The interaction of APOBEC3G with human immunodeficiency virus type 1 nucleocapsid inhibits tRNA3Lys annealing to viral RNA
The interaction of APOBEC3G with human immunodeficiency virus type 1 nucleocapsid inhibits tRNA3Lys annealing to viral RNA
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DOI：
10.1128/jvi.00162-07
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发表时间：
2007-10-01
影响因子：
5.4
通讯作者：
Kleiman, Lawrence
中科院分区：
文献类型：
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作者：
Guo, Fei;Cen, Shan;Kleiman, Lawrence
含有人类APOBEC3G （hA3G）的人类免疫缺陷病毒1型（HIV-1）在新感染细胞中产生病毒DNA的能力降低。这种ha3g促进的抑制至少部分是由于胞苷脱氨非依赖性的启动逆转录能力的降低。HIV-1核衣壳（NCp7）是hA3G并入病毒粒子和病毒RNA与tRNA(3)(Lys)（逆转录引物tRNA）之间退火所必需的。在此，我们提出证据表明，hA3G与核衣壳的相互作用是抑制逆转录起始所必需的。在没有或存在hA3G的情况下，通过ncp7促进tRNA(3)（Lys）退火合成病毒RNA，在体外产生tRNA(3)（Lys）引物复合物。测定了hA3G对tRNA(3)（Lys）对病毒RNA退火的影响以及tRNA(3)（Lys）对3启动逆转录的能力。我们的结果显示如下。(i)电泳带移和引物结合位点分析表明，hA3G分别使tRNA(3)（Lys）的退火减少了44%和60%，但不会破坏已形成的退火复合物。（ii） hA3G抑制tRNA(3)（Lys）引物70 ~ 80%。（iii）退火过程中，hA3G抑制tRNA(3)（Lys）引物需要hA3G与NCp7相互作用。因此，当NCp7的锌指突变体不能与hA3G相互作用时，tRNALys的退火对hA3G抑制不敏感。不依赖ncp7的DNA到病毒RNA的退火也对hA3G的抑制不敏感。这些结果表明，hA3G不会通过与病毒RNA的结合来立体阻断IRNA与退火。退火和引物不受另一个RNA结合蛋白QKI-6的影响。
Human immunodeficiency virus type 1 (HIV-1) containing human APOBEC3G (hA3G) has a reduced ability to produce viral DNA in newly infected cells. At least part of this hA3G-facilitated inhibition is due to a cytidine deamination-independent reduction in the ability to initiate reverse transcription. HIV-1 nucleocapsid (NCp7) is required both for the incorporation of hA3G into virions and for the annealing between viral RNA and tRNA(3)(Lys), the primer tRNA for reverse transcription. Herein we present evidence that the interaction of hA3G with nucleocapsid is required for the inhibition of reverse transcription initiation. A tRNA(3)(Lys) priming complex was produced in vitro by the NCp7-facilitated annealing of tRNA(3)(Lys) to synthetic viral RNA in the absence or presence of hA3G. The effect of hA3G on the annealing of tRNA(3)(Lys) to viral RNA and the ability of tRNA(3)(Lys) to 3 initiate reverse transcription was measured. Our results show the following. (i) Electrophoretic band shift and primer binding site assays show that hA3G reduces the annealing of tRNA(3)(Lys) 44 and 60%, respectively, but does not disrupt the annealed complex once formed. (ii) hA3G inhibits tRNA(3)(Lys) priming 70 to 80%. (iii) Inhibition 3 of tRNA(3)(Lys) priming by hA3G requires an interaction between hA3G and NCp7 during annealing. Thus, annealing of tRNALys is insensitive to hA3G inhibition when facilitated by a zinc finger mutant of NCp7 unable 3 to interact with hA3G. NCp7-independent annealing of DNA to viral RNA also is insensitive to hA3G inhibition. These results indicate that hA3G does not sterically block IRNA vs annealing by binding to viral RNA. Annealing and priming are not affected by another RNA binding protein, QKI-6.