcher at the CIBER of Hepatic and Digestive Diseases, has shown that liver cells with invasive features have high levels of clathrin, a protein whose involvement in liver cancer was unknown until now. (
  • When membrane proteins are produced in E. coli , they overload the cell's bi-layers and cause the cells to die. (
  • He also discusses whether experiments showing correlation of changes in plasma membrane cholesterol with differentiation and the formation of adherens junctions in endothelial cells are consistent with a model in which lipid rafts influence the regulation of these processes. (
  • Neither artificial membrane slabs, nor 'live cells' imaged under conditions in which cells have a shabby life that doesn't last long (how much of this is due to the mistreatment of the membrane proteins? (
  • To create the bionanoelectronic platform the LLNL team turned to lipid membranes, which are ubiquitous in biological cells. (
  • In animal cells, PM proteins represent a point for potential therapeutic intervention, making the PM a source of drug targets, for instance in cancer research ( 1 ). (
  • Cells were incubated with a membrane-impermeable bivalent ligand (biotin-PEG2000-DIR) consisting of biotin joined to a dimethyl-indole red (DIR) fluorogen by a polyethylene glycol linker, thus tethering the fluorogen to the scAvd-FRB fusion protein. (
  • Epithelial membrane protein 2 (EMP2), a tetraspan protein that promotes recruitment of integrins to lipid rafts, is highly expressed in AT1 cells but has no known function in lung biology. (
  • Taken together, we propose that EMP2-dependent membrane organization ensures proper display on AT1 cells of a suite of proteins required to instruct paracellular neutrophil traffic into the alveolus. (
  • Despite experimental progress in recent years, the characterization of lateral organization in biological membranes, however, remains challenging due to the lack of tools to study fluctuating nanoscale assemblies in living cells. (
  • Together with our experimental collaborator Bert Poolman , we aim to unravel the lipid-mediated driving forces underlying protein sorting and clustering, and predict physical mechanisms that could be relevant in real cells. (
  • The Thermo Scientific Mem-PER Plus Membrane Protein Extraction Kit enables small-scale solubilization and enrichment of integral and membrane-associated proteins from cultured cells and tissues using a simple reagent-based procedure and a bench-top microcentrifuge (Figure 1). (
  • Schematic presentation of the membrane protein extraction work flow with Mem-PER Plus Membrane Protein Extraction Kit from the mammalian cells. (
  • First, the cells are permeabilized with a mild detergent containing the Permeabilization Buffer, with the aim to liberate soluble cytosolic proteins. (
  • To study membrane proteins, scientists currently use X-ray free electron lasers -- highly advanced sources of hard X-rays. (
  • This workshop will draw together both the theoretical and experimental communities that study membrane proteins in order to address the challenges of developing a quantitative and predictive understanding of the relationship between membrane protein structure and function. (
  • Membrane enzymes may have many activities, such as oxidoreductase, transferase or hydrolase. (
  • Membrane enzymes have many activities. (
  • This class of proteins includes enzymes such as monoamine oxidase and fatty acid amide hydrolase . (
  • The immobilization of enzymes (for biocatalysis) and specific protein channels (for selective transport) is an important area of research where both selective separations and reactivity is needed. (
  • Shedding of plasma membrane proteins. (
  • Instead, the process called docking establishes the first physical contact between a vesicle and the target membrane. (
  • After the initial recognition step, tethers bring the vesicle into closer contact with the target membrane until interaction between SNAREs leads to trans -SNARE-complex formation and membrane fusion 2 . (
  • Accordingly, they also represent important targets for drug development, and an estimated 60% of currently available drugs are believed to target membrane proteins. (
  • This is exemplified by the fact that 30% of a large number of genomes encodes membrane proteins and that about 50% of currently used drugs target membrane proteins. (
  • The sources that have yielded the majority of the few known membrane-protein structures are organisms in which the target membrane protein is naturally abundant. (
  • that bacteriorhodopsin (bR) can be refolded from an SDS-denatured state ( 5 ), SDS has been commonly used to study the folding of helical membrane proteins. (
