. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "HIV-1 Vpu counteracts the Tetherin-induced retention of HIV-1(delVpu) virion particles. Vpu colocalizes with Tetherin in co-expression cells" . "HIV-1 Vpu downregulates BST-2. The transmembrane/ion channel domain and conserved serines in the cytoplasmic domain of Vpu are required for the Vpu-mediated downregulation of BST-2" . "Cholesterol-binding compound amphotericin B methyl ester (AME) inhibits the ability of HIV-1 Vpu to counteract the activity of CD317/BST-2/tetherin" . "All three major structural domains (amino-terminal cytoplasmic tail, transmembrane domain, and extracellular coiled-coil domain) of BST-2 are involved in Vpu-mediated antagonism of tetherin" . "HIV-1 Vpu reduces steady-state expression of BST-2 in transfected HeLa cells and in HIV-infected macrophages, but not in HIV-infected CEMx174 and H9 cells" . "Human-monkey tetherin chimeras reveal that the transmembrane domains (amino acids I33V, I36L, P40L, and T45I) of tetherin are determinants of sensitivity/resistance to Vpu" . "HIV-1 Vpu interacts with BST-2 in the trans-Golgi network or in early endosomes, leading to lysosomal degradation of BST-2. Vpu-mediated downregulation of BST-2 depends on cellular ubiquitination machinery via betaTrCP" . "Mutation of a single amino acid (T45I) in the transmembrane region of BST-2 results in insensitivity to HIV-1 Vpu while maintaining antiviral activity" . "Deletion of amino acids leucine's 22/23 in BST-2 significantly diminishes its association with Vpu, leading to its resistance to antagonism by Vpu" . "HIV-1 Vpu co-immunoprecipitates with BST-2 in HEK293T cells and in HeLa Tet-Off cells. Deletion of two leucine residues at positions 22 and 23 in tetherin diminishes its association with Vpu" . "The betaTrCP binding motif DSGxxS of Vpu is required for optimal downregulation of BST-2 and enhancement of virion-release. Vpu serine (S52/S56) mutants are severely impaired for their ability to counteract tetherin antiviral activity" . "The plasma membrane clathrin adaptor protein complex AP-2 (mu2) is required for optimal downregulation of cell surface BST-2 by Vpu" . "A functional ER-associated degradation pathway is required for Vpu-induced tetherin degradation. P97 ATPase (VCP) knockdown partially impairs Vpu-mediated tetherin degradation" . "HIV-1 Vpu and beta-TrCP co-immunoprecipitate with tetherin" . "Vpu requires a functional polyubiquitin/proteasome system for efficient tetherin degradation. K48R ubiquitin mutant partially blocks Vpu-mediated tetherin downregulation" . "Monomeric tetherin and non-glycosylated tetherin are expressed at the cell surface and are sensitive to Vpu-induced downregulation" . "HIV-1 Vpu proteins from nonpandemic HIV-1 O and P strains are poor mediators of human tetherin downregulation. Vpus from nonpandemic HIV-1 N strains are as good tetherin antagonists as those from pandemic HIV-1 M strains" . "HIV-1 Vpu antagonizes the effects of BCA2 on HIV-1 particle production in \"tetherin-positive\" cells" . "In HIV-1-producing cells, CD317 relocalizes predominantly to TfR-positive recycling endosomes, to EEA1-postive early endosomes, and to gin97-positive trans-Golgi network compartments, with some present on late endocytic structures" . "Lysine residues (K18/K21) in tetherin are determinants for Vpu-mediated depletion of tetherin. This depletion, however, is dispenable for potent antagonism of the tetherin-mediated restriction of HIV-1 particle release" . "HIV-1 Vpu interacts with CD317 via its transmembrane region (amino acids 4-27) in living cells" . "Vpu interferes with tetherin trafficking to the cell-surface and causes a relocalization of the cellular tetherin