Figure 7

Specificity of interaction of SIVsyk Vpu proteins and tetherin. (A) Anti-tetherin activities of HIV-1 Vpu and indicated SIVsyk Vpu-EGFP proteins against H(+5)-tetherin expressed in LLCMK2 cells, measured by HIV-1 VLP release assay. Mean fold-enhancement of HIV-1 VLP release in the presence of anti-tetherin proteins is shown relative to baseline (control) levels in their absence, for n = 2 independent experiments. (B) Partial sequence alignment of human, macaque (Mac) and MH-tetherin showing the N-terminal cytoplasmic tail, the transmembrane (TM) domain and the start of the extracellular domain. Mac-tetherin starts at M-11 of the full-length Macaca mulatta tetherin [9]. MH-tetherin has N-terminal cytoplasmic tail and TM domains of Mac-tetherin with a human tetherin extracellular domain. (C) Western blot of expression of indicated tetherin constructs, from lysates of transfected 293A cells. (D) Anti-tetherin activities of HIV-1 Vpu and indicated SIVsyk Vpu-EGFP proteins against MH-tetherin expressed in LLCMK2 cells, measured by HIV-1 VLP release assay. Mean fold enhancement of VLP release in presence of Vpu proteins is shown relative to baseline (control) levels in absence of Vpu, for n = 2 independent experiments.