Control of HIV-1 env RNA splicing and transport:: investigating the role of hnRNP A1 in exon splicing silencer (ESS3a) function
Control of HIV-1 env RNA splicing and transport:: investigating the role of hnRNP A1 in exon splicing silencer (ESS3a) function
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DOI：
10.1016/s0042-6822(03)00400-8
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发表时间：
2003-09-15
期刊：
影响因子：
3.7
通讯作者：
Cochrane, A
中科院分区：
文献类型：
--
作者：
Asai, K;Platt, C;Cochrane, A
HIV-1病毒RNA剪接和转运的控制对病毒的成功复制起着重要的作用。先前的研究已经在HIV-1的末端外显子中发现了一个外显子剪接增强子（ESE）和一个双部外显子剪接沉默子（ESS3a和ESS3b），它们参与了剪接和rev介导的病毒RNA输出的调节。为了明确ESS3a的功能机制，我们进行了实验，以更好地确定ESS3a活性所需的顺式和反式组分。整个30-nt元件的突变导致ESS功能的部分丧失。发现组合突变具有加性效应，表明存在多个结合位点。相互作用因素的分析确定hnRNP A1是调节ESS3a活性的复合体的一个组成部分。然而，随后的结合分析确定hnRNP A1仅与ESS3a的一部分相互作用，这表明参与了另一个宿主因子。对突变对rev介导的输出影响的平行分析确定，突变对剪接和RNA运输的影响之间没有直接关联。与这一假设一致，用hnRNP A1结合位点替代ESS3a被发现不足以阻断rev介导的RNA输出。(C) 2003 Elsevier Science（美国）版权所有。
The control of HIV-1 viral RNA splicing and transport plays an important role in the successful replication of the virus. Previous studies have identified both an exon splicing enhancer (ESE) and a bipartite exon splicing silencer (ESS3a and ESS3b) within the terminal exon of HIV-1 that are involved in modulating both splicing and Rev-mediated export of viral RNA. To define the mechanism of ESS3a function, experiments were carried out to better define the cis and trans components required for ESS3a activity. Mutations throughout the 30-nt element resulted in partial loss of ESS function. Combining mutations was found to have an additive effect, suggesting the presence of multiple binding sites. Analysis of interacting factors identified hnRNP A1 as one component of the complex that modulates ESS3a activity. However, subsequent binding analyses determined that hnRNP A1 interacts with only one portion of ESS3a, suggesting the involvement of another host factor. Parallel analysis of the effect of the mutations on Rev-mediated export determined that there is not a direct correlation between the effect of the mutations on splicing and RNA transport. Consistent with this hypothesis, replacement of ESS3a with consensus hnRNP A1 binding sites was found to be insufficient to block Rev-mediated RNA export. (C) 2003 Elsevier Science (USA). All rights reserved.