Lining of the STOMACH, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. The surface cells produce MUCUS that protects the stomach from attack by digestive acid and enzymes. When the epithelium invaginates into the LAMINA PROPRIA at various region of the stomach (CARDIA; GASTRIC FUNDUS; and PYLORUS), different tubular gastric glands are formed. These glands consist of cells that secrete mucus, enzymes, HYDROCHLORIC ACID, or hormones.
Specialized regions of the cell membrane composed of pits coated with a bristle covering made of the protein CLATHRIN. These pits are the entry route for macromolecules bound by cell surface receptors. The pits are then internalized into the cytoplasm to form the COATED VESICLES.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The main structural coat protein of COATED VESICLES which play a key role in the intracellular transport between membranous organelles. Each molecule of clathrin consists of three light chains (CLATHRIN LIGHT CHAINS) and three heavy chains (CLATHRIN HEAVY CHAINS) that form a structure called a triskelion. Clathrin also interacts with cytoskeletal proteins.
Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.
Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.
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.
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.
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.
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).
Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.
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 semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
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.
A family of large adaptin protein subunits of approximately 100 kDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 2.
Vesicles formed when cell-membrane coated pits (COATED PITS, CELL-MEMBRANE) invaginate and pinch off. The outer surface of these vesicles is covered with a lattice-like network of the protein CLATHRIN. Shortly after formation, however, the clathrin coat is removed and the vesicles are referred to as ENDOSOMES.
An adaptor protein complex primarily involved in the formation of clathrin-related endocytotic vesicles (ENDOSOMES) at the CELL MEMBRANE.
Established cell cultures that have the potential to propagate indefinitely.
A family of high molecular weight GTP phosphohydrolases that play a direct role in vesicle transport. They associate with microtubule bundles (MICROTUBULES) and are believed to produce mechanical force via a process linked to GTP hydrolysis. This enzyme was formerly listed as EC
A class of proteins involved in the transport of molecules via TRANSPORT VESICLES. They perform functions such as binding to the cell membrane, capturing cargo molecules and promoting the assembly of CLATHRIN. The majority of adaptor proteins exist as multi-subunit complexes, however monomeric varieties have also been found.
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.
An iron-binding beta1-globulin that is synthesized in the LIVER and secreted into the blood. It plays a central role in the transport of IRON throughout the circulation. A variety of transferrin isoforms exist in humans, including some that are considered markers for specific disease states.
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.
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.
Glycoproteins found on the membrane or surface of cells.
The engulfing of liquids by cells by a process of invagination and closure of the cell membrane to form fluid-filled vacuoles.
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.
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.
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.
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 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.
A complex of polyene antibiotics obtained from Streptomyces filipinensis. Filipin III alters membrane function by interfering with membrane sterols, inhibits mitochondrial respiration, and is proposed as an antifungal agent. Filipins I, II, and IV are less important.
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.
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.
Minute projections of cell membranes which greatly increase the surface area of the cell.
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.
A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.
The rate dynamics in chemical or physical systems.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
Membrane glycoproteins found in high concentrations on iron-utilizing cells. They specifically bind iron-bearing transferrin, are endocytosed with its ligand and then returned to the cell surface where transferrin without its iron is released.
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.
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.
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.
A complex of antigenic proteins obtained from the brush border of kidney tubules. It contains two principal components LOW DENSITY LIPOPROTEIN RECEPTOR-RELATED PROTEIN-2 and LDL-RECEPTOR RELATED PROTEIN-ASSOCIATED PROTEIN. The name of this complex is derived from researcher, Dr. Walter Heymann, who developed an experimental model of membranous glomerulonephritis (GLOMERULONEPHRITIS) by injecting this antigenic complex into rats to induce an autoimmune response.
An organization of cells into an organ-like structure. Organoids can be generated in culture. They are also found in certain neoplasms.
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)
Receptors on the plasma membrane of nonhepatic cells that specifically bind LDL. The receptors are localized in specialized regions called coated pits. Hypercholesteremia is caused by an allelic genetic defect of three types: 1, receptors do not bind to LDL; 2, there is reduced binding of LDL; and 3, there is normal binding but no internalization of LDL. In consequence, entry of cholesterol esters into the cell is impaired and the intracellular feedback by cholesterol on 3-hydroxy-3-methylglutaryl CoA reductase is lacking.
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.
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.
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)
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.
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.
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.
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.
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)
A protein phytotoxin from the seeds of Ricinus communis, the castor oil plant. It agglutinates cells, is proteolytic, and causes lethal inflammation and hemorrhage if taken internally.
An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.
A C-type lectin that is a cell surface receptor for ASIALOGLYCOPROTEINS. It is found primarily in the LIVER where it mediates the endocytosis of serum glycoproteins.
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.
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.
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.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
A family of large adaptin protein complex subunits of approximately 90-130 kDa in size.
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).
Protein of the annexin family with a probable role in exocytotic and endocytotic membrane events.
Vesicles formed when cell-membrane coated pits (COATED PITS, CELL-MEMBRANE) invaginate and pinch off. The outer surface of these vesicles are covered with a lattice-like network of coat proteins, such as CLATHRIN, coat protein complex proteins, or CAVEOLINS.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
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 sum of the weight of all the atoms in a molecule.
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.
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)
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
A family of proteins that play a role as cofactors in the process of CLATHRIN recycling in cells.
Transport proteins that carry specific substances in the blood or across cell membranes.
Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
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.
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.
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.
Agents used to occlude dental enamel pits and fissures in the prevention of dental caries.
Proteins prepared by recombinant DNA technology.
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.
One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.
Structures which are part of the CELL MEMBRANE or have cell membrane as a major part of their structure.
Solutions that have a greater osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
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.
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.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
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.
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.
A subclass of clathrin assembly proteins that occur as monomers.
Proteins found in any species of bacterium.
Antibodies produced by a single clone of cells.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A subtype of dynamin found primarily in the NEURONS of the brain.
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 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.
A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.
Elements of limited time intervals, contributing to particular results or situations.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
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 prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking DOPAMINE RECEPTORS. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup.
Iron-containing proteins that are widely distributed in animals, plants, and microorganisms. Their major function is to store IRON in a nontoxic bioavailable form. Each ferritin molecule consists of ferric iron in a hollow protein shell (APOFERRITINS) made of 24 subunits of various sequences depending on the species and tissue types.
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)
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.
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.
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)
A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.
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.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
A clathrin adaptor protein complex primarily involved in clathrin-related transport at the TRANS-GOLGI NETWORK.
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.
Endogenous glycoproteins from which SIALIC ACID has been removed by the action of sialidases. They bind tightly to the ASIALOGLYCOPROTEIN RECEPTOR which is located on hepatocyte plasma membranes. After internalization by adsorptive ENDOCYTOSIS they are delivered to LYSOSOMES for degradation. Therefore receptor-mediated clearance of asialoglycoproteins is an important aspect of the turnover of plasma glycoproteins. They are elevated in serum of patients with HEPATIC CIRRHOSIS or HEPATITIS.
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.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
The ability of a substrate to allow the passage of ELECTRONS.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
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).
Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
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 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)
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.
The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
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.
A 6-kDa polypeptide growth factor initially discovered in mouse submaxillary glands. Human epidermal growth factor was originally isolated from urine based on its ability to inhibit gastric secretion and called urogastrone. Epidermal growth factor exerts a wide variety of biological effects including the promotion of proliferation and differentiation of mesenchymal and EPITHELIAL CELLS. It is synthesized as a transmembrane protein which can be cleaved to release a soluble active form.
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.
Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.
Specific hemagglutinin subtypes encoded by VIRUSES.
A family of DNA binding proteins that regulate expression of a variety of GENES during CELL DIFFERENTIATION and APOPTOSIS. Family members contain a highly conserved carboxy-terminal basic HELIX-TURN-HELIX MOTIF involved in dimerization and sequence-specific DNA binding.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.
An acidifying agent that has expectorant and diuretic effects. Also used in etching and batteries and as a flux in electroplating.
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)
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 cultured line of C3H mouse FIBROBLASTS that do not adhere to one another and do not express CADHERINS.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
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.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
Cell lines whose original growing procedure consisted being transferred (T) every 3 days and plated at 300,000 cells per plate (J Cell Biol 17:299-313, 1963). Lines have been developed using several different strains of mice. Tissues are usually fibroblasts derived from mouse embryos but other types and sources have been developed as well. The 3T3 lines are valuable in vitro host systems for oncogenic virus transformation studies, since 3T3 cells possess a high sensitivity to CONTACT INHIBITION.
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.
The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.
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.
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.
A family of highly conserved and widely expressed sodium-phosphate cotransporter proteins. They are electrogenic sodium-dependent transporters of phosphate that were originally identified as retroviral receptors in HUMANS and have been described in yeast and many other organisms.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
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).)
Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
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.
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.
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 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)
Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.
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)
A layer of epithelium that lines the heart, blood vessels (ENDOTHELIUM, VASCULAR), lymph vessels (ENDOTHELIUM, LYMPHATIC), and the serous cavities of the body.
A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymes
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.
Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
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)
Cyclic GLUCANS consisting of seven (7) glucopyranose units linked by 1,4-glycosidic bonds.
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.
Single membrane vesicles, generally made of PHOSPHOLIPIDS.
Measurement of the intensity and quality of fluorescence.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
Proteins obtained from ESCHERICHIA COLI.
The relationship between the dose of an administered drug and the response of the organism to the drug.
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.-.
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 cell surface receptor involved in regulation of cell growth and differentiation. It is specific for EPIDERMAL GROWTH FACTOR and EGF-related peptides including TRANSFORMING GROWTH FACTOR ALPHA; AMPHIREGULIN; and HEPARIN-BINDING EGF-LIKE GROWTH FACTOR. The binding of ligand to the receptor causes activation of its intrinsic tyrosine kinase activity and rapid internalization of the receptor-ligand complex into the cell.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
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.
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.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
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.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
A class of sphingolipids found largely in the brain and other nervous tissue. They contain phosphocholine or phosphoethanolamine as their polar head group so therefore are the only sphingolipids classified as PHOSPHOLIPIDS.
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.
A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.
A receptor that is specific for IGF-II and mannose-6-phosphate. The receptor is a 250-kDa single chain polypeptide which is unrelated in structure to the type 1 IGF receptor (RECEPTOR, IGF TYPE 1) and does not have a tyrosine kinase domain.
Compounds containing carbohydrate or glycosyl groups linked to phosphatidylinositols. They anchor GPI-LINKED PROTEINS or polysaccharides to cell membranes.
Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.

Enhancement of endocytosis due to aminophospholipid transport across the plasma membrane of living cells. (1/613)

Formation of intracellular vesicles is initiated by membrane budding. Here we test the hypothesis that the plasma membrane surface area asymmetry could be a driving force for vesicle formation during endocytosis. The inner layer phospholipid number was therefore increased by adding exogenous aminophospholipids to living cells, which were then translocated from the outer to the inner layer of the membrane by the ubiquitous flippase. Addition of either phosphatidylserine or phosphatidylethanolamine led to an enhancement of endocytosis, showing that the observed acceleration does not depend on the lipid polar head group. Conversely, a closely related aminophospholipid that is not recognized by the flippase, lyso-alpha-phosphatidylserine, inhibited endocytosis, and similar results were obtained with a cholesterol derivative that also remains in the plasma membrane outer layer. Thus an increase of lipid concentration in the inner layer enhanced internalization, whereas an increase of the lipid concentration in the outer layer inhibited internalization. These experiments suggest that transient asymmetries in lipid concentration might contribute to the formation of endocytic vesicles.  (+info)

Inhibition of clathrin-coated pit assembly by an Eps15 mutant. (2/613)

Recent data have shown that Eps15, a newly identified component of clathrin-coated pits constitutively associated with the AP-2 complex, is required for receptor-mediated endocytosis. However, its precise function remains unknown. Interestingly, Eps15 contains three EH (Eps15-Homology) domains also found in proteins required for the internalization step of endocytosis in yeast. Results presented here show that EH domains are required for correct coated pit targeting of Eps15. Furthermore, when cells expressed an Eps15 mutant lacking EH domains, the plasma membrane punctate distribution of both AP-2 and clathrin was lost, implying the absence of coated pits. This was further confirmed by the fact that dynamin, a GTPase found in coated pits, was homogeneously redistributed on the plasma membrane and that endocytosis of transferrin, a specific marker of clathrin-dependent endocytosis, was strongly inhibited. Altogether, these results strongly suggest a role for Eps15 in coated pit assembly and more precisely a role for Eps15 in the docking of AP-2 onto the plasma membrane. This hypothesis is supported by the fact that a GFP fusion protein encoding the ear domain of (alpha)-adaptin, the AP-2 binding site for Eps15, was efficiently targeted to plasma membrane coated pits.  (+info)

Direct demonstration of the endocytic function of caveolae by a cell-free assay. (3/613)

The endocytic function of caveolae was challenged by taking advantage of a cell-free assay directly measuring the detachment of receptor-containing vesicles from isolated plasma membranes. Plasma membranes from cultured cells surface-labeled with 125I-cholera toxin (segregating in caveolae) were isolated as described previously. Following incubation of these labeled membranes in the presence of nucleotide(s) and cytosol, a significant proportion of the initially membrane-associated radioactivity was released into the incubation medium in sedimentable form (14*10(6 )g). Results of biochemical, morphological, and fractionation analysis of the material containing the released radioactivity directly demonstrated that caveolae are plasma membrane domains involved in an endocytic process and resulting in the formation of caveolae-derived vesicles. In addition, these studies allowed a direct comparison of caveolae- and clathrin-coated pit-mediated endocytosis and reveal that these two processes diverge in terms of kinetics, cytosol and nucleotide requirements as well as in terms of the density and size of the endocytic vesicles formed.  (+info)

Characterization of the internalization pathways for the cystic fibrosis transmembrane conductance regulator. (4/613)

Mutations in the gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) chloride channel give rise to the most common lethal genetic disease of Caucasian populations, CF. Although the function of CFTR is primarily related to the regulation of apical membrane chloride permeability, biochemical, immunocytochemical, and functional studies indicate that CFTR is also present in endosomal and trans Golgi compartments. The molecular pathways by which CFTR is internalized into intracellular compartments are not fully understood. To define the pathways for CFTR internalization, we investigated the association of CFTR with two specialized domains of the plasma membrane, clathrin-coated pits and caveolae. Internalization of CFTR was monitored after cell surface biotinylation and quantitation of cell surface CFTR levels after elution of cell lysates from a monomeric avidin column. Cell surface levels of CFTR were determined after disruption of caveolae or clathrin-coated vesicle formation. Biochemical assays revealed that disrupting the formation of clathrin-coated vesicles inhibited the internalization of CFTR from the plasma membrane, resulting in a threefold increase in the steady-state levels of cell surface CFTR. In contrast, the levels of cell surface CFTR after disruption of caveolae were not different from those in control cells. In addition, although our studies show the presence of caveolin at the apical membrane domain of human airway epithelial cells, we were unable to detect CFTR in purified caveolae. These results suggest that CFTR is constitutively internalized from the apical plasma membrane via clathrin-coated pits and that CFTR is excluded from caveolae.  (+info)

Cutting edge: receptor-mediated endocytosis of heat shock proteins by professional antigen-presenting cells. (5/613)

Immunization with heat shock proteins (HSPs) induces Ag-specific CTL responses. The specificity of the immune response is based on peptides associated with HSPs. To investigate how exogenous HSP/peptide complexes gain access to the MHC class I-restricted Ag presentation pathway, we incubated the monocytic cell line P388D1 and the dendritic cell line D2SC/1 with gold-labeled HSPs gp96 and HSC70. We show that HSPs bind specifically to the surface of these APCs and are internalized spontaneously by receptor-mediated endocytosis, demonstrating the existence of specific receptors for HSPs on these cells. In addition, we observe colocalization of internalized HSPs and surface MHC class I molecules in early and late endosomal structures. These findings provide possible explanations for the immunogenicity of HSP/peptide complexes and for the transfer of HSP-associated peptides onto MHC class I molecules.  (+info)

Bradykinin-induced internalization of the human B2 receptor requires phosphorylation of three serine and two threonine residues at its carboxyl tail. (6/613)

The binding of bradykinin (BK) to B2 receptor triggers the internalization of the agonist-receptor complex. To investigate the mechanisms and the receptor structures involved in this fundamental process of receptor regulation, the human B2 receptor was mutated within its cytoplasmic tail by complementary strategies of truncation, deletion, and amino acid substitution. Ligand binding, signal transduction, internalization as well as phosphorylation were studied for the mutated receptors expressed in COS, CHO, and HEK 293 cells. Truncation of 44 out of 55 amino acid residues of the receptor's cytoplasmic tail corresponding to positions 321-364 did not alter the kinetics of BK binding and the receptor coupling to phospholipase C and phospholipase A2. By contrast, truncations after positions 320 and 334, deletions within the segment covering positions 335-351, as well as alanine substitution of serine and threonine residues within segment 335-351 diminished the internalization capacity of the mutant receptors. Mutants with a markedly reduced internalization potential failed to produce BK-induced receptor phosphorylation suggesting that phosphorylation may be involved in receptor internalization. The mutagenesis approaches converged at the conclusion that three serines in positions 339, 346, and 348 and two threonines in positions 342 and 345, contained in a sequence segment that is highly conserved between species, have a critical role in the ligand-dependent internalization and phosphorylation of kinin receptors and can intervene in these processes in an alternative manner. However, mutants lacking these residues were still sensitive to dominant-negative forms of beta-arrestin and dynamin, suggesting the existence of additional receptor structure(s) involved in the receptor sequestration through clathrin-coated vesicles.  (+info)

Inhibition of the receptor-binding function of clathrin adaptor protein AP-2 by dominant-negative mutant mu2 subunit and its effects on endocytosis. (7/613)

Although interactions between the mu2 subunit of the clathrin adaptor protein complex AP-2 and tyrosine-based internalization motifs have been implicated in the selective recruitment of cargo molecules into coated pits, the functional significance of this interaction for endocytosis of many types of membrane proteins remains unclear. To analyze the function of mu2-receptor interactions, we constructed an epitope-tagged mu2 that incorporates into AP-2 and is targeted to coated pits. Mutational analysis revealed that Asp176 and Trp421 of mu2 are involved in the interaction with internalization motifs of TGN38 and epidermal growth factor (EGF) receptor. Inducible overexpression of mutant mu2, in which these two residues were changed to alanines, resulted in metabolic replacement of endogenous mu2 in AP-2 complexes and complete abrogation of AP-2 interaction with the tyrosine-based internalization motifs. As a consequence, endocytosis of the transferrin receptor was severely impaired. In contrast, internalization of the EGF receptor was not affected. These results demonstrate the potential usefulness of the dominant-interfering approach for functional analysis of the adaptor protein family, and indicate that clathrin-mediated endocytosis may proceed in both a mu2-dependent and -independent manner.  (+info)

Functional properties of leptin receptor isoforms: internalization and degradation of leptin and ligand-induced receptor downregulation. (8/613)

