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.
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 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.
Membrane-bound compartments which contain transmitter molecules. Synaptic vesicles are concentrated at presynaptic terminals. They actively sequester transmitter molecules from the cytoplasm. In at least some synapses, transmitter release occurs by fusion of these vesicles with the presynaptic membrane, followed by exocytosis of their contents.
Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.
An organization of cells into an organ-like structure. Organoids can be generated in culture. They are also found in certain neoplasms.
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.
Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.
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 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 700-kDa cytosolic protein complex consisting of seven equimolar subunits (alpha, beta, beta', gamma, delta, epsilon and zeta). COATOMER PROTEIN and ADP-RIBOSYLATION FACTOR 1 are principle components of COAT PROTEIN COMPLEX I and are involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.
Membrane-limited structures derived from the plasma membrane or various intracellular membranes which function in storage, transport or metabolism.
TRANSPORT 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 COP (coat protein complex) proteins, either COPI or COPII. COPI coated vesicles transport backwards from the cisternae of the GOLGI APPARATUS to the rough endoplasmic reticulum (ENDOPLASMIC RETICULUM, ROUGH), while COPII coated vesicles transport forward from the rough endoplasmic reticulum to the Golgi apparatus.
A saclike, glandular diverticulum on each ductus deferens in male vertebrates. It is united with the excretory duct and serves for temporary storage of semen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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.
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
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.
Vesicles derived from the GOLGI APPARATUS containing material to be released at the cell surface.
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.
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.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Condensed areas of cellular material that may be bounded by a membrane.
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.
A subclass of clathrin assembly proteins that occur as monomers.
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.
A family of large adaptin protein subunits of approximately 90 KDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 1.
A protein complex comprised of COATOMER PROTEIN and ADP RIBOSYLATION FACTOR 1. It is involved in transport of vesicles between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.
An adaptor protein complex primarily involved in the formation of clathrin-related endocytotic vesicles (ENDOSOMES) at the CELL MEMBRANE.
The sum of the weight of all the atoms in a molecule.
A bile salt formed in the liver by conjugation of deoxycholate with taurine, usually as the sodium salt. It is used as a cholagogue and choleretic, also industrially as a fat emulsifier.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
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.
A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. They play a role in the intracellular transport of molecules contained within membrane vesicles. Vesicular transport proteins are distinguished from MEMBRANE TRANSPORT PROTEINS, which move molecules across membranes, by the mode in which the molecules are transported.
A family of 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 3.6.1.50.
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.
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 constitutively expressed subfamily of the HSP70 heat-shock proteins. They preferentially bind and release hydrophobic peptides by an ATP-dependent process and are involved in post-translational PROTEIN TRANSLOCATION.
Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
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.
The rate dynamics in chemical or physical systems.
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)
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.
A family of large adaptin protein complex subunits of approximately 90-130 kDa in size.
Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.
A family of medium adaptin protein subunits of approximately 45 KDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 3 and ADAPTOR PROTEIN COMPLEX 4.
ADP-RIBOSYLATION FACTOR 1 is involved in regulating intracellular transport by modulating the interaction of coat proteins with organelle membranes in the early secretory pathway. It is a component of COAT PROTEIN COMPLEX I. This enzyme was formerly listed as EC 3.6.1.47.
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.
A fungal metabolite which is a macrocyclic lactone exhibiting a wide range of antibiotic activity.
Transport proteins that carry specific substances in the blood or across cell membranes.
MONOMERIC GTP-BINDING PROTEINS that were initially recognized as allosteric activators of the MONO(ADP-RIBOSE) TRANSFERASE of the CHOLERA TOXIN catalytic subunit. They are involved in vesicle trafficking and activation of PHOSPHOLIPASE D. This enzyme was formerly listed as EC 3.6.1.47
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)
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 engulfing of liquids by cells by a process of invagination and closure of the cell membrane to form fluid-filled vacuoles.
An enzyme that catalyzes the hydrolysis of an alpha L-fucoside to yield an alcohol and L-fucose. Deficiency of this enzyme can cause FUCOSIDOSIS. EC 3.2.1.51.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Phosphoric acid esters of mannose.
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.
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.
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.
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.
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)
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
A family of proteins that play a role as cofactors in the process of CLATHRIN recycling in cells.
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.
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.
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.
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.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.
A family of small adaptin protein complex subunits of approximately 19 KDa in size.
Macromolecular complexes formed from the association of defined protein subunits.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
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)
A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.
Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)
The 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.
An enzyme that catalyzes the HYDROLYSIS of terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides. The enzyme plays a role in the processing of newly formed N-glycans and in degradation of mature GLYCOPROTEINS. There are multiple isoforms of alpha-mannosidase, each having its own specific cellular location and pH optimum. Defects in the lysosomal form of the enzyme results in a buildup of mannoside intermediate metabolites and the disease ALPHA-MANNOSIDOSIS.
A narcotic analgesic morphinan used as a sedative in veterinary practice.
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
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.
A clathrin adaptor protein complex primarily involved in clathrin-related transport at the TRANS-GOLGI NETWORK.
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.-.
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.
Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.
Established cell cultures that have the potential to propagate indefinitely.
A diverse class of enzymes that interact with UBIQUITIN-CONJUGATING ENZYMES and ubiquitination-specific protein substrates. Each member of this enzyme group has its own distinct specificity for a substrate and ubiquitin-conjugating enzyme. Ubiquitin-protein ligases exist as both monomeric proteins multiprotein complexes.
Glycoside hydrolases that catalyze the hydrolysis of alpha or beta linked MANNOSE.
An energy dependent process following the crosslinking of B CELL ANTIGEN RECEPTORS by multivalent ligands (bivalent anti-antibodies, LECTINS or ANTIGENS), on the B-cell surface. The crosslinked ligand-antigen receptor complexes collect in patches which flow to and aggregate at one pole of the cell to form a large mass - the cap. The caps may then be endocytosed or shed into the environment.
Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.
Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.
The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.
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 group of alicyclic hydrocarbons with the general formula R-C5H9.
A subtype of dynamin found primarily in the NEURONS of the brain.
Electrophoresis in which agar or agarose gel is used as the diffusion medium.
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.
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.
Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.
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.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)
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.
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.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
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.
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 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.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Techniques used to demonstrate or measure an immune response, and to identify or measure antigens using antibodies.
Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.
Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The threadlike, vascular projections of the chorion. Chorionic villi may be free or embedded within the DECIDUA forming the site for exchange of substances between fetal and maternal blood (PLACENTA).
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.
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.2.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
A hexosaminidase specific for non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. It acts on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES. Two specific mammalian isoenzymes of beta-N-acetylhexoaminidase are referred to as HEXOSAMINIDASE A and HEXOSAMINIDASE B. Deficiency of the type A isoenzyme causes TAY-SACHS DISEASE, while deficiency of both A and B isozymes causes SANDHOFF DISEASE. The enzyme has also been used as a tumor marker to distinguish between malignant and benign disease.
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.
Minute projections of cell membranes which greatly increase the surface area of the cell.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
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.
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.
A superfamily of small proteins which are involved in the MEMBRANE FUSION events, intracellular protein trafficking and secretory processes. They share a homologous SNARE motif. The SNARE proteins are divided into subfamilies: QA-SNARES; QB-SNARES; QC-SNARES; and R-SNARES. The formation of a SNARE complex (composed of one each of the four different types SNARE domains (Qa, Qb, Qc, and R)) mediates MEMBRANE FUSION. Following membrane fusion SNARE complexes are dissociated by the NSFs (N-ETHYLMALEIMIDE-SENSITIVE FACTORS), in conjunction with SOLUBLE NSF ATTACHMENT PROTEIN, i.e., SNAPs (no relation to SNAP 25.)
The absence of light.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
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.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
A family of vesicular transport proteins characterized by an N-terminal transmembrane region and two C-terminal calcium-binding domains.
A class of MOLECULAR CHAPERONES found in both prokaryotes and in several compartments of eukaryotic cells. These proteins can interact with polypeptides during a variety of assembly processes in such a way as to prevent the formation of nonfunctional structures.
The distal terminations of axons which are specialized for the release of neurotransmitters. Also included are varicosities along the course of axons which have similar specializations and also release transmitters. Presynaptic terminals in both the central and peripheral nervous systems are included.
The process of cleaving a chemical compound by the addition of a molecule of water.
Enzymes that catalyze the hydrolysis of N-acylhexosamine residues in N-acylhexosamides. Hexosaminidases also act on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
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).
The region of the stem beneath the stalks of the seed leaves (cotyledons) and directly above the young root of the embryo plant. It grows rapidly in seedlings showing epigeal germination and lifts the cotyledons above the soil surface. In this region (the transition zone) the arrangement of vascular bundles in the root changes to that of the stem. (From Concise Dictionary of Biology, 1990)
A POSTURE in which an ideal body mass distribution is achieved. Postural balance provides the body carriage stability and conditions for normal functions in stationary position or in movement, such as sitting, standing, or walking.
A family of structurally related proteins that were originally discovered for their role in cell-cycle regulation in CAENORHABDITIS ELEGANS. They play important roles in regulation of the CELL CYCLE and as components of UBIQUITIN-PROTEIN LIGASES.
A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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 enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
The outer layer of the adrenal gland. It is derived from MESODERM and comprised of three zones (outer ZONA GLOMERULOSA, middle ZONA FASCICULATA, and inner ZONA RETICULARIS) with each producing various steroids preferentially, such as ALDOSTERONE; HYDROCORTISONE; DEHYDROEPIANDROSTERONE; and ANDROSTENEDIONE. Adrenal cortex function is regulated by pituitary ADRENOCORTICOTROPIN.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.
A family of synaptic vesicle-associated proteins involved in the short-term regulation of NEUROTRANSMITTER release. Synapsin I, the predominant member of this family, links SYNAPTIC VESICLES to ACTIN FILAMENTS in the presynaptic nerve terminal. These interactions are modulated by the reversible PHOSPHORYLATION of synapsin I through various signal transduction pathways. The protein is also a substrate for cAMP- and CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASES. It is believed that these functional properties are also shared by synapsin II.
Neurotoxic proteins from the venom of the banded or Formosan krait (Bungarus multicinctus, an elapid snake). alpha-Bungarotoxin blocks nicotinic acetylcholine receptors and has been used to isolate and study them; beta- and gamma-bungarotoxins act presynaptically causing acetylcholine release and depletion. Both alpha and beta forms have been characterized, the alpha being similar to the large, long or Type II neurotoxins from other elapid venoms.
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
A subfamily of Q-SNARE PROTEINS which occupy the same position as syntaxin 1A in the SNARE complex and which also are most similar to syntaxin 1A in their AMINO ACID SEQUENCE. This subfamily is also known as the syntaxins, although a few so called syntaxins are Qc-SNARES.
A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
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.
Two-phase systems in which one is uniformly dispersed in another as particles small enough so they cannot be filtered or will not settle out. The dispersing or continuous phase or medium envelops the particles of the discontinuous phase. All three states of matter can form colloids among each other.
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 proteins that bind acetylcholine with high affinity and trigger intracellular changes influencing the behavior of cells. Cholinergic receptors are divided into two major classes, muscarinic and nicotinic, based originally on their affinity for nicotine and muscarine. Each group is further subdivided based on pharmacology, location, mode of action, and/or molecular biology.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
Contractile tissue that produces movement in animals.
A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.
Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.
An interstitial lung disease of unknown etiology, occurring between 21-80 years of age. It is characterized by a dramatic onset of a "pneumonia-like" illness with cough, fever, malaise, fatigue, and weight loss. Pathological features include prominent interstitial inflammation without collagen fibrosis, diffuse fibroblastic foci, and no microscopic honeycomb change. There is excessive proliferation of granulation tissue within small airways and alveolar ducts.
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.
A type of extracellular vesicle, containing RNA and proteins, that is secreted into the extracellular space by EXOCYTOSIS when MULTIVESICULAR BODIES fuse with the PLASMA MEMBRANE.
Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.
Cells that store epinephrine secretory vesicles. During times of stress, the nervous system signals the vesicles to secrete their hormonal content. Their name derives from their ability to stain a brownish color with chromic salts. Characteristically, they are located in the adrenal medulla and paraganglia (PARAGANGLIA, CHROMAFFIN) of the sympathetic nervous system.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
A vesicular transport protein expressed predominately in NEURONS. Synaptotagmin helps regulate EXOCYTOSIS of SYNAPTIC VESICLES and appears to serve as a calcium sensor to trigger NEUROTRANSMITTER release. It also acts as a nerve cell receptor for certain BOTULINUM TOXINS.
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.
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.
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
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.
The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.
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.
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.
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.
A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A large superfamily of transcription factors that contain a region rich in BASIC AMINO ACID residues followed by a LEUCINE ZIPPER domain.
The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.
A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.
A blue-green biliprotein widely distributed in the plant kingdom.

