ID Q4QUN0_9HIV1 Unreviewed; 31 AA.
AC Q4QUN0;
DT 19-JUL-2005, integrated into UniProtKB/TrEMBL.
DT 19-JUL-2005, sequence version 1.
DT 24-JAN-2024, entry version 45.
DE RecName: Full=Protein Vpu {ECO:0000256|ARBA:ARBA00018094, ECO:0000256|RuleBase:RU364058};
DE AltName: Full=U ORF protein {ECO:0000256|ARBA:ARBA00031215, ECO:0000256|RuleBase:RU364058};
DE AltName: Full=Viral protein U {ECO:0000256|ARBA:ARBA00030659, ECO:0000256|RuleBase:RU364058};
DE Flags: Fragment;
GN Name=vpu {ECO:0000256|RuleBase:RU364058, ECO:0000313|EMBL:AAX38642.1};
OS Human immunodeficiency virus 1.
OC Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC Ortervirales; Retroviridae; Orthoretrovirinae; Lentivirus.
OX NCBI_TaxID=11676 {ECO:0000313|EMBL:AAX38642.1};
OH NCBI_TaxID=9606; Homo sapiens (Human).
RN [1] {ECO:0000313|EMBL:AAX38642.1}
RP NUCLEOTIDE SEQUENCE.
RC STRAIN=HS507 {ECO:0000313|EMBL:AAX38642.1};
RX PubMed=15956571; DOI=10.1128/JVI.79.13.8249-8261.2005;
RA Gerhardt M., Mloka D., Tovanabutra S., Sanders-Buell E., Hoffmann O.,
RA Maboko L., Mmbando D., Birx D.L., McCutchan F.E., Hoelscher M.;
RT "In-depth, longitudinal analysis of viral quasispecies from an individual
RT triply infected with late-stage human immunodeficiency virus type 1, using
RT a multiple PCR primer approach.";
RL J. Virol. 79:8249-8261(2005).
CC -!- FUNCTION: Enhances virion budding, by targeting human CD4 and
CC Tetherin/BST2 to proteasome degradation. Degradation of CD4 prevents
CC any unwanted premature interactions between viral Env and its receptor
CC human CD4 in the endoplasmic reticulum. Degradation of antiretroviral
CC protein Tetherin/BST2 is important for virion budding, as BST2 tethers
CC new viral particles to the host cell membrane. Mechanistically, Vpu
CC bridges either CD4 or BST2 to BTRC, a substrate recognition subunit of
CC the Skp1/Cullin/F-box protein E3 ubiquitin ligase, induces their
CC ubiquitination and subsequent proteasomal degradation. The alteration
CC of the E3 ligase specificity by Vpu seems to interfere with the
CC degradation of host IKBKB, leading to NF-kappa-B down-regulation and
CC subsequent apoptosis. Acts as a viroporin that forms an oligomeric ion
CC channel in membranes. Modulates the host DNA repair mechanisms to
CC promote degradation of nuclear viral cDNA in cells that are already
CC productively infected in order to suppress immune sensing and proviral
CC hyper-integration (superinfection). Manipulates PML-NBs and modulates
CC SUMOylation of host BLM protein thereby enhancing its DNA-end
CC processing activity toward viral unintegrated linear DNA. Also inhibits
CC RAD52-mediated homologous repair of viral cDNA, preventing the
CC generation of dead-end circular forms of single copies of the long
CC terminal repeat and permitting sustained nucleolytic attack.
CC {ECO:0000256|RuleBase:RU364058}.
CC -!- SUBCELLULAR LOCATION: Host membrane {ECO:0000256|RuleBase:RU364058};
CC Single-pass type I membrane protein {ECO:0000256|RuleBase:RU364058}.
CC Membrane {ECO:0000256|ARBA:ARBA00004479}; Single-pass type I membrane
CC protein {ECO:0000256|ARBA:ARBA00004479}.
CC -!- SIMILARITY: Belongs to the HIV-1 VPU protein family.
CC {ECO:0000256|RuleBase:RU364058}.
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DR EMBL; AY821325; AAX38642.1; -; Genomic_DNA.
DR GO; GO:0033644; C:host cell membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0016020; C:membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0042609; F:CD4 receptor binding; IEA:InterPro.
DR GO; GO:0005261; F:monoatomic cation channel activity; IEA:InterPro.
DR GO; GO:0032801; P:receptor catabolic process; IEA:InterPro.
DR GO; GO:0019076; P:viral release from host cell; IEA:UniProtKB-UniRule.
DR Gene3D; 1.10.195.10; HIV-1 VPU cytoplasmic domain; 1.
DR InterPro; IPR008187; Vpu.
DR InterPro; IPR009032; Vpu_cyt_dom_sf.
DR Pfam; PF00558; Vpu; 1.
DR SUPFAM; SSF57647; HIV-1 VPU cytoplasmic domain; 1.
PE 3: Inferred from homology;
KW Apoptosis {ECO:0000256|RuleBase:RU364058};
KW Host membrane {ECO:0000256|RuleBase:RU364058};
KW Host-virus interaction {ECO:0000256|RuleBase:RU364058};
KW Ion channel {ECO:0000256|RuleBase:RU364058};
KW Ion transport {ECO:0000256|RuleBase:RU364058};
KW Membrane {ECO:0000256|RuleBase:RU364058};
KW Transport {ECO:0000256|RuleBase:RU364058}.
FT NON_TER 1
FT /evidence="ECO:0000313|EMBL:AAX38642.1"
SQ SEQUENCE 31 AA; 3408 MW; C5B46C7E9D349270 CRC64;
EDSGNESDGD TEELSTMVDM GHLRLLDVND L
//