Direct evidence for translational regulation by leader RNA and Tat protein of human immunodeficiency virus type 1.
Direct evidence for translational regulation by leader RNA and Tat protein of human immunodeficiency virus type 1.
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人类免疫缺陷病毒 1 型前导 RNA 和 Tat 蛋白翻译调节的直接证据。
DOI：
10.1073/pnas.87.19.7492
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发表时间：
1990
影响因子：
11.1
通讯作者：
Silverman,RH
中科院分区：
文献类型：
--
作者：
SenGupta,DN;Berkhout,B;Gatignol,A;Zhou,AM;Silverman,RH
研究了人免疫缺陷病毒1型（HIV-1） RNA先导蛋白和Tat蛋白在兔网织细胞裂解液中的翻译作用。在体外重组质粒中产生了与人干扰素- γ mRNA融合的自然或突变的HIV-1先导RNA杂交种。发现HIV-1先导RNA通过两种机制抑制翻译。通过混合HIV-1先导RNA和指示性干扰素mRNA，证明了3倍的反式抑制翻译。相比之下，HIV-1先导物在裂解物中引起50倍的顺式抑制，其中两种反式抑制因子，双链rna依赖性蛋白激酶和（2'-5'）低聚腺苷酸合成酶被抑制。相比之下，在大肠杆菌中产生的纯化HIV-1 Tat蛋白可以从HIV-1先导干扰素mRNA中翻译4倍，但不能从缺乏HIV序列的干扰素mRNA或从总poly(A)+ RNA中翻译。在“反式反应”序列（TAR）环中含有单碱基替换的mRNA或在TAR中含有替代茎环的mRNA的翻译都受到Tat的刺激。Tat对翻译的增强主要是由于缓解了顺式抑制，因为即使在双链rna依赖性蛋白激酶被2-氨基嘌呤抑制的裂解物中也发现了这种作用。这些结果表明，翻译在HIV-1的复制周期中是一个重要的控制水平。
Translational effects of the RNA leader and Tat protein of human immunodeficiency virus type 1 (HIV-1) were investigated in rabbit reticulocyte lysate. Hybrid RNA species with natural or mutated HIV-1 leader fused to human interferon- gamma mRNA were produced in vitro from recombinant plasmids. HIV-1 leader RNA was found to inhibit translation through two mechanisms. A 3-fold trans-inhibition of translation was demonstrated by mixing hybrid HIV-1 leader RNA with indicator interferon mRNA. By comparison, HIV-1 leader caused a 50-fold cis-inhibition in lysate in which two trans-inhibitory factors, double-stranded RNA-dependent protein kinase and (2'-5')oligoadenylate synthetase, were suppressed. In contrast, purified HIV-1 Tat protein produced in Escherichia coli enhanced by 4-fold translation from HIV-1 leader-interferon mRNA but not from interferon mRNA lacking HIV sequences or from total poly(A)+ RNA. Translation of mRNA containing either a single base substitution in the loop of the "trans-acting responsive" sequence (TAR) or an alternative stem-loop in TAR was nevertheless stimulated by Tat. The enhancement of translation by Tat was largely due to relief of cis-inhibition, since the effect was found even in lysate in which double-stranded RNA-dependent protein kinase was inhibited with 2-aminopurine. These results suggest that translation is an important level of control in the replication cycle of HIV-1.