charged multivesicular body protein 3; chromatin-modifying protein 3; neuroendocrine differentiation factor; vacuolar protein sorting-associated protein 24; hVps24 (CHMP3, CGI149, NEDF, VPS24, CGI-149)

Function

• component of ESCRT3 in the multivesicular body pathway
  • within ESCRT3, interacts directly with CHMP2A & CHMP4A
  • participates in ATP-dependent disassembly of ESCRT3
• selectively binds to phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2) & PtdIns(3,4)P2
• role in late stages of cytokinesis
• role in endosomal sorting/trafficking of EGF receptor
• isoform 2 prevents stress-mediated cell death & accumulation of reactive oxygen species when expressed in yeast cells
• in vitro, heteromerizes with CHMP2A (but not CHMP4) to form helical tubular structures that expose membrane-interacting sites on the outside whereas VPS4B can associate on the inside of the tubule
• interacts with CHMP2A
• interacts with CHMP4A
  • interaction requires release of CHMP4A autoinhibition
• interacts with VPS4A
• interacts with STAMBP
  • interaction appears to relieve autoinhibition of CHMP3
• may interact with IGFBP7

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, membrane; lipid-anchor, endosome
• late endosome membrane (probable)
• localizes to the midbody of dividing cells

Alternative splicing

named isoforms=4

Expression

• widely expressed
• expressed in heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas

Pathology

• overexpression strongly inhibits HIV-1 release.

More general terms

• charged multivesicular body protein (CHMP)
• myristoylated protein
• phosphoprotein

Component of

• endosomal sorting complex required for transport-3 (ESCRT3)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=100526
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=51652
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:100526
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:51652
• OMIM: https://mirror.omim.org/entry/610052
• UniProt: http://www.uniprot.org/uniprot/Q9Y3E7.html