Long (ObRb) and short (ObRa) leptin receptor isoforms are thought to play essential roles in mediating leptin signaling and the transport and degradation of leptin, respectively. Although the capacity of these cloned receptor species to mediate signal transduction has been reported, there is no information on the ability of individual receptor species to mediate leptin internalization and degradation or to undergo ligand-induced downregulation. We therefore studied these parameters in Chinese hamster ovary (CHO) cells stably expressing either ObRa or ObRb isoforms of the leptin receptor. We determined that both ObRa and ObRb mediated internalization of 125I-labeled leptin by a temperature- and coated pit-dependent mechanism. Both ObRa and ObRb also mediated degradation of 125I-leptin by a lysosomal mechanism, and this was more efficiently mediated by ObRa in these cells. Neither leptin internalization nor degradation by ObRa was affected by mutation of the conserved Box 1 motif. By studying deletion mutants of ObRa, we found that efficient internalization was dependent on a motif located between amino acids 8 and 29 of the intracellular domain of ObRa. Exposure of cells expressing ObRa or ObRb to unlabeled leptin for 90 min at 37 degrees C produced downregulation of available surface receptors, and this effect was of greater magnitude in cells expressing ObRb. Whereas CHO cells expressing the growth hormone receptor showed marked downregulation of ligand binding after exposure to dexamethasone (DEX) or phorbol myristic acid (PMA), PMA had no effect on expression of ObRa or ObRb, and DEX reduced binding to cells expressing ObRb by 15%. Thus, the two leptin receptor isoforms, ObRa and ObRb, mediate leptin internalization by a coated pit-dependent mechanism, leptin degradation by a lysosomal pathway, and ligand-induced receptor downregulation. The differential capacity of the two receptor isoforms may relate to the different roles of the receptor isoforms in the biology of leptin.  (+info)