Clathrin and two components of the COPII complex, Sec23p and Sec24p, could be involved in endocytosis of the Saccharomyces cerevisiae maltose transporter. (1/342)

The Saccharomyces cerevisiae maltose transporter is a 12-transmembrane segment protein that under certain physiological conditions is degraded in the vacuole after internalization by endocytosis. Previous studies showed that endocytosis of this protein is dependent on the actin network, is independent of microtubules, and requires the binding of ubiquitin. In this work, we attempted to determine which coat proteins are involved in this endocytosis. Using mutants defective in the heavy chain of clathrin and in several subunits of the COPI and the COPII complexes, we found that clathrin, as well as two cytosolic subunits of COPII, Sec23p and Sec24p, could be involved in internalization of the yeast maltose transporter. The results also indicate that endocytosis of the maltose transporter and of the alpha-factor receptor could have different requirements.  (+info)

LST1 is a SEC24 homologue used for selective export of the plasma membrane ATPase from the endoplasmic reticulum. (2/342)

In Saccharomyces cerevisiae, vesicles that carry proteins from the ER to the Golgi compartment are encapsulated by COPII coat proteins. We identified mutations in ten genes, designated LST (lethal with sec-thirteen), that were lethal in combination with the COPII mutation sec13-1. LST1 showed synthetic-lethal interactions with the complete set of COPII genes, indicating that LST1 encodes a new COPII function. LST1 codes for a protein similar in sequence to the COPII subunit Sec24p. Like Sec24p, Lst1p is a peripheral ER membrane protein that binds to the COPII subunit Sec23p. Chromosomal deletion of LST1 is not lethal, but inhibits transport of the plasma membrane proton-ATPase (Pma1p) to the cell surface, causing poor growth on media of low pH. Localization by both immunofluorescence microscopy and cell fractionation shows that the export of Pma1p from the ER is impaired in lst1Delta mutants. Transport of other proteins from the ER was not affected by lst1Delta, nor was Pma1p transport found to be particularly sensitive to other COPII defects. Together, these findings suggest that a specialized form of the COPII coat subunit, with Lst1p in place of Sec24p, is used for the efficient packaging of Pma1p into vesicles derived from the ER.  (+info)

Identification of the putative mammalian orthologue of Sec31P, a component of the COPII coat. (3/342)

The regulation of intracellular vesicular trafficking is mediated by specific families of proteins that are involved in vesicular budding, translocation, and fusion with target membranes. We purified a vesicle-associated protein from hepatic microsomes using sequential column chromatography and partially sequenced it. Oliogonucleotides based on these sequences were used to clone the protein from a rat liver cDNA library. The clone encoded a novel protein with a predicted mass of 137 kDa (p137). The protein had an N terminus WD repeat motif with significant homology to Sec31p, a member of the yeast COPII coat that complexes with Sec13p. We found that p137 interacted with mammalian Sec13p using several approaches: co-elution through sequential column chromatography, co-immunoprecipitation from intact cells, and yeast two-hybrid analysis. Morphologically, the p137 protein was localized to small punctate structures in the cytoplasm of multiple cultured cell lines. When Sec13p was transfected into these cells, it demonstrated considerable overlap with p137. This overlap was maintained through several pharmacological manipulations. The p137 compartment also demonstrated partial overlap with ts045-VSVG protein when infected cells were incubated at 15 degrees C. These findings suggest that p137 is the mammalian orthologue of Sec31p.  (+info)

Sec24p and Iss1p function interchangeably in transport vesicle formation from the endoplasmic reticulum in Saccharomyces cerevisiae. (4/342)

The Sec23p/Sec24p complex functions as a component of the COPII coat in vesicle transport from the endoplasmic reticulum. Here we characterize Saccharomyces cerevisiae SEC24, which encodes a protein of 926 amino acids (YIL109C), and a close homologue, ISS1 (YNL049C), which is 55% identical to SEC24. SEC24 is essential for vesicular transport in vivo because depletion of Sec24p is lethal, causing exaggeration of the endoplasmic reticulum and a block in the maturation of carboxypeptidase Y. Overproduction of Sec24p suppressed the temperature sensitivity of sec23-2, and overproduction of both Sec24p and Sec23p suppressed the temperature sensitivity of sec16-2. SEC24 gene disruption could be complemented by overexpression of ISS1, indicating functional redundancy between the two homologous proteins. Deletion of ISS1 had no significant effect on growth or secretion; however, iss1Delta mutants were found to be synthetically lethal with mutations in the v-SNARE genes SEC22 and BET1. Moreover, overexpression of ISS1 could suppress mutations in SEC22. These genetic interactions suggest that Iss1p may be specialized for the packaging or the function of COPII v-SNAREs. Iss1p tagged with His(6) at its C terminus copurified with Sec23p. Pure Sec23p/Iss1p could replace Sec23p/Sec24p in the packaging of a soluble cargo molecule (alpha-factor) and v-SNAREs (Sec22p and Bet1p) into COPII vesicles. Abundant proteins in the purified vesicles produced with Sec23p/Iss1p were indistinguishable from those in the regular COPII vesicles produced with Sec23p/Sec24p.  (+info)

Sfb2p, a yeast protein related to Sec24p, can function as a constituent of COPII coats required for vesicle budding from the endoplasmic reticulum. (5/342)

The COPII coat is required for vesicle budding from the endoplasmic reticulum (ER), and consists of two heterodimeric subcomplexes, Sec23p/Sec24p, Sec13p/Sec31p, and a small GTPase, Sar1p. We characterized a yeast mutant, anu1 (abnormal nuclear morphology) exhibiting proliferated ER as well as abnormal nuclear morphology at the restrictive temperature. Based on the finding that ANU1 is identical to SEC24, we confirmed a temperature-sensitive protein transport from the ER to the Golgi in anu1-1/sec24-20 cells. Overexpression of SFB2, a SEC24 homologue with 56% identity, partially suppressed not only the mutant phenotype of sec24-20 cells but also rescued the SEC24-disrupted cells. Moreover, the yeast two-hybrid assay revealed that Sfb2p, similarly to Sec24p, interacted with Sec23p. In SEC24-disrupted cells rescued by overexpression of SFB2, some cargo proteins were still retained in the ER, while most of the protein transport was restored. Together, these findings strongly suggest that Sfb2p functions as the component of COPII coats in place of Sec24p, and raise the possibility that each member of the SEC24 family of proteins participates directly and/or indirectly in cargo-recognition events with its own cargo specificity at forming ER-derived vesicles.  (+info)

Mutants affecting the structure of the cortical endoplasmic reticulum in Saccharomyces cerevisiae. (6/342)

We find that the peripheral ER in Saccharomyces cerevisiae forms a dynamic network of interconnecting membrane tubules throughout the cell cycle, similar to the ER in higher eukaryotes. Maintenance of this network does not require microtubule or actin filaments, but its dynamic behavior is largely dependent on the actin cytoskeleton. We isolated three conditional mutants that disrupt peripheral ER structure. One has a mutation in a component of the COPI coat complex, which is required for vesicle budding. This mutant has a partial defect in ER segregation into daughter cells and disorganized ER in mother cells. A similar phenotype was found in other mutants with defects in vesicular trafficking between ER and Golgi complex, but not in mutants blocked at later steps in the secretory pathway. The other two mutants found in the screen have defects in the signal recognition particle (SRP) receptor. This receptor, along with SRP, targets ribosome-nascent chain complexes to the ER membrane for protein translocation. A conditional mutation in SRP also disrupts ER structure, but other mutants with translocation defects do not. We also demonstrate that, both in wild-type and mutant cells, the ER and mitochondria partially coalign, and that mutations that disrupt ER structure also affect mitochondrial structure. Our data suggest that both trafficking between the ER and Golgi complex and ribosome targeting are important for maintaining ER structure, and that proper ER structure may be required to maintain mitochondrial structure.  (+info)

Kinase signaling initiates coat complex II (COPII) recruitment and export from the mammalian endoplasmic reticulum. (7/342)

The events regulating coat complex II (COPII) vesicle formation involved in the export of cargo from the endoplasmic reticulum (ER) are unknown. COPII recruitment to membranes is initiated by the activation of the small GTPase Sar1. We have utilized purified COPII components in both membrane recruitment and cargo export assays to analyze the possible role of kinase regulation in ER export. We now demonstrate that Sar1 recruitment to membranes requires ATP. We find that the serine/threonine kinase inhibitor H89 abolishes membrane recruitment of Sar1, thereby preventing COPII polymerization by interfering with the recruitment of the cytosolic Sec23/24 COPII coat complex. Inhibition of COPII recruitment prevents export of cargo from the ER. These results demonstrate that ER export and initiation of COPII vesicle formation in mammalian cells is under kinase regulation.  (+info)

The p58-positive pre-golgi intermediates consist of distinct subpopulations of particles that show differential binding of COPI and COPII coats and contain vacuolar H(+)-ATPase. (8/342)

We have studied the structural and functional properties of the pre-Golgi intermediate compartment (IC) in normal rat kidney cells using analytical cell fractionation with p58 as the principal marker. The sedimentation profile (sediterm) of p58, obtained by analytical differential centrifugation, revealed in steady-state cells the presence of two main populations of IC elements whose average sedimentation coefficients, s(H)=1150+/-58S ('heavy') and s(L)=158+/-8S ('light'), differed from the s-values obtained for elements of the rough and smooth endoplasmic reticulum. High resolution analysis of these subpopulations in equilibrium density gradients further revealed that the large difference in their s-values was mainly due to particle size. The 'light' particle population contained the bulk of COPI and COPII coats, and redistribution of p58 to these particles was observed in transport-arrested cells, showing that the two types of elements are also compositionally distinct and have functional counterparts in intact cells. Using a specific antibody against the 16 kDa proteolipid subunit of the vacuolar H(+)-ATPase, an enrichment of the V(o )domain of the ATPase was observed in the p58-positive IC elements. Interestingly, these elements could contain both COPI and COPII coats and their density distribution was markedly affected by GTP(&ggr;)S. Together with morphological observations, these results demonstrate that, in addition to clusters of small tubules and vesicles, the IC also consists of large-sized structures and corroborate the proposal that the IC elements contain an active vacuolar H(+)-ATPase.  (+info)

