Mutations at human immunodeficiency virus type 1 reverse transcriptase tryptophan repeat motif attenuate the inhibitory effect of efavirenz on virus production

作者：Chiang Chien Cheng; Wang Shiu Mei; Tseng Ying Tzu; Huang Kuo Jung; Wang Chin Tien^*

来源：Virology, 2009, 383(2): 261-270.

DOI：10.1016/j.virol.2008.10.027

• HIV-1
• Tryptophan repeat motif
• Gag-Pol
• RT dimerization
• Gag processing
• NNRTI
• Efavirenz

HIV-1 virus particle processing is mediated by protease (PR), with enzymatic activation triggered by Gag-Pol/Gag-Pol interaction. We previously reported that truncation mutations at the reverse transcriptase (RT) connection subdomain markedly impair virus particle processing, suggesting an important role for the RT subdomain in PR-mediated virus processing. A highly conserved tryptophan (Trp) repeat motif of the HIV-1 RT connection subdomain is involved in RT dimerization. Our goal in this study was to determine whether mutations at the Trp repeat motif have any effect on PR-mediated virus processing. Our results indicate that even though alanine substitutions at W401 (W401 A) or at both W401 and W402 (W401A/W402A) have no major effect on steady-state virus processing, the combined W401A/W402A mutations partially negate and the W401 A mutation almost completely negates an efavirenz (EFV)-imposed barrier to virus production. The combination of RT instability and poor enzymatic activity reflects a RT dimerization defect incurred by the mutations. We also found that an artificial p66RT carrying the W401A or W401A/W402A Mutations was packaged into virions more efficiently than wild-type p66RT and that the viral incorporation of p66RT is significantly reduced by EFV, implying a novel effect of EFV on RT-Gag interaction. Our results suggest that the Trp repeat motif may play a role in the Gag-Pol/Gag-Pol interaction that contributes to subsequent PR activation.

• 出版日期2009-1-20