In:
Retrovirology, Springer Science and Business Media LLC, Vol. 10, No. 1 ( 2013-12)
Abstract:
The acquisition of effective Vpu-mediated anti-tetherin activity to promote virion release following transmission of SIVcpz Ptt from central chimpanzees ( Pan troglodytes troglodytes ) to humans distinguishes pandemic HIV-1 group M strains from non-pandemic group N, O and P viruses and may have been a prerequisite for their global spread. Some functional motifs in the cytoplasmic region of HIV-1 M Vpus proposed to be important for anti-tetherin activity are more frequently found in the Vpu proteins of SIVcpz Ptt than in those of SIVcpz Pts infecting eastern chimpanzees ( P. t. schweinfurthii), that have not been detected in humans, and SIVgor from gorillas, which is closely related to HIV-1 O and P. Thus, SIVcpz Ptt strains may require fewer adaptive changes in Vpu than SIVcpz Pts or SIVgor strains to counteract human tetherin. Results To examine whether SIVcpz Ptt may only need changes in the transmembrane domain (TMD) of Vpu to acquire anti-tetherin activity, whereas SIVcpz Pts and SIVgor may also require changes in the cytoplasmic region, we analyzed chimeras between the TMD of an HIV-1 M Vpu and the cytoplasmic domains of SIVcpz Ptt (n = 2), SIVcpz Pts (n = 2) and SIVgor (n = 2) Vpu proteins. Unexpectedly, all of these chimeras were capable of counteracting human tetherin to enhance virion release, irrespective of the presence or absence of the putative adaptor protein binding sites and the DSGxxS β-TrCP binding motif reported to be critical for effective anti-tetherin activity of M Vpus. It was also surprising that in three of the six chimeras the gain of anti-tetherin function was associated with a loss of the CD4 degradation activity since this function was conserved among all parental HIV-1, SIVcpz and SIVgor Vpu proteins. Conclusions Our results show that changes in the TMD of SIVcpz Ptt , SIVcpz Pts and SIVgor Vpus are sufficient to render them active against human tetherin. Thus, several previously described domains in the extracellular region of Vpu are not absolutely essential for tetherin antagonism but may be required for other Vpu functions.
Type of Medium:
Online Resource
ISSN:
1742-4690
DOI:
10.1186/1742-4690-10-32
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2013
detail.hit.zdb_id:
2142602-8
SSG:
12
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