Plays a role in the transport of cargos that are too large to fit into COPII-coated vesicles and require specific mechanisms to be incorporated into membrane-bound carriers and exported from the endoplasmic reticulum. This protein is required for collagen VII (COL7A1) secretion by loading COL7A1 into transport carriers. It may participate in cargo loading of COL7A1 at endoplasmic reticulum exit sites by binding to COPII coat subunits Sec23/24 and guiding SH3-bound COL7A1 into a growing carrier. Does not play a role in global protein secretion and is apparently specific to COL7A1 cargo loading. However, it may participate in secretion of other proteins in cells that do not secrete COL7A1. It is also specifically required for the secretion of lipoproteins by participating in their export from the endoplasmic reticulum (PubMed:27138255 ...
Transport and Golgi organization protein 1 homolog; Plays a role in the transport of cargos that are too large to fit into COPII-coated vesicles and require specific mechanisms to be incorporated into membrane-bound carriers and exported from the endoplasmic reticulum. This protein is required for collagen VII (COL7A1) secretion by loading COL7A1 into transport carriers. It may participate in cargo loading of COL7A1 at endoplasmic reticulum exit sites by binding to COPII coat subunits Sec23/24 and guiding SH3-bound COL7A1 into a growing carrier. Does not play a role in global protein s ...
In this study, we showed that Sec12 recruitment to ER exit sites by interactions with cTAGE5 is necessary for collagen transport from the ER. As the interaction between cTAGE5 and Sec12 did not alter the activity of Sec12 toward Sar1, cTAGE5-mediated Sec12 concentration may be important for the localized activation of Sar1 in the vicinity of the ER exit sites. In this regard, it has been reported that Sedlin is somehow involved in the inactivation of Sar1 through interaction with TANGO1 at ER exit sites and is specifically required for collagen secretion (Venditti et al., 2012). Thus, it is interesting to speculate that the exit of collagen from the ER may rely on specific activation-inactivation mechanisms-Sar1 might first be activated by the cTAGE5-Sec12 complex and then inactivated by TANGO1-Sedlin. In this case, tight regulation of the Sar1 GTPase cycle at ER exit sites would be important for collagen secretion from the ER, although we cannot totally rule out the possibility that ...
TY - JOUR. T1 - PCTAIRE protein kinases interact directly with the COPII complex and modulate secretory cargo transport. AU - Palmer, KJ. AU - Konkel, JE. AU - Stephens, DJ. N1 - Publisher: Company of Biologists Other: Konkel, JE was a third year Bristol Biochemistry student and Nuffield summer student. PY - 2005/9. Y1 - 2005/9. U2 - 10.1242/jcs.02496. DO - 10.1242/jcs.02496. M3 - Article (Academic Journal). VL - 118 (17). SP - 3839. EP - 3847. JO - Journal of Cell Science. JF - Journal of Cell Science. SN - 0021-9533. ER - ...
Protein trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus involves specific uptake into coat protein complex II (COPII)-coated vesicles of secretory and of vesicle targeting (v-SNARE) proteins. Here, two ER to Golgi v-SNAREs, Bet1p and Bos1p, were shown to interact specifically with Sar1p, Sec23p, and Sec24p, components of the COPII coat, in a guanine nucleotide-dependent fashion. Other v-SNAREs, Sec22p and Ykt6p, might interact more weakly with the COPII coat or interact indirectly by binding to Bet1p or Bos1p. The data suggest that transmembrane proteins can be taken up into COPII vesicles by direct interactions with the coat proteins and may play a structural role in the assembly of the COPII coat complex. ...
Plant Golgi stacks are mobile organelles that can travel along actin filaments. How COPII (coat complex II) vesicles are transferred from endoplasmic reticulum (ER) export sites to the moving Golgi stacks is not understood. We have examined COPII vesicle transfer in high-pressure frozen/freeze-subst …
Marian Blanca Ramírez from the CSIC in Spain has been studying the effects of LRRK2, a protein associated with Parkinsons disease, on cell motility. A Travelling Fellowship from Journal of Cell Science allowed her to spend time in Prof Maddy Parsons lab at Kings College London, learning new cell migration assays and analysing fibroblasts cultured from individuals with Parkinsons. Read more on her story here. Where could your research take you? The deadline to apply for the current round of Travelling Fellowships is 23rd Feburary 2018. Apply now!. ...
Collagen is the most abundant protein in the animal kingdom. It is of fundamental importance during development for cell differentiation and tissue morphogenesis as well as in pathological processes such as fibrosis and cancer cell migration. However, our understanding of the mechanisms of procollagen secretion remains limited. Here, we show that TFG organizes transitional ER (tER) and ER exit sites (ERESs) into larger structures. Depletion of TFG results in dispersion of tER elements that remain associated with individual ER-Golgi intermediate compartments (ERGICs) as largely functional ERESs. We show that TFG is not required for the transport and packaging of small soluble cargoes but is necessary for the export of procollagen from the ER. Our work therefore suggests a key relationship between the structure and function of ERESs and a central role for TFG in optimizing COPII assembly for procollagen export ...
Component of the coat protein complex II (COPII) which promotes the formation of transport vesicles from the endoplasmic reticulum (ER). The coat has two main functions, the physical deformation of the endoplasmic reticulum membrane into vesicles and the selection of cargo molecules.
On page 1029, Supek et al. illustrate how a peripheral membrane protein organizes a coat protein complex involved in secretory vesicle formation.. The protein in question, yeast Sec16p, is an ER resident required in vivo for COPII-dependent vesicle budding. In vitro, Sec16p is not necessary for budding from liposomes reconstituted with pure cytosolic COPII proteins. However, this in vitro reaction depends on a nonhydrolyzable form of GTP, probably because the COPII coat falls apart when Sar1p (the initiator of coat assembly) hydrolyzes GTP. Until now, the function of Sec16p in liposome budding could not be tested, because the protein was difficult to purify. Supek et al. report conditions that stabilize Sec16p and have purified enough protein for in vitro studies. Microsomal membranes stripped of endogenous Sec16p were stimulated in vesicle budding by the purified. protein, but only in the presence of hydrolyzable GTP. Thus, the in vivo function of Sec16p may be either to slow GTP hydrolysis ...
Collagen is the most abundant protein in the animal kingdom. It is of fundamental importance during development for cell differentiation and tissue morphogenesis as well as in pathological processes such as fibrosis and cancer cell migration. However, our understanding of the mechanisms of procollag …
CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Abstract. COPII-coated ER-derived transport vesicles from Saccharomyces cerevisiae contain a distinct set of membrane-bound polypeptides. One of these polypeptides, termed Erv14p (ER-vesicle protein of 14 kD), corresponds to an open reading frame on yeast chromosome VII that is predicted to encode an integral membrane protein and shares sequence identity with the Drosophila cornichon gene product. Experiments with an epitope-tagged version of Erv14p indicate that this protein localizes to the ER and is selectively packaged into COPII-coated vesicles. Haploid cells that lack Erv14p are viable but display a modest defect in bud site selection because a transmembrane secretory protein, Axl2p, is not efficiently delivered to the cell surface. Axl2p is required for selection of axial growth
Pandey A, Fernandez MM, Steen H, Blagoev B, Nielsen MM, Roche S, Mann M, Lodish HF. Identification of a novel immunoreceptor tyrosine-based activation motif-containing molecule, STAM2, by mass spectrometry and its involvement in growth factor and cytokine receptor signaling pathways. J Biol Chem 2000;275:38633-38639 ...
Structural Component Of 3 Distinct Complexes; Subunit Of Nup84 Nuclear Pore Sub-complex (NPC), COPII Vesicle Coat, And Seh1-associated (SEA) Complex; COPII Vesicle Coat Is Required For ER To Golgi Transport; The Nup84 Subcomplex Contributes To Nucleocytoplasmic Transport, NPC Biogenesis And Processes That May Require Localization Of Chromosomes At The Nuclear Periphery, Including Transcription; Homologous To Human SEC13; Abundance Increases Under DNA Replication Stress
Structural component of 3 distinct complexes; subunit of Nup84 nuclear pore sub-complex (NPC), COPII vesicle coat, and Seh1-associated (SEA) complex; COPII vesicle coat is required for ER to Golgi transport; the Nup84 subcomplex contributes to nucleocytoplasmic transport, NPC biogenesis and processes that may require localization of chromosomes at the nuclear periphery, including transcription; homologous to human SEC13; abundance increases under DNA replication stress ...
Structural component of 3 distinct complexes; subunit of Nup84 nuclear pore sub-complex (NPC), COPII vesicle coat, and Seh1-associated (SEA) complex; COPII vesicle coat is required for ER to Golgi transport; the Nup84 subcomplex contributes to nucleocytoplasmic transport, NPC biogenesis and processes that may require localization of chromosomes at the nuclear periphery, including transcription; homologous to human SEC13; abundance increases under DNA replication stress ...
The budding process if as follows (Figure 9). Sar1p goes to the ER. Sec12p converts Sar1p-GDP to the activated GTP-bound form. This causes Sar1p to be membrane-bound. GTP is the best nucleotide for budding. Then, Sar1p-GTP recruits Sec23p and Sec13p complexes to form COPII. COPII executes the budding event. Sar1p hydrolyzes GTP, stimulated by the Sec23p subunit of the Sec23p complex. GTP hydrolysis leads to the loss of Sar1p from vesicles, causing coat instability. The Sar1p loss exposes targeting proteins on the vesicle, such as Sec22p and Bos1p. These proteins provide binding selectivity to the target proteins on the Golgi membrane. If vesicles form with a nonhydrolyzable analog like GMP-PNP, Sar1p and the COPII proteins remain on the vesicle (Figure 8). The remaining Sar1p and COPII proteins hinder access of the vesicle to the Golgi. The vesicle will not be able to fuse with the acceptor membrane.. COPII formation resembles the assembly of COPI. But, COPI and COPII are distinct. Unlike COPI, ...
These reference sequences exist independently of genome builds. Explain. These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above. ...
Member Of The P24 Family Involved In ER To Golgi Transport; Similar To Emp24p And Erv25p; Role In Misfolded Protein Quality Control; Forms A Heterotrimeric Complex With Erp1p, Emp24p, And Erv25p; Localized To COPII-coated Vesicles; ERP2 Has A Paralog, ERP4, That Arose From The Whole Genome Duplication
Synonyms for E (exit) site in Free Thesaurus. Antonyms for E (exit) site. 3 words related to ribosome: cell organ, cell organelle, organelle. What are synonyms for E (exit) site?
Precise inheritance of organelles during mitosis ensures the proper organisation and function of daughter cells. Inheritance of the Golgi complex, a single copy organelle, requires its disassembly before mitosis; Golgi disassembly is driven by mitotic inhibition of COPII-dependent export of proteins from endoplasmic reticulum exit sites (ERESs) to the Golgi. Helen Hughes and David Stephens have been investigating how ERESs are restored at the end of mitosis and, on page 4032, they report that Sec16A - the major human orthologue of Sec16, which defines the site of COPII vesicle budding in yeast - defines the site at which COPII-dependent budding reinitiates after mitosis. Using quantitative 4D imaging of HeLa cells stably expressing fluorescently labelled Sec16A, the authors show that, unlike all other COPII components, Sec16A remains associated with ERESs throughout mitosis. Moreover, Sec16A localisation is coincident with the reappearance of COPII puncta on mitotic exit. Hughes and Stephens ...
p,Coat protein I (COPI)-coated vesicles mediate retrograde transport from the Golgi to the endoplasmic reticulum (ER), as well as transport within the Golgi. Major progress has been made in defining the structure of COPI coats, in vitro and in vivo, at resolutions as high as 9 Å. Nevertheless, important questions remain unanswered, including what specific interactions stabilize COPI coats, how COPI vesicles recognize their target membranes, and how coat disassembly is coordinated with vesicle fusion and cargo delivery. Here, we use X-ray crystallography to identify a conserved site on the COPI subunit α-COP that binds to flexible, acidic sequences containing a single tryptophan residue. One such sequence, found within α-COP itself, mediates α-COP homo-oligomerization. Another such sequence is contained within the lasso of the ER-resident Dsl1 complex, where it helps mediate the tethering of Golgi-derived COPI vesicles at the ER membrane. Together, our findings suggest that α-COP ...
Exit sites (ES) are specialized domains of the endoplasmic reticulum (ER) at which cargo proteins of the secretory pathway are packaged into COPII-coated vesicles. Although the essential COPII proteins (Sar1p, Sec23p-Sec24p, Sec13p-Sec31p) have been characterized in detail and their sequential binding kinetics at ER membranes have been quantified, the basic processes that govern the self-assembly and spatial organization of ERES have remained elusive. Here, we have formulated a generic computational model that describes the process of formation of ERES on a mesoscopic scale. The model predicts that ERES are arranged in a quasi-crystalline pattern, while their size strongly depends on the cargo-modulated kinetics of COPII turnover - that is, a lack of cargo leads to smaller and more mobile ERES. These predictions are in favorable agreement with experimental data obtained by fluorescence microscopy. The model further suggests that cooperative binding of COPII components, for example mediated by regulatory
Peng, R.; Grabowski, R.; De Antoni, A.; Gallwitz, D.: Specific interaction of the yeast cis-Golgi syntaxin Sed5p and the coat protein complex II component Sec24p of endoplasmic reticulum-derived transport vesicles. Proceedings of the National Academy of Sciences USA 96, pp. 3751 - 3756 (1999 ...
The nucleus is one of the defining features of eukaryotes and the question of its origin is intimately linked to the evolution of the eukaryotic cell. It is delimited by a double lipid bilayer called the nuclear envelope, which separates the nuclear interior from the cytoplasm. The inner and outer membranes of the nucleus are continuous with one another creating a single folded envelope, interrupted by nuclear pore complexes (NPCs), which enable transport of proteins and RNA between nucleoplasm and cytoplasm.. A combination of proteomic and bioinformatic analyses has shown that numerous Nups are conserved between yeast and vertebrates. As this only describes a subset of eukaryotic diversity, comparative genomic analyses were used to establish the extent to which the NPC is conserved across the eukaryotic tree. NPCs have been suggested to share a common origin with vesicle coat proteins of the endomembrane system. An additional goal of this work was therefore to establish the distribution of ...