with a TGN marker TGN46 in the TGN, suggesting Vpu-mediated antagonism of tetherin involves binding and sequestration of tetherin in the TGN" . "Tetherin cytoplasmic tail lysine residues (K18 and K21) are ubiquitinated in the presence of HIV-1 Vpu and KSHV K5" . "HIV-1 Vpu rescues the decreased production of infectious HIV-1 virions and restores the diminished reverse transcriptase activities of the culture supernatants as a result of BST-2 inhibition" . "HIV-1 BF recombinant Vpu is associated with increased viral particle production when compared to WT B variant virus in tetherin-expressing cell lines" . "Alanine-scanning mutagenesis and Ala-to-Leu replacement through the HIV-1 Vpu transmembrane domain (residues 5-28) reveals A14 and W22 are required for tetherin antagonism" . "All potential acceptor sites (Ser3, Thr4, Ser5, Cys9, Lys18, Cys20, and Lys21) in the cytoplasmic domain of BST2 contribute to Vpu-induced ubiquitination" . "The STS sequence in the cytoplasmic domain of BST2 is required for optimal Vpu-mediated downregulation of BST2 from the cell surface and the counteraction of virion release by Vpu" . "The residues including 22 to 24 and 34 to 42 of tetherin play a crucial role in the Vpu interaction. I34, L37, and L41 of tetherin are involved in the determination of Vpu susceptibility" . "HIV-1 Vpu accelerates the turnover of mature endogenous BST-2 in both HeLa and CEMx174 cells. The interference of Vpu with the newly synthesized BST-2 results in the gradual depletion of cell surface BST-2" . "Tetherin inhibits influenza virus neuraminidase (NA) virus-like particle (VLP) release, which is antagonized by HIV-1 Vpu" . "HIV-1 Vpu-A18H downregulates the expression of BST-2 at the cell surface and enhances virion release inefficiently through a reduced interaction with BST-2" . "HRS interacts with both HIV-1 Vpu and tetherin by co-precipitation analysis" . "HRS, an ESCRT-0 complex component, is required for the Vpu-induced downregulation of BST-2, indicating that Vpu-induced BST-2 degradation involves the ESCRT/MVB pathway" . "The v-ATPase VPS4 is required for Vpu-induced cell surface downregulation of BST-2" . "Co-depletion of beta-TrCP1 and beta-TrCP2 support Vpu's activity to enhance virus release and to downregulate endogenous tetherin in TZM-bl cells" . "HIV-1 Vpu ion channel mutant S23A binds and antagonizes CD317, indicating that its ion channel function is not correlated with its ability to downregulate cell surface CD317" . "HIV-1 Vpu transmembrane mutants A14N and A18N do not support virus release in the presence of CD317, suggesting that Ala residues at position 14 and 18 are required to antagonize CD317" . "HIV-1 Vpu cytoplasmic domain mutants S56G and E59K fail to enhance HIV-1 virion release but can reduce cell surface tetherin, suggesting that downregulation of cell surface tetherin and enhancement of virion release by Vpu are not always correlated" . "HIV-1 Vpu transmembrane domain mutants V9D and I19D fail to promote HIV-1 virion release and to downregulate cell surface tetherin" . "CD317 exhibits a fast recycling kinetic that is sensitive to treatment with primaquine, a strong recycling inhibitor. HIV-1 Vpu interferes with the recycling of CD317" . "Rhesus BST2 inhibits the release of HIV-1 from cells and is resistant to HIV-1 Vpu. Transfer of residues 30-45 of human BST2 into rhesus BST2 is sufficient to confer sensitivity to Vpu" . "Endogenous tetherin cell surface expression in T-cell lines H9, CEM-CCRF and CEM-SS are different and that affects HIV-1 Vpu-mediated tetherin modulation on virus release" . "SHIV Vpu proteins can counteract human and rhesus BST-2" . "The retention of HIV-1 Vpu from group O in ER-associated