  • In their study, the researchers applied the method to the model proteins bacteriorhodopsin (a typical membrane protein) and lysozyme (a typical water-soluble protein). (
  • The researchers then demonstrated the efficacy of their technique with bacteriorhodopsin (BR), an archaea-derived photosynthetic pigment protein. (
  • Using Upside, our new ultra-fast MD approach for modeling protein folding and dynamics, we studied the force-induced unfolding of two membrane proteins, bacteriorhodopsin and GlpG, detailing how the different applications of force spectroscopies investigate different regions of the energy surface. (
  • However the rearrangements involved in the function of complex membrane proteins, e.g. transporters, still require the development of advanced methodologies [13,14]. (
  • An antiporter is an integral protein involved in secondary active transport, which couples the energy of a molecule moving down its concentration gradient to another moving up its concentration gradient. (
  • This transport of molecule across membrane can be either passive (where movement is driven by a gradient) or active (where movement is against a gradient and requires energy). (
  • It requires work to pump a molecule across a membrane against its gradient. (
  • An integral membrane protein is a protein molecule (or assembly of proteins) that in most cases spans the biological membrane with which it is associated (especially the plasma membrane ) or which, in any case, is sufficiently embedded in the membrane to remain with it during the initial steps of biochemical purification (compare peripheral membrane protein ). (
  • Each integral membrane protein molecule has an intricate relationship with the membrane within which it is situated. (
  • The protein molecule cannot function if it is not embedded within the membrane. (
  • This field has made significant advances since the elucidation of the first 3-D structure of a recombinant G Protein Coupled Receptor (GPCR), rhodopsin, with the structure of several more GPCRs having been solved in the past five years. (
  • Membrane receptor proteins are the most popular targets for drugs. (
  • It is especially difficult for GPCR receptor proteins, which are very important -- in 2012, a Nobel Prize was awarded for a study of their structure. (
  • Membrane receptor proteins relay signals between the cell's internal and external environments. (
  • Membrane proteins perform a variety of functions vital to the survival of organisms: Membrane receptor proteins relay signals between the cell's internal and external environments. (
  • This is the case when all membrane-anchoring parts of the proteins ( amphiphilic alpha helices , exposed nonpolar residues, or lipidated amino acid residues ) are missing in the experimental structures. (
  • Our results suggest that features of the amino acid sequence (possibly the positively charged amino acids) of the cytoplasmic domains of membrane proteins are important in anchoring these domains in the cytoplasm. (
  • Eight exons of LMP2 isoforms encode 12 membrane spanning segments that are connected by short hydrophilic loops and ends with a 27 amino acid cytoplasmic C-terminus domain. (
  • Transmembrane helices from these proteins have significantly different amino acid distributions to transmembrane helices from polytopic proteins. (
  • Single pass TM proteins can be categorized as Type I, which are positioned such that their carboxyl-terminus is towards the cytosol , or Type II, which have their amino-terminus towards the cytosol. (
  • Homology modeling can be used to construct an atomic-resolution model of the "target" integral protein from its amino acid sequence and an experimental three-dimensional structure of a related homologous protein. (
  • Analysis of the primary structure (amino acid sequence) of ATP-ADP translocase revealed that this protein is made up of three sequence repeats of length of 100 amino acids, in which each has two transmembrane segments. (
  • TM proteins can be categorized as Type I, which are positioned such that their amino-terminus is outside of the membrane, or Type II, which have their carboxy-terminus outside of the membrane. (
  • The three major pathways (red lines) differ by whether unfolding begins from the middle or the amino- or carboxy-terminus of the protein. (
  • The TolA protein is a 421-amino acid residue integral membrane protein composed of three domains. (
  • The constitutive mutants in UhpB resulted from insertions in the nonpolar amino-terminal half of the protein, and all insertions in that half of UhpB affected Uhp expression in some manner, which suggests that the transmembrane segments of UhpB might negatively regulate the kinase activity of the carboxyl portion. (