Coatomer coated (COPI) vesicles play a pivotal role for multiple membrane trafficking steps throughout the eukaryotic cell. Our focus is on betaCOP, one of the most well known components of the COPI multi-protein complex. Amino acid differences in be
Author: Rein, U. et al.; Genre: Journal Article; Published in Print: 2002-04-29; Open Access; Keywords: Arf; ARF-GAP; COPI; ER-Golgi SNAREs; protein transport|br/|; Title: ARF-GAP-mediated interaction between the ER-Golgi v-SNAREs and the COPI coat
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The protein encoded by this gene is reported to be a component of the Golgi matrix. It may act as a golgin protein by negatively regulating transit of secretory cargo and by acting as a structural scaffold of the Golgi. Alternative splicing results in multiple transcript variants ...
The protein encoded by this gene is reported to be a component of the Golgi matrix. It may act as a golgin protein by negatively regulating transit of secretory cargo and by acting as a structural scaffold of the Golgi. Alternative splicing results in multiple transcript variants ...
TY - JOUR. T1 - Tethering assays for COPI vesicles mediated by golgins. AU - Satoh, Ayano. AU - Malsam, Jörg. AU - Warren, Graham. N1 - Funding Information: We thank all members of the Warren, Mellman, and Toomre laboratories for helpful comments and discussions, and Marino Zerial for generous provision of purified EEA1. This work was supported by the NIH and the Ludwig Institute for Cancer Research. A.S. was supported by the American Heart Association.. PY - 2005. Y1 - 2005. N2 - A method is described that allows the attachment of COPI vesicles and Golgi membranes to glass slides that can then be analyzed using electron microscopy (EM) and immuno-EM methods. Subpopulations of COPI vesicles can be bound selectively using recombinant golgins. Alternatively, COPI vesicles can be attached to prebound Golgi membranes. Marking these vesicles selectively with biotin allows their site of attachment to be identified.. AB - A method is described that allows the attachment of COPI vesicles and Golgi ...
Transport vesicles form at a donor compartment and fuse to an acceptor compartment mediate the movement of cargo proteins within eukaryotic cells from one subcellular compartment to another. COPII vesicles specifically provide the means of transport for proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. The in vitro enrichment of COPII vesicles was undertaken with the intent of better understanding COPII dependent transport between the ER and Golgi. This approach allowed for the identification of abundant vesicle proteins, one of which is Erv14p, an ER-vesicle protein of 14 kDa. Erv14p is an integral membrane protein that localized to the ER and Golgi and was responsible for the efficient transport of at least one secretory cargo protein, Ax12p. Erv14p was not essential. However, genetic analysis of ERV14 deletion strains carrying thermosensitive alleles encoding for COPII components and other proteins known to participate in ER to Golgi vesicle trafficking revealed a variety ...
Small GTPases largely control membrane traffic, which is essential for the survival of all eukaryotes. Among the small GTP-binding proteins, ARF1 (ADP-ribosylation factor 1) and SAR1 (Secretion-Associated RAS super family 1) are commonly conserved among all eukaryotes with respect to both their functional and sequential characteristics. The ARF1 and SAR1 GTP-binding proteins are involved in the formation and budding of vesicles throughout plant endomembrane systems. ARF1 has been shown to play a critical role in COPI (Coat Protein Complex I)-mediated retrograde trafficking in eukaryotic systems, whereas SAR1 GTPases are involved in intracellular COPII-mediated protein trafficking from the ER to the Golgi apparatus. This review offers a summary of vesicular trafficking with an emphasis on the ARF1 and SAR1 expression patterns at early growth stages and in the de-etiolation process.
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In eukaryotic cells, the endoplasmic reticulum (ER) is a significant site of synthesis of both lipids and proteins, a lot of which should be transported to various other organelles. transfer proteins. Finally, we high light the current problems towards the field in handling the physiological legislation of COPII vesicle creation as well as the molecular information on how different cargoes, both lipids and proteins, are accommodated. likewise provides discrete ERES that are few in amount and so are apposed towards the Golgi fairly, whereas seems to absence this higher level of firm with COPII vesicles budding over the whole ER membrane [36]. Two suggested features of ERES are (i) to allow cargo destined for export to become efficiently packed and (ii) to make sure that ER resident protein and various other non-cargo substrates stay in the ER. The molecular make-up and framework of ERES can be an rising area that looks for to broaden our knowledge of the systems by which exclusive subdomains are ...
The most surprising results came when the authors examined the function of Ypt1, the Rab GTPase implicated in ER-to-Golgi transport. Vesicles prepared from a temperature-sensitive mutant in Ypt1, ypt1-3, had no defect on their ability to fuse with wild-type acceptor membranes. However, Ypt1 mutant acceptor membranes showed a dramatic defect in their ability to allow fusion with wild-type vesicles. Consistent with this the authors also find that very little Ypt1 is recruited onto vesicles when they are produced with purified COPII components, suggesting that Ypt1 normally associates with these vesicles after their initial COPII-dependent budding. However, unlike the membrane-embedded SNAREs, Ypt1 and Rabs are known to cycle on and off membranes with the assistance of a protein known as GDI. This protein has the ability to solvate the hydrophobic geranylgeranyl group at the COOH terminus of Rab proteins and extract them off the membrane which then allows them to attach to another membrane. This ...
Reactome is pathway database which provides intuitive bioinformatics tools for the visualisation, interpretation and analysis of pathway knowledge.
We explain Golgi Body with video tutorials and quizzes, using our Many Ways(TM) approach from multiple teachers.This lesson will discuss the structure and function of the golgi body.
Golgi Dynamics. How can it happen that the resident proteins appear to remain in place while the transient proteins, destined for other sites in the cell, move through the organelle in a cis to trans direction?. Over the years a number of ideas have been put forth they fall into two general models.. 1. Vesicle Transport Model. This model assumes that the cisternae are essentially stationary and contain their resident proteins. The transient proteins are selected and concentrated in vesicles by the process of vesicle formation that is driven by coat proteins and their interaction with cargo receptor proteins as described in the last lecture. See vesicle formation animation for review of how this works.. These transport vesicles bud from the periphery of the Golgi cisterna as shown in the picture above, and then fuse with the appropriate target cisterna (trans to the point of origin) via the normal vesicle targeting process. In this manner a transient protein makes is way down the Golgi stack, cis ...
The experience was fantastic. Wim Hagen was very efficient in setting up optimal data collection, while at the same time always involving us in decision-making. Wim collected a dataset for us that we used to obtain a 4.9 Å structure of the assembled COPII coat, now published in Nature Communications. This is the highest-resolution structure of a membrane-assembled coat, and one of the highest-resolution subtomogram averages obtained so far.. ...
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Intracellular transport between the ER and Golgi is mediated by vesicles that bud from donor membranes and then fuse with acceptor membranes. Bi-directional vesicle transport maintains distinct organelle composition through a process known as molecular sorting. Collectively, molecular sorting refers to the process of actively selecting or excluding proteins and lipids into transport vesicles. Some of the proteins involved in sorting have been identified although the mechanisms remain obscure. This dissertation examines proteins contained on ER-derived vesicles (Ervs) and how these proteins facilitate sorting. Erv function requires bi-directional ER to Golgi transport therefore it was determined how the cytoplamic tail sequences of Emp24p and Erv25p function in transport. Both Emp24p and Erv25p tail sequences are sufficient to direct anterograde transport and interact with COPII subunits, however the Erv25p tail is necessary to direct retrograde transport. A vexing question regarding p24 function ...
Calcium sensor that plays a key role in processes such as endoplasmic reticulum (ER)-Golgi vesicular transport, endosomal biogenesis or membrane repair (By similarity). Acts as an adapter that bridges unrelated proteins or stabilizes weak protein-protein complexes in response to calcium: calcium-binding triggers exposure of apolar surface, promoting interaction with different sets of proteins thanks to 3 different hydrophobic pockets, leading to translocation to membranes (By similarity). Involved in ER-Golgi transport (PubMed:27276012). Regulates ER-Golgi transport by promoting the association between PDCD6IP and TSG101, thereby bridging together the ESCRT-III and ESCRT-I complexes (By similarity). Together with PEF1, acts as calcium-dependent adapter for the BCR(KLHL12) complex, a complex involved in ER-Golgi transport by regulating the size of COPII coats (By similarity). In response to cytosolic calcium increase, the heterodimer formed with PEF1 interacts with, and bridges together the BCR(KLHL12)
Transition zones are associated with the Golgi stacks. They are close to each other. This makes sense because the communication is more efficient. Vesicles dont need to travel long distances and the existence of the Golgi apparatus itself depends on a continuous process of vesicle incoming. It has been observed that a new transition zone led quickly to the nearby formation of a new Golgi stack. On the contrary, if a transition zone disappears, the associated Golgi cisternae are also lost. Transition zones can fuse with others and one transition zone can be split in two. Their associated Golgi stacks match this behavior. Vesicles budding from the transition zones are COPII coated vesicles ( COPII: coat protein II; Figure 1). Several proteins are involved in the formation of this COPII molecular framework: Sec16, Sar1 GTPases, Sec23/24 and Sec13/31. In this order, they are assembled at the cytosolic surface of the transition zone membranes. Transition zones are the more suitable environments for ...
The chief function of Golgi body is secretion from a cell of protein materials, such as enzymes, hormones etc., that are not easily diffusible through the cell membrane. After being synthesized in the rough endoplasmic reticulum, the secretory proteins pass into the cisternae of Golgi body through the tubules of ER and Golgi body, and are stored in the Golgi vacuoles. From the vacuoles the secretory materials are released in the cytoplasm in the form of membrane bound tiny vesicels. These vesicles then pass towards the border of the cell and fuse with the cell membrane in such a manner that the secretory materials are expelled out of the cell keeping the cell membrane unbroken. By the same mechanism the Golgi body also helps in the release of neurotransmitters and neuro-hormones from nerve cells.. ...
Résumé : ORP2 is a ubiquitously expressed OSBP-related protein previously implicated in triacylglycerol (TG) metabolism at endoplasmic reticulum (ER) - lipid droplet (LD) contacts, cholesterol transport, and adrenocortical steroidogenesis. We now characterize the functional role of ORP2 by employing ORP2-knock-out (KO) hepatoma cells generated by CRISPR-Cas9 gene editing. Loss of ORP2 did not affect the major cellular phospholipids, cholesterol, or oxysterols, nor the quantity of ER-LD contact sites. However, the knock-out resulted in reduced expression of SREBP-1 target genes and mRNAs encoding glycolytic enzymes, defective TG synthesis and storage, inhibition of LD growth upon fatty acid loading, reduction of glucose uptake, glycogen synthesis, glycolysis (ECAR) and Akt activity. ORP2 was found to form a physical complex with key controllers of Akt, Cdc37 and Hsp90. In addition to the metabolic phenotypes, the ORP2-KO cells showed defects in adhesion, lamellipodieae formation, migration and ...
The Golgi body (or Golgi complex, apparatus), and Endoplasmic reticulum (ER) are both organelles found in the majority of eukaryotic cells. They are very closely associated and show both similarities and differences in structure and function.
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... β-COP), Sec21 (γ-COP), Ret2(δ-COP), and Ret3 (ζ-COP). COPI is a coatomer that coats the vesicles transporting proteins from the ... COP1 coated vesicles also contain p24 proteins that assist with cargo sorting. COP II is a coatomer that coats the vesicles ... This complex polymerizes to form the outer layer of the coat. COP II vesicles must shed their coat before they can fuse with ... Once the vesicle is coated, it begins to travel to the ER. Before the vesicle can fuse with the ER membrane, the coats ...
"ADP-ribosylation factor is a subunit of the coat of Golgi-derived COP-coated vesicles: a novel role for a GTP-binding protein ... beta-COP, dark green; zeta-COP - yellow; delta-COP - orange; betaprime-COP - light blue; alpha-COP - dark blue ... A structure of the COPI coat and the role of coat proteins in membrane vesicle assembly". Science. 349 (6244): 195-198. doi: ... Electron micrograph of in vitro-formed COPI-coated vesicles. Average vesicle diameter at the membrane level is 60 nm. ...
McMahon HT, Mills IG (August 2004). "COP and clathrin-coated vesicle budding: different pathways, common approaches". Curr. ... AP (adaptor protein) complexes are found in coated vesicles and clathrin-coated pits. AP complexes connect cargo proteins and ... and from there via small carrier vesicles to their final destination compartment. These vesicles have specific coat proteins ( ... This is an adaptor protein which helps the formation of a clathrin coat around a vesicle. This entry represents a subdomain of ...
