charged multivesicular body protein 4B; chromatin-modifying protein 4B; CHMP4b; SNF7 homolog associated with Alix 1; SNF7-2; hSnf7-2; vacuolar protein sorting-associated protein 32-2; Vps32-2; hVps32-2 (CHMP4B, C20orf178, SHAX1)

Function: - component of ESCRT3 in the multivesicular body pathway - within ESCRT3, serves as an acceptor for ESCRT1 complex - interacts with CHMP2A, CHMP4A, CHMP4C, CHMP6 within ESCRT3 - interacts with ESCRT1 component PDCD6IP - when overexpressed, membrane-assembled circular arrays of CHMP4B filaments can promote or stabilize negative curvature & outward budding - interacts with CHMP6, CHMP4C & CHMP7 - interacts with VPS4A & VPS4B - interaction with misfolded CFTR Structure: - the acidic C-terminus & the basic N-termminus are thought to render the protein in a closed, soluble & inactive conformation through an autoinhibitory intramolecular interaction - the open & active conformation, which enables membrane binding & oligomerization, is facilitated by interaction with other ESCRT components - belongs to the SNF7 family Compartment: cytoplasm, late endosome membrane Expression: - widely expressed - expressed in heart, skeletal muscle > brain, colon, thymus, spleen, kidney, liver, small intestine, placenta, lung, peripheral blood lymphocytes. Pathology: - overexpression strongly inhibits HIV-1 release - defects in CHMP4B are the cause of cataract posterior polar type 3

Properties

SIZE: entity length = 224 aa MW = 25 kD COMPARTMENT: cytoplasm MOTIF: acetylation site SITE: N-TERMINUS EFFECTOR-BOUND: acetyl coiled coil {23-183}

Database Correlations

OMIM correlations MORBIDMAP 610897 UniProt Q9H444 Pfam PF03357 Entrez Gene 128866 Kegg hsa:128866

References

UniProt :accession Q9H444