compartments confers a defect to antagonism even when interaction with tetherin is mediated through a chimeric TM domain" . "Dominant negative dynamin 2 (K44A) acts as an inhibitor of clathrin-mediated endocytosis and that it inhibits the downregulation of BST-2 from the cell surface by HIV-1 Vpu and HIV-2 Env" . "The C-terminal fragment of the clathrin assembly protein AP180 inhibits the downregulation of BST-2 from the cell surface by HIV-1 Vpu and HIV-2 Env" . "HIV-1 Vpu downregulates cell-surface BST-2 levels without qualitatively affecting the distribution of the restriction factor at the plasma membrane in HIV-1-infected Jurkat cells" . "Analysis of the chimera HIV-1 Vpu proteins from group M and O shows that alanine-18 is important for group M Vpu localization and tetherin-Vpu interaction" . "An N-terminal deletion and T45I substitution in the TMD of human tetherin render the protein unresponsive to antagonism by HIV-1 Vpu" . "NMR studies reveal that the 10AXXXAXXXAXXXW22 face of the Vpu transmembrane domain (TMD) directly binds to the large hydrophobic residues (aa 22-47) of the tetherin TMD in an anti-parallel manner" . "Reduced HIV-1 release in Rab7A-depleted cells is related to expression of the restriction factor tetherin, suggesting that Rab7A contributes to the mechanism by which Vpu counteracts tetherin and rescues HIV-1 release" . "BIT225, HIV-1 Vpu viroporin inhibitor, does not affect Vpu-tetherin interactions" . "The putative cholesterol recognition amino acid consensus (CRAC) motif (residues 25-31) of HIV-1 Vpu mediates lipid raft association of Vpu, but is dispensable for the downregulation of cell surface BST-2" . "A computer modeling method predicts that the interface is composed of Vpu residues I6, A10, A14, A18, V25 and W22, and BST-2 residues L23, I26, V30, I34, V35, L41, I42, and T45" . "IFNalpha/ribavirin treatment in vivo induces APOBEC3G, APOBEC3F, and BST-2 expression and results in hyper-mutations in viral genome and A11G/S61A mutations in HIV-1 Vpu. These two mutations in Vpu enhances the interaction between BST-2 and Vpu" . "Downregulation of CD4 and BST2 by HIV-1 Vpu is observed in HIV-1 infected humanized mice" . "The ubiquitin associated protein 1 (UBAP1)-containing ESCRT-I is essential for degradation of antiviral cell-surface protein such as tetherin (BST-2/CD317) by HIV-1 Vpu" . "HIV-1 Vpu E/L/V mutants interact with tetherin in infected cells and are incorporated into nascent virions in a tetherin-dependent manner" . "Mutation of the 59EXXXLV64 motif in HIV-1 Vpu leads to endosomal and surface localization of Vpu and modulates the trafficking of tetherin" . "Overexpression of clathrin coat-associated protein AP180 inhibits Vpu-mediated tetherin antagonism but adaptor protein-1, adaptor protein-2, and adaptor protein-3 are dispensable" . "The 59EXXXLV64 motif in HIV-1 Vpu is required for Vpu-mediated tetherin downregulation. Vpu E/L/V mutant fails to downregulate tetherin but still interact with beta-TrCP2 and HRS (ESCRT-0)" . "HIV-1 Vpu partially antagonizes the restriction of BST2 on HCV production and release from BST2 expressing Huh7.5 cells" . "P40L/T45I mutations in human tetherin leads to drastically decreased susceptibility of the mutant to HIV-1 Vpu, while susceptibility to SIVden Vpu increases to 50%, suggesting that these two residues participate in the species-specific activity of Vpu" . "Tetherin expression is upregulated following HIV-1 infection of monocytes-derived macrophages and is not fully downregulated by HIV-1 Vpu" . "inhibits" . "downregulates" . "interacts with" . "co-localizes with" . "relocalizes" . "disrupts" . "binds" . "modulates" . "degrades" . "induces ubiquitination of" .