HIV-1 VPU protein
| FUNCTION |
Vpu expression promotes virion infectivity. It acts by down-regulating several host cellular proteins, such as CD4, MHC, NK receptors or tetherin, thereby promoting infected cell survival and virion release.
It plays a role in CD4 down-regulation by mediating the proteasomal degradation of newly synthesized CD4. Vpu binds to CD4 at the endoplasmic reticulum (ER) membrane and recruits the SCF β-TrCP E3 ubiquitin ligase complex by directly interacting with β-TrCP. This ubiquitiniation event targets CD4 degradation by the cytosolic proteasome through a dislocation step of CD4 which is mediated by the p97-UFD1L-NPL4 complex .
Vpu promotes progeny virion release from infected cells by antagonizing the tethering effect of BST2/tetherin .
Vpu also induces disarms Natural Killer Cells by downregulating MHC class I , natural killer cell receptor NK, T-cell, B-cell antigen (NTB-A), as well as the activating NK cell receptor SLAMF6 PVR/CD155 .
| INTERACTIONS |
| SUBCELLULAR LOCATION |
| TIMING OF EXPRESSION |
Modulation of HIV-1-host interaction: role of the Vpu accessory protein
Mathieu Dub?, Mariana G. Bego, Catherine Paquay, ?ric A. Cohen
Retrovirology 2010; 7: 114
HIV-1 Vpu mediated downregulation of CD155 requires alanine residues 10, 14 and 18 of the transmembrane domain
Sebastian Bolduan, Tatjana Reif, Michael Schindler, Ulrich Schubert
Virology September 2014; 464-465: 375-384
HIV-1 Vpu Disarms Natural Killer Cells
Jonathan Richard, ?ric A. Cohen
Cell Host Microbe November 18, 2010; 8: 389?391
HIV-1 Vpu affects the anterograde transport and the glycosylation pattern of NTB-A
Sebastian Bolduan, Philipp Hubel, Tatjana Reif, Veronika Lodermeyer, Kristin H?hne, Jo?lle V. Fritz, Daniel Sauter, Frank Kirchhoff, Oliver T. Fackler, Michael Schindler, Ulrich Schubert
Virology June 5, 2013; 440: 190-203
The human immunodeficiency virus type 1 (HIV-1) Vpu protein interferes with an early step in the biosynthesis of major histocompatibility complex (MHC) class I molecules
T. Kerkau, I. Bacik, J. R. Bennink, J. W. Yewdell, T. H?nig, A. Schimpl, U. Schubert
J. Exp. Med. April 7, 1997; 185: 1295?1305