ESCRT-II complex subunit | |||||||||
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Identifiers | |||||||||
Symbol | ESCRT-II | ||||||||
Pfam | PF05871 | ||||||||
InterPro | IPR008570 | ||||||||
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Vacuolar protein-sorting-associated protein 25 is a protein that in humans is encoded by the VPS25 gene. [5] [6]
It is a component of the endosome-associated complex ESCRT-II (Endosomal Sorting Complexes Required for Transport protein II). ESCRT (ESCRT-I, -II, -III) complexes orchestrate efficient sorting of ubiquitinated transmembrane receptors to lysosomes via multivesicular bodies (MVBs). [7] ESCRT-II recruits the transport machinery for protein sorting at MVB. [8] In addition, the human ESCRT-II has been shown to form a complex with RNA polymerase II elongation factor ELL in order to exert transcriptional control activity. ESCRT-II transiently associates with the endosomal membrane and thereby initiates the formation of ESCRT-III, a membrane-associated protein complex that functions immediately downstream of ESCRT-II during sorting of MVB cargo. ESCRT-II in turn functions downstream of ESCRT-I, a protein complex that binds to ubiquitinated endosomal cargo. [9]
ESCRT-II is a trilobal complex composed of two copies of vps25, one copy of vps22 and the C-terminal region of vps36. The crystal structure of vps25 revealed two winged-helix domains, the N-terminal domain of vps25 interacting with vps22 and vps36. [10]
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.
AAA proteins or ATPases Associated with diverse cellular Activities are a protein family sharing a common conserved module of approximately 230 amino acid residues. This is a large, functionally diverse protein family belonging to the AAA+ protein superfamily of ring-shaped P-loop NTPases, which exert their activity through the energy-dependent remodeling or translocation of macromolecules.
Tumor susceptibility gene 101, also known as TSG101, is a human gene that encodes for a cellular protein of the same name.
Programmed cell death 6-interacting protein also known as ALIX is a protein that in humans is encoded by the PDCD6IP gene.
Charged multivesicular body protein 3 is a protein that in humans is encoded by the VPS24 gene.
Vacuolar protein sorting-associated protein 4A is a protein that in humans is encoded by the VPS4A gene.
Vacuolar protein sorting-associated protein 4B is a protein that in humans is encoded by the VPS4B gene.
Vacuolar protein sorting-associated protein 28 homolog is a protein that in humans is encoded by the VPS28 gene.
VPS29 is a human gene coding for the vacuolar protein sorting protein Vps29, a component of the retromer complex.
Charged multivesicular body protein 4b is a protein that in humans is encoded by the CHMP4B gene.
Vacuolar protein sorting-associated protein 45 is a protein that in humans is encoded by the VPS45 gene.
Charged multivesicular body protein 4a is a protein that in humans is encoded by the CHMP4A gene.
Charged multivesicular body protein 5 is a protein that in humans is encoded by the CHMP5 gene.
Charged multivesicular body protein 6 is a protein that in humans is encoded by the CHMP6 gene.
Vacuolar protein-sorting-associated protein 36 is a protein that in humans is encoded by the VPS36 gene.
Charged multivesicular body protein 1b is a protein that in humans is encoded by the CHMP1B gene.
Vacuolar-sorting protein SNF8 is a protein that in humans is encoded by the SNF8 gene.
Charged multivesicular body protein 4c is a protein that in humans is encoded by the CHMP4C gene.
The endosomal sorting complexes required for transport (ESCRT) machinery is made up of cytosolic protein complexes, known as ESCRT-0, ESCRT-I, ESCRT-II, and ESCRT-III. Together with a number of accessory proteins, these ESCRT complexes enable a unique mode of membrane remodeling that results in membranes bending/budding away from the cytoplasm. These ESCRT components have been isolated and studied in a number of organisms including yeast and humans. A eukaryotic signature protein, the machinery is found in all eukaryotes and some archaea.
Vacuolar protein sorting 37 homolog A is a protein in humans that is encoded by the VPS37A gene. It is a member of the endosomal sorting complex required for transport (ESCRT) system.