During clathrin-mediated endocytosis, it has been thought that the sensing and binding of the clathrin adaptor protein AP2 to cargo and lipids leads to the recruitment of clathrin, nucleating the formation of a clathrin-coated pit. Henne et al. have now found that this process of AP2 binding may not in fact represent either the first or the nucleation event of endocytosis. Instead, ubiquitous proteins called FCHo1/2 (F-BAR proteins) bind to the plasma membrane and define the sites of endocytosis independently of AP2. The F-BAR protein can generate very low curvatures and, at higher concentrations, generates higher curvatures like those required at the neck of budding vesicles. The C terminus of the protein has a μ-homology domain (with homology to the μ domain of the AP2 complex) that interacts with Eps15 and intersectin and via these proteins recruits AP2, which further recruits clathrin. Thus, a curvature-inducing protein can act to nucleate clathrin-coated pit assembly during ...
To complement studies that have demonstrated the prominent phosphorylation of a 50-kD coated vesicle polypeptide in vitro, we have evaluated the phosphorylation of coated membrane proteins in intact cells. A co-assembly assay has been devised in which extracts of cultured rat sympathetic neurons labeled with [32P]-Pi were combined with unlabeled carrier bovine brain coat proteins and reassembled coat structures were isolated by gradient centrifugation. Two groups of phosphorylated polypeptides, of 100-110 kD (pp100-110) and 155 kD (pp155) apparent molecular mass, were incorporated into reassembled coats. The neuronal pp100-110 are structurally and functionally related to the 100-110-kD component of the bovine brain assembly protein (AP), a protein complex that also contains 50-kD and 16.5-kD components and is characterized by its ability to promote the reassembly of clathrin coat structures under physiological conditions of pH and ionic strength (Zaremba, S. and J. H. Keen, 1983, J. Cell Biol., ...
Looking for coated pit? Find out information about coated pit. A cell surface depression that is coated with clathrin on its cytoplasmic surface and functions in receptor-mediated endocytosis Explanation of coated pit
Coated pit: …of the membrane called a coated pit, which is lined by a special protein known as clathrin. As the coated pit invaginates, it is pinched off in the cytoplasm to form a coated vesicle. The coated vesicle fuses with cytoplasmic endosomes (membrane-enclosed vesicles) and then with cell organelles called lysosomes,…
Glyvuk et al (2010) argue that the CME of SV membranes represents a kinetic bottleneck of the recycling pathway. Under conditions of sustained activity BE provides a compensatory mechanism to balance high exocytic load with matching endocytic activity. Vacuolar membrane invaginations are then consumed by undefined budding events that chop these membranes into small vesicles that may re‐enter the SV cycle (Figure 1A). It is this consumption step that the authors envision to depend on AP‐1/σ1B (Figure 1B). The experimental evidence for this model at present remains indirect. AP‐1, as its relative AP‐2, is one of the major recruitment factors for clathrin and loss of either protein complex results in depletion of clathrin‐coated pits from TGN/endosomes or the plasmalemma, respectively. Why then do AP‐1/σ1B‐KO mice accumulate clathrin‐coated pits on endosome‐like vacuoles? One possibility is that other σ1 isoproteins such as σ1A do a poor job in functionally replacing σ1B on ...
The structure of the appendage domain of β2 adaptin is similar to that of α‐adaptin in that it has two subdomains with similar topology, but with a difference of ∼46° in the orientation between the two subdomains. Like the α‐appendage, the β2‐appendage domain binds AP180, epsin and eps15, and therefore is likely to be involved in recruiting proteins involved in controlling CCV formation to sites of coated pit formation in vivo. The two proteins possess a partly conserved binding site of high hydrophobic potential on the C‐terminal platform domain, suggesting that they bind similar motifs i.e. DΦF/W. The binding site residues are also conserved in β1‐adaptin from the adaptor AP1, so this homologue would be predicted to bind the same ligands as β2. Indeed, a GSTβ1 appendage construct does bind to eps15, and weakly to clathrin and epsin (data not shown). Although the α and β2 appendages share some of the same ligands, they bind to them with different relative affinities: the ...
Trading pits are home to risky business / Its every man for himself in commodities In between are 270 minutes of organized mayhem as New York Mercantile Exchange traders scream across a pit, wave their arms and shove each other for position in that cruelest and most unpredictable of financial arenas -- the global commodities markets. Almost all are men, and some are so hooked on life on the edge that if the market gets slow, they will head for the traders lounge for a $500-a-hand poker game. People say Ive got a great job because its just 4 1/2 hours a day, but Im getting yelled at, spit on, elbowed, pushed; I mean its tough in there, says Beau Roffman, a 44-year-old trader from Monmouth Beach, N.J., during a 50- minute lunch break. Roffman, a soft-spoken Grateful Dead fan, has survived 20 years in the crude oil futures pit. From 1986 to 1990, the price of a barrel of light, sweet crude oil stayed between $15 and $20 in constant dollars. An oil company pumps crude out of the ground in
Balls pits are ridden with bacteria causes health risks to children including skin infections, sepsis and meningitis, scientists find
Ball pits are colorful, fun and ... crawling with germs, according to a study published late last month in the American Journal of Infection Control.
Yasmin Young of the 2 to 6 Takeover will be hosting Stand Up for Pits at Helium Comedy Club this Sunday! Get the details here!
Reactome is pathway database which provides intuitive bioinformatics tools for the visualisation, interpretation and analysis of pathway knowledge.
Reactome is pathway database which provides intuitive bioinformatics tools for the visualisation, interpretation and analysis of pathway knowledge.
The design of the milking bail, pipework and pit are important factor in keeping cows and people safe and can ensure good cow flow into the dairy.
Ford, M.G.J., Mills, I.G., Peter, B.J., Vallis, Y., Praefcke, G.J.K., Evans, P.R. and McMahon, H.T. (2002) Curvature of clathrin-coated pits driven by epsin. Nature 419: 361-366 (abstract). (.pdf) supplemental data. (see also News and Views and highlights in Nature Cell Biology, Nature reviews in molecular cell biology, and a mini review in Cell (Cell October 18, 2002: 111 (2):143-146)(summary) ...
Well dogs off the streets can snap at any time. those breeds arent safe. look at the news.. of course responded with the fact that most pits in the news arent really pits and if you looked at a picture or DNA tested now theyre probably actually a lab mix.. and if youre going to make that argument that thats like saying any kid that grew up on the streets is going to shoot someone just because of where they came from. I also brought up that in true street pits and fighting pit rings that dogs that are human aggressive were worth nothing to their owners. if they got bit and had to go to the hospital and had to explain what happened multiple times people got suspicous ...
I have never seen a dog affect so many peoples lives. From my 80 year old grandmother to proud pit bull haters. One by one Chubbs won them over one by one with his happy-go-lucky attitude, super smile and gentleness. Chubbs is the reason I became a pit bull owner myself. I was a little apprehensive when my cousin told me he was going to get a pit bull for his family. After meeting Chubby, he inspired me to start researching the breed. What I found shocked me! Pit bulls are great dogs! I now am the proud owner of my Layla ...
Camouflaged Spiked Pit Trap CR 8. XP 4,800. Type mechanical; Perception DC 25; Disable Device DC 20. EFFECTS. Trigger location; Reset manual. Effect 50-ft.-deep pit (5d6 falling damage); pit spikes (Atk +15 melee, 1d4 spikes per target for 1d6+5 damage each); DC 20 Reflex avoids; multiple targets (all targets in a 10-ft.-square area). ...
Our Boat-Shaped Sand Pit promises hours of outdoor fun for your kids and friends. With ample space for two to three kids, the sand pit is constructed of treated timber to withstand the elements. The boat-shaped sand pit also comes with a realistic...
Pit Trap CR 1. XP 400. Type mechanical; Perception DC 20; Disable Device DC 20. EFFECTS. Trigger location; Reset manual. Effect 20-ft.-deep pit (2d6 falling damage); DC 20 Reflex avoids; multiple targets (all targets in a 10-ft.-square area). ...
Pop, drop and retrieve with the Ball Pit Gym! This colorful ball pit gym has different ball activity stations where baby can pop, drop or slide the balls in, out
Spedometer & Tachometer Combination Gauge, 2:1 Ratio and more at White s Pit Stop. Find the best selection of high performance parts and custom auto accessories including Spedometer & Tachometer Combination Gauge, 2:1 Ratio . Guaranteed low prices!
The battle of South Aliso Street began with a low growl in the underbrush and a sudden attack by three pit bulls, city Councilman Brian Barnwell recalls. One bit deeply into his foot, another ripped
Review: Doctor Who meets Doom3 - This was an excellent 2-part episode, although I had never been seen the older ones, I never thought the doctor would...
I didnt even make it to the 50mil this time around because I was too busy and didnt have the patience so nice job reaching that goal! But for a diva... lets just say at least you got 500 essence shards out of it ...
We were at a play centre today and I noticed a girl, around 5yr pushing a young boy around 2yrs (It was in the ball pit part). I went in to see if I could help and then noticed my 4.5yr old kicking this boy! (For no reason) I asked the - page 5
To assess the role of clathrin in the bulk endocytic flow of rat foetal fibroblasts, the rate of internalization of fluid-phase and membrane-lipid tracers were compared, under control conditions and after inhibition of endocytic clathrin-coated pit formation. After intracellular potassium depletion or upon cell transfer into 0.35 M NaCl, the rate of internalization of receptor-bound transferrin and the residual membrane area of plasmalemmal clathrin-coated pits and vesicles were similarly decreased by approximately 90%. In contrast, the initial rate (, 5 min) of intracellular accumulation of the fluid-phase tracer HRP was not affected. Both in control and treated cells, the rate of HRP accumulation declined after approximately 5 min, and was twofold lower in treated cells, due to enhanced regurgitation. After correction for regurgitation, the endocytic rate constant was similar to measurements at shorter intervals and identical in control and treated cells. Similarly, the rate of internalization ...
TY - JOUR. T1 - Glycoproteins of coated pits, cell junctions, and the entire cell surface revealed by monoclonal antibodies and immunoelectron microscopy.. AU - Murphy, T. L.. AU - Decker, G.. AU - August, Thomas. PY - 1983/8. Y1 - 1983/8. N2 - Topographical descriptions of three major plasma membrane glycoproteins of murine 3T3 cells were obtained by immunoelectron microscopy with monoclonal antibodies. A glycoprotein of Mr 80,000 was distributed throughout the total cell surface. A second of Mr 90,000 was concentrated in coated pits, and a third of Mr 100,000 was localized at cell junctions.. AB - Topographical descriptions of three major plasma membrane glycoproteins of murine 3T3 cells were obtained by immunoelectron microscopy with monoclonal antibodies. A glycoprotein of Mr 80,000 was distributed throughout the total cell surface. A second of Mr 90,000 was concentrated in coated pits, and a third of Mr 100,000 was localized at cell junctions.. UR - ...
Characterization of clathrin-coated vesicles isolated from MPR-deficient fibroblasts. The material contained in fractions 8 to 10 of the density gradients sho
Computer simulations of ion-bombardment events which recrystallize the target demonstrate pit formation at 1.0 keV. Atoms are ejected from the first two target layers in the pit region. The remainder of the pit is created by replacement-collision sequences. Linear-cascade and spike-regime events are dynamically indistinguishable. © 1983 The American Physical Society.. ...
The 3-layer or Catalyst Coated Membrane (CCM) version of the popular 5-layer Hydrogen/Oxygen MEA, this high performance Membrane Electrode Assembly (MEA) is used where performance and efficiency is critical and when you need a free-floating GDL layer. It can be used in Hydrogen/Air or Hydrogen/Oxygen Fuel Cells. The standard configuration features a high Platinum loading (4 mg/cm²) and a 0.005 membrane (Nafion® 115). Custom sizes and configurations are also available with no minimum order quantities and short lead times even for custom configurations.. ...
A broad irregular penannular ring ditch, possibly a henge, and pits are visible as cropmarks on aerial photographs. The internal diameter of the enclosure is 43m and the external diameter is between 58m and 65m. The enclosure is defined by a broad and very irregular ditch which measures between 5m and 14m wide. There is an entrance, 12m wide, which faces north-east roughly in the direction of the contour, and towards the river Avon. A line of eight pits curves around part of the enclosure, facing the entrance. More possible pits, possibly forming part of a circle around the enclosure, are situated on the east and south sides of the enclosure . Another pit is situated within the south east part of the enclosure. Yet more possible pits, situated between 20m and 70m to the south west of the enclosure, may be associated features. There are a number of potentially confusing geological cropmarks in the area. It is therefore possible that some of the pits could be natural, or that some man-made pits in ...
Eukaryotic cells constantly form and internalize plasma membrane vesicles in a process known as endocytosis. Endocytosis serves a variety of housekeeping and specialized cellular functions, and it can be mediated by distinct molecular pathways. Among them, internalization via clathrin-coated pits, l …
Guarda Foto stock di Crosssection Of The Gastric Or Stomach Epithelium Showing The Numerous Gastric Pits On The Surface Of The Mucosa Sem. Cerca foto premium ad alta risoluzione su Getty Images.
A time-lapse camera on the rim of Puu Ōō crater captured this image at dawn. The view is towards the southeast, and shows two glowing pits in the southern portion of the crater floor. Our overflight the next day showed that these pits are filled with small lava ponds ...
Rabbit Polyclonal Anti-Clathrin interactor 1 Antibody. Validated: WB, ICC/IF, IHC, IHC-P. Tested Reactivity: Human, Mouse, Rat. 100% Guaranteed.
The latest tips and news on Pit Bulls are on POPSUGAR Pets. On POPSUGAR Pets you will find everything you need on pets and Pit Bulls.
Dog lovers often blame the media for making pit bulls out to be vicious, mean dogs, and certified dog trainers and even animal control officers say there are no bad dogs - just bad owners.
Is your pit bull in good health and you want to make sure he stays that way? Or perhaps your companion is getting older and youre wondering if there is anything you can do to reduce the risk of illness during her senior years?
There are many dangers when working on a dairy, from working with machinery to animals, it is essential to stress safety with employees
There was an article in the WSJ titled Stocks Are Riskier Than You Think. The article was very long and tried to make too many points but there was one particularly useful passage; If youre expecting stocks to outperform, say, 70% of the time, you need to think about how…
സാധാരണയായി ആഘാതം പ്രതിരോധം മെച്ചപ്പെടുത്തുന്നതിനായി ക്രോസ് ബാർ പിച്ച് 50mm കൂടെ താമ്രജാലം ഉണ്ടാക്കി ജി.എം. ഡ്രെയിനേജ് കുഴിയിൽ കവർ ജി.എം. ഡ്രെയിനേജ് കുഴിയിൽ കവർ. ലോഡ് ക്ലാസ്
Assembly protein recruiting clathrin and adapter protein complex 2 (AP2) to cell membranes at sites of coated-pit formation and clathrin-vesicle assembly. May be required to determine the amount of membrane to be recycled, possibly by regulating the size of the clathrin cage. Involved in AP2-dependent clathrin-mediated endocytosis at the neuromuscular junction. Plays a crucial role in fetal and adult hematopoiesis, and normal prenatal and postnatal growth and viability.
Internalization of cargo proteins and lipids at the cell surface occurs in both a constitutive and signal-regulated manner through clathrin-mediated and other endocytic pathways. Clathrin-coated vesicle formation is a principal uptake route in response to signalling events. Protein-lipid and protein-protein interactions control both the targeting of signalling molecules and their binding partners to membrane compartments and the assembly of clathrin coats. An emerging aspect of membrane trafficking research is now addressing how signalling cascades and vesicle coat assembly and subsequently disassembly are integrated.
Clathrin-mediated endocytosis involves cargo selection and membrane budding into vesicles with the aid of a protein coat. Formation of invaginated pits on the plasma membrane and subsequent budding of vesicles is an energetically demanding process that involves the cooperation of clathrin with many different proteins. Here we investigate the role of the brain-enriched protein epsin 1 in this process. Epsin is targeted to areas of endocytosis by binding the membrane lipid phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P(2)). We show here that epsin 1 directly modifies membrane curvature on binding to PtdIns(4,5)P(2) in conjunction with clathrin polymerization. We have discovered that formation of an amphipathic alpha-helix in epsin is coupled to PtdIns(4,5)P(2) binding. Mutation of residues on the hydrophobic region of this helix abolishes the ability to curve membranes. We propose that this helix is inserted into one leaflet of the lipid bilayer, inducing curvature. On lipid monolayers epsin alone is
The major challenge in membrane filtration is fouling which reduces the membrane performance. Fouling is mainly due to the adhesion of foulants on the membrane surfaces. In this work, we studied the fouling behaviour of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) isoporous membrane and the mussel inspired polydopamine/L-cysteine isoporous zwitterionic membrane. Polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) isoporous membranes were fabricated via self-assembly and non-solvent induced phase separation method. Subsequently, the isoporous membrane was modified by a mild mussel-inspired polydopamine (PDA) coating; the isoporous surface structure and the water flux was retained. Zwitterionic L-cysteine was further anchored on the PDA coated membranes via Michael addition reaction at pH 7 and 50 °C to alleviate their antifouling ability with foulants solution. The membranes were thoroughly characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic ...
The pit is loaded with logs measuring 2.4 m or less, which will fit easily across the pit. Care must be taken, during loading, to fill as many gaps between logs as possible with branches and small wood to improve volumetric efficiency. The long length of the wood which can be loaded into pits means that crosscutting with axes is still a practical method for the small operator without capital. Nevertheless, chain saws are widely used. To ensure that the wood is properly heated for carbonization, the hot gas is allowed to pass along the floor of the pit by placing the charge on a crib of logs. Photo. 7. Earth pit during burning. Note steel chimneys and cover used made of steel sheets sprung between stakes. Joints between sheets sealed with earth. Ghana. Photo. Lejeune. First, about five logs, cut to the width of the pit, are laid evenly spaced along the length; then four logs each equal to the length of the pit are evenly spaced on top of the first layer. This crib structure supports the charge ...
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.
This gene encodes a component of vacuolar ATPase (V-ATPase), a multisubunit enzyme that mediates acidification of intracellular compartments of eukaryotic cells. V-ATPase dependent acidification is necessary for such intracellular processes as protein sorting, zymogen activation, receptor-mediated endocytosis, and synaptic vesicle proton gradient generation. V-ATPase is composed of a cytosolic V1 domain and a transmembrane V0 domain. The V1 domain consists of three A and three B subunits, two G subunits plus the C, D, E, F, and H subunits. The V1 domain contains the ATP catalytic site. The V0 domain consists of five different subunits: a, c, c, c, and d. This gene is one of four genes in man and mouse that encode different isoforms of the a subunit. Alternatively spliced transcript variants encoding the same protein have been described. Mutations in this gene are associated with renal tubular acidosis associated with preserved hearing. [provided by RefSeq, Jul 2008] ...
Housing bans are preventing pits at the shelter from finding homes, and that is truly sad. But many residents of NYCHA claim that the pits that live in their buildings are being abused, trained for fighting, and bred for profit. The ban and the breed-specific neutering/spaying proposals would ideally save dogs lives in the long run, while unfortunately creating more suffering in the short term. As much as I love this breed, I want to see them thrive with good homes. I want to stop seeing heart breaking stories about them. I think the best way to achieve this is to bring them back to being the reliable family pet, and not allowing them to be abused, over-bred, and tortured by thugs. Without allowing them to over-breed, we can bring the pit bull back from the inner-city back into the suburbs, where I am sure they will live longer healthier lives ...
Now you know where the smells coming from. The 10-foot pit in front of you houses a mass of ravenous, groaning dead. The pale bodies lumbering around in the pit are well-preserved, but still obviously dead: patches of flayed skin and missing appendages attest to this. An autopsy platform (little more than a slab of stone with manacles attached) houses another body, this one partly cut to pieces. A disembodied hand crawls along the floor before your very eyes. A tall man, garbed all in white cloth, looks at you with empty eyes from before the table. 15ft.-by-25ft. room with a 10ft.-by-5ft. alcove in the southwest, 10ft. high, pit 10ft. deep. Autopsy table (alcove A1-2) with a manacled alchemical zombie (Strength DC 26 to break). Eleven more alchemical zombies shuffling around in the pit. A wooden rack on the western wall containing several jars of formaldehyde, two flasks of acid, a vial of antitoxin, a flask of unholy water, a scalpel (masterwork Small dagger) and a shrunken head (see below). ...
For the past eight weeks Ive been trolling Petfinder and craigslist for a new dog to join our happy family. I had no idea it would be this hard. The popular breeds, if they appear at all in the shelters, go very quickly, and many times a golden mix is understood to be golden (and pit bull) mix (but mostly pit bull). I understand that pits get a lot of media attention while goldies actually have more reported biting incidents, but when you go to the shelters and the pits are lunging for you while the goldies just kind of sit there, you start to believe the hype. Minimes BFF just got a dog when they werent even looking for one. They happened to be at the Cherry Blossom Festival where the local SPCA was having an adoption tent and they found a really nice dog and adopted her. Just like that. Our luck is such that we would have gotten the dog home and she would start destructive chewing whenever the toilet flushed, or howl all night, or would walk on a leash only if we whistled I wanna be ...