  • Proteins destined for the secretory pathway are translocated into the endoplasmic reticulum (ER), where they are subjected to a variety of post-translational modifications before they reach their final destination. (
  • In their study, published in the June issue of Journal of Biological Chemistry, the scientists have linked the newly discovered protein MG53 to a pathway that repairs human muscle tissue along with the proteins caveolin-3 (Cav3) and dysferlin. (
  • The Sec and Tat export pathways operate in parallel, with the Sec machinery transporting unstructured precursors and the Tat pathway transporting folded proteins. (
  • Phorbol myristate acetate (PMA), a protein kinase C activator which stimulates PBL though an alternate pathway, caused a 90-100% reduction of T3 and T4 MFI, a 25% reduction in T8 MFI, and a 400% increase in T11 MFI after 2 days. (
  • This 'shielded wire' configuration allows us to use membrane pores as the only pathway for the ions to reach the nanowire," Noy said. (
  • These ideas are illustrated with selected examples that focus upon α-helical membrane proteins, and which demonstrate how such minimalist membrane proteins might be integrated into living biosystems. (
  • Tethers determine whether a potential fusion interaction should occur, through recognition of specific proteins found on a vesicle surface, such as Rab proteins or coat proteins 4 . (
  • The envelope stress sensor, CpxA and its interaction with E. coli membranes were studied. (
  • Thus, it is inferred that the self-assembly induced by dimerization is unlikely in situ, and that some interaction between proteins is required for cluster formation. (
  • 1. interaction by an amphipathic α-helix parallel to the membrane plane (in-plane membrane helix) 2. (
  • interaction by a covalently bound membrane lipid ( lipidation ) 4. (
  • Spirochetal bacteria possess two membranes and the proteins present in the outer membrane are at the site of interaction with host tissue and the immune system. (
  • The aim is in this case to tune the interaction between protein and support and thereby also influence the spatial mobility of the lipid membrane and its components. (
  • Non-integral MPs are usually transiently immobilized on the surface of the cytoplasmic face of the plasma membrane via interaction either with polar groups of the lipids and/or surface-spanned integral MPs, or can be anchored into the membrane through post-translational lipidation. (
  • Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a disorder of the nervous system. (
  • Dogu O, Krebs CE, Kaleagasi H, Demirtas Z, Oksuz N, Walker RH, Paisán-Ruiz C. Rapid disease progression in adult-onset mitochondrial membrane protein-associated neurodegeneration. (
  • Hartig M, Prokisch H, Meitinger T, Klopstock T. Mitochondrial membrane protein-associated neurodegeneration (MPAN). (
  • This specific transport protein is located in the inner mitochondrial membrane that allows ATP and ADP to be transported across the membrane since ATP and ADP cannot diffuse across the inner mitochondrial membrane by itself. (
  • ATP-ADP translocase is in high abundance and it makes up about 15% of the protein content in the inner mitochondrial membrane. (
  • A famous example from the superfamily is cytochrome c oxidase , the last enzyme in the respiratory electron transport chain located in the mitochondrial membrane (see graph). (
  • Membrane proteins are a common type of proteins along with soluble globular proteins , fibrous proteins , and disordered proteins . (
  • Bulky globular proteins require specialized transport systems for insertion into membranes. (
  • Adding integral membrane proteins to lipid bilayers also changes the bending rigidity, whilst adding a simple peripheral membrane protein has no effect. (
  • What makes them distinct are the lipid membranes - tiny bubbles of grease within which the mysteries of life occur. (
  • Protein incorporation into lipid membranes has been determined by TEM. (
  • Julio Martinez, a UC Davis graduate student and another co-author added: "Besides some preliminary work, using lipid membranes in nanoelectronic devices remains virtually untapped. (
  • This postdoctoral position is part of a project where we investigate the structure of membrane-coupled proteins of the Bcl-2 family by using mainly solid-state NMR methods (complementary also neutron scattering approaches). (
  • Previous extensive experience of protein structure determination by solid-fast NMR is required and previous experience with membrane proteins is highly meriting. (
