Q5R658 · VPS4B_PONAB

Function

function

Involved in late steps of the endosomal multivesicular bodies (MVB) pathway. Recognizes membrane-associated ESCRT-III assemblies and catalyzes their disassembly, possibly in combination with membrane fission. Redistributes the ESCRT-III components to the cytoplasm for further rounds of MVB sorting. MVBs contain intraluminal vesicles (ILVs) that are generated by invagination and scission from the limiting membrane of the endosome and mostly are delivered to lysosomes enabling degradation of membrane proteins, such as stimulated growth factor receptors, lysosomal enzymes and lipids. VPS4A/B are required for the exosomal release of SDCBP, CD63 and syndecan (By similarity).
(Microbial infection) In conjunction with the ESCRT machinery also appears to function in topologically equivalent membrane fission events, such as the terminal stages of cytokinesis and enveloped virus budding (lentiviruses).

Catalytic activity

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site174-181ATP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentlate endosome membrane
Molecular FunctionATP binding
Molecular FunctionATP hydrolysis activity
Biological Processcell division
Biological Processendosomal transport
Biological Processprotein transport
Biological Processvacuole organization

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Vacuolar protein sorting-associated protein 4B
  • EC number

Gene names

    • Name
      VPS4B

Organism names

Accessions

  • Primary accession
    Q5R658

Proteomes

Subcellular Location

Late endosome membrane
; Peripheral membrane protein
Note: Membrane-associated in the prevacuolar endosomal compartment.

Keywords

PTM/Processing

Features

Showing features for chain, modified residue.

TypeIDPosition(s)Description
ChainPRO_00003313791-444Vacuolar protein sorting-associated protein 4B
Modified residue93Phosphoserine
Modified residue102Phosphoserine
Modified residue108Phosphoserine
Modified residue410Phosphoserine

Keywords

Interaction

Subunit

Proposed to be monomeric or homodimeric in nucleotide-free form and to oligomerize upon binding to ATP to form two stacked hexameric or heptameric rings with a central pore through which ESCRT-III substrates are translocated in an ATP-dependent manner. In vitro, associates on the inside of a helical tubular structure formed by a CHMP2A-CHMP3 polymer. Interacts with CHMP1A, CHMP1B, CHMP2A, CHMP4B and CHMP6. Interacts with VPS4A; the interaction suggests a heteromeric assembly with VPS4A. Interacts with VTA1 (By similarity).

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for domain, coiled coil, compositional bias, region.

TypeIDPosition(s)Description
Domain4-82MIT
Coiled coil19-82
Compositional bias78-116Basic and acidic residues
Region78-117Disordered

Domain

The MIT domain serves as an adapter for ESCRT-III proteins. It forms an asymmetric three-helix bundle that binds amphipathic MIM (MIT interacting motif) helices along the groove between MIT helices 2 and 3 present in a subset of ESCRT-III proteins thus establishing the canonical MIM-MIT interaction. In an extended conformation along the groove between helices 1 and 3, also binds to a type-2 MIT interacting motif (MIM2).

Sequence similarities

Belongs to the AAA ATPase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    444
  • Mass (Da)
    49,330
  • Last updated
    2004-12-21 v1
  • Checksum
    B6549F4E19C210F4
MSSTSPNLQKAIDLASKAAQEDKAGNYEEALQLYQHAVQYFLHVVKYEAQGDKAKQSIRAQCTEYLDRAEKLKEYLKNKEKKAQKPVKEGQPSPADEKGNDSDGEGESDDPEKKKLQNQLQGAIVIERPNVKWSDVAGLEGAKEALKEAVILPIKFPHLFTGKRTPWRGILLFGPPGTGKSYLAKAVATEANNSTFFSISSSDLVSKWLGESEKLVKNLFQLARENKPSIIFIDEIDSLCGSRSENESEAARRIKTEFLVQMRGVGVDNDGILVLGATNIPWVLDSAIRRRFEKRIYIPLPEPHARAAMFKLHLGTTQNSLTEADFRELGRKTDGYSGADISIIVRDALMQPVRKVQSATHFKKVRGPSRADPNHLVDDLLTPCSPGDPGAIEMTWMDVPGDKLLEPVVSMSDMLRSLSNTKPTVNEHDLLKLKKFTEDFGQEG

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias78-116Basic and acidic residues

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CR860638
EMBL· GenBank· DDBJ
CAH92758.1
EMBL· GenBank· DDBJ
mRNA

Genome annotation databases

Similar Proteins

Disclaimer

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