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Vesicular Transport Proteins
A vesicular transport protein, or vesicular transporter, is a membrane protein that regulates or facilitates the movement of specific molecules across a vesicle's membrane. As a result, vesicular transporters govern the concentration of molecules within a vesicle. Types Examples include: * Archain * ARFs * Clathrin * Caveolin * Dynamin and related proteins, such as the EHD protein family * Rab proteins * SNAREs * Vesicular transport adaptor proteins e.g. Sorting nexins * Synaptotagmin * TRAPP complex * Synaptophysin * Auxilin Pathways There are multiple pathways, each using its own coat and GTPase. * COP 1 (Cytosolic coat protein complex ) : retrograde transport; Golgi ----> Endoplasmic reticulum * COP 2 (Cytosolic coat protein complex ) : anterograde transport; RER -----> cis-Golgi * Clathrin : trans-Golgi ----> Lysosomes, Plasma membrane ----> Endosomes (receptor-mediated endocytosis) See also * Membrane transport protein A membrane transport protein (or simply tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure Of The Vesicular Transport Protein Sec17
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and "rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third category of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synaptophysin
Synaptophysin, also known as the major synaptic vesicle protein p38, is a protein that in humans is encoded by the ''SYP'' gene. Genomics The gene is located on the short arm of X chromosome (Xp11.23-p11.22). It is 12,406 bases in length and lies on the minus strand. The encoded protein has 313 amino acids with a predicted molecular weight of 33.845 kDa. Molecular biology The protein is a synaptic vesicle glycoprotein with four transmembrane domains weighing 38kDa. It is present in neuroendocrine cells and in virtually all neurons in the brain and spinal cord that participate in synaptic transmission. It acts as a marker for neuroendocrine tumors, and its ubiquity at the synapse has led to the use of synaptophysin immunostaining for quantification of synapses. The exact function of the protein is unknown: it interacts with the essential synaptic vesicle protein synaptobrevin, but when the synaptophysin gene is experimentally inactivated in animals, they still develop and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MeSH D12
A mesh is a barrier made of connected strands of metal, fiber, or other flexible or ductile materials. A mesh is similar to a web or a net in that it has many attached or woven strands. Types * A plastic mesh may be extruded, oriented, expanded, woven or tubular. It can be made from polypropylene, polyethylene, nylon, PVC or PTFE. * A metal mesh may be woven, knitted, welded, expanded, sintered, photo-chemically etched or electroformed (screen filter) from steel or other metals. * In clothing, mesh is loosely woven or knitted fabric that has many closely spaced holes. Knitted mesh is frequently used for modern sports jerseys and other clothing like hosiery and lingerie * A mesh skin graft is a skin patch that has been cut systematically to create a mesh. Meshing of skin grafts provides coverage of a greater surface area at the recipient site, and also allows for the egress of serous or sanguinous fluid. However, it results in a rather pebbled appearance upon healing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Transport Protein
A membrane transport protein (or simply transporter) is a membrane protein involved in the movement of ions, small molecules, and macromolecules, such as another protein, across a biological membrane. Transport proteins are integral transmembrane proteins; that is they exist permanently within and span the membrane across which they transport substances. The proteins may assist in the movement of substances by facilitated diffusion or active transport. The two main types of proteins involved in such transport are broadly categorized as either ''channels'' or ''carriers''. The solute carriers and atypical SLCs are secondary active or facilitative transporters in humans. Collectively membrane transporters and channels are known as the transportome. Transportomes govern cellular influx and efflux of not only ions and nutrients but drugs as well. Difference between channels and carriers A carrier is not open simultaneously to both the extracellular and intracellular environments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor-mediated Endocytosis
Receptor-mediated endocytosis (RME), also called clathrin-mediated endocytosis, is a process by which cells absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane (invagination). This process forms vesicles containing the absorbed substances and is strictly mediated by receptors on the surface of the cell. Only the receptor-specific substances can enter the cell through this process. Process Although receptors and their ligands can be brought into the cell through a few mechanisms (e.g. caveolin and lipid raft), clathrin-mediated endocytosis remains the best studied. Clathrin-mediated endocytosis of many receptor types begins with the ligands binding to receptors on the cell plasma membrane. The ligand and receptor will then recruit adaptor proteins and clathrin triskelions to the plasma membrane around where invagination will take place. Invagination of the plasma membrane then occurs, forming a clathrin-coated pit. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosome
Endosomes are a collection of intracellular sorting organelles in eukaryotic cells. They are parts of endocytic membrane transport pathway originating from the trans Golgi network. Molecules or ligands internalized from the plasma membrane can follow this pathway all the way to lysosomes for degradation or can be recycled back to the cell membrane in the endocytic cycle. Molecules are also transported to endosomes from the trans Golgi network and either continue to lysosomes or recycle back to the Golgi apparatus. Endosomes can be classified as early, sorting, or late depending on their stage post internalization. Endosomes represent a major sorting compartment of the endomembrane system in cells. Function Endosomes provide an environment for material to be sorted before it reaches the degradative lysosome. For example, low-density lipoprotein (LDL) is taken into the cell by binding to the LDL receptor at the cell surface. Upon reaching early endosomes, the LDL dissociates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysosome
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane proteins, and its lumenal proteins. The lumen's pH (~4.5–5.0) is optimal for the enzymes involved in hydrolysis, analogous to the activity of the stomach. Besides degradation of polymers, the lysosome is involved in various cell processes, including secretion, plasma membrane repair, apoptosis, cell signaling, and energy metabolism. Lysosomes act as the waste disposal system of the cell by digesting used materials in the cytoplasm, from both inside and outside the cell. Material from outside the cell is taken up through endocytosis, while material from the inside of the cell is digested through autophagy. The sizes of the organelles vary greatly—the larger ones can be more than 10 times the size of the smaller ones. They were discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Réseau Express Régional
The Réseau Express Régional ( en, Regional Express Network), commonly abbreviated RER (), is a hybrid commuter rail and rapid transit system serving Paris and its Île-de-France, suburbs. It acts as a combined city-centre underground rail system and suburbs-to-city-centre commuter rail. In the city centre it acts much like the Paris Métro, though faster, having fewer stops. This has made it a model for proposals to improve transit within other cities. The network consists of five lines: RER A, A, RER B, B, RER C, C, RER D, D and RER E, E. The network has 257 stations and has interchanges with the Paris Métro, Métro and Transilien, commuter rail within the City of Paris and the suburbs. The lines are identified by letters to avoid confusion with the Métro lines, which are identified by numbers. The network is still expanding: RER E, which opened in 1999, is planned for westward extension toward La Défense and Mantes-la-Jolie in two phases by 2024–2026. Characteristi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COP 2
The Coat Protein Complex II, or COPII, is a group of proteins that facilitate the formation of vesicles to transport proteins from the endoplasmic reticulum to the Golgi apparatus or endoplasmic-reticulum–Golgi intermediate compartment. This process is termed anterograde transport, in contrast to the retrograde transport associated with the COPI complex. COPII is assembled in two parts: first an inner layer of Sar1, Sec23, and Sec24 forms; then the inner coat is surrounded by an outer lattice of Sec13 and Sec31. Function The COPII coat is responsible for the formation of vesicles from the endoplasmic reticulum (ER). These vesicles transport cargo proteins to the Golgi apparatus (in yeast) or the endoplasmic-reticulum-Golgi intermediate compartment (ERGIC, in mammals). Coat assembly is initiated when the cytosolic Ras GTPase Sar1 is activated by its guanine nucleotide exchange factor Sec12. Activated Sar1-GTP inserts itself into the ER membrane, binding preferentially to are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoplasmic Reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. The two types of ER share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of the cell. RER is found mainly toward the nucleus of cell and SER towards the cell membrane or plasma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golgi Apparatus
The Golgi apparatus (), also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic cells. Part of the endomembrane system in the cytoplasm, it packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination. It resides at the intersection of the secretory, lysosomal, and endocytic pathways. It is of particular importance in processing proteins for secretion, containing a set of glycosylation enzymes that attach various sugar monomers to proteins as the proteins move through the apparatus. It was identified in 1897 by the Italian scientist Camillo Golgi and was named after him in 1898. Discovery Owing to its large size and distinctive structure, the Golgi apparatus was one of the first organelles to be discovered and observed in detail. It was discovered in 1898 by Italian physician Camillo Golgi during an investigation of the nervous system. After first observing it under his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