"COP and clathrin-coated vesicle budding: different pathways, common approaches". Curr. Opin. Cell Biol. 16 (4): 379-91. doi: ... Adaptor protein (AP) complexes are found in coated vesicles and clathrin-coated pits. AP complexes connect cargo proteins and ... Clathrin coats contain both clathrin (acts as a scaffold) and adaptor complexes that link clathrin to receptors in coated ... lipids to clathrin at vesicle budding sites, as well as binding accessory proteins that regulate coat assembly and disassembly ...
COP 1 (Cytosolic coat protein complex ) : retrograde transport; Golgi ----> Endoplasmic reticulum COP 2 (Cytosolic coat protein ... As a result, vesicular transporters govern the concentration of molecules within a vesicle. Examples include: Archain ARFs ... is a membrane protein that regulates or facilitates the movement of specific molecules across a vesicle's membrane. ... each using its own coat and GTPase. ...
Activated Arf1p then recruits coat protein β-COP, a subunit of the COP-I complex, to cargo-bound receptors on the membrane.[9] ... of SNARE proteins in the Golgi which would otherwise be bound to coat protein-coated vesicles and removed with the vesicles ... Coat protein recruitment is necessary for proper vesicle formation and transport. Brefeldin A reversibly inhibits the function ... protein transport from the Golgi apparatus to the endoplasmic reticulum indirectly by preventing association of COP-I coat [2] ...
1991). "Beta-COP, a 110 kd protein associated with non-clathrin-coated vesicles and the Golgi complex, shows homology to beta- ... "Physical interaction of the HIV-1 Nef protein with beta-COP, a component of non-clathrin-coated vesicles essential for membrane ... Orcl L, Palmer DJ, Amherdt M, Rothman JE (1993). "Coated vesicle assembly in the Golgi requires only coatomer and ARF proteins ... Lowe M, Kreis TE (1997). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. 271 (48): 30725-30. doi: ...
En bloc incorporation of coatomer subunits during the assembly of COP-coated vesicles.. The Journal of cell biology. 1994-03, ... 並且介導COPⅡ囊泡的形成。根據COPⅡ囊泡裝配的貨物分子大小,Sec31 C端的氨基酸序列可以成不同幾何形狀的COPⅡ籠型,從而使COPⅡ囊泡容納前膠原、
1991). "ADP-ribosylation factor is a subunit of the coat of Golgi-derived COP-coated vesicles: a novel role for a GTP-binding ... Eugster A, Frigerio G, Dale M, Duden R (August 2000). "COP I domains required for coatomer integrity, and novel interactions ... "Site-specific photocrosslinking to probe interactions of Arf1 with proteins involved in budding of COPI vesicles". Methods. 20 ...
Lowe M, Kreis TE (1997). "In vivo assembly of coatomer, the COP-I coat precursor.". J. Biol. Chem. 271 (48): 30725-30. PMID ... a cytosolic protein complex containing subunits of non-clathrin-coated Golgi transport vesicles.". Nature 349 (6306): 248-51. ... 2002). "Interaction of gamma-COP with a transport motif in the D1 receptor C-terminus.". Eur. J. Cell Biol. 81 (2): 77-85. PMID ... 2001). "Identification and characterization of novel isoforms of COP I subunits.". J. Biochem. 128 (5): 793-801. PMID 11056392. ...
... which govern the intracellular trafficking of proteins in coat protein (COP)-coated vesicles. Mutations in the SAR1B gene are ... Schekman R, Orci L (March 1996). "Coat proteins and vesicle budding". Science. 271 (5255): 1526-33. doi:10.1126/science. ... "Mutations in a Sar1 GTPase of COPII vesicles are associated with lipid absorption disorders". Nature Genetics. 34 (1): 29-31. ... "Mutations in a Sar1 GTPase of COPII vesicles are associated with lipid absorption disorders". Nature Genetics. 34 (1): 29-31. ...
Coat complexes that have been well characterized so far include coat protein-I (COP-I), COP-II, and clathrin. Clathrin coats ... vesicles that have a morphologically characteristic coat made up of the cytosolic protein clathrin. Clathrin-coated vesicles ( ... Coats function to deform the donor membrane to produce a vesicle, and they also function in the selection of the vesicle cargo ... Coated vesicles were first purified by Barbara Pearse, who discovered the clathrin coat molecule in 1976. Endocytosis. For ...
Lowe M, Kreis TE (1997). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. 271 (48): 30725-30. doi: ... a cytosolic protein complex containing subunits of non-clathrin-coated Golgi transport vesicles". Nature. 349 (6306): 248-51. ... Bermak JC, Li M, Bullock C, Weingarten P, Zhou QY (2002). "Interaction of gamma-COP with a transport motif in the D1 receptor C ... Yamasaki K, Hayashida S, Miura K, Masuzaki H, Ishimaru T, Niikawa N, Kishino T (Nov 2000). "The novel gene, gamma2-COP (COPG2 ...
For the membrane coated vesicle used in transport, see here. Fagol Caspase recruitment domain-containing protein 16 is an ... Lee SH, Stehlik C, Reed JC (Sep 2001). "Cop, a caspase recruitment domain-containing protein and inhibitor of caspase-1 ... 2006). "Protective role of Cop in Rip2/caspase-1/caspase-4-mediated HeLa cell death". Biochim. Biophys. Acta. 1762 (8): 742-54 ...
... clathrin-coated vesicles MeSH A11.284.430.214.190.875.190.880.180.180 - cop-coated vesicles MeSH A11.284.430.214.190.875. ... transport vesicles MeSH A11.284.430.214.190.875.190.880.180 - coated vesicles MeSH A11.284.430.214.190.875.190.880.180.160 - ... 190.880.810 - secretory vesicles MeSH A11.284.430.214.190.875.190.880.830 - synaptic vesicles MeSH A11.284.430.214.190.875. ... coated pits, cell-membrane MeSH A11.284.149.165.175.160 - caveolae MeSH A11.284.149.165.355 - glycocalyx MeSH A11.284.149.165. ...
"ADP-ribosylation factor is a subunit of the coat of Golgi-derived COP-coated vesicles: a novel role for a GTP-binding protein ... COPI-coated vesicle. • عصارة خلوية. • Golgi membrane. • غشاء خلوي. • protein-containing complex. • glutamatergic synapse. ... Golgi to transport vesicle transport. • post-Golgi vesicle-mediated transport. • actin filament organization. • lysosomal ... synaptic vesicle budding. • small GTPase mediated signal transduction. • cellular copper ion homeostasis. • long-term synaptic ...
COP coat proteins, the N-ethylmaleimide sensitive factor, the small transmembrane proteins of the p24 family, the p38 MAP ... "An endosomal beta COP is involved in the pH-dependent formation of transport vesicles destined for late endosomes". The Journal ... "Characterization of the early endosome and putative endocytic carrier vesicles in vivo and with an assay of vesicle fusion in ... Gruenberg, J. E.; Howell, K. E. (1986-12-01). "Reconstitution of vesicle fusions occurring in endocytosis with a cell-free ...
Orcl L, Palmer DJ, Amherdt M, Rothman JE (1993). "Coated vesicle assembly in the Golgi requires only coatomer and ARF proteins ... Eugster A, Frigerio G, Dale M, Duden R (2000). "COP I domains required for coatomer integrity, and novel interactions with ARF ... is a cytosolic protein complex that binds to dilysine motifs and reversibly associates with Golgi non-clathrin-coated vesicles ... Eugster A, Frigerio G, Dale M, Duden R (August 2000). "COP I domains required for coatomer integrity, and novel interactions ...
It is one of seven proteins in the COPI coatomer complex that coats vesicles as they bud from the Golgi complex. COPG has been ... Lowe, M; Kreis T E (November 1996). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. UNITED STATES. 271 ... Lowe M, Kreis TE (1997). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. 271 (48): 30725-30. doi: ... 2000). "Duplication of genes encoding non-clathrin coat protein gamma-COP in vertebrate, insect and plant evolution". FEBS Lett ...
Chow VT, Quek HH (1997). "Alpha coat protein COPA (HEP-COP): presence of an Alu repeat in cDNA and identity of the amino ... Orcl L, Palmer DJ, Amherdt M, Rothman JE (1993). "Coated vesicle assembly in the Golgi requires only coatomer and ARF proteins ... The subunits are designated alpha-COP, beta-COP, beta-prime-COP, gamma-COP, delta-COP, epsilon-COP, and zeta-COP. The alpha-COP ... Lowe M, Kreis TE (November 1996). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. 271 (48): 30725-30. ...
The Golgi coatomer complex (see MIM 601924) constitutes the coat of nonclathrin-coated vesicles and is essential for Golgi ... Lowe M, Kreis TE (November 1996). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. 271 (48): 30725-30. ... Lowe M, Kreis TE (1997). "In vivo assembly of coatomer, the COP-I coat precursor". J. Biol. Chem. 271 (48): 30725-30. doi: ... Stenbeck G, Harter C, Brecht A, Herrmann D, Lottspeich F, Orci L, Wieland FT (1993). "beta'-COP, a novel subunit of coatomer". ...
Vesicle coat proteins frequently contain alpha solenoids and share common domain architecture with some NPC proteins. Three ... Field, Mark C.; Sali, Andrej; Rout, Michael P. (13 June 2011). "On a bender-BARs, ESCRTs, COPs, and finally getting your coat ... vesicle coat proteins, and nuclear pore complexes". Current Opinion in Cell Biology. 21 (1): 4-13. doi:10.1016/j.ceb.2008.12. ... and Clathrin Vesicle Coats". Cell. 142 (1): 123-132. doi:10.1016/j.cell.2010.05.030. PMC 2943847. PMID 20579721. Forwood, Jade ...
The best characterized type of vesicle is the clathrin coated vesicle (CCV). The formation of a COPII vesicle at the ... Components of COPI (cop one) a coatomer, and TSET (T-set) a membrane trafficking complex have similar heterotetramers of the AP ... but the coat of COPI is not closely related to the coats of either CCVs or COPII vesicles. AP-5 is associated with 2 proteins, ... but the ultrastructure of that coat is not known. The coat of AP-4 is unknown. An almost universal feature of coat assembly is ...
... coated vesicle) moodustumisel osaleb valk dünamiin. Vesiikul kaetakse klatriiniga, et toimuks suunatud liikumine Golgi ... Sõltuvalt sihtmembraanist jaotatakse COP valgud järgnevalt kaheks: *COP I - transpordib vesiikuleid cis-Golgi kompleksist ... COP valgud. Nende moodustatud katte tekkeks on vaja lisaenergiat, mis saadakse ATP hüdrolüüsi käigus. ... Selle mehhanismi puhul on retseptorid kogunenud plasmamembraani teatud piirkonda, mida nimetatakse kaetud lohuks (coated-pit). ...
These contents digest the jelly coat and eventually the vitelline membrane. In addition to the release of acrosomal vesicles, ... Red-veined darters (Sympetrum fonscolombii) flying "in cop" (male ahead), enabling the male to prevent other males from mating ... The acrosomal vesicles of the sperm fuse with the plasma membrane and are released. In this process, molecules bound to the ... Resact is a 14 amino acid peptide purified from the jelly coat of A. punctulata that attracts the migration of sperm. ...
Cargo then progress toward the trans face in COPI-coated vesicles. This model proposes that COPI vesicles move in two ... ARFs are small GTPases which regulate vesicular trafficking through the binding of COPs to endosomes and the Golgi. BFA ... Proteins are delivered from the ER to the cis face using COPII-coated vesicles. ... Once matured, the TGN cisternae dissolve to become secretory vesicles. While this progression occurs, COPI vesicles continually ...
These contents digest the jelly coat and eventually the vitelline membrane. In addition to the release of acrosomal vesicles, ... Red-veined darters (Sympetrum fonscolombii) flying "in cop" (male ahead), enabling the male to prevent other males from mating ... The acrosomal vesicles of the sperm fuse with the plasma membrane and are released. In this process, molecules bound to the ... Resact is a 14 amino acid peptide purified from the jelly coat of A. punctulata that attracts the migration of sperm. ...
Hydrolysis of bound GTP by ARF protein triggers uncoating of Golgi-derived COP-coated vesicles.. G Tanigawa, L Orci, M Amherdt ... Coat assembly is triggered when ARF binds GTP, initiating transport vesicle budding, and coat disassembly is triggered when ARF ... Hydrolysis of bound GTP by ARF protein triggers uncoating of Golgi-derived COP-coated vesicles. ... helps to provide vectoriality to vesicle transport. ...
β-COP, a Coat Protein of Nonclathrin-Coated Vesicles of the Golgi Complex, is Involved in Transport of Vesicular Stomatitis ... 1993) β-COP, a Coat Protein of Nonclathrin-Coated Vesicles of the Golgi Complex, is Involved in Transport of Vesicular ... is a subunit of the coat of Golgi-derived COP-coated vesicles: a novel role for a GTP-binding protein. Cell 67: 239-253PubMed ... Duden R, Griffiths G, Frank R, Argos P, Kreis TE (1991) ß-COP, a 110kD protein associated with nonclathrin coated vesicles and ...
Sorting by COP I-coated vesicles under interphase and mitotic conditions. B Sönnichsen, B Sönnichsen ... COP I-coated vesicles were analyzed for their content of resident Golgi enzymes (N-acetylgalactosaminyltransferase; N- ... B Sönnichsen, R Watson, H Clausen, T Misteli, G Warren; Sorting by COP I-coated vesicles under interphase and mitotic ... provides clues to the function of COP I vesicles in transport through the Golgi apparatus. ...
Hydrolysis of bound GTP by ARF protein triggers uncoating of Golgi-derived COP-coated vesicles. G Tanigawa, G Tanigawa ... Coat assembly is triggered when ARF binds GTP, initiating transport vesicle budding, and coat disassembly is triggered when ARF ... Hydrolysis of bound GTP by ARF protein triggers uncoating of Golgi-derived COP-coated vesicles.. J Cell Biol 15 December 1993; ... Trimeric binding of the 70-kD uncoating ATPase to the vertices of clathrin triskelia: a candidate intermediate in the vesicle ...
3.2 Formation of clathrin and COP-coated vesicles. This unit explains the function of the cytoskeleton and its role in ... 3.3 Fusion of vesicles with the target membrane. This unit explains the function of the cytoskeleton and its role in ... This unit explains the function of the cytoskeleton and its role in controlling transport of vesicles between different ... This unit explains the function of the cytoskeleton and its role in controlling transport of vesicles between different ...
To exit the ER, proteins are packaged into COPII vesicles through direct interaction with the COPII coat or aided by specific ... COP-Coated Vesicles / metabolism * Cell Membrane / metabolism * Endoplasmic Reticulum / metabolism* * Gene Deletion ... To exit the ER, proteins are packaged into COPII vesicles through direct interaction with the COPII coat or aided by specific ...
COP-Coated Vesicles / metabolism* * COP-Coated Vesicles / ultrastructure * Endoplasmic Reticulum / metabolism* * Endoplasmic ... Furthermore, STAM proteins interact with coat protein II (COPII) proteins, probably at endoplasmic reticulum (ER) exit sites, ...
... β-COP), Sec21 (γ-COP), Ret2(δ-COP), and Ret3 (ζ-COP). COPI is a coatomer that coats the vesicles transporting proteins from the ... COP1 coated vesicles also contain p24 proteins that assist with cargo sorting. COP II is a coatomer that coats the vesicles ... This complex polymerizes to form the outer layer of the coat. COP II vesicles must shed their coat before they can fuse with ... Once the vesicle is coated, it begins to travel to the ER. Before the vesicle can fuse with the ER membrane, the coats ...
"ADP-ribosylation factor is a subunit of the coat of Golgi-derived COP-coated vesicles: a novel role for a GTP-binding protein ... beta-COP, dark green; zeta-COP - yellow; delta-COP - orange; betaprime-COP - light blue; alpha-COP - dark blue ... A structure of the COPI coat and the role of coat proteins in membrane vesicle assembly". Science. 349 (6244): 195-198. doi: ... Electron micrograph of in vitro-formed COPI-coated vesicles. Average vesicle diameter at the membrane level is 60 nm. ...