PIT RULES USED FOR CONTESTS DECIDING THE GAMER OF TWO DOGS (GAME = PLUCKY, UNYIELDING IN MANNER, READY AND WILLING) Rule 1: The principals shall select a referee who is familiar with the rules and who is satisfactory to both sides. The referee will then appoint his Timekeeper. Each handler will select a man to act as his chief second or cornerman, whose duties are to wash the opponents dog, and to remain near this dogs corner as an observer. Rule 2: Each handler is to furnish two clean towels and a suitable blanket, to be used by his opponent. Either handler may demand that the opposing handler and his cornerman bare their arms to the elbows; also the handler may taste his opponents dogs water before or after the contest (up until the referee has rendered his decision on the contest). Rule 3: No water, sponges, towels or any other accessories are allowed in the pit at any time, except the referee who shall have in his possession an adequate breaking stick and a pencil; also a copy of these ...
What were made of Organic Shea ButterPressed from the pit of the karite fruit grown on the shea tree, which is commonly found in Africa. These pits are collected, dried in the sun and then roasted. The result is a soft and creamy butter with amazing healing properties. Shea Butter contains nutrients such as vitamins A
Executioners Run is an adventure that is meant to be used when one or more of the characters commit a serious crime in Port Nyanzaru. It is custom that serious criminals are taken, in groups of six, to Executioners Run in the Old City. Here the accused face a gauntlet of jungle creatures and traps, and those who climb the knotted rope on the other side of the pit are given their freedom as well as... [click here for more ...
City Inspector Jeremy Crowe said the recreational fires must be contained in a UL approved outdoor pit or fireplace. The pit also must be placed on a noncombustible surface and must be equipped with a spark arrester, spark screen or any other manufactured non-combustible device to prevent spark or ember release into the air or the ground. The fire pits must remain in place at all times ...
A deadly plague ravages your world. Your last hope: a legendary alien facility dug deep into the Feldspar Mountains...a massive Pit, built by the ancient Suulka.If The Pit really exists, there might be something left. Something that will give your doctors a fighting chance at the cure.
I wont say where, but I stumbled upon another forum recently, and my eye was drawn by a very familiar style of photoshopped image. Yes, Pitizen Ape+Lust is doing his thing elsewhere. He goes by a different name, but his work is drawing amazed gasps over there just as it used to do here...and who knows where else before the Pit ...
ST. PETERSBURG - Three pit bulls, which bit two people earlier this month, are scheduled to be euthanized.Officials with Pinellas County Animal Services determined those pit bulls - among
Pit bulls are controversial dogs. Properly known as American pit bull terriers, they are a powerful, athletic and tenacious breed that, unfortunately, are therefore a target for misuse and abuse by ...
Read reviews, compare customer ratings, see screenshots, and learn more about Pits of Death. Download Pits of Death and enjoy it on your iPhone, iPad, and iPod touch.
Originally from the pit at Tradesports(TM) (RIP 2008) ... on trading, risk, economics, politics, policy, sports, culture, entertainment, and whatever else might increase awareness, interest and liquidity of prediction markets. ...
When I saw this article, I thought it was a little overwrought. Now, Im not so sure. I have family in the APS, and apparently there are people there who seem seriously depressed. Like to the point where other staff are worried about them and talking about it. Ive also had my own encounters with people who have non-ironically said Fuck Queensland to me assuming I had the same opinion. Ill be with a group of progressives in a few hours, so I think thatll be a much more painful experience than I was expecting ...
The Pit and the Pendulum: Seven students answer an advertisement to participate in an experiment to explore how the sensation of pain can be eliminate...
Police have levied charges against a Groton woman whose pit bull attacked and injured a 74-year-old Groton man and killed his dog.
Police have levied charges against a Groton woman whose pit bull attacked and injured a 74-year-old Groton man and killed his dog.
Authorities have issued issued an arrest warrant for a Midwest City man accused of abandoning two pit bulls because they needed to be bathed.
Sandy ground caves in steeply at the right of the photograph to form a cliff and pit of fine white sand. A wheelbarrow sits in front of the base of the pit. Bare trees form a background. In the foreground left of the pit is a pile of crooked sticks ...
Chromalox is a thermal technology company. We engineer thermal solutions for the worlds toughest industrial heating applications.
Why isnt there a way to remove a stint? Not just adding? There are tracks where the game chooses 3 stints and two pit stops, and you cant change it. In some tracks I want to make only one pit stop and I have to do it mid race and
ယေဘုယျအားဖြင့်သက်ရောက်မှု၏ခုခံမြှင့်တင်ရန်လက်ဝါးကပ်တိုင် bar ကိုစေး၏ 50mm နှင့်အတူဆန်ခါနှင့်ဖန်ဆင်း GM က သို့ဖြစ်. ရေဆင်းစနစ်ကိုပြုပြင်ခြင်းတှငျးဖုံး GM ကရေနုတ်မြောင်းတွင်းကိုအဖုံး။ Loading ၏ class
Budding of the plasma membrane then occurs, forming a clathrin coated pit.[1] Other receptors can nucleate a clathrin-coated ... The cargo ligand and receptor will then recruit adaptor proteins and clathrin triskelions to the outside membrane of the cell ... A mature pit will be cleaved from the plasma membrane through the use of membrane binding and fission proteins such as dynamin ... "Cell. 166 (4): 907-919. doi:10.1016/j.cell.2016.07.004. PMC 5418658. PMID 27499021.. ...
... are found in virtually all cells and form domains of the plasma membrane termed clathrin-coated pits. Coated pits can ... This large protein assists in the formation of a coated pit on the inner surface of the plasma membrane of the cell. This pit ... of the plasma membrane of a fibroblast is made up of coated pits. As a coated pit has a life of about a minute before it buds ... Gaidarov I, Santini F, Warren RA, Keen JH (May 1999). "Spatial control of coated-pit dynamics in living cells". Nature Cell ...
He and Hopkins showed that the specific membrane endocytosed by coated pits on motile cells is returned by exocytosis to the ... This led him to propose that, as a cell moves, membrane from internal stores is added at the front of the cell-enabling the ... Bretscher, MS (1996). "Getting Membrane Flow and the Cytoskeleton to Cooperate in Moving Cells". Cell. 87 (4): 601-606. doi: ... 1996). "Actin-Based Cell Motility and Cell Locomotion". Cell. 84 (3): 371-379. doi:10.1016/S0092-8674(00)81281-7. PMID 8608590 ...
... many LDL receptors concentrate in clathrin-coated pits. Both LDL and its receptor form vesicles within a cell via endocytosis. ... which both alters membrane fluidity and maintains membrane integrity so that animal cells do not need to build cell walls (like ... of all animal cell membranes. It is required to build and maintain membranes and modulates membrane fluidity over the range of ... Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. It is a ...
Cell. 1978 Nov; 15 (3) :919-33. [11] Coated pits, coated vesicles, and receptor-mediated endocytosis. Nature. 1979 Jun 21; 279 ... Cell. 1994 Apr 8; 77 (1) :53-62 [48] Sterol-regulated release of SREBP-2 from cell membranes requires two sequential cleavages ... Cell. 1977 Nov; 12 (3) :629-41. [9] A mutation that impairs the ability of lipoprotein receptors to localise in coated pits on ... Cell. 1983 Mar; 32 (3) :941-51. [19] Depletion of intracellular potassium arrests coated pit formation and receptor-mediated ...
... s secrete and maintain the basement membrane. There are numerous coated vesicles and coated pits along the basolateral ... Podocytes are cells in the Bowman's capsule in the kidneys that wrap around capillaries of the glomerulus. Podocytes make up ... List of human cell types derived from the germ layers "Podocyte" at Dorland's Medical Dictionary Lote, Christopher J. ... Cell. Biol. 23 (10): 3575-82. doi:10.1128/mcb.23.10.3575-3582.2003. PMC 164754. PMID 12724416. Ciani L; Massella L; Ruggiero B ...
... coated pits, cell-membrane MeSH A11. - caveolae MeSH A11. - glycocalyx MeSH A11.284.149.165. ... k562 cells MeSH A11.251.860.180.750 - pc12 cells MeSH A11.251.860.180.880 - u937 cells MeSH A11.284.149.165 - cell membrane ... cho cells MeSH A11.251.210.505 - l cells (cell line) MeSH A11.251.210.520 - llc-pk1 cells MeSH A11.251.210.700 - 3t3 cells MeSH ... l cells MeSH A11.329.228.900 - 3t3 cells MeSH A11.329.228.900.080 - balb 3t3 cells MeSH A11.329.228.900.550 - nih 3t3 cells ...
Endocytosis is when a cell absorbs a molecule, such as a protein, from outside the cell by engulfing it with the cell membrane ... The particles are absorbed through the use of clathrin-coated pits. These clathrin-coated pits are short lived and serve only ... but also add and subtract membrane from the cell's plasma membrane. The surface area of the membrane is determined[citation ... The clathrin-coated pit invaginates into the cytosol and forms a clathrin-coated vesicle. The clathrin proteins will then ...
"A mutation that impairs the ability of lipoprotein receptors to localise in coated pits on the cell surface of human ... "Regulated step in cholesterol feedback localized to budding of SCAP from ER membranes". Cell. 102 (3): 315-23. doi:10.1016/ ... Goldstein JL, Anderson RG, Brown MS (Jun 1979). "Coated pits, coated vesicles, and receptor-mediated endocytosis". Nature. 279 ... "Depletion of intracellular potassium arrests coated pit formation and receptor-mediated endocytosis in fibroblasts". Cell. 33 ( ...
Increased accessibility of these sites in receptor-bound arrestin targets the arrestin-receptor complex to the coated pit. ... Arrestins shuttle between cell nucleus and cytoplasm. Their nuclear functions are not fully understood, but it was shown that ... Active phosphorylated GPCRs recruit arrestin to the plasma membrane. Receptor binding induces a global conformational change ... which promotes receptor internalization via coated pits and subsequent transport to internal compartments, called endosomes. ...
... or the clathrin coated-pit in the membrane. This is closely related to one of its main functions which is the catalysis of ... cell division, cellular morphogenesis and force production in eukaryotic cells. There is a constant modulation of the balance ... Cell. 157 (6, p1405-1415, 5 June 2014): 1405-1415. doi:10.1016/j.cell.2014.03.061. PMC 4726456. PMID 24906155. Friedmann, DR; ... Cell. 136 (3): 551-564. doi:10.1016/j.cell.2008.11.043. PMID 19185337. Kalebic, Nereo; Sorrentino, Simona; Perlas, Emerald; ...
1), and contain twice as many clathrin-coated pits per membrane unit, compared with two other major liver cells, Kupffer cells ... The name scavenger endothelial cells (SECs) has been coined to denote the endothelial cells in vertebrates that are geared to ... these specialized endothelial cells are located either in the heart endocardium or in endothelial cells of the kidney ... endothelial and Kupffer cells". Cell and Tissue Research. 304 (2): 221-30. doi:10.1007/s004410100348. PMID 11396716. Sørensen, ...
"The first five seconds in the life of a clathrin-coated pit". Cell. 150 (3): 495-507. doi:10.1016/j.cell.2012.05.047. PMC ... An almost universal feature of coat assembly is the recruitment of the various adaptor complexes to the "donor" membrane by the ... Another almost universal feature of coat assembly is that the adaptors are recruited first, and they then recruit the coats. ... Part 2: Lipid rafts as a membrane organizing principle Part 3: Biogenesis of glycolipid-rich apical membranes. ...
Moya M, Dautry-Varsat A, Goud B, Louvard D, Boquet P (August 1985). "Inhibition of coated pit formation in Hep2 cells blocks ... The profuse binding of ricin to surface membranes allows internalization with all types of membrane invaginations. The ... Nichols BJ, Lippincott-Schwartz J (October 2001). "Endocytosis without clathrin coats". Trends Cell Biol. 11 (10): 406-12. doi: ... RTB has been shown to bind to the cell surface on the order of 106-108 ricin molecules per cell surface. ...
Peripheral membrane protein/Lipid-anchored protein. Other. *Caveolae/Coated pits. *Cell junctions ... plasmatic membrane (Pfeffer, 1900),[13] plasma membrane, cytoplasmic membrane, cell envelope and cell membrane.[14][15] Some ... Intracellular membranes. The content of the cell, inside the cell membrane, is composed of numerous membrane-bound organelles, ... The basic function of the cell membrane is to protect the cell from its surroundings. The cell membrane controls the movement ...
Peripheral membrane protein/Lipid-anchored protein. Other. *Caveolae/Coated pits. *Cell junctions ... plasmatic membrane (Pfeffer, 1900),[15] plasma membrane, cytoplasmic membrane, cell envelope and cell membrane.[16][17] Some ... Intracellular membranes. The content of the cell, inside the cell membrane, is composed of numerous membrane-bound organelles, ... It was also inferred that cell membranes were not vital components to all cells. Many refuted the existence of a cell membrane ...
... the ligand-receptor complex accumulates in the coated pits. In many cells these pits and complexes begin to concentrate in one ... The aggregation of fluorescently tagged antibodies that are associated with proteins on membranes of living cells. The ... Immunofluorescence Patching and Capping: Plasma Membrane Protein Redistribution Patching and Capping: Plasma Membrane Protein ... the patches coalesce to form a cap at one pole of the cell (capping). Not all cells form caps, but most do form patches. The ...
... allowing the clathrin pit to excise itself from the cell membrane and become a cytoplasmic vesicle.[63] Once the clathrin coat ... consisting of a clathrin-coated pit underneath a section of AMPAR-containing plasma membrane and interacting proteins, is the ... The Ca2+ that enters the cell triggers the upregulation of AMPARs to the membrane, which results in a long-lasting increase in ... "Cell. 135 (3): 535-48. doi:10.1016/j.cell.2008.09.057. PMC 2585749 . PMID 18984164.. ...
LDL receptors are inserted into the plasma membrane and diffuse freely until they associate with clathrin-coated pits. When LDL ... the clathrin-coated pits are endocytosed into the cell. Vesicles containing LDL receptors bound to LDL are delivered to the ... LDL receptors are typically returned to the plasma membrane, where they repeat this cycle. If LDL receptors bind to PCSK9, ... Lipoproteins transfer lipids (fats) around the body in the extracellular fluid, making fats available to body cells for ...
... "coated pit," where such units are concentrated and then stabilized by a framework of clathrins. A pinched-off coated pit is ... For a cell to respond to FSH, only a small percentage (~1%) of receptor sites need to be activated.[citation needed] Cyclic AMP ... Upregulation refers to the increase in the number of receptor sites on the membrane. Estrogen upregulates FSH receptor sites. ... DNA in the cell nucleus binds to phosphorylated proteins through the cyclic AMP response element (CRE), which results in the ...
The NPxY motif functions in signal transduction and the targeting of receptors to coated pits and consists of the sequence ... in the non-lipid raft sections of cell membranes. Unlike LDLR, VLDLR does not exhibit any feedback mechanism, and hence ... In general, lipoprotein receptors undergo a process by which they are endocytosed with their ligand into clathrin-coated pits. ... Endocytosis is mediated through NPxY sequences known to signal for receptor internalization through clathrin-coated pits. The ...
... allowing the clathrin pit to excise itself from the cell membrane and become a cytoplasmic vesicle. Once the clathrin coat ... The complex, consisting of a clathrin-coated pit underneath a section of AMPAR-containing plasma membrane and interacting ... The Ca2+ that enters the cell triggers the upregulation of AMPARs to the membrane, which results in a long-lasting increase in ... Intracellular AMPARs are subsequently sorted for degradation by lysosomes or recycling to the cell membrane. For the latter, ...
The cleaved glycoproteins are incorporated into the virion envelope when the virus buds and release from the cell membrane.[23] ... Unlike most enveloped viruses which use clathrin coated pits for cellular entry and bind to their receptors in a pH dependent ... The main targets of the virus are antigen-presenting cells, mainly dendritic cells) and endothelial cells.[25][26][27] In 2012 ... The Lassa virus gains entry into the host cell by means of the cell-surface receptor the alpha-dystroglycan (alpha-DG),[18] a ...
Endocytosis is initiated via low pH levels and coated pits that are made up of clathrin. The virus is then able to fuse with ... Virus entry into the host cell occurs when viral G glycoproteins attach to host cell surface receptors, initiating endocytosis ... Once the virus fuses to the hosts membrane, replication occurs. The five proteins in SCV are transcribed from their (-)RNA by ... RNA viruses, such as SCV, are not able to be translated by the host because cells do not have the machinery to copy it, ...
"The first five seconds in the life of a clathrin-coated pit". Cell. 150 (3): 495-507. doi:10.1016/j.cell.2012.05.047. PMC ... is thought to help curve the membrane as the clathrin coated pit forms. The muniscins are early arriving proteins involved in ... "Intersectin 1 forms complexes with SGIP1 and Reps1 in clathrin-coated pits". Biochemical and Biophysical Research ... Robinson MS (2015). "Forty Years of Clathrin-coated Vesicles". Traffic. 16 (12): 1210-38. doi:10.1111/tra.12335. PMID 26403691 ...
The receptor proteins that are attached to the specific solutes go inside coated pits, forming a vesicle. The vesicles then ... The cell releases secretory proteins known as exocytosis. Ions travel across cell membranes through channels, pumps or ... There are different ways through which cells can transport substances across the cell membrane. The two main pathways are ... Animal cells, plant cells and microorganism cells show similarities in their functions even though they vary in structure.[page ...
269, 3928-3933 Apical and basolateral coated pits of MDCK cells differ in their rates of maturation into coated vesicles, but ... J. Cell Biol. 142, 51-57. Tyrosine-based Membrane Protein Sorting Signals Are Differentially Interpreted by Polarized Madin- ... Cell. Neurosci. 17, 855-871 Measles virus spreads in rat hippocampal neurons by cell-to-cell contact and in a polarized fashion ... Hussein Naim is a Lebanese-Swiss biochemist and molecular virologist, known for his research in cell biology (membrane protein ...
... whereas STORM has allowed imaging of faster processes such as membrane diffusion of clathrin coated pits or mitochondrial ... "Dynamic clustered distribution of hemagglutinin resolved at 40 nm in living cell membranes discriminates between raft theories ... Cell. 143 (7): 1047-58. doi:10.1016/j.cell.2010.12.002. PMC 3272504. PMID 21168201. Shtengel, Gleb and Galbraith, James A. and ... A number of works have been published as early as 2007 performing PALM/STORM on live cells. The ability to perform live super- ...
"Nef-mediated clathrin-coated pit formation". The Journal of Cell Biology. 139 (1): 37-47. doi:10.1083/jcb.139.1.37. PMC 2139808 ... transports mannose-6-phosphate receptor to plasma membrane through direct interaction with AP-1 complex". Cell. 103 (4): 569-81 ... "A dileucine motif in HIV-1 Nef is essential for sorting into clathrin-coated pits and for downregulation of CD4". Current ... "A novel clathrin adaptor complex mediates basolateral targeting in polarized epithelial cells". Cell. 99 (2): 189-98. doi: ...
Gloves, masks, laboratory coats, and goggles are advised while in contact with an infected person, to avoid contact with blood ... The "Swollen baby syndrome" occurs in newborns, infants and toddlers with pitting edema, abdominal distension and hemorrhage.[6 ... It is possible to acquire the infection through broken skin or mucous membranes that are directly exposed to infectious ... Other laboratory findings in Lassa fever include lymphocytopenia (low white blood cell count), thrombocytopenia (low platelets ...
Low-density lipoproteins are taken into the cell by LDL receptor-mediated endocytosis in clathrin-coated pits, and then ... Cholesterol is required to build and maintain cell membranes; it regulates membrane fluidity over a wide range of temperatures ... It plays a central role in many biochemical processes, such as the building of cell membranes and the synthesis of steroid ... By serving as ligands for specific receptors on cell membranes, the apolipoproteins that reside on the surface of a given ...
... -coated vesicles (CCV) selectively sort cargo at the cell membrane, trans-Golgi network, and endosomal compartments for ... Role of the Clathrin Terminal Domain in Regulating Coated Pit Dynamics Revealed by Small Molecule Inhibition,Cell, Volume 146, ... In non-dividing cells, the formation of clathrin-coated vesicles occurs continuously. Formation of clathrin-coated vesicles is ... and can help deform the membrane, and thus clathrin-coated vesicles can bud. In a cell, a triskelion floating in the cytoplasm ...
... which is either secreted by surface cells or more usually by underlying glands. The mucous membrane in the mouth continues as ... This is how gallstones form when a small piece of calcium gets coated with either cholesterol or bilirubin and the bile ... These include the various cells of the gastric glands, taste cells, pancreatic duct cells, enterocytes and microfold cells. ... Underlying the mucous membrane in the mouth is a thin layer of smooth muscle tissue and the loose connection to the membrane ...
clathrin-coated pit. • secretory granule lumen. • endosome membrane. • extracellular exosome. • extracellular space. • clathrin ... basal part of cell. • endocytic vesicle. • extracellular region. • cell surface. • basal plasma membrane. • extrinsic component ... membrane organization. • ferrous iron import across plasma membrane. • post-translational protein modification. • cellular ... coated vesicle membrane. • cytoplasmic vesicle. • endoplasmic reticulum lumen. Biological process. • positive regulation of ...
Detergents are key reagents to extract protein by lysis of the cells and tissues: They disorganize the membrane's lipid bilayer ... The compounds that coat a micelle are typically amphiphilic in nature, meaning that micelles may be stable either as droplets ... The polar "heads" of the surfactant molecules coating the micelle interact more strongly with water, so they form a hydrophilic ... surfactants can irritate and damage the skin because surfactants disrupt the lipid membrane that protects skin and other cells ...
... penetrate the host xylem through pits in the membrane.[16] The oscula then swell to secure their position within the xylem ... Shortly after the host xylem is penetrated, Striga sieve tubes develop and approach the host phloem within eight cells.[17][18] ... An example is TAN222, the "striga-resistant" maize variety which is coated with the systemic herbicide imazapyr, to which it is ... Within 12 hours of initial haustorium growth, the haustorium recognizes the host root and begins rapid cell division and ...
Most animal epithelial cells have a fuzz-like coating on the external surface of their plasma membranes. This coating consists ... and other cells. In 1970, Martinez and Palomo discovered the cell coat in animal cells, which is known as the glycocalyx. ... Peripheral membrane protein/Lipid-anchored protein. Other. *Caveolae/Coated pits. *Cell junctions ... diseased cells, or invading organisms. Included in the glycocalyx are cell-adhesion molecules that enable cells to adhere to ...
membrane. • clathrin-coated pit. • filamentous actin. • plasma membrane. • nuclear membrane. • cytoplasm. • cell cortex. • ... clathrin-coated endocytic vesicle. • protein complex. • apical part of cell. • clathrin-coated vesicle membrane. • ruffle. • ... cell nucleus. • intracellular membrane-bounded organelle. • cell projection. • ruffle membrane. • DNA-directed RNA polymerase ... "The Journal of Cell Biology. 143 (6): 1535-45. doi:10.1083/jcb.143.6.1535. PMC 2132970. PMID 9852149.. ...