  • In an earlier study, he and his team analyzed the three-dimensional structure of EHDs in an inactive form - i.e. not bound to the membrane. (
  • For membrane proteins, the extrapolations are fraught with considerable uncertainty as the denaturants may have complex effects on the membrane or micellar structure. (
  • These small crystals are now used to study the structure of membrane proteins. (
  • Knowing the structure of a protein makes it much faster and cheaper to find a drug. (
  • The scattering of X-rays on the crystal lattice then gives the structure of the protein. (
  • Scientists from MIPT and JINR have succeeded in achieving better results than the SONICC method (or rather its main component, SHG), while also demonstrating sensitivity to the subtle features of a protein structure that will be extremely important in further research studies. (
  • The last model system was another integral membrane protein with a distinct structure but also a different function. (
  • Compared to other classes of proteins, the determination of membrane protein structure s has remained a challenge in large part due to the difficulty in establishing experimental conditions where the correct conformation of the protein in isolation from its native environment is preserved. (
  • Until now, it has been assumed that these functions underlie a static structure of mitochondrial membranes. (
  • On the other hand, experimental investigation of the structure and function of individual membrane proteins is routinely thwarted by the general difficulty of preparing large quantities of properly folded protein. (
  • One way to figure out how a protein functions is to determine its structure. (
  • However, all membranes do have the same basic structure. (
  • The structure of only a few integral membrane proteins is known at atomic resolution, because they tend to denature on removal from the membrane, under which condition they are impossible to crystallize for analysis by X-ray diffraction . (
  • Natural proteins are intricate and complex, which can obscure the core physical principles underlying their structure and function. (
  • Building simplified model proteins can, therefore, be a useful way to cut through this complexity and understand the fundamental connections between sequence, structure and function. (
  • Researchers at Karolinska Institutet, Sweden, have developed a nanoparticle technology that can be used to stabilise membrane proteins so that their structure can be studied in a lipid environment. (
  • The photosynthetic reaction center is a membrane protein as well - the very first membrane protein whose structure could be elucidated. (
  • All these processes involve a large array of proteins with highly diverse structure and function. (
  • We proposed to apply a chemical cross-linking, mass spectrometry and modeling method called MS3D to the structure determination of the rhodopsin-transducin membrane protein complex (RTC). (
  • Herein we describe experimental progress made to adapt the MS3D approach for characterizing membrane protein systems, and computational progress in experimental design, data analysis and protein structure modeling. (
  • Membrane proteins represent about one third of the proteins encoded in a cell's genome, and, because of their key physiological roles, more than half of drug targets. (
  • Potential targets for vaccine development are H. pylori-specific proteins that are surface-exposed and highly antigenic. (
  • An evidence of their important role is the fact that they are the targets of more than half of today's drugs, and significant effort has therefore been devoted to the development of bioanalytical instruments capable of measuring membrane-protein controlled reactions. (
  • Computational analysis of membrane proteins: the largest class of drug targets. (
  • Membrane proteins are the targets of more than 60 per cent of drugs in clinical use. (
  • Membrane proteins are common, and medically important-about a third of all human proteins are membrane proteins, and these are targets for more than half of all drugs. (
  • Membrane proteins are the targets of over 50% of all modern medicinal drugs. (
  • Epstein-Barr virus (EBV) latent membrane protein 2 (LMP2) are two viral proteins of the Epstein-Barr virus. (
  • There are three transmembraneous viral proteins embedded in the envelope: the glycoproteins hemagglutinin (HA) and neuraminidase (NA), which protrude at the viral surface as "spikes," and-in minor quantities-the proton channel protein M2. (