Membrane Proteins of COP-Coated Vesicles. p. 15. Membrane Proteins of Clathrin-Coated Vesicles. p. 17. ... Reconstitution of Coated Vesicles from Chemically Defined Liposomes. p. 19. Polymerization of Coatomer and COPI Bud Formation. ... Acyl-CoA and Vesicle Trafficking, Lessons from Yeast Mutants. p. 200. Allosteric Effects of Long-Chain Acyl-CoA on Vesicle ... Nuclear Vesicle Fusion Requires GTP Hydrolysis. p. 288. Early Evidence for a Putative Role of ARFs in Nuclear Vesicle Dynamics ...
COP and clathrin-coated vesicle budding: different pathways, common approaches.. Curr. Opin. Cell Biol. 16 379-91 2004 ... This traffic is bidirectional, to ensure that proteins required to form vesicles are recycled. Vesicles have specific coat ... As coat proteins polymerise, vesicles are formed and budded from membrane-bound organelles. Coatomer complexes also influence ... Coatomer protein complex I (COPI)-coated vesicles are involved in transport between the endoplasmic reticulum and the Golgi but ...
Two human ARFGAPs associated with COP-I-coated vesicles. Traffic 2007;8:1644-1655 ... Proinsulin is produced in the endoplasmic reticulum and packaged into secretory vesicles in the Golgi apparatus. Several ... Nearby genes include PACSIN3, which encodes a protein involved in vesicle formation, transport, and endocytosis whose ... defective vesicle trafficking. In sum, all these possibilities could manifest themselves by the exocytosis of more preprotein ...
T. Serafini and J.E. Rothman, Purification of Golgi Cisternae-Derived COP-Coated Vesicles. ... M. Pypaert and G. Warren, Morphological Studies of Formation of Coated Pits and Coated Vesicles in Broken Cells. ... P.G. Woodman and G. Warren, Isolation and Characterization of Functional, Clathrin Coated, Endocytic Vesicles. ... E. Sztul, Transcytotic Vesicle Fusion with the Plasma Membrane.. B.M. Mullock and J.P. Luzio, Reconstitution of Rat Liver ...
Two human ARFGAPs associated with COP-I-coated vesicles. (PMID: 17760859) Frigerio G … Duden R (Traffic (Copenhagen, Denmark) ... Gamma-COP appendage domain - structure and function. (PMID: 14690497) Watson PJ … Owen DJ (Traffic (Copenhagen, Denmark) 2004) ... Among its related pathways are Vesicle-mediated transport and Transport to the Golgi and subsequent modification. Gene Ontology ...
Misteli, T., and Warren, G. (1994). COP-coated vesicles are involved in the mitotic fragmentation of Golgi stacks in a cell- ... Sönnichsen, B., Watson, R., Clausen, H., Misteli, T., and Warren, G. (1996). Sorting by COP I-coated vesicles under interphase ... recruit several coat complexes, including GGA1-3/clathrin, AP-1/clathrin, AP-3/clathrin, and AP-4 coats (Bonifacino and Glick, ... The specificity of vesicle traffic to the Golgi is encoded in the golgin coiled-coil proteins. Science 346:1256898. doi: ...
Traffic COPs and the formation of vesicle coats. Trends Cell Biol. 6: 468. ... Evidence that phospholipase D mediates ADP ribosylation factor-dependent formation of coated vesicles. J. Cell Biol. 134: 295. ... is necessary for the docking of coatamer proteins to the lipid membrane in vesicle formation (31). These findings suggest a ... constitutive PLD activity in certain membrane preparations has been shown to be sufficient to allow vesicle formation in the ...
COP and clathrin-coated vesicle budding: different pathways, common approaches. Curr. Opin. Cell Biol. 16: 379-391. ... To analyze the morphology of the obtained vesicles, they were coated to anti-MHC class II beads and analyzed by EM. The ... In additional experiments the milk vesicle preparation was coated to anti-MHC class II Dynabeads and/or anti-CD81 latex beads, ... 2⇑C). Vesicles from mature milk were positive for HLA-ABC for all individuals, whereas vesicles of colostrum from five of eight ...
COP-coated vesicles in intracellular protein transport. Harter, C.. * A strobilurin fungicide enhances the resistance of ... cDNA microarray analysis of gene expression during Fe-deficiency stress in barley suggests that polar transport of vesicles is ...
COP-Coated Vesicles/metabolism*. *Endoplasmic Reticulum/metabolism*. *Fungal Proteins/genetics/metabolism*. *Pichia/genetics/ ... During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has ... During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has ...
Hydrolysis of bound GTP by ARF protein triggers uncoating of Golgi-derived COP-coated vesicles. J. Cell Biol. 123:1365-1371. ... COPI-coated vesicles were purified via sucrose density centrifugation. 50% of the vesicle fractions (V) and 0.5% of input (I) ... Two human ARFGAPs associated with COP-I-coated vesicles. Traffic. 8:1644-1655. ... The formation of coat protein complex I (COPI)-coated vesicles is regulated by the small guanosine triphosphatase (GTPase) ...
Question 6 options: Cop II coated vesicles move cargo from the ER to the Golgi. Starting nearest the nucleus and moving toward ...
There are two major families of coat proteins, COP and clathrin. COP proteins are involved in vesicle formation in the ER and ... The transient proteins are selected and concentrated in vesicles by the process of vesicle formation that is driven by coat ... Proteins are carried from the ER to the Golgi by vesicles (transitional vesicles). These vesicles bud from the ER cisternae ... See vesicle formation animation for review of how this works.. These transport vesicles bud from the periphery of the Golgi ...
Two human ARFGAPs associated with COP-I-coated vesicles.. Frigerio G, Grimsey N, Dale M, Majoul I and Duden R ... In contrast to ARFGAP1, both ARFGAP2 and ARFGAP3 are associated with COP-I-coated vesicles generated from Golgi membranes in ... The formation of coat protein complex I (COPI)-coated vesicles is regulated by the small guanosine triphosphatase (GTPase) ... by regulating the uncoating of coat protein I (COPI)-coated vesicles. Depletion of ArfGAP1 by RNA interference, however, causes ...
Probable coat proteins of plant COP-coated vesicles. Plant Physiol. 119, 1437-1445. ... which between them promote accurate vesicle targeting and vesicle fusion (although their detailed modes of action are still ... and Golgi movement is considered essential for efficient targeting and consumption of transport vesicles. These vesicles may ... 2000). Actin coating of secretory granules during regulated exocytosis correlates with the release of rab3D. Proc. Natl. Acad. ...
Soluble secretory proteins are transported from the ER to ERGIC in vesicles coated with COP-II coat proteins. The sorting of ... Schekman R, Orci L (1996) Coat proteins and vesicle budding. Science 271:1526-1533PubMedCrossRefGoogle Scholar ... one COP-I dependent and the other COP-I independent. The COP-I-independent pathway is specifically regulated by Rab6 and is ... The role of COP-I in Golgi-to-ER transport of distinct marker proteins has been described. For example, anti-COP-I antibodies ...
Activated Arf1p then recruits coat protein β-COP, a subunit of the COP-I complex, to cargo-bound receptors on the membrane.[9] ... of SNARE proteins in the Golgi which would otherwise be bound to coat protein-coated vesicles and removed with the vesicles ... Coat protein recruitment is necessary for proper vesicle formation and transport. Brefeldin A reversibly inhibits the function ... protein transport from the Golgi apparatus to the endoplasmic reticulum indirectly by preventing association of COP-I coat [2] ...
Harter C. COP-coated vesicles in intracellular protein transport. FEBS Lett. 1995;369(1):89-92. CrossRefPubMed ... Vesicle coats: structure, function, and general principles of assembly. Trends Cell Biol. 2013;23(6):279-288. CrossRefPubMed ... The COPII cage: unifying principles of vesicle coat assembly. Nat Rev Mol Cell Biol. 2006;7(10):727-738. CrossRefPubMed ... A novel class of clathrin-coated vesicles budding from endosomes. J Cell Biol. 1996;132(1-2):21-33. CrossRefPubMed ...
ARF1 has been shown to play a critical role in COPI (Coat Protein Complex I)-mediated retrograde trafficking in eukaryotic ... The ARF1 and SAR1 GTP-binding proteins are involved in the formation and budding of vesicles throughout plant endomembrane ... COPs) on donor organelles. The activation of small GTPases is essential for vesicle formation from a donor membrane. In ... Protein coats are classified into three types for transport vesicles: COPI, COPII, and clathrin coats [7,8]. Arrangement of ...
and Wieland, FT. et al. (1992) γ-COP, a coat subunit of non-clathrin-coated vesicles with homology to Sec21p. FEBS Letters, ... ADP-ribosylation factor and phosphatidic acid levels in Golgi membranes during budding of coatomer-coated vesicles. ... and Sollner, TH. (1997) Binding of the synaptic vesicle v-SNARE, synaptotagmin, to the plasma membrane t-SNARE, SNAP-25, can ... and Tschochner, H. et al. (1996) Architecture of coatomer: Molecular characterization of δ-COP and protein interactions within ...
  • How COPII (coat complex II) vesicles are transferred from endoplasmic reticulum (ER) export sites to the moving Golgi stacks is not understood. (nih.gov)
  • We have examined COPII vesicle transfer in high-pressure frozen/freeze-substituted plant cells by electron tomography. (nih.gov)
  • Formation of each COPII vesicle is accompanied by the assembly of a ribosome-excluding scaffold layer that extends approximately 40 nm beyond the COPII coat. (nih.gov)
  • These COPII scaffolds can attach to the cis-side of the Golgi matrix, and the COPII vesicles are then transferred to the Golgi together with their scaffolds. (nih.gov)
  • When Atp115-GFP, a green fluorescent protein (GFP) fusion protein of an Arabidopsis thaliana homolog of the COPII vesicle-tethering factor p115, was expressed, the GFP localized to the COPII scaffold and to the cis-side of the Golgi matrix. (nih.gov)
  • We postulate that the COPII scaffold first binds to and then fuses with the cis-side of the Golgi matrix, transferring its enclosed COPII vesicle to the cis-Golgi. (nih.gov)
  • To exit the ER, proteins are packaged into COPII vesicles through direct interaction with the COPII coat or aided by specific cargo receptors. (nih.gov)
  • For example, the coatomer COP1 (coat protein complex 1) is responsible for reverse transport of recycled proteins from Golgi and pre-Golgi compartments back to the ER, while COPII buds vesicles from the ER to the Golgi [ PMID: 11208122 ]. (ebi.ac.uk)
  • COPII vesicles Clathrin vesicles Glyceraldehyde 3-phosphate dehydrogenase#ER to Golgi transport Exomer Coat+Protein+Complex+I at the US National Library of Medicine Medical Subject Headings (MeSH) Serafini T, Orci L, Amherdt M, Brunner M, Kahn RA, Rothman JE (1991). (wikipedia.org)
  • During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has been proposed to play two distinct roles: negatively regulating COPII turnover and organizing COPII assembly at tER sites. (nih.gov)
  • ARF1 has been shown to play a critical role in COPI (Coat Protein Complex I)-mediated retrograde trafficking in eukaryotic systems, whereas SAR1 GTPases are involved in intracellular COPII-mediated protein trafficking from the ER to the Golgi apparatus. (mdpi.com)
  • The COPII cage: unifying principles of vesicle coat assembly. (springermedizin.at)
  • Finally, we describe the striking similarities that exist between the COPI system and the two other characterized types of vesicular carriers: COPII- and clathrin-coated vesicles. (deepdyve.com)
  • The transport protein particle (TRAPP) was originally identified in as a vesicle tethering factor for COPII‐coated vesicles at the Golgi (Sacher et al , 2001 ). (embopress.org)
  • Thus, the human genome encodes four forms of Sec24, the cargo selection subunit of the COPII vesicular coat, and this is proposed to increase the range of cargo accommodated by human COPII-coated vesicles. (rcsb.org)
  • In this study, we combined X-ray crystallographic and biochemical analysis with functional assays of cargo packaging into COPII vesicles to establish molecular mechanisms for cargo discrimination by human Sec24 subunits. (rcsb.org)
  • A comparative analysis of crystal structures of the four human Sec24 isoforms establishes the structural determinants for discrimination among these transport signals, and provides a framework to understand how an expansion of coat subunits extends the range of cargo proteins packaged into COPII-coated vesicles. (rcsb.org)
  • Three classes of coated vesicles are well established to mediate transport in the exo- and endocytic pathway: COPII vesicles for ER export, COPI vesicles for retrograde Golgi-ER and bidirectional intra-Golgi transport, and clathrin-coated vesicles operating in the late secretory and endocytic pathway. (db-engine.de)
  • In contrast to COPII and clathrin coats, the heptameric large COPI coat component coatomer is recruited en bloc to the membrane, so that both the inner and outer shell of the vesicle are formed at the same time. (db-engine.de)
  • Here, we investigate regulation of coat protein complex II (COPII) recruitment onto ER export sites in permeabilized cells. (dundee.ac.uk)
  • The Sec13 protein functions in various intracellular compartments including the nuclear pore complex, COPII-coated vesicles, and inside the nucleus as a transcription regulator. (elsevier.com)
  • tries to understand the roles COPII and COPI play in vesicle budding. (dcyphr.org)
  • If vesicles form with a nonhydrolyzable analog like GMP-PNP, Sar1p and the COPII proteins remain on the vesicle (Figure 8). (dcyphr.org)
  • The remaining Sar1p and COPII proteins hinder access of the vesicle to the Golgi. (dcyphr.org)
  • Formation of COPII-coated vesicles do not need acyl coenzyme A. (dcyphr.org)
  • COPII vesicles have specific protein packages. (dcyphr.org)
  • Waters MG, Serafini T, Rothman JE (1991) "Coatomer": a cytosolic protein complex containing subunits of non-clathrin-coated Golgi transport vesicles. (springer.com)
  • The coatomer is a protein complex that coats membrane-bound transport vesicles. (wikipedia.org)
  • COPI is a coatomer that coats the vesicles transporting proteins from the Golgi complex to the ER. (wikipedia.org)
  • COPI is a coatomer , a protein complex [1] that coats vesicles transporting proteins from the cis end of the Golgi complex back to the rough endoplasmic reticulum (ER), where they were originally synthesized , and between Golgi compartments. (wikipedia.org)
  • Vesicles have specific coat proteins (such as clathrin or coatomer) that are important for cargo selection and direction of transfer [ PMID: 15261670 ]. (ebi.ac.uk)
  • This entry represents the C-terminal domain of the beta subunit from coatomer proteins (Beta-coat proteins). (ebi.ac.uk)
  • Coatomer protein complex I (COPI)-coated vesicles are involved in transport between the endoplasmic reticulum and the Golgi but also participate in transport from early to late endosomes within the endocytic pathway [ PMID: 12893528 ]. (ebi.ac.uk)