A cell membrane can be thought of as a capacitor in that positive and negative ions are stored on both sides of the membrane. ... 2010). "Intersectin 1 forms complexes with SGIP1 and Reps1 in clathrin-coated pits". Biochemical and Biophysical Research ... the membrane this induces a mechanical force on the membrane so that it causes the vesicle membrane and presynaptic membrane to ... 5) In the periactive zone the membrane proteins are sequestered and are endocytosed forming a clathrin coated vesicle. (6) The ...
Irritation of mucous membranes[edit]. Hydrogen peroxide is an irritant and cytotoxic. Hydrogen peroxide with concentrations of ... Hemolytic disease of the newborn:[9] This disease occurs when a newborn's red blood cells are being attacked by antibodies from ... Bonding, which also masks tooth stains, is when a thin coating of composite material is applied to the front of a person's ... It produces a yellow-brown discolouration and can also cause the enamel's smooth surface to be rough and pitted which causes ...
membrane. • clathrin coat. • Cellbilen. • trans-Golgi network. • endolysosome membrane. • membrane coat. • clathrin-coated pit ... "A large-scale conformational change couples membrane recruitment to cargo binding in the AP2 clathrin adaptor complex.". Cell. ... endocytic vesicle membrane. • cytosol. • clathrin-coated endocytic vesicle membrane. • ... Wnt signaling pathway, planar cell polarity pathway. • membrane organization. • neurotransmitter receptor internalization. • ...
The male gamete cell, sperm, is usually motile whereas the female gamete cell, the ovum, is generally larger and sessile. The ... In Greater Ani Crotophaga major this vaterite coating is thought to act as a shock absorber, protecting the calcite shell from ... Diagram of a fish egg: A. vitelline membrane B. chorion C. yolk D. oil globule E. perivitelline space F. embryo ... cassowary eggs are heavily pitted. Tiny pores in bird eggshells allow the embryo to breathe. The domestic hen's egg has around ...
Electron microscopy experiments show IFNAR receptors concentrated in clathrin-coated pits, and inhibition of clathrin-mediated ... doi:10.1016/j.cell.2015.12.027. PMC 4733246. PMID 26824652.. *^ a b c d e Owens T, Khorooshi R, Wlodarczyk A, Asgari N (March ... thereby reducing membrane expression,[15] or it can result in recycling of the receptor without an extended impact on membrane ... Additionally, IFNs largely impact cell health and viability, with effects on apoptosis, autophagy, cell differentiation, and ...
Peripheral membrane protein/Lipid-anchored protein. Other. *Caveolae/Coated pits. *Cell junctions ... This membrane stretches and spirally wraps itself over and over as the in-folding of the Schwann cell surface continues. As a ... An action potential is a spike of both positive and negative ionic discharge that travels along the membrane of a cell.[9] The ... This process is sequenced by the in-folding of the Schwann cell surface so that a double membrane of the opposing faces of the ...
"The Plant Cell. 12 (7): 1031-1040. doi:10.1105/tpc.12.7.1031. ISSN 1040-4651. PMC 149047. PMID 10899972.. ... The pericarp of the fruit is fused with the seed coat referred to as "caryopsis", typical of the grasses, and the entire kernel ... They feature a large hopper that feeds the uniformly sized maize kernels (or wood pellets or cherry pits) into the fire. ... swelling or itching of mucous membranes, diarrhea, vomiting, asthma and, in severe cases, anaphylaxis. It is unclear how common ...
Once the pit has been pinched off the plasma membrane due to the actions of two other proteins called amphiphysin and dynamin, ... Translocation: The receptor is, along with the part of the membrane it is embedded in, brought to the inside of the cell, where ... of beta-arrestin with the AP-2 adaptor is required for the clustering of beta 2-adrenergic receptor into clathrin-coated pits ... Used in the endocrine system for peptide and amino-acid derivative hormones that bind to GCPRs on the cell membrane of a target ...
Although some mucins are membrane-bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in ... "American Journal of Respiratory Cell and Molecular Biology. 36 (2): 183-90. doi:10.1165/rcmb.2006-0291TR. PMC 2176109. PMID ... The dense "sugar coating" of mucins gives them considerable water-holding capacity and also makes them resistant to proteolysis ... Abnormal deposits of mucin are responsible for the non-pitting facial edema seen in untreated hypothyroidism. This edema is ...
Each typically has a cell membrane formed of phospholipids, cytoplasm and a nucleus. All of the different cells of an animal ... In simple animals this may just be a coat of glycoproteins.[13] In more advanced animals, many glands are formed of epithelial ... Their forked tongues are used as organs of taste and smell and some species have sensory pits on their heads enabling them to ... The outer epithelial layer may include cells of several types including sensory cells, gland cells and stinging cells. There ...
Anker SD, Ponikowski P, Varney S, Chua TP, Clark AL, Webb-Peploe KM, Harrington D, Kox WJ, Poole-Wilson PA, Coats AJ (1997). " ... Hemodialysis with high-flux polyacrylonitrile membranes. ACE inhibitors are ADEC pregnancy category D, and should be avoided in ... Cell Mol Biol (Noisy le Grande). 47 (6): 1063-7. PMID 11785658.. [verification needed] ... a South American pit viper, in 1965.[64] Ferreira then went to John Vane's laboratory as a postdoctoral fellow with his already ...
Cell. 1978 Nov;15(3):919-33. [11] Coated pits, coated vesicles, and receptor-mediated endocytosis. Nature. 1979 Jun 21;279(5715 ... Cell. 1994 Apr 8;77(1):53-62 [49] Sterol-regulated release of SREBP-2 from cell membranes requires two sequential cleavages, ... Cell. 1977 Nov;12(3):629-41. [9] A mutation that impairs the ability of lipoprotein receptors to localise in coated pits on the ... Cell. 1983 Mar;32(3):941-51. [19] Depletion of intracellular potassium arrests coated pit formation and receptor-mediated ...
Suzuki, E. (2002). "High-resolution scanning electron microscopy of immunogold-labelled cells by the use of thin plasma coating ... "Peeking into Pit Fields: A Multiple Twinning Model of Secondary Plasmodesmata Formation in Tobacco". Plant Cell. 20 (6): 1504- ... Freeze-fracturing, freeze-etch or freeze-and-break is a preparation method particularly useful for examining lipid membranes ... Epidermal cells from the inner surface of an onion flake. Beneath the shagreen-like cell walls one can see nuclei and small ...
... itself upon fusing with a single sperm cell and thereby changes its cell membrane to prevent fusion with other sperm. Zinc ... These contents digest the jelly coat and eventually the vitelline membrane. In addition to the release of acrosomal vesicles, ... contained in the central cell) in the centre of the gametophyte. The resulting cell is triploid (3n). This triploid cell ... "Cell. 184 (11): 2860-2877.e22. doi:10.1016/j.cell.2021.04.013. PMC 8162515. PMID 33964210.. ...
Peripheral membrane protein/Lipid-anchored protein. Other. *Caveolae/Coated pits. *Cell junctions ... A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many ... Alpha-helical proteins are present in the inner membranes of bacterial cells or the plasma membrane of eukaryotes, and ... Membrane Proteins of known 3D Structure *^ Elofsson, A.; Heijne, G. V. (2007). "Membrane Protein Structure: Prediction versus ...
... of β-arrestin with the AP-2 adaptor is required for the clustering of β2-adrenergic receptor into clathrin-coated pits". J. ... Cell. Biol. 9, 639-50. *Lefkowitz, R.J. & Whalen, E.J. (2004). Beta-arrestins: traffic cops of cell signaling. Curr. Opin. Cell ... Lizozomne membrane su bogate u protonskim pumpama te njihova unutrašnjost ima nizak pH (≈4.8 vs. pH≈7.2 citozola), što uzrokuje ... 33,0 33,1 Tan CM, Brady AE, Nickols HH, Wang Q, Limbird LE (2004). "Membrane trafficking of G protein-coupled receptors". Annu ...
Peripheral membrane protein/Lipid-anchored protein. Other. *Caveolae/Coated pits. *Cell junctions ... Protein: cell membrane proteins (other than Cell surface receptor, enzymes, and cytoskeleton) ... by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS ... In the CNS, cells called oligodendrocyte precursor cells (OPCs; the precursors of oligodendrocytes) differentiate into mature ...
Within these were cells of six stages. The cells could be operated independently, or consecutively within a section. Similarly ... To prevent predetonation by an external neutron, the tamper was coated in a thin layer of boron.[201] A polonium-beryllium ... The idea was that such boxes could be formed into a cascade of pumps and membranes, with each successive stage containing a ... The hemispheres for the first plutonium pit (or core) were produced and delivered on 2 July 1945. Three more hemispheres ...
Coated pits, cell-membrane Specialised regions of the cell membrane composed of pits coated with a bristle covering made of the ... These pits are the entry route for macromolecules bound by cell surface receptors. The pits are then internalised into the ... Retrieved from "" ...
The coated vesicle fuses with cytoplasmic endosomes (membrane-enclosed vesicles) and then with cell organelles called lysosomes ... of the membrane called a coated pit, which is lined by a special protein known as clathrin. As the coated pit invaginates, it ... is pinched off in the cytoplasm to form a coated vesicle. ... of the membrane called a coated pit, which is lined by a ... As the coated pit invaginates, it is pinched off in the cytoplasm to form a coated vesicle. The coated vesicle fuses with ...
Clathrin was not endocytosed with the insulin receptor and the inhibitor of clathrin-coated pit-mediated endocytosis, ... Cell membranes Is the Subject Area "Cell membranes" applicable to this article? Yes. No. ... Coated pits Is the Subject Area "Coated pits" applicable to this article? Yes. No. ...
Cell membrane {ECO:0000250}. Membrane, CC coated pit {ECO:0000250}; Peripheral membrane protein CC {ECO:0000250}; Cytoplasmic ... KW Cell membrane; Coated pit; Complete proteome; Endocytosis; Membrane; KW Protein transport; Reference proteome; Transport. FT ... DR GO; GO:0051285; C:cell cortex of cell tip; IDA:PomBase. DR GO; GO:0032153; C:cell division site; IDA:PomBase. DR GO; GO: ... the coat surrounding the cytoplasmic face of coated vesicles in CC the plasma membrane. {ECO:0000250}. CC -!- SIMILARITY: ...
... confocal microscopy to study the formation of clathrin-coated structures at the plasma membranes of BSC1 and HeLa cells ... Conclusions/Significance These results suggest that AP-2 is essential for endocytic clathrin coated-pit and coated-vesicle ... These observations suggest that AP-2 is essential for endocytic coated-pit and coated-vesicle formation. We also find that AP-2 ... They also indicate that under normal conditions, functional endocytic clathrin coated pits are required for LDL internalization ...
Coated Pits, Cell-membrane. Specialized regions of the cell membrane composed of pits coated with a bristle covering made of ... These pits are the entry route for macromolecules bound by cell surface receptors. The pits are then internalized into the ... The cellulose acetate based membranes with polyvinylpyrrolidone coated silver nanoparticles,.... Influence of salinity on the ... ERASE Silver Coated Foley Catheter, Comparator Silver Coated Catheter. Location. Oconnee Regional Medical Center. ...
Functions as a cell surface receptor and performs physiological functions on the surface of neurons relevant to neurite growth ... Plasma Membrane. *clathrin-coated pit Source: UniProtKB-SubCell. *. Other locations. *cell surface Source: UniProtKB-SubCell ... Plasma membrane. *Cell membrane UniRule annotation. Automatic assertion according to rulesi ... Membrane. ,p>This section describes post-translational modifications (PTMs) and/or processing events.,p>,a href=/help/ptm_ ...
We report super-resolution fluorescence imaging of live cells with high spatiotemporal resolution using stochastic optical ... Coated Pits, Cell-Membrane / metabolism * Endocytosis * Fluorescent Dyes * Image Processing, Computer-Assisted / methods ... and 3D super-resolution images of living cells, using clathrin-coated pits and the transferrin cargo as model systems. Bright, ... Fast, three-dimensional super-resolution imaging of live cells Nat Methods. 2011 Jun;8(6):499-508. doi: 10.1038/nmeth.1605. ...
receptor mediated* endocytosis... uptake @ membrane sites w receptors. - coated pits with protein clathrin Sumanas, Inc. ... How Things Get In/Out of Cells The Cell Membrane.... 1. Unit Membrane Hypothesis - all membranes look alike*. ... cell wall Fluid Mosaic model* & Extra-cellular Matrix*-common to animal cells. Functions of Membrane Proteins*. Concept ... Membrane Transport Concept Activity - chapter 7.2 - Selective Permeability of Membranes,. Concept Activity - chapter 7.3 - ...
Cell membrane. Membrane , coated pit. AP-2 appears to be excluded from internalizing CCVs and to disengage from sites of ... Lane 1 : HEK293 cell lysate. Lane 2 : SKBR-3 cell lysate. Lane 3 : MCF-7 cell lysate. Lysates/proteins at 20 µg per lane.. ... Lane 1 : MCF-7 cell lysate. Lane 2 : SKBR-3 cell lysate. Lysates/proteins at 10 µg per lane.. Secondary. All lanes : HRP ... in membrane-associated AP-2. The membrane-specific phosphorylation event appears to involve assembled clathrin which activates ...
PE 1: Evidence at protein level; KW Calcium; Cell membrane; Cell projection; Coated pit; KW Complete proteome; Disulfide bond; ... Membrane, coated pit CC {ECO:0000269,PubMed:22340494}. Cell projection, dendrite CC {ECO:0000269,PubMed:20637285}. Cell ... DR GO; GO:0009986; C:cell surface; ISO:MGI. DR GO; GO:0005905; C:clathrin-coated pit; IDA:MGI. DR GO; GO:0005737; C:cytoplasm; ... DR GO; GO:0045177; C:apical part of cell; IDA:MGI. DR GO; GO:0016324; C:apical plasma membrane; IDA:UniProtKB. DR GO; GO: ...
Cell membrane. Membrane , coated pit. AP-2 appears to be excluded from internalizing CCVs and to disengage from sites of ... Lane 1 : 293T cell lysate Lane 2 : 293T cell lysate treated with Calyculin A. Lysates/proteins at 10 µg per lane.. Predicted ... in membrane-associated AP-2. The membrane-specific phosphorylation event appears to involve assembled clathrin which activates ... Cell Biology. Epigenetics. Metabolism. Developmental Biology. By research area. Immunology. Microbiology. Neuroscience. Signal ...
Cell membrane. Membrane, coated pit; Peripheral membrane protein; Cytoplasmic side. Note=AP-2 appears to be excluded from ... Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence ... The complex is part of the protein coat on the cytoplasmic face of coated vesicles which links clathrin to receptors in ... Nef-mediates down modulation of cell surface receptors by recruiting them to clathrin adapters. Nef-mediates down modulation of ...
Cell membrane. Membrane, coated pit; Peripheral membrane protein; Cytoplasmic side. Note=AP-2 appears to be excluded from ... Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence ... Phosphorylation at Tyr-737 by SRC occurs at the plasma membrane in clathrin-coated vesicles (CCVs). *P63010-AP2B1_HUMAN ... The encoded protein is found on the cytoplasmic face of coated vesicles in the plasma membrane. Two transcript variants ...
Budding of the plasma membrane then occurs, forming a clathrin coated pit.[1] Other receptors can nucleate a clathrin-coated ... The cargo ligand and receptor will then recruit adaptor proteins and clathrin triskelions to the outside membrane of the cell ... A mature pit will be cleaved from the plasma membrane through the use of membrane binding and fission proteins such as dynamin ... "Cell. 166 (4): 907-919. doi:10.1016/j.cell.2016.07.004. PMC 5418658. PMID 27499021.. ...
Cell membrane. Single-pass type I membrane protein. Membrane, clathrin-coated pit. Golgi apparatus. Early endosome. Late ... Low density lipoprotein (LDL) is normally bound at the cell membrane and taken into the cell ending up in lysosomes where the ... Low density lipoprotein (LDL) is normally bound at the cell membrane and taken into the cell ending up in lysosomes where the ... Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence ...
May play a role in transporting DAB2 from the plasma membrane to specific cellular targets (By similarity). May play a role in ... Appears to be involved in a very early step of clathrin-mediated endocytosis in polarized epithelial cells (By similarity). May ... Functions in a variety of intracellular processes such as vesicular membrane trafficking and cell migration (By similarity). ... Cell membrane, Cell projection, Coated pit, Cytoplasm, Cytoplasmic vesicle, Golgi apparatus, Membrane, Nucleus ...
It occurs on the membrane via clathrin-coated pits (CCPs). In this thesis, we studied CCPs behavior when cells are under ... Seeding cells on anisotropic fibronectin patterns, we were able to manipulate where and how long CCPs appear on the cell. ... is one of the major pathway through which cells internalize nutrients and membrane proteins. ... Together, these results showed that CCPs distribution and behavior are regulated by mechanical cues in a cell. In the last ...
The cells were also co-transfected with β2-YFP to mark coated pits. Fig. 6 demonstrates that, after incubation of cells ... Spatial control of coated-pit dynamics in living cells. Nat. Cell Biol. 1, 1-7. ... called clathrin-coated pits. Ligand-receptor complexes destined for internalization are selectively recruited into coated pits ... In our experiments, EGF and transferrin receptors were efficiently recruited into coated pits in cells overexpressing Rab5(S34N ...
clathrin coat of coated pit Human retinal pigmented epithelial (RPE) cells labeled for clathrin-coated pits (green), focal ... negative regulation of cell adhesion involved in substrate-bound cell migration Cellular Component. cell-substrate adherens ... cell communication Cellular Component. gap junction Replica of a freeze-fractured gap junction presents the inner half-membrane ... cell cortex The cortex of Paramecium consists of a plasma membrane and alveolar sacs, with their inner and outer alveolar ...
Phosphoinositide-AP-2 interactions required for targeting to plasma membrane clathrin-coated pits. J. Cell Biol. 146:755-764. ... Clathrin-coated pits contain an integral membrane protein that binds the AP-2 subunit with high affinity. J. Biol. Chem. 265: ... Clathrin-coated vesicles in nervous tissue are involved primarily in synaptic vesicle recycling. J. Cell Biol. 118:1379-1388. ... The classical whole-cell configuration was obtained by rupturing the patch membrane of a gigaohm seal formed between the ...
2005) N-WASP deficiency impairs EGF internalization and actin assembly at clathrin-coated pits. J Cell Sci 118:3103-3115. ... 1999) Inhibition of clathrin-coated pit assembly by an Eps15 mutant. J Cell Sci 112:1303-1311. ... Cell culture and examinations of the actin cytoskeleton in HeLa cells.. Culturing of COS-7 and HeLa cells and evaluations of F- ... 2007) The WASP-WAVE protein network: connecting the membrane to the cytoskeleton. Nat Rev Mol Cell Biol 8:37-48. ...
2002). Curvature of clathrin-coated pits driven by epsin. Nature 419, 361-366. doi:10.1038/nature01020. ... 1996). Modulation of membrane dynamics and cell motility by membrane tension. Trends Cell Biol. 6, 85-89. doi:10.1016/0962-8924 ... Live-cell imaging. Live cell imaging of COS7 cells, HEK293 cells, and neuronal cultures were imaged using Leica TCS confocal ... A) Whole-cell image of a cortical neuron coexpressing F-BAR(1)-EGFP and LifeAct-mRFPruby. (B-I) F-BAR(1)-coated membrane shows ...
HeLa cells expressing LCb-RFP and Dyn-2-EGFP were imaged by spinning disk microscopy. The fluorescenc ... Clathrin-Coated Vesicles/metabolism*/ultrastructure. *Coated Pits, Cell-Membrane/metabolism*/ultrastructure. *Dynamins/ ... Flat clathrin lattices: stable features of the plasma membrane. Grove J, Metcalf DJ, Knight AE, Wavre-Shapton ST, Sun T, ... HeLa cells expressing LCb-RFP and Dyn-2-EGFP were imaged by spinning disk microscopy. The fluorescence signals associated with ...
... and other molecules involved in communication between cells. ... and membrane scission observed in live cells. Cell 121: 593-606 ... Coupling between clathrin-coated-pit invagination, cortactin recruitment, ... The Nanomechanics of Endocytosis and Exocytosis in Live Cells. Jahn, R., T. Lang & T. C. Sudhof. 2003. Membrane fusion. Cell ... Exocytosis of single chromaffin granules in cell-free inside-out membrane patches. Nat. Cell Biol. 5: 358-362.. Dernick, G., L ...
Membrane, coated pit {ECO:0000250,UniProtKB:P17427}; Peripheral membrane protein {ECO:0000250,UniProtKB:P17427}; Cytoplasmic ... CHO Cells. Purified From HEK 293 Cell culture Supernatant.. Goat. chicken. Sheep. Swine. Donkey. Guinea Pig. Horse. Hamster. ... Cell membrane {ECO:0000250,UniProtKB:P17427}; Peripheral membrane protein {ECO:0000250,UniProtKB:P17427}; Cytoplasmic side {ECO ... All lanes : Anti-AP2A2 Antibody (Center) at 1:1000 dilution Lane 1: A431 whole cell lysate Lane 2: HepG2 whole cell lysate ...
b) Binding of WNV particle at the plasma membrane of Vero cells. (c) Uptake of WNV particle (arrow) by coated pit (arrowheads ... Inhibition of clathrin-coated pit assembly by an Eps15 mutant. J. Cell Sci.112(Pt. 9):1303-1311. ... the inhibition of clathrin-coated pits formation at the plasma membrane did not affect the binding of WNV particles to the cell ... The formation of clathrin-coated pits at the plasma membrane during the process of receptor-mediated endocytosis requires the ...
Phosphoinositide-AP-2 interactions required for targeting to plasma membrane clathrin-coated pits. J. Cell Biol. 146:755-764. ... to the membranes at which clathrin-coated pits nucleate. A GTPγS-stimulated recruitment of clathrin/AP-2 coats to endosomes was ... Recruitment of coat proteins onto Golgi membranes in intact and permeabilized cells: effects of brefeldin A and G protein ... Consistent with its effects on clathrin/AP-2-coated pit formation and with previous observations (Malecz et al., 2000), cells ...
Clathrin-mediated endocytosis shuts down during mitosis in eukaryotic cells because all of the required actin is hoarded by the ... From prophase to anaphase, shallow clathrin-coated pits form at the plasma membrane, but the cell never internalizes them. ... The second theory suggested that elevated tension in the plasma membrane prevents clathrin-coated pits from pinching off into ... is sequestered at the cell cortex, and CME cant proceed because actin is required to help stretch the clathrin-coated pits to ...
Effect of membrane tension on the number of dynamin molecules recruited to coated pits at the time of membrane fission. The ... Five cells were used per condition. (A) Histogram of the total number of dynamin molecules recruited to coated pits of cells ... Bottom Line: The first is associated with coated pit maturation; the second, with fission of the membrane neck of a coated pit. ... Bottom Line: The first is associated with coated pit maturation; the second, with fission of the membrane neck of a coated pit. ...
  • The pits are then internalised into the cytoplasm to form the coated vesicles . (
  • FUNCTION: Adaptins are components of the adaptor complexes which CC link clathrin to receptors in coated vesicles. (
  • Note=Component of CC the coat surrounding the cytoplasmic face of coated vesicles in CC the plasma membrane. (
  • into membrane vesicles. (
  • Adaptor protein complexes function in protein transport via transport vesicles in different membrane traffic pathways. (
  • AP-2 is involved in clathrin-dependent endocytosis in which cargo proteins are incorporated into vesicles surrrounded by clathrin (clathrin-coated vesicles, CCVs) which are destined for fusion with the early endosome. (
  • This gene encodes the alpha 1 adaptin subunit of the adaptor protein 2 (AP-2) complex found in clathrin coated vesicles. (
  • The complex is part of the protein coat on the cytoplasmic face of coated vesicles which links clathrin to receptors in vesicles. (
  • The protein encoded by this gene is one of two large chain components of the assembly protein complex 2, which serves to link clathrin to receptors in coated vesicles. (
