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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] |
AP2M1
AP-2 complex subunit mu is a protein that in humans is encoded by the ''AP2M1'' gene. Function This gene encodes a subunit of the heterotetrameric coat assembly protein complex 2 (AP2), which belongs to the adaptor complexes medium subunits family. The encoded protein is required for the activity of a vacuolar ATPase, which is responsible for proton pumping occurring in the acidification of endosomes and lysosomes. The encoded protein may also play an important role in regulating the intracellular trafficking and function of CTLA-4 protein. Two transcript variants encoding different isoforms have been found for this gene. Interactions AP2M1 has been shown to interact with CTLA-4 and Alpha-1B adrenergic receptor The alpha-1B adrenergic receptor (α1B-adrenoreceptor), also known as ADRA1B, is an alpha-1 adrenergic receptor, and also denotes the human gene encoding it. The crystal structure of the α1B-adrenergic receptor has been determined in complex with .... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muniscins
The muniscin protein family was initially defined in 2009 as proteins having 2 homologous domains that are involved in 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 ... mediated endocytosis (CME) and have been reviewed. In addition to FCHO1, FCHO2 and Syp1, SGIP1 is also included in the family because it contains the μ (mu) homology domain and is involved in CME, even though it does not contain the F-BAR domain Muniscins are known as alternate cargo adaptors. That is, they participate in selecting which cargo molecules are internalized via CME. Additionally, the structure of the dimer, with its concave face oriented toward the plasma membrane, is thought to help curve the membrane as the clathrin coated pit forms. The muniscins are early arriving proteins involved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exomer
Exomer is a heterotetrameric protein complex similar to COPI and other adaptins. It was first described in the yeast ''Saccharomyces cerevisiae''. Exomer is a cargo adaptor important in transporting molecules from the Golgi apparatus toward the cell membrane. The vesicles it is found on are different from COPI vesicles in that they do not appear to have a "coat" or "scaffold" around them. An overview of the cellular localization of exomer and other cargo adaptoris shown here Exomer binds to 2 molecules of ADP-ribosylation factor 1 (Arf1) as showin this figure A hinge region of exomer is thought to be important for forming to a highly curved membrane vesicle as showin this figure The steps of assembly of exomer on a Golgi membrane are showin this figure See also * AP2 adaptor complex *Clathrin vesicles *COPII 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 Golg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsin
Epsins are a family of highly conserved membrane proteins that are important in creating membrane curvature. Epsins contribute to membrane deformations like endocytosis, and block Vesicle (biology), vesicle formation during mitosis. Structure Epsin contains various protein domains that aid in function. Starting at the N-terminus is the ENTH domain. ENTH stands for Epsin N-Terminal Homolog. The ENTH domain is approximately 150 amino acids long and is highly conserved across species. It is composed of seven Alpha helix, α-helices and an eighth helix that is not aligned with the seven helices that make up a superhelical fold. The role of the ENTH domain is to bind membrane lipids which is currently thought to aid in the invagination of the plasma membrane to form clathrin-coated vesicles. Additionally, located toward the C-terminus of the ENTH domain are two to three ubiquitin interacting motifs which aids in ubiquitin dependent recruitment. Following the ENTH domain there is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphiphysin
Amphiphysin is a protein that in humans is encoded by the ''AMPH'' gene. Function This gene encodes a protein associated with the cytoplasmic surface of synaptic vesicles. A subset of patients with stiff person syndrome who were also affected by breast cancer are positive for autoantibodies against this protein. Alternate splicing of this gene results in two transcript variants encoding different isoforms. Additional splice variants have been described, but their full length sequences have not been determined. Amphiphysin is a brain-enriched protein with an N-terminal lipid interaction, dimerisation and membrane bending BAR domain, a middle clathrin and adaptor binding domain and a C-terminal SH3 domain. In the brain, its primary function is thought to be the recruitment of dynamin to sites of clathrin-mediated endocytosis. There are 2 mammalian amphiphysins with similar overall structure. A ubiquitous splice form of amphiphysin-2 (BIN1) that does not contain clathrin or adapto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAP1LC3A
Microtubule-associated proteins 1A/1B light chain 3A is a protein that in humans is encoded by the ''MAP1LC3A'' gene. Two transcript variants encoding different isoforms have been found for this gene. Function MAP1A and MAP1B are microtubule-associated proteins which mediate the physical interactions between microtubules and components of the cytoskeleton. MAP1A and MAP1B each consist of a heavy chain subunit and multiple light chain subunits. The protein encoded by this gene is one of the light chain subunits and can associate with either MAP1A or MAP1B. MAPLC3A is one of the mammalian homologues of yeast ATG8, an important marker and effector of autophagy. Regulation MAP1LC3A is regulated by several post-translational modifications. These include covalent linkage of the C-terminus to phosphatidylethanolamine in autophagic membranes, and phosphorylation by protein kinase A, which downregulates its autophagy functions. Noncovalent interactions are important for its car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AP2S1
AP-2 complex subunit sigma is a protein that in humans is encoded by the ''AP2S1'' 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 b .... One of two major clathrin-associated adaptor complexes, AP-2, is a heterotetramer which is associated with the plasma membrane. This complex is composed of two large chains, a medium chain, and a small chain. This gene encodes the small chain of this complex. Alternative splicing has been observed in this gene and results in two known transcripts. References Further reading * * * * * * * * * * * * * External links * {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AP2B1
AP-2 complex subunit beta is a protein that in humans is encoded by the ''AP2B1'' gene. Function The protein encoded by this gene is one of two large chain components of the AP2 adaptor complex, which serves to link clathrin to receptors in coated vesicles. The encoded protein is found on the cytoplasmic face of coated vesicles in the plasma membrane. Two transcript variants encoding different isoforms have been found for this gene. Interactions AP2B1 has been shown to interact with: * AP1M2, * Arrestin beta 2, * BUB1B, * LDLRAP1 and * TGF beta receptor 2 Transforming growth factor, beta receptor II (70/80kDa) is a TGF beta receptor. ''TGFBR2'' is its human gene. It is a tumor suppressor gene. Function This gene encodes a member of the serine/threonine protein kinase family and the TGFB recepto .... References Further reading * * * * * * * * * * * * * * * * External links * {{gene-17-stub ... [...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] |