  • The formation of coat protein complex I (COPI)-coated vesicles is regulated by the small guanosine triphosphatase (GTPase) adenosine diphosphate ribosylation factor 1 (Arf1), which in its GTP-bound form recruits coatomer to the Golgi membrane. (rupress.org)
  • The coatomer is a cytosolic protein complex that binds to dilysine motifs and reversibly associates with Golgi non-clathrin-coated vesicles, which further mediate biosynthetic protein transport from the ER, via the Golgi up to the trans Golgi network. (abcam.com)
  • The coatomer is cytoplasmic or polymerized on the cytoplasmic side of the Golgi, as well as on the vesicles/buds originating from it. (abcam.com)
  • Assembly of the coatomer (COPI) onto non-clathrin coated vesicles is regulated by ADP-ribosylation factor (ARF). (novusbio.com)
  • In addition to the coatomer (a cytosol-derived complex of seven polypeptide chains, one of which is beta-COP), the non-clathrin (COP) coat of Golgi-derived vesicles contains stoichiometric amounts of a small (M(r) approximately 20,000) GTP-binding protein, the ADP-ribosylation factor (ARF). (nih.gov)
  • In vivo assembly of coatomer, the COP-I coat precursor. (wikipedia.org)
  • COP I domains required for coatomer integrity, and novel interactions with ARF and ARF-GAP. (wikipedia.org)
  • Recently, the two coatomer subunits γ-COP and ζ-COP were found to exist in two isoforms. (db-engine.de)
  • In our view, the formation of a COPI transport vesicle involves the following minimal set of components: donor membranes with transmembrane proteins acting as coat and/or cargo receptors (e.g. members of the p24 family), cytosolic Arf1, cytosolic coatomer and auxiliary enzymes that serve as nucleotide exchange factors for activation on the membrane of Arf1 (GBF1) and GTPase activating proteins for the activation of GTP hydrolysis by Arf1 (Arf GAPs). (db-engine.de)
  • In collaboration with John Briggs' and Irmi Sinning's groups we are interested in the structure of the coat protein coatomer as a monomeric, soluble complex, as well as in its membrane bound form as a coating network. (db-engine.de)
  • K. Sohn, L. Orci, M. Ravazzola, M. Amherdt, M. Bremser, F. Lottspeich, K. Fiedler, J. B. Helms, and F. Wieland (1996) A major transmembrane protein of Golgi-derived COPI-coated vesicles involved in coatomer binding. (db-engine.de)
  • Cytoplasmic dilysine motifs on transmembrane proteins are captured by coatomer α‐COP and β′‐COP subunits and packaged into COPI‐coated vesicles for Golgi‐to‐ER retrieval. (embopress.org)
  • The dilysine motif is recognized by coatomer subunits ( Cosson and Letourneur, 1994 ), and dilysine‐tagged transmembrane cargo is thereby packaged into COPI(coatomer)‐coated vesicles for retrograde transport to the ER ( Letourneur et al , 1994 ). (embopress.org)
  • However, the mode of KxKxx motif recognition by coatomer was not resolved in this study because the dilysine‐binding site on β′‐COP was partially occluded by a crystal contact ( Jackson et al , 2012 ). (embopress.org)
  • To dissect which replication stage(s) was affected by coatomer inactivation, we used visual and biochemical assays to independently measure the efficiency of viral entry and gene expression in hamster (ldlF) cells depleted of the temperature-sensitive ε-COP subunit. (asm.org)
  • Coatomer is comprised of 7 subunits (α-, β-, β′-, δ-, ε-, γ-, and ζ-COP) that are recruited as subcomplexes from the cell cytosol to Golgi membranes by the GTPase ADP ribosylation factor 1 (Arf1) ( 7 ). (asm.org)
  • This entry represents the small sigma and mu subunits of various adaptins from different AP clathrin adaptor complexes (including AP1, AP2, AP3 and AP4), and the zeta and delta subunits of various coatomer (COP) adaptors. (embl.de)
  • Coatomer consists of two subcomplexes: the membrane-targeting, ADP ribosylation factor 1 (Arf1):GTP-binding βγδζ-COP F-subcomplex, which is related to the adaptor protein (AP) clathrin adaptors, and the cargo-binding αβ'ϵ-COP B-subcomplex. (princeton.edu)
  • Sec21p is a constituent of the COPI vesicle coatomer. (agrisera.com)
  • This gene encodes a protein subunit of the coatomer complex associated with non-clathrin coated vesicles. (genetex.com)
  • The coatomer complex, also known as the coat protein complex 1, forms in the cytoplasm and is recruited to the Golgi by activated guanosine triphosphatases. (genetex.com)
  • Proteins synthesised on the ribosome and processed in the endoplasmic reticulum are transported from the Golgi apparatus to the trans-Golgi network (TGN), and from there via small carrier vesicles to their final destination compartment. (ebi.ac.uk)
  • [1] Brefeldin A inhibits protein transport from the Golgi apparatus to the endoplasmic reticulum indirectly by preventing association of COP-I coat [2] to the Golgi membrane . (wikipedia.org)
  • [5] It is currently used solely in research mainly as an assay tool for studying membrane traffic and vesicle transport dynamics between the endoplasmic reticulum and Golgi apparatus. (wikipedia.org)
  • Brefeldin A inhibits vesicle formation and transport between the endoplasmic reticulum and the Golgi apparatus which ultimately results in collapse of the Golgi apparatus into the endoplasmic reticulum via membrane fusion. (wikipedia.org)
  • ArfGAP1 is a prototype of GTPase-activating proteins for ADP-ribosylation factors (ARFs) and has been proposed to be involved in retrograde transport from the Golgi apparatus to the endoplasmic reticulum (ER) by regulating the uncoating of coat protein I (COPI)-coated vesicles. (genes2cognition.org)
  • The directed movement of substances from the endoplasmic reticulum (ER) to the Golgi, mediated by COP II vesicles. (yeastgenome.org)
  • The directed movement of substances from the Golgi back to the endoplasmic reticulum, mediated by vesicles bearing specific protein coats such as COPI or COG. (cathdb.info)
  • Unexpectedly, we provide evidence that the vRNP components and the Rab11 protein are present at the membrane of a modified, tubulated endoplasmic reticulum (ER) that extends all throughout the cell, and on irregularly coated vesicles (ICVs). (nature.com)
  • They also revealed very diverse mechanisms of interaction between viruses and the highly dynamic organelles of the endomembrane system, such as the nuclear membrane, endoplasmic reticulum (ER), Golgi apparatus, endosomes, and vesicles. (nature.com)
  • Syt-17 is localized to the Golgi complex in hippocampal neurons, where it coordinates import of vesicles from the endoplasmic reticulum to support neurite outgrowth and facilitate axon regrowth after injury. (nature.com)
  • Our results suggest that XN impairs the endoplasmic reticulum-to-Golgi translocation of the SREBP cleavage-activating protein (SCAP)-SREBP complex by binding to Sec23/24 and blocking SCAP/SREBP incorporation into common coated protein II vesicles. (pubmedcentralcanada.ca)
  • This distribution overlaps that of several Golgi and vesicle markers, including mannosidase II, p58, trans-Golgi network (TGN)38, and β-COP and is distinct from the endoplasmic reticulum markers calnexin and Bip. (pnas.org)
  • The system of coat protein (COP)II vesicle fission through the endoplasmic reticulum (ER) remains unclear. (techxprtz.com)
  • Coat protein complex 1 (COPI) is integral in the sorting and retrograde trafficking of proteins and lipids from the Golgi apparatus to the endoplasmic reticulum (ER). (xenbase.org)
  • We present the structure of the C-terminal μ-homology domain of the yeast δ-COP subunit in complex with the WxW motif from its binding partner, the endoplasmic reticulum-localized Dsl1 tether. (princeton.edu)
  • The coat consists of large protein subcomplexes that are made of seven different protein subunits, namely α, β, β', γ, δ , ε and ζ . (wikipedia.org)
  • These sorting signals, or motifs, typically contain the amino acid sequence KKXX or KXKXX, which interact with COPI subunits α-COP and β'-COP. (wikipedia.org)
  • The β′- and α-COP subunits form an arch over the γζβδ-COP subcomplex, orienting their N-terminal domains such that the K(X)KXX cargo-motif binding sites are optimally positioned against the membrane. (wikipedia.org)
  • Brefeldin A added to cells causes the rapid and reversible dissociation of a Golgi-associated peripheral membrane protein (M(r) 110,000) which was found to be identical to one of the subunits of the coat of Golgi-derived (non-clathrin) coated vesicles, beta-COP, implying that brefeldin A prevents transport by blocking the assembly of coats and thus the budding of enclosed vesicles. (nih.gov)
  • Identification and characterization of novel isoforms of COP I subunits. (wikipedia.org)
  • Subsequent yeast genetic studies implicated the N‐terminal β‐propeller domains of α‐COP and β′‐COP, the sequence‐related large subunits of αβ′ε‐COP ( Eugster et al , 2004 ). (embopress.org)
  • An evolutionary path can be deduced from the earliest origins of the heterotetramer/scaffold coat to its multiple manifestations in modern organisms, including the mammalian muniscins, descendants of the TSET medium subunits. (elifesciences.org)
  • Two similar sets of protein complexes-each containing four different subunits-ensure that the molecules are packaged inside the correct vesicles. (elifesciences.org)
  • When GTP-bound, two ARF1 small GTPase molecules associate with the membrane and bind COPI via the β-COP and γ-COP subunits. (xenbase.org)
  • The average density relative to starting membranes for resident enzymes (14-30%), cargo (16-23%), and recycling proteins (81-125%) provides clues to the function of COP I vesicles in transport through the Golgi apparatus. (rupress.org)
  • Coatomers reversibly associate with Golgi (non-clathrin-coated) vesicles to mediate protein transport and for budding from Golgi membranes [ PMID: 17041781 ]. (ebi.ac.uk)
  • [9] The lack of active Arf1p prevents coat protein recruitment, which then ultimately induces the fusion of neighboring ER and Golgi membranes due to lack of vesicle formation. (wikipedia.org)
  • ALPS motifs are unstructured in solution but form an amphipathic α helix once bound to highly curved membranes as present on a vesicle. (rupress.org)
  • Spiral Coating of the Endothelial Caveolar Membranes as Revealed by Electron Tomography and Template Matching. (springermedizin.at)
  • We describe a method to pull membrane nanotubes from lipid vesicles to study the interaction of proteins or any curvature-active molecule with curved membranes in vitro . (jove.com)
  • Clathrin-coated pits and CCVs can be identified in thin-section electron microscopy (EM) by the characteristic bristle density seen on the cytosolic side of coated membranes ( Fig. 1 A). EM imaging of deep-etched surfaces show these coats to be highly ordered polygonal arrays ( Fig. 1 B) ( 5 ), an organization also seen for isolated CCVs and clathrin cages ( Fig. 1 C) ( 6 , 7 ). (sciencemag.org)
  • Serafini T, Orci L, Amherdt M, Brunner M, Kahn RA, Rothman JE (1991) ADP-ribosylation factor (ARF) is a subunit of the coat of Golgi-derived COP-coated vesicles: a novel role for a GTP-binding protein. (springer.com)
  • Activated Arf1p then recruits coat protein β-COP, a subunit of the COP-I complex, to cargo-bound receptors on the membrane. (wikipedia.org)
  • T. Serafini, G. Stenbeck, A. Brecht, F. Lottspeich, L. Orci, J. E. Rothman, and F. Wieland (1991) A Coat Subunit of Golgi-Derived non-Clathrin Coated Vesicles with Homology to the Clathrin Coated Vesicle Coat Protein b-Adaptin. (db-engine.de)
  • Whole exome or genome sequencing of two families with a neuro-developmental syndrome, variable microcephaly and cataracts revealed biallelic variants in COPB1, which encodes the beta-subunit of COPI (β-COP). (xenbase.org)
  • M. Pypaert and G. Warren , Morphological Studies of Formation of Coated Pits and Coated Vesicles in Broken Cells. (elsevier.com)
  • A ) Thin-section EM illustrating the bristle coat associated with clathrin-coated pits and coated vesicles. (sciencemag.org)
  • This traffic is bidirectional, to ensure that proteins required to form vesicles are recycled. (ebi.ac.uk)
  • S. Tooze and W. Huttner , Cell-Free Formation of Immature Secretory Granules and Constitutive Secretory Vesicles from the Trans-Golgi Network. (elsevier.com)
  • [9] Coat protein recruitment is necessary for proper vesicle formation and transport. (wikipedia.org)
  • This is because lack of vesicle formation results in a buildup of SNARE proteins in the Golgi which would otherwise be bound to coat protein-coated vesicles and removed with the vesicles once they bud off. (wikipedia.org)
  • These vesicles bud from the ER cisternae through the formation of coated buds as described in the last lecture. (ubc.ca)
  • COP proteins are involved in vesicle formation in the ER and in the cis portion of the Golgi. (ubc.ca)
  • The ARF1 and SAR1 GTP-binding proteins are involved in the formation and budding of vesicles throughout plant endomembrane systems. (mdpi.com)
  • The activation of small GTPases is essential for vesicle formation from a donor membrane. (mdpi.com)
  • Wieland F, Hartert C. Mechanisms of vesicle formation: Insights from the COP system. (springermedizin.at)
  • We provide evidence that depletion of PHB induces intense membrane-trafficking activity at the ER-Golgi interface, as revealed by formation of GM130-positive Golgi tubules, and recruitment of p115, β -COP, and GBF1 to the Golgi complex. (hindawi.com)
  • In this Commentary, we summarise recent data on the role of cavins in caveola formation, highlighting structural studies that provide new insights into cavin coat assembly. (biologists.org)
  • Coat components are involved in multiple tasks such as cargo selection, curvature formation at the donor membrane, vesicle fission and initiation of uncoating. (db-engine.de)
  • We are studying the cooperation of these proteins in the formation of the COPI coat and in the scission of COPI coated buds with a wide range of methods in Biochemistry, Molecular Biology, Cell Biology and Biophysics. (db-engine.de)
  • Pubmed ID: 11826310 Brefeldin A (BFA) causes a block in the secretory system of eukaryotic cells by inhibiting vesicle formation at the Golgi apparatus. (jove.com)
  • But, GMP-PNP, a nonhydrolyzable analog of GTP, can cause vesicle formation as well. (dcyphr.org)
  • Vesicle formation requires both proteins in vitro. (dcyphr.org)
  • To study budding and vesicle formation, they did an analytical budding assay. (dcyphr.org)
  • In the activated form, Arf1 recruits and interacts with its effector proteins, such as coat components, SNAREs and cargo proteins in order to drive vesicle formation. (biologists.org)
  • E. Sztul , Transcytotic Vesicle Fusion with the Plasma Membrane. (elsevier.com)
  • The synaptotagmin (syt) proteins have been widely studied for their role in regulating fusion of intracellular vesicles with the plasma membrane. (nature.com)
  • But, there has also been a fascination with understanding the basic mechanisms that underlie endocytosis: for example, how plasma membrane is induced to form vesicles, how cell surface components are selectively included into these vesicles, and how the vesicle membrane and content are delivered to intracellular compartments. (sciencemag.org)
