F6LXE4 · F6LXE4_9HIV1

Function

function

Counteracts the innate antiviral activity of host APOBEC3F and APOBEC3G. Forms a complex with host APOBEC3F and APOBEC3G thus preventing the entry of these lethally hypermutating enzymes into progeny virions. Recruits an active E3 ubiquitin ligase complex composed of elongin BC, CUL5, and RBX2 to induce polyubiquitination of APOBEC3G and APOBEC3F. In turn, they are directed to the 26S proteasome for degradation. Vif interaction with APOBEC3G also blocks its cytidine deaminase activity in a proteasome-independent manner, suggesting a dual inhibitory mechanism. May interact directly with APOBEC3G mRNA in order to inhibit its translation. Seems to play a role in viral morphology by affecting the stability of the viral nucleoprotein core. Finally, Vif also contributes to the G2 cell cycle arrest observed in HIV infected cells.

Miscellaneous

HIV-1 lineages are divided in three main groups, M (for Major), O (for Outlier), and N (for New, or Non-M, Non-O). The vast majority of strains found worldwide belong to the group M. Group O seems to be endemic to and largely confined to Cameroon and neighboring countries in West Central Africa, where these viruses represent a small minority of HIV-1 strains. The group N is represented by a limited number of isolates from Cameroonian persons. The group M is further subdivided in 9 clades or subtypes (A to D, F to H, J and K).
Required for replication in 'nonpermissive' cells, including primary T-cells, macrophages and certain T-cell lines, but is dispensable for replication in 'permissive' cell lines, such as 293T cells. In nonpermissive cells, Vif-defective viruses can produce virions, but they fail to complete reverse transcription and cannot successfully infect new cells.
Vif-defective viruses show catastrophic failure in reverse transcription due to APOBEC-induced mutations that initiate a DNA base repair pathway and compromise the structural integrity of the ssDNA. In the absence of Vif, the virion is morphologically abnormal.

Features

Showing features for site.

TypeIDPosition(s)Description
Site150-151Cleavage in virion (by viral protease)

GO annotations

AspectTerm
Cellular Componentcytoplasm
Cellular Componenthost cell cytoplasm
Cellular Componenthost cell plasma membrane
Cellular Componentplasma membrane
Cellular Componentvirion component
Molecular FunctionRNA binding
Biological Processviral life cycle

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Virion infectivity factor
  • Short names
    Vif
  • Alternative names
    • SOR protein
  • Cleaved into 2 chains
    • p17
    • p7

Gene names

    • Name
      vif

Organism names

Accessions

  • Primary accession
    F6LXE4

Subcellular Location

Cell membrane
; Peripheral membrane protein
Cytoplasm
Host cell membrane
; Peripheral membrane protein
Host cytoplasm
Virion
Membrane
; Peripheral membrane protein
Note: In the cytoplasm, seems to colocalize with intermediate filament vimentin. A fraction is associated with the cytoplasmic side of cellular membranes, presumably via the interaction with Pr55Gag precursor. Incorporated in virions at a ratio of approximately 7 to 20 molecules per virion.

Keywords

PTM/Processing

Features

Showing features for chain, modified residue.

TypeIDPosition(s)Description
ChainPRO_50233575841-150p17
ChainPRO_50233575851-192Virion infectivity factor
Modified residue96Phosphothreonine; by host MAP4K1
Modified residue144Phosphoserine; by host
ChainPRO_5023357586151-192p7
Modified residue155Phosphothreonine; by host
Modified residue165Phosphoserine; by host MAP4K1
Modified residue188Phosphothreonine; by host

Post-translational modification

Highly phosphorylated on serine and threonine residues.
Polyubiquitinated and degraded by the proteasome in the presence of APOBEC3G.
Processed in virion by the viral protease.

Keywords

Expression

Induction

Expressed late during infection in a Rev-dependent manner.

Interaction

Subunit

Homomultimer; in vitro and presumably in vivo. Interacts with viral RNA and Pr55Gag precursor; these interactions mediate Vif incorporation into the virion. Interacts with the viral reverse transcriptase. Interacts with human APOBEC3F and APOBEC3G. Interacts with host UBCE7IP1 isoform 3/ZIN and possibly with SAT. Interacts with host tyrosine kinases HCK and FYN; these interactions may decrease level of phosphorylated APOBEC3G incorporation into virions. Interacts with host ABCE1; this interaction may play a role in protecting viral RNA from damage during viral assembly. Forms an E3 ligase complex by interacting with host CUL5 and elongin BC complex (ELOB and ELOC). Interacts with host MDM2; this interaction targets Vif for degradation by the proteasome.

Family & Domains

Features

Showing features for region, motif, compositional bias.

TypeIDPosition(s)Description
Region14-17Interaction with host APOBEC3F; F1-box
Region40-44Interaction with host APOBEC3G; G-box
Region54-72Interaction with host APOBEC3F and APOBEC3G; FG-box
Region74-79Interaction with host APOBEC3F; F2-box
Region75-114RNA-binding
Motif108-139HCCH motif
Motif144-153BC-box-like motif
Region151-164Multimerization
Compositional bias164-179Basic and acidic residues
Region164-192Disordered
Region171-172Membrane association

Domain

The BC-like-box motif mediates the interaction with elongin BC complex.
The HCCH motif (H-x5-C-x18-C-x5-H) mediates the interaction with CUL5.

Sequence similarities

Belongs to the primate lentivirus group Vif protein family.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    192
  • Mass (Da)
    22,734
  • Last updated
    2011-07-27 v1
  • Checksum
    C0EF9D405ED04FB7
MENRWQVMIVWQVDRMRIRTWKSLVKYHMYRSGKAKKWFYRHHYESNHPRISSEVHIPLGEAKLVVTTYWGLHTGERDWHLGQGVSIEWRKRRYSTQVDPDLADHLIHLYYFDCFSDSAIRQAILGYRVSPSCEYQAGHNKVGSLQYLALTALITPKKIKPPLPSVKKLTEDRWNKPQKTMGHRGSHTMHGH

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias164-179Basic and acidic residues

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
JF495005
EMBL· GenBank· DDBJ
AEG75753.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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