  • This step requires a group of proteins called tethers, which can be extended coiled-coil proteins or multi-subunit tether complexes. (
  • Most multi-subunit tether complexes have two business ends: one interacts with Rab proteins and the other interacts with SNAREs through a tether subunit protein that is a member of the Sec1/Munc18 (SM) family. (
  • In addition, we will also use neutron reflectometry on these lipid protein complexes. (
  • Although membrane proteins play an important role in all organisms, their purification has historically, and continues to be, a huge challenge for protein scientists. (
  • The time required to prepare the protein-loaded mesophase and to set up a crystallization plate manually is about 1 h. (
  • Cartoon representation of the events proposed to take place during the crystallization of an integral membrane protein from the lipidic cubic mesophase. (
  • Co-crystallization of the protein with native lipid (cholesterol) is shown in this illustration. (
  • Their membrane-anchoring α-helices have been removed to facilitate the extraction and crystallization . (
  • Integral membrane proteins from the endoplasmic reticulum induce the development of tubular structures in vitro by forming oligomers in the plane of the membrane. (
  • G.G. Gayer, J.T. Campanelli, and R.H. Scheller , Regulation of Membrane Protein Organization at the Neuromuscular Junction. (
  • This volume reviews the regulation of membrane protein distribution, organization, and function at the plasma membrane by the cytoskeleton. (
  • This is an exciting development, published in PLoS Computational Biology, which shows that the membrane's elastic forces can ultimately dictate the formation, organization, and therefore effects, of the proteins within it. (
  • Furthermore, although the role of lipids has long been underestimated, they now take center stage as we begin to understand their role in membrane trafficking, signaling, nanodomain organization, energy storage, or the regulation of membrane protein activity. (
  • Just perused the article 'From Dynamics to Membrane Organization- Experimental Breakthroughs Occasion a ''Modeling Manifesto'' in the August 21 issue. (
  • The H-NS protein also plays a role in the organization of the chromosome In addition to hns , each of the evolved strains carries one or two more mutations that may have contributed to the improved performance of the strains. (
  • Furthermore, preferential anionic lipid sequestering by MGS was shown to induce a different fatty acid modeling of E. coli membranes. (
  • We demonstrate our framework for making batch amounts which are compatible with the large scale production of biomimetic membranes for water purification based on the use of the E. coli expression system. (
  • Now we have cloned all of the membrane proteins of E. coli and are continuing production. (
  • In the study of Gul E. coli was evolved and strains were selected that produced enhanced levels of correctly folded protein. (
  • For instance, about 1000 of the ~4200 proteins of E. coli are thought to be membrane proteins, 600 of which have been experimentally verified to be membrane resident. (
  • Added 'precipitants' shift the equilibrium away from stability in the cubic membrane. (
  • The thermodynamic stability of proteins is typically measured at high denaturant concentrations and then extrapolated back to zero denaturant conditions to obtain unfolding free energies under native conditions. (
  • We therefore sought to measure stability under native conditions, using a method that does not perturb the properties of the membrane or membrane mimetics. (
  • Methods to measure the thermodynamic stability of membrane proteins have largely followed methods developed for soluble protein folding ( 1 ). (
  • We introduced SDS unfolding to measure the thermodynamic stability of the membrane enzyme diacylglycerol kinase ( 9 ) and a similar approach can be used to measure bR thermodynamic stability ( 10 , 11 ). (
  • Helical membrane protein folding, stability, and evolution. (
  • Linking these proteins creates a mechanism that allows damaged membranes to be repaired, which may transform treatment for patients who suffer from severe complications of diseases such as muscular dystrophy , as well as cardiovascular disorders and conditions related to advancing age. (
  • In addition to a comprehensive coverage of the properties and uses of non-conventional surfactants, this book therefore also offers a concise, accessible introduction to membrane protein biochemistry and biophysics. (
  • When Michel studied biochemistry in Tübingen and Würzburg, textbooks stated as an irrevocable fact that membrane proteins could not be crystallized. (