  • The encoded protein is found on the cytoplasmic face of coated vesicles in the plasma membrane. (
  • This process forms vesicles containing the absorbed substances and is strictly mediated by receptors on the surface of the cell. (
  • Endocytic vesicles release their clathrin coat and fuse with early endosomes. (
  • Arrows indicate multiple sites where invaginaton along the membrane suggests vesicles formi. (
  • NMDA receptors (NMDARs) can exit the Golgi/TGN via clathrin-coated vesicles. (
  • After synaptic vesicle fusion, vesicle proteins are retrieved from the plasma membrane and recycled into new synaptic vesicles to sustain neuronal transmission. (
  • In electron micrographs of the frog neuromuscular junction, invaginating vesicles at presynaptic terminals are enveloped by a coat ( Heuser and Reese, 1973 ). (
  • The acidification of endocytic vesicles trigger a conformational change in the viral envelope protein and subsequent release of viral genome at appropriate location of the cells for replication. (
  • During mitosis, membrane tension is high, the actin (purple) is sequestered at the cell cortex, and CME can't proceed because actin is required to help stretch the clathrin-coated pits to form full vesicles (2). (
  • For decades, scientists observed clathrin-mediated endocytosis (CME)-the process of forming vesicles to pull protein cargo into a cell-ceasing during mitosis in mammalian cells. (
  • The second theory suggested that elevated tension in the plasma membrane prevents clathrin-coated pits from pinching off into closed vesicles. (
  • The results make sense in light of previous studies suggesting that when cell membranes are stretched tight there is a greater need for actin to form clathrin-coated vesicles. (
  • While other researchers were consumed with showing a direct role for actin in the formation of endocytic vesicles, this study shows that if actin is not available, vesicle budding cannot occur," says Linton Traub, a cell biologist at the University of Pittsburgh who was not involved in the study. (
  • The polyhedral protein lattice coats eukaryotic cell membranes (vesicles) and coated pits and appears to be involved in protein secretion and membrane trafficking. (
  • The fibrous protein forms a characteristic polyhedral coat on the surface of coated pits and coated vesicles. (
  • Clathrin-coated vesicles are important vehicles of membrane traffic in cells. (
  • Plant cells expand by exocytosis of wall material contained in Golgi-derived vesicles. (
  • Vesicles formed when cell-membrane coated pits ( Coated pits , Cell-membrane ) invaginate and pinch off. (
  • Eukaryotic cells constantly form and internalize plasma membrane vesicles in a process known as endocytosis. (
  • The AP-2 adaptor complex has been thought of as a key structural and functional component of plasma membrane-derived coated pits and vesicles, and it is found in stoichiometric amounts in isolated clathrin-coated vesicles. (
  • and Conner and Schmid, provide compelling evidence that challenges the assumption that AP-2 adaptors are necessary components of endocytic clathrin-coated vesicles. (
  • 100 nm in diameter) vesicles that have a morphologically characteristic coat made up of the cytosolic protein clathrin. (
  • Clathrin-coated vesicles (CCVs) are found in virtually all cells and form domains of the plasma membrane termed clathrin-coated pits. (
  • Potocytosis is a form of receptor-mediated endocytosis that uses caveolae vesicles to bring molecules of various sizes into the cell. (
  • Early endosomes are often located in the periphery of the cell, and receive most types of vesicles coming from the cell surface. (
  • In exocytosis , materials are exported out of the cell via secretory vesicles. (
  • In this process, the Golgi complex packages macromolecules into transport vesicles that travel to and fuse with the plasma membrane. (
  • In pinocytosis or "cellular drinking," the cell engulfs drops of fluid by pinching in and forming vesicles that are smaller than the phagosomes formed in phagocytosis. (
  • Although these cells can form clathrin-coated pits, they struggle to develop into vesicles. (
  • 1989). The function of endocytosis is the opposite of exocytosis , in which materials packaged in secretory vesicles inside the cell fuse with the plasma membrane and open to the exterior space, releasing the material (Alberts et al. (
  • The material tends to remain sequestered in vesicles and does not mix with other macromolecules or organelles in the cytoplasm , other than specific membranes for which it is destined, causing a directed transfer between the inside and outside of the cell (Alberts et al. (
  • 1989). Typically, the internalized molecules trapped in the intracellular vesicles eventually fuse with the membrane-bound lysosomes and are degraded (Khalil et al. (
  • The membrane folds around the object, and the object is sealed off into large vesicles, called phagosome or vacuoles , generally larger than 250 nm in diameter (Alberts et al. (
  • However, microglia cells showed endocytic vesicles containing only bacterial cell debris. (
  • These AP complexes are essential components of the clathrin-coated vesicles. (
  • One minute after injection ricin is seen in coated pits, coated vesicles and cisternal-shaped endosomes. (
  • Exosomes, 50- to 100-nm vesicles, derived from endosomes forming multivesicular bodies, are abundantly released by tumor cells ( 8 , 12 , 13 ). (
  • Note: Predominantly localizes to endocytic vesicles, and upon stimulation by the ligand is internalized via clathrin-coated pits. (
  • [10] Immunocytochemical visualization of coated pits and vesicles in human fibroblasts: relation to low density lipoprotein receptor distribution. (
  • [11] Coated pits, coated vesicles, and receptor-mediated endocytosis. (
  • [12] LDL receptors in coated vesicles isolated from bovine adrenal cortex: binding sites unmasked by detergent treatment. (
  • Essential components depicted on vesicles are v-SNAREs (type synaptobrevin, Syb) and a Ca2+ -sensor which, however, does not participate in all intracellular membrane interactions and whose identity (e.g., for trichocyst exocytosis) is not known in ciliates. (
  • As the coated pit invaginates, it is pinched off in the cytoplasm to form a coated vesicle. (
  • Adaptor protein complexes are vesicle coat components and appear to be involved in cargo selection and vesicle formation. (
  • AP-2 seems to play a role in the recycling of synaptic vesicle membranes from the presynaptic surface. (
  • A mature pit will be cleaved from the plasma membrane through the use of membrane binding and fission proteins such as dynamin (as well as other BAR domain proteins), [2] forming a clathrin-coated vesicle that then uncoats and typically fuses to a sorting endosome . (
  • Ligand-receptor complexes destined for internalization are selectively recruited into coated pits followed by coat invagination, constriction and scission of the clathrin-coated vesicle containing cargo ( Kirchhausen, 2000 ). (
  • Recycling is thought to be initiated by the recruitment of clathrin to patches of membrane containing synaptic vesicle proteins. (
  • The reformed vesicle with a geodesic coat is budded into the cytoplasm. (
  • Clathrin-mediated endocytosis of synaptic vesicle membranes involves the recruitment of clathrin and AP-2 adaptor complexes to the presynaptic plasma membrane. (
  • Synaptic vesicle (SV) * membranes are formed and recycled by clathrin-mediated endocytosis at the presynaptic plasmalemma. (
  • 26 are enough for coated vesicle release in cells partially depleted of dynamin by RNA interference.We discuss how these results restrict models for the mechanism of dynamin-mediated membrane scission. (
  • 2013). We examined the effect of membrane tension on the number of dynamin molecules that have accumulated at the time of coated vesicle release in SUM-Dyn2 cells expressing mCherry-LCa. (
  • Thus AP-2 is not essential for clathrin-coated vesicle formation at the plasma membrane, and AP-2 can be viewed simply as one adaptor among many involved in the recruitment of different receptors to clathrin-coated pits. (
  • The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. (
  • Pinocytosis, which usually occurs from highly ruffled regions of the plasma membrane, is the invagination of the cell membrane to form a pocket, which then pinches off into the cell to form a vesicle (.5-5 µm in diameter) filled with a large volume of extracellular fluid and molecules within it (equivalent to ~100 CCVs). (
  • This fusion causes the vesicle to spill its contents out of the cell. (
  • Once bound, the coated pit on which the bound receptor protein is located then invaginates , or pinches in, to form a coated vesicle. (
  • Similar to the digestive process in non-specific phagocytosis, this coated vesicle then fuses with a lysosome to digest the engulfed material and release it into the cytosol. (
  • The clathrin-coated pit then pinches off inside the cell in a process called fission to form a bubble-like structure called a vesicle, which transports the molecule to its destination. (
  • Overall, these results suggest that a main role of epsin is to help actin interact with the clathrin-coated pits and generate the force required for a pit to develop into a vesicle. (
  • However, epsin also performs many other roles, including recruiting a membrane protein (a so-called SNARE) that directs the fate of the vesicle to the clathrin-coated pit. (
  • Endocytosis is a process where cells ingest material (macromolecules, low-molecular weight molecules , and particles) from outside the cell by enclosing it with a portion of their cell membrane and bringing it into the cell in a membrane-bound vesicle. (
  • In other words, a small portion of the cell membrane (plasma membrane) invaginates and progressively encloses the extracellular substance, and then pinches off inside the cell to form a membrane-bound, intracellular vesicle with the ingested material (Alberts et al. (
  • The membrane pit forms a vesicle (lower right) around the molecules within the cell cytoplasm (blue). (
  • CCP assembly is accompanied or followed by the progressive invagination of the membrane, eventually leading to the dynamin-dependent scission of a clathrin-coated vesicle (CCV) that delivers its cargo to the endosomal system ( 1 , 2 ). (
  • [7] Role of the coated endocytic vesicle in the uptake of receptor-bound low density lipoprotein in human fibroblasts. (
  • AP-4 is localized to TGN, and mediates vesicle trafficking from TGN to endosomes or basolateral plasma membrane. (
  • Fission of the formed vesicle subsequently allows the physical internalization of the membrane proteins together with their associated ligands and lipids. (
  • in: Protist 161 (2010), 4, pp. 497-516 doi:10.1016/j.protis.2010.05.001 How to Design a Highly Organized Cell: An Unexpectedly High Number of Widely Diversified SNARE Proteins Positioned at Strategic Sites in the Ciliate, Paramecium tetraurelia Introduction There are only scattered data available on molecular aspects of vesicle trafficking in protozoa, notably in ciliates. (
  • The assembly and function of SNAREs during vesicle docking and membrane fusion is outlined in Figure 1. (
  • Details on essential steps and molecular components in vesicle-target membrane interaction. (
  • Paramecium as a Model System - From Past to Present Over a long time, Paramecium cells have served as a model system for several important aspects of vesicle trafficking. (
  • This gene encodes a clathrin assembly protein, which recruits clathrin and adaptor protein complex 2 (AP2) to cell membranes at sites of coated-pit formation and clathrin-vesicle assembly. (
  • Clathrin is recruited to endocytic sites on the plasma membrane by the AP2 adaptor complex. (
  • Agonist activation leads to sustained recruitment of CCR5 to FCLs.Quantitative molecular imaging indicated that FCLs partitioned receptors at the cell surface.Our observations suggest that FCLs provide stable platforms for the recruitment of endocytic cargo. (
  • Semliki Forest virus ( 27 ), vesicular stomatitis virus ( 18 ), influenza virus ( 30 ), ecotropic murine leukemia virus ( 2 , 34 , 44 ), and Hantaan virus ( 28 ) gain entry into cells through a pH-dependent endocytic pathway. (
  • Royle's team is now addressing how the endocytic machinery is able to sense high membrane tension and recruit actin within cells of tissues undergoing physical stretching or in polarized epithelial cells, which have different tensions at their basolateral and apical membranes. (
  • The endocytic pathway of mammalian cells consists of distinct membrane compartments, which internalize molecules from the plasma membrane and recycle them back to the surface (as in early endosomes and recycling endosomes), or sort them to degradation (as in late endosomes and lysosomes). (
  • Blocking endocytic membrane recycling affected the intracellular distribution of DAG but not of PI 4,5-P 2 . (
  • We show that Nt PLC3 is targeted by its EF and C2 domains to the plasma membrane laterally at the pollen tube tip and that it maintains, together with endocytic membrane recycling, an apical domain enriched in PI 4,5-P 2 and DAG required for polar cell growth. (
  • Epsin is an evolutionarily conserved endocytic clathrin adaptor whose most critical function(s) in clathrin coat dynamics remain(s) elusive. (
  • Through understanding the various endocytic uptake pathways, mechanisms can be improved for successful non-viral delivery of therapeutic genes to the particular target cells, such as necessary for gene therapy (Khalil et al. (
  • Higher tensions inhibit both the binding of the endocytic complex to the membrane and mechanical deformation of the membrane during invagination. (
  • Clathrin-mediated endocytosis, an essential process for plasma membrane homeostasis and cell signaling, is characterized by stunning heterogeneity in the size and lifetime of clathrin-coated endocytic pits (CCPs). (
  • CME is initiated by the adaptor-mediated assembly of metastable clathrin-coated pits (CCPs) that dynamically exchange their components with soluble endocytic proteins. (
  • 10 min) for plasma membrane organization ( 5 , 6 ) distinct from endocytic carriers (i.e. (
  • Endocytic CCPs display a wide heterogeneity in size and lifetime within cells that ranges from less than 20 s to a few minutes ( 7 - 10 ). (
  • The endocytic pathway of ricin in sinusoidal liver endothelial cells (EC) was traced by means of immunocytochemical labeling of ultrathin cryosections. (
  • The protein encoded by this gene is an endocytic receptor involved in several cellular processes, including intracellular signaling, lipid homeostasis, and clearance of apoptotic cells. (
  • The use of endocytic proteins in bacterial infection is conserved, and the proteins used are similar to those used in cell-cell adhesion. (
  • The AP (adaptor protein) complexes are heterotetrameric protein complexes that mediate intracellular membrane trafficking along endocytic and secretory transport pathways. (
  • A constitutive, high-capacity plasma-membrane-recycling activity in the axonal growth cones is identified, which is mediated by a novel bulk endocytic pathway that is mechanistically related to macropinocytosis. (
  • Microbial infection) In case of HIV-1 infection, may function as a receptor for extracellular Tat in neurons, mediating its internalization in uninfected cells. (
  • Although the plasma membrane-localized activity of Rab5 was not detected by light microscopy, overexpression of a GDP-bound mutant of CFP-Rab5(S34N) inhibited internalization of the epidermal growth factor receptor by retaining receptors in clathrin-coated pits. (
  • A number of different internalization and trafficking pathways are utilized by animal viruses to gain entry into host cells. (
  • Among them, internalization via clathrin-coated pits, lipid raft/caveolae-mediated endocytosis and macropinocytosis/phagocytosis are the most extensively characterized. (
  • After internalization of the TGF-alpha/EGFR complex, EGFR recycles back to the plasma membrane, where it can be restimulated. (
  • Clathrin-coated pits mediate the internalization of clustered receptors from the cell surface in a process termed receptor-mediated endocytosis. (
  • Epsin binds to several other proteins implicated in clathrin-dependent endocytosis, including clathrin itself, and to plasma membrane proteins specifically 'tagged' for internalization. (
  • Absorptive endocytosis molecules are bound to the cell surface and concentrated before internalization, with the molecules interacting preferentially with generic complementary binding sites, such as lectin or charged interaction (Khalil et al. (
  • Using fluorescent or EM visible dyes to tag specific molecules in living cells, it is possible to follow the internalization of cargo molecules and the evolution of a clathrin-coated pit by fluorescence microscopy and immuno electron microscopy. (
  • Furthermore, a very recent study has established targeted internalization of SWNTs into cancer cells that express specific cellsurface receptors and subsequent use as high near-infrared (NIR) absorbing agents for cancer-cell destruction without harming normal cells. (
  • LPAR1 requires membrane cholesterol for association with beta-arrestin, which targets the receptor to clathrin-coated pits for internalization. (
  • Based on these features, tetraspanins might well become involved in exosome-recipient cell binding, which proceeds via receptor-ligand interaction, fusion, or internalization ( 8 , 13 , 17 , 25 ). (
  • Nanosilicate attachment to the cell membrane and subsequent cellular internalization activated stress-responsive pathways such as mitogen-activated protein kinase (MAPK), which subsequently directed hMSC differentiation toward osteogenic and chondrogenic lineages. (
  • Our hypothesis is that agLDL internalization by vascular smooth muscle cells (VSMCs) may trigger TF-procoagulant activity. (
  • The intracellular portion of the 85 kd subunit contains a consensus NP x Y sequence known to be essential for internalization of receptors via coated pits. (
  • Following the recruitment of early adaptor proteins, which recognize transmembrane cargo proteins such as receptors and channels destined for internalization, endocytosis progresses through the formation of a coated pit. (
  • Exposure to Cdt results in binding to the cell surface followed by internalization and translocation of the active subunit, CdtB, to intracellular compartments. (
  • These pits are the entry route for macromolecules bound by cell surface receptors . (
  • Although receptors and their ligands can be brought into the cell through a few mechanisms (e.g. caveolin ), clathrin -mediated endocytosis remains the best studied. (
  • Clathrin-mediated endocytosis of many receptor types begins with the cargo ligands in the luminal compartment of the cell binding to receptors on the cell membrane. (
  • [1] Other receptors can nucleate a clathrin-coated pit allowing formation around the receptor. (
  • To achieve internalisation of nanoparticles into cells, such as T cells , antibodies can be used to target the nanoparticles to specific receptors on the cell surface (such as CCR5 ). (
  • Overexpression of CFP-Rab5(S34N)CAAX prevented endocytosis of receptors by retaining them in coated pits. (
  • Some receptors are recycled back to the plasma membrane with or without the ligand, whereas others are sent to the late endosomal compartment and lysosomes for degradation ( Sorkin and von Zastrow, 2002 ). (
  • Between the clathrin and the membrane-bound receptors is a layer of proteins known as adaptors. (
  • Conner and Schmid overexpressed an accessory kinase that inhibits AP-2 function and similarly found selective effects on the uptake of different receptors from the cell surface. (
  • Coated pits can concentrate large extracellular molecules that have different receptors responsible for the receptor-mediated endocytosis of ligands, e.g. low density lipoprotein, transferrin, growth factors, antibodies and many others. (
  • They are principally sorting organelles where many endocytosed ligands dissociate from their receptors in the acid pH of the compartment, and from which many of the receptors recycle to the cell surface (via tubules). (
  • These are probably mediated through specific cell-surface interactions with chemoattractant receptors on cells of the immune system and key enzymes of the fibrinolytic cascade, respectively. (
  • The interaction of the G protein and specific cell surface receptors may be involved. (
  • Illustration of receptor-mediated endocytosis, where receptors on cells allow them to engulf target molecules (red). (
  • It is a requirement of G protein-coupled receptor functioning that receptors are embedded into membranes for proper structure. (
  • It was found that QDs interact with scavenger receptors, and enter cells via a clathrin coated pit mediated pathway. (
  • The recovery of membrane microdomains in exosomes is of particular interest with respect to tetraspanins, which organize clusters of tetraspanins, additional transmembrane proteins, and membrane-proximal signaling proteins, such as integrins, G protein-coupled receptors, proteases, and protein kinase C ( 10 , 18 - 20 ). (
  • MRs may be considered an efficient and fairly rapid cell-activated mechanism to express or mask surface receptors aimed at triggering specific response pathways. (
  • cholinergic r's membrane receptors on cells of effector organs, innervated by cholinergic nerve fibers and responsive to the acetylcholine secreted by these fibers. (
  • Fc r's specific membrane receptors for antigen-antibody complexes or aggregated immunoglobulins that bind a site in the Fc portion of the immunoglobulin molecule and may exhibit specificity for particular immunoglobulin classes. (
  • 2014 ). Whereas the former phenomenon depends on the leakiness of tumor vessels (defined as enhanced permeability and retention or EPR effect) (Jain and Stylianopoulos 2010 ), the latter involves surface functionalization of NPs with ligands specific to receptors on the tumor cell surface. (
  • [9] A mutation that impairs the ability of lipoprotein receptors to localise in coated pits on the cell surface of human fibroblasts. (
  • Death receptors were initially recognised as potent inducers of apoptotic cell death and soon ambitious attempts were made to exploit selective ignition of controlled cellular suicide as therapeutic strategy in malignant diseases. (
  • At the time of discovery, a subgroup of the TNFRSF, the so-called death receptors (DR), attracted considerable interest as robust cell-death induction upon ligand binding was recognised and triggered the ambitious goal for exploitation in therapeutic settings such as cancer therapy. (
  • It is demonstrated the active induction of macropinocytosis (accompanied by actin reorganisation, ruffling of plasma membrane, and engulfment of large volumes of extracellular fluid) by stimulation of cancer-related receptors and show that the epidermal growth factor (EGF) receptor significantly enhances the cellular uptake of exosomes. (
  • Receptors without the O-linked glycosylation are cleaved inside the cell with release of the extracellular domain. (
  • The multimerized Abs target the cell surface receptors HER2, death receptor 5, and CD20, and are more efficacious than their parent mAbs in triggering antitumor cellular responses, indicating they could be useful both as reagents for study as well as novel therapeutics. (
  • Actin filaments are shown to be essential during the initial penetration of the virus across the plasma membrane, whereas microtubules are involved in the trafficking of internalized virus from early endosomes to lysosomes for uncoating. (
  • Phagosomes fuse with lysosomes to form phagolysosomes, whereas fluid and macromolecules ingested by pinocytosis first are transfered to endosomes (membrane-bound organelles ) and then carried to lysosomes (Alberts et al. (
  • 1989). Amino acids , sugars , and nucleotides that occur as breakdown products from material from phagosomes and endosomes fusing with lysosomes is transported across the lysosomal membrane into the cytosol, where they can be used by cell (Alberts et al. (
