Protein Vpu - P19554 (VPU_HV1S1)

 

Protein Feature View of PDB entries mapped to a UniProtKB sequence  

  • Number of PDB entries for P19554: 3
 
Function
Enhances virion budding by targeting host CD4 and Tetherin/BST2 to proteasome degradation. Degradation of CD4 prevents any unwanted premature interactions between viral Env and its host receptor CD4 in the endoplasmic reticulum. Degradation of antiretroviral protein Tetherin/BST2 is important for virion budding, as BST2 tethers new viral particles to the host cell membrane. Mechanistically, Vpu bridges either CD4 or BST2 to BTRC, a substrate recognition subunit of the Skp1/Cullin/F-box protein E3 ubiquitin ligase, induces their ubiquitination and subsequent proteasomal degradation. The alteration of the E3 ligase specificity by Vpu seems to promote the degradation of host IKBKB, leading to NF-kappa-B down-regulation and subsequent apoptosis. Ion channel activity has also been suggested, however, formation of cation-selective channel has been reconstituted ex-vivo in lipid bilayers. It is thus unsure that this activity plays a role in vivo. UniProt
Pathway Maps
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Subunit Structure
Forms pentamers or hexamers. Interacts with host CD4 and BRTC; these interactions induce proteasomal degradation of CD4. Interacts with host BST2; this interaction leads to the degradadation of host BST2. Interacts with host FBXW11. Interacts with host AP1M1; this interaction plays a role in the mistrafficking and subsequent degradation of host BST2. UniProt
Domain
The N-terminal and transmembrane domains are required for proper virion budding, whereas the cytoplasmic domain is required for CD4 degradation. The cytoplasmic domain is composed of 2 amphipathic alpha helix. UniProt
  • Organism: isolate HXB2
  • Length:
  • UniProt
  • Other Gene names: vpu
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The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
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