Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69974, Israel.
Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69974, Israel.
Virology. 2015 Sep;483:13-20. doi: 10.1016/j.virol.2015.04.018. Epub 2015 May 15.
Most currently-used antiretroviral drugs inhibit the reverse-transcriptase (RT) of HIV. The differences between HIV-1 and HIV-2 RTs explain why some of the anti-HIV-1 drugs are not effective against HIV-2. One major difference between the two HIV RTs is the low ribonuclease H (RNase H) activity of HIV-2 RT relative to HIV-1 RT. Our previous studies showed that residue Gln294 in HIV-2 RT accounts for this RNase H reduction (the comparable residue in HIV-1 RT is Pro294), as the Q294P mutant of HIV-2 RT has ~10-fold higher RNase H. Here, we show that infectious HIV-2 cannot bear the replacement of the RT's Gln294 by the HIV-1 RT Pro counterpart, as it results in substantially reduced HIV-2 replication and fast reversions to the wild-type Gln294 virus. These findings prove the critical role of maintaining low RT-associated RNase H activity in HIV-2. In contrast, HIV-1 can tolerate an about 10-fold higher RNase H.
大多数目前使用的抗逆转录病毒药物抑制 HIV 的逆转录酶 (RT)。HIV-1 和 HIV-2 RT 之间的差异解释了为什么一些抗 HIV-1 药物对 HIV-2 无效。两种 HIV RT 之间的一个主要区别是 HIV-2 RT 的核糖核酸酶 H (RNase H) 活性相对较低,而 HIV-1 RT 则较高。我们之前的研究表明,HIV-2 RT 中的残基 Gln294 导致了这种 RNase H 减少(HIV-1 RT 中的可比残基是 Pro294),因为 HIV-2 RT 的 Q294P 突变体具有约 10 倍更高的 RNase H。在这里,我们表明,不能承受 RT 的 Gln294 被 HIV-1 RT Pro 对应物取代的传染性 HIV-2,因为它导致 HIV-2 复制显著减少和快速回复到野生型 Gln294 病毒。这些发现证明了在 HIV-2 中维持低 RT 相关 RNase H 活性的关键作用。相比之下,HIV-1 可以耐受约 10 倍更高的 RNase H。