  • The LPAR1 is subsequently sorted through Rab-5 dependent early and recycling endosomes before it is recycled back to the cell surface or degraded in lysosomes. (
  • The prevailing view is that AP-2 mediates endocytosis from the plasma membrane, whereas AP-1, AP-3, and AP-4 participate in the protein sorting from the trans-Golgi network and/or endosomes to lysosomes. (
  • Both late endosomes and lysosomes showed labeling for Igp120, the lysosomal membrane glycoprotein. (
  • LDLR is found distributed from plasma membrane to intracellular compartments, cell surface (in the presence of PCSK9) and also localizes to Golgi apparatus as well as early/late endosomes and lysosomes. (
  • By immunofluorescence and cell fractionation, the exocyst subunits were found to selectively associate with AP-1B-containing membranes that were both distinct from AP-1A-positive TGN elements and more closely apposed to transferrin receptor-positive recycling endosomes. (
  • For example, CD1b isoform is internalized in clathrin-coated pits via a tyrosine-based motif in its cytoplasmic tail (YXXΦ where Y is tyrosine, X is any amino acid, and Φ is a bulky hydrophobic residue), sorted to early endosomes, late endosomes/lysosomes, and MHC II-rich compartments (MIICs), and recycled back to the plasma membrane. (
  • OCRL1 knockdown did result in a significant increase in secretion of the lysosomal hydrolase cathepsin D, consistent with a role for OCRL1 in membrane trafficking between the trans -Golgi network and endosomes. (
  • OCRL1 is localized primarily at the trans -Golgi network (TGN) and is also associated with a subset of endosomes and with clathrin-coated pits, suggesting a potential function of this enzyme in membrane traffic through these compartments ( 8 , 9 , 15 , 16 , 46 ). (
  • Beta adaptin is a subunit of the plasma membrane CC adaptor (By similarity). (
  • Binds LDL, the major cholesterol-carrying lipoprotein of plasma, and transports it into cells by endocytosis. (
  • Receptor-mediated endocytosis ( RME ), also called clathrin-mediated endocytosis , is a process by which cells absorb metabolites , hormones , proteins - and in some cases viruses - by the inward budding of the plasma membrane ( invagination ). (
  • Budding of the plasma membrane then occurs, forming a clathrin coated pit. (
  • May play a role in transporting DAB2 from the plasma membrane to specific cellular targets (By similarity). (
  • To test whether the Rab5(S34N) mutant affects endocytosis directly at the plasma membrane, CFP-Rab5 was fused to the plasma membrane targeting sequence of K-Ras containing a CAAX motif. (
  • The resulting chimeric CFP-Rab5-CAAX was located mainly in the plasma membrane and was capable of binding GTP as judged by FRET microscopy with the Rabaptin5-based sensor. (
  • Interestingly, EEA.1 sensor did not follow activated Rab5-CAAX to the plasma membrane, suggesting that the interaction of EEA.1 with Rab5 plays a secondary role in EEA.1 targeting. (
  • These data suggest that the dominant-negative effect of the Rab5(S34N) mutant on the late stages of endocytosis can be mediated through the inhibition of cytosol-associated or plasma-membrane-associated rather than endosome-associated regulators of Rab proteins. (
  • This process is accomplished in small areas of the plasma membrane coated on the cytoplasmic surface with a clathrin lattice, called clathrin-coated pits. (
  • F-BAR(3) induces filopodia in both cell types, though less potently than F-BAR(2), whereas F-BAR(1) prevents filopodia formation in cortical neurons and reduces plasma membrane dynamics. (
  • As measured by fluorescence recovery after photobleaching, F-BAR(2) displays faster molecular dynamics than F-BAR(3) and F-BAR(1) at the plasma membrane, which correlates well with its increased potency to induce filopodia. (
  • Interestingly, acute phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5) P 2 ] depletion in cells does not interfere with plasma membrane localization of F-BAR(2), which is compatible with our result showing that F-BAR(2) binds to a broad range of negatively-charged phospholipids present at the plasma membrane, including phosphatidylserine (PtdSer). (
  • Flat clathrin lattices: stable features of the plasma membrane. (
  • The molecular exchange of clathrin triskelia between the cytosolic pool and CCSs at the plasma membrane remains a contentious topic. (
  • The underlying molecular mechanisms for targeting to and specific activation of N-WASP at the neuronal plasma membrane, however, have thus far remained elusive. (
  • Constitutive plasma membrane-targeting experiments in vivo indicate that specifically actin nucleation at the cell cortex is triggered by syndapins. (
  • The topology of the plasma membrane of eukaryotic cells is dictated by underlying actin cytoskeletal structures. (
  • In contrast, human immunodeficiency virus type 1 ( 33 , 34 ), severe acute respiratory syndrome coronavirus ( 43 ), and amphotrophic murine leukemia virus ( 34 ) are observed to fuse at the plasma membrane and the nucleocapsids are released into the cytoplasm. (
  • From prophase to anaphase, shallow clathrin-coated pits form at the plasma membrane, but the cell never internalizes them. (
  • Scientists used LLSM to study the dynamics of pit formation in the plasma membrane on the cell surface. (
  • Cholesterol is a waxy steroid of fat that is manufactured in the liver or intestines to produce hormones and cell membranes and transported in the blood plasma of all mammals. (
  • EGFRs stimulated with TGF-alpha recycled back to the plasma membrane, where they could be reactivated with ligand. (
  • 2011) and thereby subjected to a higher plasma membrane tension accumulated approximately the same number as did control cells (Figure 7, B-F). Thus there appears to be a threshold requirement for membrane scission, even when tension is unphysiologically high. (
  • In addition, it suggests that the two apparently distinct clathrin assembly modes, namely coated pits and coated plaques, observed in experimental investigations might be a consequence of varied tensions in the plasma membrane. (
  • Caveolae are the most commonly reported non-clathrin-coated plasma membrane buds, which exist on the surface of many, but not all cell types. (
  • They can constitute up to a third of the plasma membrane area of the cells of some tissues, being especially abundant in smooth muscle, type I pneumocytes, fibroblasts, adipocytes, and endothelial cells. (
  • Phosphatidyl inositol 4,5-bisphosphate (PI 4,5-P 2 ) accumulates in a Rac/Rop-dependent manner in the pollen tube tip plasma membrane, where it may control actin organization and membrane traffic. (
  • Yellow fluorescent protein (YFP) fused to Nt PLC3, or to its EF and C2 domains, accumulated laterally at the pollen tube tip plasma membrane in a pattern complementary to the distribution of PI 4,5-P 2 . (
  • have indicated that excess plasma membrane material is retrieved by endocytosis at the flanks of the pollen tube tip and rapidly recycled to the secretory system. (
  • Rac/Rop-type Rho family small GTPases accumulate at the plasma membrane specifically at the tip of elongating pollen tubes and are key regulators of polar cell expansion ( Zheng and Yang, 2000 ). (
  • In phagocytosis or "cellular eating," the cell's plasma membrane surrounds a macromolecule or even an entire cell from the extracellular environment and buds off to form a food vacuole or phagosome . (
  • A and B, Immunogold labeling of AQP2 in clathrin-coated pits (arrows) at the apical plasma membrane of collecting duct principal cells. (
  • First, the cargo interacts with adaptor proteins that help cluster them in the cell's outer membrane, called the plasma membrane. (
  • This causes the protein clathrin to assemble into a lattice at the cytosolic side of the plasma membrane and deform the membrane into a pit. (
  • In addition, a portion of the epsin molecule can insert into the plasma membrane and help it to curve, which is important for forming the invaginated pit. (
  • Endocytosis is used by cells because most substances important to them are large polar molecules, and thus cannot pass through the hydrophobic plasma membrane . (
  • Many substances needed by the cell cannot cross the plasma membrane because of their size or hydrophilic nature. (
  • 2006) succinctly define endocytosis as "the cellular uptake of macromolecules and solutes into membrane-bound vesiciles derived by the invagination and pinching off of pieces of the plasma membrane. (
  • Localized topological changes of the plasma membrane upon exocytosis visualized by polarized TIRFM. (
  • The RNP-M complex migrates to an area of the plasma membrane containing glycoprotein inserts, and the M-protein initiates coiling. (
  • The M-RNP complex binds with the glycoprotein, and the completed virus buds from the plasma membrane. (
  • Within the central nervous system (CNS), there is preferential viral budding from plasma membranes. (
  • Plasma membrane tethers formed by latex beads pull back on the beads with a force that was related to the in-plane bilayer tension and membrane- cytoskeletal adhesion. (
  • Although biochemical factors are clearly involved in the alterations in mitosis, we suggest that endocytosis is blocked primarily by the increase in apparent plasma membrane tension. (
  • Figure of the LPAR1, a G protein-coupled receptor, spanning the plasma membrane seven times. (
  • The LPAR1 spans the plasma membrane seven times in a barrel conformation with three extracellular and three intracellular loops. (
  • At steady state, LPAR1 is located on the plasma membrane at the cell surface until it binds LPA, which triggers dynamin2-dependent, clathrin-mediated endocytosis into the cell. (
  • Clathrin-mediated endocytosis (CME) is an essential cell physiological process that dynamically controls the composition of the plasma membrane and thereby regulates a plethora of functions ranging from nutrient uptake and cell signaling to the formation of morphogen gradients and synaptic transmission ( 1 - 3 ). (
  • Membrane rafts (MRs) are clusters of lipids, organized in a "quasicrystalline" liquid-order phase, organized on the cell surface and whose pattern of molecules and physicochemical properties are distinct from those of the surrounding plasma membrane. (
  • Membrane rafts (MRs) represent specialized portions of the cell plasma membrane involved in the signalling response to incoming stimuli. (
  • MRs have been described in two forms, either flat portions of plasma membrane, named lipid rafts, or flask-like of about 70 nm in diameter, named caveolae. (
  • In the last years, several investigations, using either artificial (liposomes) or cellular plasma membranes and a variety of techniques [ 7 - 9 ] confirmed the existence of "quasicrystalline" regions, suggesting that organization in domains is a common feature of biological membranes. (
  • LDL Receptor (low-density lipoprotein receptor or LDLR) is a key determinant of plasma cholesterol levels and as a ubiquitously expressed cell membrane glycoprotein, it binds LDL, the major cholesterol-carrying lipoprotein of plasma, and transports it into cells via endocytosis. (
  • Here, we discuss the manipulation of clathrin by pathogens, with specific attention to the processes that occur at the plasma membrane. (
  • I contrast these scenarios to traditional and revised autogenous models according to which eukaryotic endomembranes evolved by the inward budding of a prokaryotic cell's plasma membrane. (
  • AP-2 plays a role in clathrin-dependent endocytosis from the plasma membrane. (
  • All biological cells are bounded by a lipid bilayer known as the plasma membrane. (
  • In addition, the cells of higher organisms contain specialized intracellular membrane compartments, which interact with each other and with the plasma membrane. (
  • This gene codes for a key protein called FCHO1, which is found at the plasma membrane," Klein explains. (
  • These findings therefore imply that the immunological defects observed in the patient cohort can be attributed to a failure to initiate endocytosis at the plasma membrane. (
  • To investigate the impact of the loss of FCHO1 at the cellular level, Łyszkiewicz and colleagues deleted the gene in a cultured T-cell line, and discovered that the mutant cells were unable to remove the activated T-cell receptor from the plasma membrane. (
  • Cholesterol is a lipid found in the cell membranes of all tissues, and it is transported in the blood plasma of all animals . (
  • Recently, cholesterol has also been implicated in cell signalling processes, where it has been suggested that it forms lipid rafts in the plasma membrane . (
  • It also reduces the permeability of the plasma membrane to hydrogen ions ( protons ) and sodium ions . (
  • The role of cholesterol in caveolae-dependent and clathrin-dependent endocytosis can be investigated by using methyl beta cyclodextrin (MβCD) to remove cholesterol from the plasma membrane. (
  • Although previously typically considered an event associated with the plasma membrane, it is now appreciated that the formation and metabolism of PtdIns(3,4,5)P 3 occur on multiple membranes with distinct kinetics. (
  • Extracellular mitogenic signals bind and activate receptor tyrosine kinases at the plasma membrane, thereby recruiting and subsequently activating phosphoinositide 3-kinases (PI3Ks). (
  • Distinct pools of PtdIns(3,4,5)P 3 in the plasma membrane control such processes as the formation of the basolateral membrane in epithelial cells ( 7 ), orientation of the mitotic spindle in adherent cells ( 8 ), and formation of the axonal growth cone in neurons ( 9 ). (
  • The major research topic in the group aims to elucidate the highly dynamic process of endocytosis at the plasma membrane in plant cells. (
  • Newly synthesized glycoproteins destined for transport to the plasma membrane or to the endosomal-lysosomal system travel together through the ER and the Golgi complex only to be sorted from each other upon exit from the TGN ( Mellman and Warren, 2000 ). (
  • Expression of βarr2-GFP together with a fusion protein of Smo with a portion of Myc (Myc-Smo), which is constitutively active when overexpressed in mammalian cells ( 10 , 11 ), led to redistribution of βarr2-GFP from the cytosol to the plasma membrane, where it was found in a punctate pattern ( Fig. 1B ). (
  • However, it is not expressed on pre-B cells and differentiated plasma cells. (
  • Capillary endothelial cells from mammalian cardiac muscle caught in the act of fluid-phase micropinocytosis. (
  • Abgent has over fifteen years of experience producing recombinant proteins in E. coli and mammalian cells (CHO and HEK293, etc), and we have added a powerful yeast expression platform to our menu of services. (
  • RESTORATION HARDWARE: During interphase, mammalian cells have low membrane tension, and clathrin-mediated endocytosis (CME) proceeds normally with no special need for actin (1). (
  • 2] It is an essential structural component of mammalian cell membranes. (
  • Study in mammalian cells confirm a reduction in clathrin coat size in an increased tension environment. (
  • Mammalian cells use receptor-mediated endocytosis to take cholesterol into cells. (
  • Mammalian cells use __________ to import cholesterol. (
  • One of them is epsin, the collective name for a family of three very similar proteins in mammalian cells. (
  • Phagocytosis generally is restricted to specialized phagocytic mammalian cells, such as macrophages, monocytes, and neutrohiles, which help to clear large pathogens such as bacteria or yeast , or debris such as dead cells and fat deposits in arteries (Khalil et al. (
  • To investigate the generality of carbon nanotubes for the transportation of proteins and DNA inside mammalian cells, we used, in our current work, two different mammalian cells lines, adherent HeLa cells and non-adherent HL60 cells. (
  • Mitosis in mammalian cells is accompanied by a dramatic inhibition of endocytosis. (
  • CDT uptake and intracellular transport in mammalian cells. (
  • Chezzi, C. 2008-07-01 00:00:00 This study was aimed at investigating the possible involvement of the actin cytoskeleton in the modulation of host permissiveness to A/NWS/33 human influenza virus infection in two mammalian (MDCK and LLC-MK2) cell lines in vitro. (
  • Molecules of the tumor necrosis factor (TNF) superfamily (TNFSF) and TNF-receptor superfamily (TNFRSF) are highly conserved and found in almost all mammalian cells. (
  • Cholesterol is required in the membrane of mammalian cells for normal cellular function, and is either synthesized in the endoplasmic reticulum , or derived from the diet, in which case it is delivered by the bloodstream in low-density lipoproteins . (
  • Although CD22 is highly conserved throughout mammalian species, murine and human CD22 are known to exhibit significant differences in their specificities that appear to have evolved to compensate for changes in the glycan ligands expressed on B cells. (
  • F-BAR domain only protein 1 (FCHo1) belongs to the F-BAR family, whose members have been implicated in cell membrane processes such as membrane invagination, tubulation and endocytosis [ PMID: 23384583 ]. (
  • An invagination of a cell membrane with a distinctive protein coat on the inner cytoplasmic surface of the lipid membrane. (
  • Our results indicate that a key evolutionary conserved function of epsin, in addition to other roles that include, as we show here, a low affinity interaction with SNAREs, is to help generate the force that leads to invagination and then fission of clathrin-coated pits. (
  • The deep invagination of clathrin-coated pits that leads to fission is assisted by actin, a protein that assembles into filaments that are suggested to generate the forces needed for this process. (
  • Appears to be involved in a very early step of clathrin-mediated endocytosis in polarized epithelial cells (By similarity). (
  • Electron micrograph of the junctional complex of intestinal epithelial cells of the rat shows the apical-most zonula occludens (tight junction), the zonula adherens (medium junction) and the macula ad. (
  • Human induced pluripotent stem cells differentiate into retinal pigment epithelial cells. (
  • Telomerase immortalized human corneal epithelial (hTCEpi) cells and primary human corneal epithelial cells were tested for their ability to migrate in response to EGF and TGF-alpha. (
  • After incubation in the indicated amounts of ligand, primary human corneal epithelial cells were fixed and stained with Giemsa, and cells at the origin (top of membrane) were removed. (
  • Some evidence indicates that a portion of the total cellular LPAR1 localizes to the nuclear membrane in PC12 cells, micro-vascular endothelial cells, and human bronchial epithelial cells. (
  • Immunocytochemistry/ Immunofluorescence: LDL R Antibody (C7) [NBP1-78159] - Image from a customer review on porcine intestinal epithelial cells IPEC-J2. (
  • AP-1 also mediates basolateral sorting in epithelial cells. (
  • Most epithelial cells contain two AP-1 clathrin adaptor complexes. (
  • The transport of iron into the brain is regulated by the expression of the transferrin receptor on capillary endothelial cells and on epithelial cells in the choroid plexus. (
  • To examine this possibility, we investigated the effects of siRNA-mediated OCRL1 knockdown on biosynthetic and postendocytic membrane traffic in canine and human renal epithelial cells. (
  • Megalin, a member of the LDL receptor family, is a 600-kDa transmembrane protein that recycles at the apical domain of polarized epithelial cells ( 10 ). (
  • Activated Rab5 was detected by FRET microscopy in endosomal compartments and often concentrated in microdomains in the endosomal membrane. (
  • Membranes divide cells into compartments, and remodeling of those membranes is an important step in any change of cell size or transfer of components to and from the surface. (
  • Dr. Greene studies the role of molecular chaperones and their co-factors in the formation of vesicular compartments from clathrin-coated pits in the cellular membrane during endocytosis. (
  • Upon ligand binding, receptor recruitment in specialized membrane compartments, formation of receptor-ligand clusters and internalisation processes constitute key regulatory elements. (
  • These five AP complexes localize to different intracellular compartments and mediate membrane trafficking in distinct pathways. (
  • Following assembly with β2-microglobulin in the endoplasmic reticulum, all CD1 isoforms are transported to the cell surface but are subsequently delivered to distinct endosomal and/or lysosomal compartments. (
  • In order to deliver CdtB to intracellular compartments the holotoxin must first bind to target cell surfaces. (
  • They undergo rapid polarization in the presence of N-formylmethionyl-leucyl-phenylalanine (fMLP), during which cells not only present anisotropic morphology but also have asymetric distribution of cellular structures and signaling molecules. (
  • The first step in the initiation of a successful virus infection cycle requires animal viruses binding to specific molecules on the cellular surface and followed by penetration into the host cells for the release of viral genome for replication. (
  • Understanding what is required for endocytosis may allow for its control," Royle says, "either turning on the process to get mitotic cells to take up drugs or [turning it off] to prevent cells from engulfing molecules or viruses. (
  • Effect of membrane tension on the number of dynamin molecules recruited to coated pits at the time of membrane fission. (
  • The total number of dynamin molecules recruited to clathrin-coated pits was determined as in Figure 5 using Sum-Dyn2 briefly exposed for 10 min to media of different osmolarities. (
  • A) Histogram of the total number of dynamin molecules recruited to coated pits of cells incubated in hyper-osmotic medium at the time of membrane fission (78 pits). (
  • The pit grows deeper over time as more clathrin molecules assemble, eventually resulting in a deeply invaginated clathrin-coated pit that encloses the cargo to be taken up by the cell. (
  • Many of the molecules ingested by cells by either phagocytosis or pinocytosis end up in lysosomes to be degraded. (
  • The target molecules are first shown outside the cell (centre left). (
  • Angewandte Chemie Nanotechnology DOI: 10.1002/ange.200503389 Carbon Nanotubes as Intracellular Transporters for Proteins and DNA: An Investigation of the Uptake Mechanism and Pathway** Nadine Wong Shi Kam, Zhuang Liu, and Hongjie Dai* New materials for the intracellular transport of biological cargos such as DNA, proteins, and drug molecules have been actively sought to effectively breach the cell-membrane barriers for delivery and enabling functionality of extracellular agents. (
  • The Cell and Developmental Biology Center aims to understand the molecules and the molecular interactions inside cells that build the organelle systems that support basic and specialized functions to control cell fate and behavior. (
  • As their name implies, APs select and link specific cargo molecules to the clathrin molecules, participating in the membrane assembly of clathrin-coated pits. (
  • This prediction implied the possibility that several types of domains could exist, having different patterns of component molecules, and perhaps even coexisting within the membrane. (
  • Currently, it is generally accepted that MRs exist within the plane of the membrane, where the pattern of molecules and the physicochemical properties are distinct from the environment [ 10 , 11 ]. (
  • Examples of cell death associated with dysfunctional macropinocytosis are reviewed and the possibility that small molecules capable of altering macropinosome trafficking or function might be useful as therapeutic agents against cancers that are resistant to drugs that work by inducing apoptosis is raised. (
  • In particular, the receptor is expressed, 10 000 to 100 000 molecules per cell, on the surface of proliferating cells (Gatter et al 1983, Chitambar et al 1983). (