  • Clathrin coats are involved in two crucial transport steps: (i) receptor-mediated and fluid-phase endocytosis from the plasma membrane to early endosomes and (ii) transport from the trans-Golgi network (TGN) to endosomes. (sciencemag.org)
  • In endocytosis, the clathrin coat is assembled on the cytoplasmic face of the plasma membrane, forming pits that invaginate to pinch off (scission) and become free clathrin-coated vesicles (CCVs) ( Fig. 1 A). In cultured cells, the assembly of a CCV takes ∼1 min, and several hundred to a thousand or more can form every minute ( 3 ). (sciencemag.org)
  • B ) Deep-etch image of the cytosolic side of a plasma membrane showing the polygonal lattices of a coated pit and an invaginating coated vesicle. (sciencemag.org)
  • Electron micrograph of in vitro-formed COPI-coated vesicles. (wikipedia.org)
  • Moelleken, J. 2006-10-14 00:00:00 COPI-coated vesicles are protein and liquid carriers that mediate transport within the early secretory pathway. (deepdyve.com)
  • We are interested in the molecular mechanisms underlying intracellular transport by COPI coated vesicles. (db-engine.de)
  • In Situ Localization and in Vitro Induction of Plant COPI-Coated Vesicles. (agrisera.com)
  • In contrast, COPI-coated vesicles keep ADP ribosylation factor (ARF) when the vesicles form with GTP or with GTPγS. (dcyphr.org)
  • Coat assembly is triggered when ARF binds GTP, initiating transport vesicle budding, and coat disassembly is triggered when ARF hydrolyzes GTP, allowing the uncoated vesicle to fuse. (rupress.org)
  • Before the vesicle can fuse with the ER membrane, the coats surrounding the vesicle must dissociate. (wikipedia.org)
  • COP II vesicles must shed their coat before they can fuse with the cis-Golgi membrane. (wikipedia.org)
  • Small COP II coated vesicles form from the ER and then fuse directly with the cis-Golgi. (yeastgenome.org)
  • The vesicle will not be able to fuse with the acceptor membrane. (dcyphr.org)
  • Arf GTPase-activating protein (GAP) catalyzed GTP hydrolysis in Arf1 triggers uncoating and is required for uptake of cargo molecules into vesicles. (rupress.org)
  • The clathrin-mediated endocytic pathway has recently received considerable attention because of (i) the identification of an array of molecules that orchestrate the assembly of clathrin-coated vesicles and the selection of the vesicle cargo and (ii) the resolution of structures for a number of these proteins. (sciencemag.org)
  • Moving molecules, such as proteins, between these compartments is essential for living eukaryotic cells, and these molecules are usually trafficked inside membrane-bound packages called vesicles. (elifesciences.org)
  • For the first time, we have demonstrated that Cog3p depletion is accompanied by reduction in Cog1, 2, and 4 protein levels and by accumulation of COG complex-dependent (CCD) vesicles carrying v-SNAREs GS15 and GS28 and cis-Golgi glycoprotein GPP130. (rupress.org)
  • We show that ε-COP depletion for 12 h caused a primary block to virus internalization and a secondary defect in viral gene expression. (asm.org)
  • COP-coated Golgi-derived vesicles mediate intra-Golgi transport. (dcyphr.org)
  • Fusion Rapidly Follows Vesicle Transport to the Target Membrane in Protein Transport through the Golgi Apparatus in Vitro . (springer.com)
  • Kreis TE (1992) Regulation of vesicular and tubular membrane traffic of the Golgi complex by coat proteins. (springer.com)
  • Transport from one compartment of this pathway to another is mediated by vesicular carriers, which are formed by the controlled assembly of coat protein complexes (COPs) on donor organelles. (mdpi.com)
  • Some of these CCD vesicles appeared to be vesicular coat complex I (COPI) coated. (rupress.org)
  • Problems with COP II early secretory pathways can lead to a disease called Congenital Dyserythropoietic Anemia type II. (wikipedia.org)
  • COP and clathrin-coated vesicle budding: different pathways, common approaches. (ebi.ac.uk)
  • Among its related pathways are Vesicle-mediated transport and Transport to the Golgi and subsequent modification . (genecards.org)
  • Genomic analysis shows that the increased complexity of trafficking pathways in mammalian cells involves an expansion of the number of SNARE, Rab and COP proteins. (rcsb.org)
  • Their function is to select cargo for packaging into transport vesicles, and together with membrane-deforming scaffolding proteins such as clathrin and the COPI B-subcomplex, they facilitate the trafficking of proteins and lipids between membrane compartments in the secretory and endocytic pathways. (elifesciences.org)
  • A novel class of clathrin-coated vesicles budding from endosomes. (springermedizin.at)
  • In addition, endosomes were also found to assemble distinct, clathrin-like coats. (nih.gov)
  • Since microinjection of antibodies to beta-COP inhibits the entry of enveloped viruses via the endocytic pathway, it is apparent that the recruitment of COP-I or COP-I-related proteins plays an important role in the function of endosomes in intact cells. (nih.gov)
  • Scheel J, Kreis TE (1991) Motor protein independent binding of endocytic carrier vesicles to microtubules in vitro. (springer.com)
  • Morphologically visible coats are seen on many vesicles that mediate transport between membrane-bound compartments in the cell. (sciencemag.org)
  • Before the COP I protein can coat vesicles on the Golgi membrane, it must interact with a small GTPase called ARF1 (ADP ribosylation factor). (wikipedia.org)
  • Next, the ARF1 protein recruits COP1 to the golgi complex membrane by interacting with β-COP and γ-COP. (wikipedia.org)
  • When ARF1 switches to its GDP- bound conformation, it causes the COP1 coat to destabilize. (wikipedia.org)
  • When released, the vesicle's coat is shed and ARF1 and COPI dissociate. (xenbase.org)
  • The small GTPase Arf1 is involved in most, if not all, vesicle generation events at the level of the Golgi apparatus. (biologists.org)
  • Coats function to deform the donor membrane to produce a vesicle, and they also function in the selection of the vesicle cargo. (sciencemag.org)
  • The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. (rupress.org)
  • Coat protein, or COPI, is an ADP ribosylation factor (ARF)-dependent protein involved in membrane traffic. (wikipedia.org)
  • Furthermore, the mammalian COG complex physically interacts with GS28 and COPI and specifically binds to isolated CCD vesicles. (rupress.org)
  • Mutations designed on the basis of the structure in conjunction with isothermal titration calorimetry confirm the mode of binding and show that mammalian δ-COP binds related tryptophan-based motifs such as that from ArfGAP1 in a similar manner. (princeton.edu)
  • Furthermore, in these cells proteins resident in or cycling through the cis-Golgi, including ERGIC-53, beta-COP, and GM130, accumulate in the ER-Golgi intermediate compartment, and Golgi-to-ER retrograde transport is blocked. (genes2cognition.org)
  • W.A. Braell , Detection of Endocytic Vesicle Fusion in Vitro Using an Assay Based on the Avidin-Biotin Association Reaction. (elsevier.com)
  • Vice versa we suggest the term "exoplasmosis" (as already suggested in a 1964 publication) for cis-membrane fusion events, where the interior of a vesicle is released to an extraplasmatic environment (the extracellular space or the lumen of a compartment). (springermedizin.at)
  • The best-studied isoform, syt-1, is targeted to synaptic vesicles, where it triggers membrane fusion in response to Ca 2+ 1 . (nature.com)
  • Sar1p dissociates from GTP vesicles, allowing for fusion. (dcyphr.org)
  • Rather, GTP hydrolysis is important for the fusion of the vesicle. (dcyphr.org)
  • Duden R, Griffiths G, Frank R, Argos P, Kreis TE (1991) ß-COP, a 110kD protein associated with nonclathrin coated vesicles and cisternae of the Golgi complex shows homology to b-adaptin. (springer.com)
  • T. Serafini and J.E. Rothman , Purification of Golgi Cisternae-Derived COP-Coated Vesicles. (elsevier.com)
  • If these proteins are to be moved, they must be moved as part of membrane vesicles, and any enzymes that act on the proteins must be contained in the vesicles or cisternae that contain the proteins. (ubc.ca)
  • Even if they get out of the ER into the cis cisternae of the Golgi, their ER targeting signal gets them sorted into vesicles that bring them back to the ER. (ubc.ca)
  • We suggest that ArfGAP2 and ArfGAP3 are coat protein-dependent ArfGAPs, whereas ArfGAP1 has a more general function. (rupress.org)
  • Duden R, Allan VJ, Kreis TE (1991) Involvement of 0-COP in membrane traffic through the Golgi complex. (springer.com)
  • COP I coat proteins function in intra-Golgi trafficking and in maintaining the normal structure of the Golgi complex ( Duden, 2003 ). (rupress.org)
  • Indeed, like beta-COP, ARF is dissociated from the Golgi complex by treatment with brefeldin A and brefeldin A prevents ARF from associating in vitro, but the mechanism of this action by brefeldin A has been unclear. (nih.gov)
  • The antibody recognizes an epitope in the β-COP protein (110 kDa) and stains the periphery of the Golgi complex using immunocytochemical techniques. (genetex.com)
  • Clathrin coats contain both clathrin and adaptor complexes that link clathrin to receptors in coated vesicles. (embl.de)
  • [12] instead, they are linked to one another via the γζβδ-COP subcomplexes, forming an interconnected assembly . (wikipedia.org)
  • Vesicle coats: structure, function, and general principles of assembly. (springermedizin.at)
  • Accordingly, endosome function is likely to be governed by the regulated assembly of cytoplasmic coat complexes. (nih.gov)
  • Arf has a number of disparate activities including maintenance of organelle integrity, assembly of coat proteins, as a co-factor for cholera toxin and as an activator of phospholipase D. The Arf family is divided functionally into the Arf and the Arf-like (Arl) proteins. (novusbio.com)
  • M. Bremser, W. Nickel, M. Schweikert, M. Ravazzola, M. Amherd, C.A. Hughes, T.H. Söllner, J. E. Rothman, and F. T. Wieland (1999) Coupling of coat assembly and vesicle budding to packaging of putative cargo receptors. (db-engine.de)
  • We have reinvestigated the early responses of plant cells to BFA with novel tools, namely, tobacco Bright Yellow 2 (BY-2) suspension-cultured cells expressing an in vivo green fluorescent protein-Golgi marker, electron microscopy of high-pressure frozen/freeze-substituted cells, and antisera against Atgamma-COP, a component of COPI coats, and AtArf1, the GTPase necessary for COPI coat assembly. (jove.com)
  • In cells with low sterol levels, SREBP cleavage-activating protein (SCAP) binds to Sec23/24, which clusters the SCAP/SREBP complex into common coated protein II (COP II) vesicles ( 4 ). (pubmedcentralcanada.ca)
  • These involve the recognition of targeting determinants on the cytoplasmic domains of many membrane proteins as well as the formations of specific transport vesicles. (nih.gov)
  • However, the past decade has seen the emergence of the cavin family of peripheral membrane proteins as essential coat components and regulators of caveola biogenesis. (biologists.org)
  • Cavins are peripheral membrane proteins that coat the caveolar surface, with caveolins embedded in the interior membrane layer. (biologists.org)
  • Clathrin, on the other hand is involved in forming vesicles in the trans Golgi network and at the cell surface. (ubc.ca)
  • This unit explains the function of the cytoskeleton and its role in controlling transport of vesicles between different subcellular compartments. (nottingham.ac.uk)
  • COPI polymerises on the membrane enabling its deformation/curvature, and eventually budding and scission of the transport vesicle. (xenbase.org)
  • such as for example dynamin endophilin and amphiphysin have already been shown to are likely involved in vesicle fission (14). (techxprtz.com)
  • Vesicles formed with crude cytosolic proteins contain Bos1p, Sec22p, and Ypt1p. (dcyphr.org)
  • The researchers find Sec22p in vesicles formed with pure cytosolic proteins. (dcyphr.org)
  • Flow Cytometry: SEC23A Antibody [NBP2-34842] - Analysis of COP II was done on PC-12 cells. (novusbio.com)
  • Immunocytochemistry/ Immunofluorescence: SEC23A Antibody [NBP2-34842] - Analysis of COP II (green) showing staining in the cytoplasm of PC12 cells (right) compared to a negative control without primary antibody (left). (novusbio.com)
  • This peptide may be used for neutralization and control experiments with the polyclonal antibody that reacts with this product and rat COP I alpha, catalog ab2913 . (abcam.cn)
  • A homozygous splice donor site variant in Family 1 results in two aberrant transcripts, one of which causes skipping of exon 8 in COPB1 pre-mRNA, and a 36 amino acid in-frame deletion, resulting in the loss of a motif at a small interaction interface between β-COP and β'-COP. (xenbase.org)
  • Traffic COPs of the early secretory pathway. (ebi.ac.uk)
  • Other protein components of the COPI vesicle include the p24 family of proteins, which serve diverse roles in the early secretory pathway (reviewed in Schuiki and Volchuk, 2012). (reactome.org)
  • The first step in the COP II pathway is the recruitment of a small GTPase named Sar1 to the ER membrane. (wikipedia.org)
  • We also show that the Saccharomyces cerevisiae Arf GTPase-activating protein (GAP) homolog Gcs1p uses a related WxxF motif at its extreme C terminus to bind to δ-COP at the same site in the same way. (princeton.edu)
  • Cytoplasmic coat proteins involved in endosome function. (nih.gov)
  • Background: TMP21, a type I transmembrane protein, is a member of the p24 cargo protein family, which is highly enriched in the ER, the Golgi and coat protein (COP) I and II transport vesicles (1,2). (cellsignal.com)
  • The phenotypes observed in the triple ArfGAP knockdown cells are similar to those seen in beta-COP-depleted cells. (genes2cognition.org)
  • Both the triple ArfGAP- and beta-COP-depleted cells accumulate characteristic vacuolar structures that are visible under electron microscope. (genes2cognition.org)
  • There are two major families of coat proteins, COP and clathrin. (ubc.ca)
  • Among these are members of the COP-I and ARF families of coat proteins. (nih.gov)
  • In addition, we found that luteolin suppressed coat protein I complex expression, which was related to influenza virus entry and endocytic pathway. (springermedizin.de)
  • This complex polymerizes to form the outer layer of the coat. (wikipedia.org)
  • The name "COPI" refers to the specific coat protein complex that initiates the budding process on the cis -Golgi membrane. (wikipedia.org)
  • These vesicles then transport the SCAP/SREBP complex from the ER to the Golgi, wherein two proteases, site-1 protease (S1P) and site-2 protease (S2P), sequentially cleave SREBPs ( 5 , 6 ). (pubmedcentralcanada.ca)
  • Activated small guanine triphosphatases (GTPases) attract coat proteins to specific membrane export sites, thereby linking coatomers to export cargos. (ebi.ac.uk)