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VPS26A
Vacuolar protein sorting-associated protein 26A is a protein that in humans is encoded by the ''VPS26A'' gene. This gene belongs to a group of vacuolar protein sorting (VPS) genes. The encoded protein is a component of a large multimeric complex, termed the retromer complex, involved in retrograde transport of proteins from endosomes to the trans-Golgi network. The close structural similarity between the yeast and human proteins that make up this complex suggests a similarity in function. Expression studies in yeast and mammalian cells indicate that this protein interacts directly with VPS35, which serves as the core of the retromer complex. Alternative splicing results in multiple transcript variants encoding different isoforms. Structure Vps26 is a 38-kDa subunit that has a two-lobed structure with a polar core that resembles the arrestin family of trafficking adaptor. This fold consist of two related β-sandwich subdomains with a fibronectin type III domain topology. The tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retromer
Retromer is a complex of proteins that has been shown to be important in recycling transmembrane receptors from endosomes to the Golgi apparatus, ''trans''-Golgi network (TGN). Background Retromer is a heteropentameric complex, which in humans is composed of a less defined membrane-associated sorting nexin dimer (SNX1, SNX2, SNX5, SNX6), and a vacuolar protein sorting (Vps) trimer containing VPS26A, Vps26, VPS29, Vps29, VPS35, Vps35. Although the SNX dimer is required for the recruitment of retromer to the endosomal membrane, the cargo binding function of this complex is contributed by the core trimer through the binding of Vps35 subunit to various cargo molecules including cation-dependent mannose-6-phosphate receptor, M6PR GPR177, wntless and sortilin 1, sortilin. Early study on sorting of acid hydrolases such as carboxypeptidase Y (CPY) in S. cerevisiae mutants has led to the identification of retromer in mediating the retrograde trafficking of the pro-CPY receptor (SORCS1, Vp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clathrin
Clathrin is a protein that plays a major role in the formation of coated vesicles. Clathrin was first isolated and named by Barbara Pearse in 1976. It forms a triskelion shape composed of three clathrin heavy chains and three light chains. When the triskelia interact they form a polyhedral lattice that surrounds the vesicle, hence the protein's name, which is derived from the Latin ''clathrum'' meaning lattice. Coat-proteins, like clathrin, are used to build small vesicles in order to transport molecules within cells. The endocytosis and exocytosis of vesicles allows cells to communicate, to transfer nutrients, to import signaling receptors, to mediate an immune response after sampling the extracellular world, and to clean up the cell debris left by tissue inflammation. The endocytic pathway can be hijacked by viruses and other pathogens in order to gain entry to the cell during infection. Structure The clathrin triskelion is composed of three clathrin heavy chains inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Protein phosphorylation often activates (or deactivates) many enzymes. Glucose Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by :D-glucose + ATP → D-glucose-6-phosphate + ADP : ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition) Hepatic cells are freely permeable to glucose, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amine group is bonded to the carboxylic group of another amino acid, making it a chain. That leaves a free carboxylic group at one end of the peptide, called the C-terminus, and a free amine group on the other end called the N-terminus. By convention, peptide sequences are written N-terminus to C-terminus, left to right (in LTR writing systems). This correlates the translation direction to the text direction, because when a protein is translated from messenger RNA, it is created from the N-terminus to the C-terminus, as amino acids are added to the carboxyl end of the protein. Chemistry Each amino acid has an amine group and a carboxylic group. Amino acids link to one another by peptide bonds which form through a dehydration reaction that j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Differences Between Vps26A And Vps26B
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as biological organisms, minerals and chemicals. Abstract structures include data structures in computer science and musical form. Types of structure include a hierarchy (a cascade of one-to-many relationships), a network featuring many-to-many links, or a lattice featuring connections between components that are neighbors in space. Load-bearing Buildings, aircraft, skeletons, anthills, beaver dams, bridges and salt domes are all examples of load-bearing structures. The results of construction are divided into buildings and non-building structures, and make up the infrastructure of a human society. Built structures are broadly divided by their varying design approaches and standards, into categories including building str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phospholipid
Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typically have omega-3 fatty acids EPA and DHA integrated as part of the phospholipid molecule. The phosphate group can be modified with simple organic molecules such as choline, ethanolamine or serine. Phospholipids are a key component of all cell membranes. They can form lipid bilayers because of their amphiphilic characteristic. In eukaryotes, cell membranes also contain another class of lipid, sterol, interspersed among the phospholipids. The combination provides fluidity in two dimensions combined with mechanical strength against rupture. Purified phospholipids are produced commercially and have found applications in nanotechnology and materials science. The first phospholipid identified in 1847 as such in biological tissues was lecith ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AP2 Adaptor Complex
The AP2 adaptor complex is a multimeric protein that works on the cell membrane to internalize cargo in clathrin-mediated endocytosis. It is a stable complex of four adaptins which give rise to a structure that has a core domain and two appendage domains attached to the core domain by polypeptide linkers. These appendage domains are sometimes called 'ears'. The core domain binds to the membrane and to cargo destined for internalisation. The alpha and beta appendage domains bind to accessory proteins and to clathrin. Their interactions allow the temporal and spatial regulation of the assembly of clathrin-coated vesicles and their endocytosis. The AP-2 complex is a heterotetramer consisting of two large adaptins (α and β), a medium adaptin (μ), and a small adaptin (σ): * complex 2 ** AP2A1 (α unit 1) ** AP2A2 (α unit 2) ** AP2B1 (β unit) ** AP2M1 (μ unit) ** AP2S1 (σ unit) Structure The AP2 adaptor complex exists in two primary conformations: the open conformation (active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-terminal
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus. Chemistry Each amino acid has a carboxyl group and an amine group. Amino acids link to one another to form a chain by a dehydration reaction which joins the amine group of one amino acid to the carboxyl group of the next. Thus polypeptide chains have an end with an unbound carboxyl group, the C-terminus, and an end with an unbound amine group, the N-terminus. Proteins are naturally synthesized starting from the N-terminus and ending at the C-terminus. Function C-terminal retention signals While the N-terminus of a protein often cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibronectin Type III Domain
The Fibronectin type III domain is an evolutionarily conserved protein domain that is widely found in animal proteins. The fibronectin protein in which this domain was first identified contains 16 copies of this domain. The domain is about 100 amino acids long and possesses a beta sandwich structure. Of the three fibronectin-type domains, type III is the only one without disulfide bonding present. Fibronectin domains are found in a wide variety of extracellular proteins. They are widely distributed in animal species, but also found sporadically in yeast, plant and bacterial proteins. Human proteins containing this domain ABI3BP; ANKFN1; ASTN2; AXL; BOC; BZRAP1; C20orf75; CDON; CHL1; CMYA5; CNTFR; CNTN1; CNTN2; CNTN3; CNTN4; CNTN5; CNTN6; COL12A1; COL14A1; COL20A1; COL7A1; CRLF1; CRLF3; CSF2RB; CSF3R; DCC; DSCAM; DSCAML1; EBI3; EGFLAM; EPHA1; EPHA10; EPHA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-protein Coupled Receptor
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of protein family, evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell (biology), cell and activate cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times. Text was copied from this source, which is available under Attribution 2.5 Generic (CC BY 2.5) license. Ligands can bind either to extracellular N-terminus and loops (e.g. glutamate receptors) or to the binding site within transmembrane helices (Rhodopsin-like family). They are all activated by agonists although a spontaneous auto-activation of an empty receptor can also be observed. G protein-coupled receptors are found only in eukaryotes, including y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