  • LCs employ I-A molecules for presentation of peptide antigens to CD4 T cells. (
  • These findings have changed our classic view that T cells recognize only peptide antigens presented by MHC class I or class II molecules. (
  • It is widely used for the specific uptake of certain substances required by the cell (examples include LDL via the LDL receptor or iron via transferrin ). (
  • These processes involve the uptake of larger membrane areas than clathrin-mediated endocytosis and caveolae pathway. (
  • LDLs bind to specific receptor proteins on the cell surface, thereby triggering their uptake by receptor-mediated endocytosis. (
  • Endocytosis, or the vesicular uptake of extracellular materials, is a means whereby the macromolecules can be internalized by a cell. (
  • Activation of this pathway results in up-regulation of ACKR2 from endosomal compartment to cell membrane, increasing its efficiency in chemokine uptake and degradation. (
  • CME is responsible for the uptake of fluids and the retrieval of proteins from the cell membrane, at sites that are marked by binding of the protein clathrin to its inner surface. (
  • The receptor-apotransferrin complex recycles to the cell surface for a renewed round of iron uptake. (
  • CD1a mediates the presentation of nonpeptide antigens to T cells, while langerin facilitates uptake of microbial fragments and perhaps their delivery to a specialized subcellular compartment. (
  • AP-2 also serves as a cargo receptor to selectively sort the membrane proteins involved in receptor-mediated endocytosis. (
  • The low density lipoprotein receptor (LDLR) gene family consists of cell surface proteins involved in receptor-mediated endocytosis of specific ligands. (
  • However, receptor-mediated endocytosis is also actively implicated in transducing signals from the cell periphery to the nucleus. (
  • Various macromolecules and viruses enter cells by means of receptor-mediated endocytosis. (
  • Unlike phagocytosis and pinocytosis, receptor-mediated endocytosis is an extremely selective process of importing materials into the cell. (
  • In receptor-mediated endocytosis, the cell will only take in an extracellular molecule if it binds to its specific receptor protein on the cell's surface. (
  • Receptor-mediated endocytosis of ricin in rat liver endothelial cells. (
  • The family Flaviviridae are positive-sense, single-stranded RNA viruses that replicate in the cytoplasm of infected cells. (
  • After adsorption, the virus penetrates the host cell and enters the cytoplasm by pinocytosis (via clathrin-coated pits). (
  • The viral membranes fuse to the endosomal membranes, causing the release of viral RNP into the cytoplasm (uncoating). (
  • Some investigators thought viruses were directly penetrating the cell membrane into the cytoplasm, while others argued the pathogens were first engulfed into clathrin-coated pits. (
  • β-Arrestin 2 tagged with green fluorescent protein (βarr2-GFP), when expressed alone, was diffusely distributed throughout the cytoplasm of human embryonic kidney 293 (HEK293) cells ( Fig. 1A ). (
  • Recognizes human CD91, a type I membrane protein which is also known as the alpha 2 macroglobulin receptor (alpha 2 MR). Recognizes an epitope in the extracellular region of the 500kD alpha chain. (
  • The response to extracellular mitogenic stimuli requires the transduction of signals from the cell periphery to the interior of the cell. (
  • It is a homo-dimer consisting of two identical monomers joined by two disulfide bindings at cystein residues 89 and 92 in the extracellular domain just outside the cell membrane (Jing and Trowbridge 1987). (
  • and once the membrane is invaginated, a protein such as dynactin may be responsible for the fission event. (
  • 50 nm in diameter) flask-shape pits in the membrane that resemble the shape of a cave (hence the name caveolae). (
  • Cell membrane transit by virus was seen to involve two distinct structures resembling caveolae and macropinosomes. (
  • Cholesterol is essential for the structure and function of invaginated caveolae and clathrin-coated pits, including the caveolae-dependent endocytosis and clathrin-dependent endocytosis. (
  • MRC Laboratory for Molecular Cell Biology, London WC1E 6BT, United Kingdom Institute of Immunity and Transplantation, University College London, London NW3 2PF, United Kingdom [email protected] [email protected] (
  • So Stone ordered skin biopsies from Despota and his parents and sent the cells to a pair of young researchers who had carved a niche in cholesterol biology at the University of Texas Southwestern Medical School in Dallas, TX. (
  • When Despota's cells arrived in Texas, Michael Brown and Joseph Goldstein, now feted in biochemists' circles, had made substantial inroads into the biology of cholesterol metabolism in human cells. (
  • The Laboratory of Cell Biology is led by Dr. Edward Korn, who has been studying the function and regulation of the actomyosin system in its diverse forms since he discovered the first unconventional non-filamentous myosin, myosin I (containing only a single heavy chain), in the single-cell soil protozoan Acanthamoeba castellanii , approximately forty years ago. (
  • Dr. Korn's laboratory brings the tools of biochemistry and cell biology to focus on three research areas: the role of the actin cytoskeleton in Dictyostelium fruiting body development, the molecular basis of the regulation of actin-activated ATPase activity in myosin II, and the mechanism of association of myosin I with cell membranes. (
  • She has applied her wealth of experience in the cell biology of protein folding and membrane trafficking toward deciphering the mechanisms of prion formation and propagation. (
  • It has recently emerged that clathrin functions as a scaffold for actin assembly, in the context of both pathogen infection and cell biology. (
  • Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, 20892, U.S.A. (
  • If you are interested to work on the interplay between cell and structural biology, please contact us. (
  • We previously found that increases in cellular PIP 2 mediated by overexpression of phosphatidylinositol 4-phosphate 5-kinase type Iβ (PI5KIβ) in Madin-Darby canine kidney (MDCK) cells stimulated delivery kinetics of a subset of apical membrane proteins ( 18 ). (
  • Upon PMA treatment, CD4 becomes localized in clathrin-coated pits, suggesting that the down-regulation is a clathrin-mediated endocytosis process ( 3 ). (
  • Specialised regions of the cell membrane composed of pits coated with a bristle covering made of the protein clathrin. (
  • They then bind (upper right) to receptor proteins (orange) on a cell membrane pit coated by the protein clathrin (yellow). (
  • The expression of this receptor in lymphatic endothelial cells and overexpression in vascular tumors suggested its function in chemokine-driven recirculation of leukocytes and possible chemokine effects on the development and growth of vascular tumors. (
  • Acts as a regulator of inflammatory leukocyte interactions with lymphatic endothelial cells (LECs) and is required for immature/mature dendritic cells discrimination by LECs. (
  • Like many siglecs, CD22 interacts with endogenous ligands on B cells in cis , and on other cells, such as T cells and bone marrow vessel endothelial cells in trans . (
  • Clathrin-associated adaptor protein (AP) complexes which can bind directly to both the clathrin lattice and to the lipid and protein components of membranes are considered to be the major clathrin adaptors contributing the CCV formation. (
  • The cargo ligand and receptor will then recruit adaptor proteins and clathrin triskelions to the outside membrane of the cell around where budding will form. (
  • Clathrin is linked to cargo and membranes by the clathrin adaptor complex ( Keen, 1987 ). (
  • Once the complex has been endocytosed, iron is released to the cytosol for further transport inside the cell, for example to the mitochondria. (
  • BAR-domain-containing proteins often contain multiple other domains, including the actin-binding domain WH2, GTPase-activating protein (GAP) and guanine-nucleotide-exchange factor (GEF) domains, and Src homology 3 (SH3) domains, leading to the interplay between cellular membranes and the actin cytoskeleton. (
  • Disruption of host cell cytoskeleton (actin filaments and microtubules) with cytochalasin D and nocodazole showed significant reduction in virus infectivity. (
  • Clathrin-mediated endocytosis shuts down during mitosis in eukaryotic cells because all of the required actin is hoarded by the cytoskeleton. (
  • Using two different methods that released some of the actin from the cytoskeleton but did not decrease membrane tension, they demonstrated that it is possible to restart endocytosis. (
  • Therefore, we studied the reaction of Arabidopsis root hairs to the actin-depolymerizing drugs CD and LA. The results show that an increase in instability of the actin cytoskeleton can induce cell expansion over a larger area. (
  • We further show that the orientation of polarized growth depends on an intact microtubule cytoskeleton, as is known for intercalary growing cells. (
  • This defect correlated with a perturbation of the coupling between the clathrin coat and the actin cytoskeleton, which we confirmed in a cell-free assay of endocytosis. (
  • Eukaryotes possess, among other distinguishing features, an intracellular dynamic membrane system through which there is a constant flow of membranes scaffolded by an internal cytoskeleton. (
  • The multidomain structure of p80/85 and its colocalization with F-actin in normal and src-transformed cells suggest that these proteins may associate with components of the cytoskeleton and contribute to organization of cell structure (Wu, 1991). (
  • The properties of cortactin indicate that it may be important for microfilament-membrane interactions as well as transducing signals from the cell surface to the cytoskeleton. (
  • These include effects on actin assemblies at cellular membranes, the organization of endosomal subcompartments, Ca 2+ -regulated exocytosis and midbody formation during cytokinesis. (
  • Thus, despite the similarity of the two AP-1 complexes, AP-1A and AP-1B exhibit great specificity for endosomal transport versus cell polarity. (
  • These types of membrane microdomains are also recovered in exosomes ( 8 , 14 , 15 ). (
  • These events are dependent upon toxin binding to cholesterol in the context of lipid rich membrane microdomains often referred to as lipid rafts. (
  • Cholesterol binding in the context of membrane microdomains was demonstrated utilizing both model membranes and live cells including both lymphocytes and macrophages ( 10 - 12 ). (
  • By labeling proteins either directly or via SNAP tags with photoswitchable dyes, we obtained two-dimensional (2D) and 3D super-resolution images of living cells, using clathrin-coated pits and the transferrin cargo as model systems. (
  • The medium subunit (μ2) of AP2 binds to cargo proteins and phosphatidylinositol-4,5-bisphosphate on the cell surface. (
  • Clathrin-dependent endocytosis is one of the mechanisms used by cells to internalize specific proteins (cargo) from their surface. (
  • A prolonged circulation half-life is generally regarded as a common prerequisite for either process, and NPs have been demonstrated to alter the pharmacokinetics (PK) of the cargo and enhance its circulation half-life, thereby promoting delivery specifically to the tumor and reducing collateral damage to healthy cells (Chow et al. (
  • They recognize and concentrate cargo proteins into vesicular carriers that mediate transport from a donor membrane to a target organellar membrane. (
  • They bind to sorting signals in the cytoplasmic tails of cargo proteins, recruit clathrin and other accessory proteins, and then concentrate the cargo proteins into vesicular carriers, which transport from the donor membrane to the target organelle membrane ( Figure 1 ). (
  • Core domains are responsible for the cargo protein binding and membrane localization. (
  • The clathrin lattice serves as a mechanical scaffold but is itself unable to bind directly to membrane components. (
  • Syndapins furthermore specifically bind to phosphatidylserine-containing membranes via their extended F-BAR domain. (
  • Here we demonstrate that syndapins bind to membranes directly via their eF-BAR domain and are capable of releasing N-WASP autoinhibition. (
  • Phagocytosis is the process by which cells bind and internalize particulate matter larger than around 0.75 µm in diameter, such as small-sized dust particles, cell debris, microorganisms and apoptotic cells. (
  • A unique class of these proteins - annexins - can bind to certain membrane phospholipids in a Ca 2+ -dependent manner, providing a link between Ca 2+ signalling and membrane functions. (
  • At the core of this specificity may be the ability of LtxA to bind to integrin LFA1 , the transmembrane receptor of cells of the immune system that mediates cell attachment and signaling.Its binding induces the formation of pores on the membrane of monocytes, lymphocytes, neutrophils, and other myeloid and lymphoid cells. (
  • complement receptor a membrane receptor that can bind activated complement components. (
  • Although cis ligands of tend to mask the CD22 binding site, CD22 is able to interact with trans ligands on contacting cells (B cells and T cells), and to bind to synthetic multivalent ligands that have sufficient avidity. (
  • Several investigators have demonstrated that the CdtC subunit of several Cdts, including the A. actinomycetemcomitans Cdt, bind to membrane cholesterol ( 10 - 17 ). (
  • In the present study, we investigated whether an increase in instability (i.e., turnover) in the subapical fine F-actin in root hairs can trigger the exocytosis process by which plant cells grow. (
  • Such activities probably regulate membrane-related processes like membrane-domain organization and membrane transport in endocytosis and exocytosis. (
  • Exocytosis is important in expulsion of waste materials out of the cell and in the secretion of cellular products such as digestive enzymes or hormones. (
  • Depending on the stimulation, the cell‐surface expansion by enlargeosome exocytosis is not always recycled but can induce release of specific membranes, possibly important in the pericellular environment. (
  • Similar to homologous proteins in other systems, pollen tube Rac/Rop appears to coordinate F-actin organization, membrane traffic, Ca 2+ signaling, and possibly other cellular processes essential for tip growth by controlling multiple signal transduction pathways. (
  • Analysis of cell-nanosilicate interactions by monitoring changes in transcriptome profile uncovered key biophysical and biochemical cellular pathways triggered by nanosilicates. (
  • Depending on individual (patho-) physiological circumstances, cell-type and involved receptor-ligand system, cellular responses range from activation of pro-inflammatory and potentially pro-tumoural pathways such as nuclear factor κB (NFκB), to caspase-dependent and -independent mechanisms of cell death induction. (
  • Our study is a very good example of how systematic studies of patients with rare genetic diseases can contribute to the discovery of new genes and signaling pathways that regulate the differentiation and functions of the cells that orchestrate the immune system," says Klein. (
  • In order to be internalized, the receptor-ligand complexes must first cluster into clathrin-coated pits. (
  • This study reveals that EGFR-mediated cell migration is limited by ligand-stimulated downregulation of the EGFR. (
  • Data are plotted as the average fold change in the number of migrated cells (±SEM) for each ligand concentration ( n = 4). (
  • Once internalized, the ligand dissociates from the receptor, and is targeted to degradation while the receptor is recycled back to the cell membrane. (
  • While both recognize the sequence Siaα-2-6Galβ-1-4GlcNAc expressed abundantly on B cells, murine CD22 prefers Neu5Gc (not found in humans) over Neu5Ac, while human CD22 exhibits highest affinity for sulfated sialoside, Neu5Acα-2-6Galβ-1-4[6S]GlcNAc, demonstrating significant evolution of ligand specificity with conservation of function. (
  • This section documents what is currently known about CD22, its carbohydrate ligand(s), and how they interact to mediate cell communication. (
  • Despite these differences, activation of B cells in both species results in down regulation of the highest affinity ligand. (
  • In murine B cells, activation causes de novo synthesis of sialosides with NeuAc instead of NeuGc through down regulation of CMP-sialic acid hydroxylase [7] , while in human B cells, differentiation of B cells in germinal centers coincides with loss of the sulfate from the high affinity sulfated ligand (3) [2] . (
  • Tissue factor (TF) is a transmembrane cell surface glycoprotein of 45 to 50 kDa that forms a complex with activated factor VII, initiating blood coagulation and leading to the focal production of thrombin via the successive activation of factor IX, factor X, and prothrombin. (
  • identification of a 420-kD cell surface glycoprotein specific for the activated conformation of α 2 -macroglobulin. (
  • The CDT heterotrimeric holotoxin, consisting of the CdtA, CdtB and CdtC protein subunits, binds to a cell membrane receptor located within lipid rafts. (
  • Low density lipoprotein (LDL) is normally bound at the cell membrane and taken into the cell ending up in lysosomes where the protein is degraded and the cholesterol is made available for repression of microsomal enzyme 3-hydro. (
  • Low density lipoprotein (LDL) is normally bound at the cell membrane and taken into the cell ending up in lysosomes where the protein is degraded and the cholesterol is made available for repression of microsomal enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting step in cholesterol synthesis. (
  • QDs were found to associate with macrophage cell membranes within 2.5 minutes, and are confined to lysosomes 9 minutes after exposure. (
  • Endocytosis includes pinocytosis (cell drinking) and phagocytosis (cell eating). (
  • Like phagocytosis, pinocytosis is a non-specific process in which the cell takes in whatever solutes that are dissolved in the liquid it envelops. (
  • Pinocytosis (literally, cell-drinking). (
  • Pinocytosis, on the other hand, is found in all cells (Khalil et al. (
  • It harbours binding sites for cytoplasmic protein ligands that can be targeted to membranes through the annexin-core-mediated phospholipid interaction. (
  • The restriction of the exosome-target cell interaction ( 13 , 16 ) relies on the exosomal proteins and target cell ligands ( 21 ). (
  • Hinge and ear domains are important to the interaction with coat proteins and regulatory/accessory proteins. (
  • this interaction is required for efficient alpha-tubulin acetylation, hence clathrin-coated pits are sites of microtubule acetylation. (
  • studies have suggested that fucose moieties as well as glycosphingolipids might be involved in the interaction of this subunit with the cell surface ( 13 , 18 - 20 ). (
  • These data suggest that clathrin-dependent retrieval of SV membranes may at least in part depend on phosphoinositide metabolism. (
  • The surface region interacting with to the Y-X-X-Phi motif is inaccessible in cytosolic AP-2, but becomes accessible through a conformational change following phosphorylation of AP-2 mu subunit at 'Tyr-156' in membrane-associated AP-2. (
  • The AP-2 alpha subunit binds polyphosphoinositide-containing lipids, positioning AP-2 on the membrane. (
  • It is rapidly taken up by endocytosis of the active CdtB protein subunit in a clathrin-coated pit. (
  • The 85-kd subunit constitutes the membrane-spanning domain of the receptor that noncovalently anchors the 515-kd subunit to the cell surface. (
  • Eukaryotic cells contain various Ca 2+ -effector proteins that mediate cellular responses to changes in intracellular Ca 2+ levels. (
  • These tyrosine motifs are involved in regulation of BCR signaling and also mediate its constitutive clathrin mediated endocytosis, an activity believed to be tied to its regulation of cell signaling. (
  • This finding nixed the idea that increased membrane tension alone is responsible for the endocytosis shutdown, and instead led the team to propose that actin availability determines whether endocytosis proceeds. (
  • The cytosolic surface of coated pits is covered by coat proteins . (
  • Figure 3: The regulation of membrane-actin interactions by annexin A2. (
  • Swairjo, M. A. & Seaton, B. A. Annexin structure and membrane interactions: a molecular perspective. (
  • This communication sought to further investigate nanoparticle /cell interactions, ensuing toxicity and cellular responses within biological systems. (
  • Physicochemical properties of nanoparticle s, including charge and surface functional groups were found to play a role in nanoparticle -cell interactions. (
  • The Laboratory of Cell and Tissue Morphodynamics, led by Dr. Clare Waterman, has made pioneering discoveries into the complex and dynamic mechanical interactions between organelle systems within cells that are required for directed movement. (
  • However, little information exists on exosome-endothelial cell (EC) interactions or the proangiogenic role of tetraspanins, which are a constitutive component of exosomes. (
  • Here, we investigate the interactions of 2D nanosilicates, a layered clay, with human mesenchymal stem cells (hMSCs) at the whole-transcriptome level by high-throughput sequencing (RNA-seq). (
  • This approach in understanding nanomaterial-cell interactions illustrates how change in transcriptomic profile can predict downstream effects following nanomaterial treatment. (
  • 1993). In the cell, SNAREs contribute to the specificity of such interactions (Bethani et al. (
  • We[1, 2] have suggested that SWNTs traverse the cellular membrane through endocytosis, whereas Pantarotto et al. (
  • Coordination of membrane deformation and cytoskeletal dynamics lies at the heart of many biological processes critical for cell polarity, motility and morphogenesis. (
  • In addition to its role in signaling, PIP 2 also regulates cytoskeletal dynamics as well as numerous steps in membrane traffic ( 14 , 50 ). (
  • The transition from interphase to mitosis in eukaryotic cells is accompanied by dramatic inhibition of endocytosis as well as profound changes in cellular architecture. (
  • AP complexes play important roles in maintaining the normal physiological function of eukaryotic cells. (
  • We have recently shown that Slit-Robo GTPase-activating protein 2 (srGAP2) regulates neuronal morphogenesis through the ability of its F-BAR domain to regulate membrane deformation and induce filopodia formation. (
  • Additionally, exosomes contain selectively enriched mRNA and miRNA that regulate gene expression in target cells ( 16 ). (
  • SWI/SNF complexes have been shown to regulate gene activation, cell growth, the cell cycle and differentiation (1). (
  • [1] [2] 9-O-acetylation of sialic acid abrogates binding of CD22, which is thought to regulate the binding of cis ligands on B cells. (
  • This core domain enables Ca 2+ -bound annexins to peripherally dock onto membranes that contain negatively charged phospholipids. (
  • We report super-resolution fluorescence imaging of live cells with high spatiotemporal resolution using stochastic optical reconstruction microscopy (STORM). (
  • Carbocyanine dye orientation in red cell membrane studied by microscopic fluorescence polarization. (
  • flow cell cytometry and confocal fluorescence microscopy. (
  • Clathrin-mediated endocytosis (CME) is one of the major pathway through which cells internalize nutrients and membrane proteins. (
  • Modulated activity of phosphatidylinositol lipid kinases and phosphatases contributes to intricately orchestrated lipid gradients that define the signaling status of the pathway at multiple sites within the cell. (
  • treatment of cells with Retro-2 leads to a decrease in CdtB-Golgi association. (
  • This specificity is mediated by receptor proteins located on depressed areas of the cell membrane called coated pits . (