A Carboxy-Terminally Truncated Human CPSF6 Lacking Residues Encoded by Exon 6 Inhibits HIV-1 cDNA Synthesis and Promotes Capsid Disassembly
A Carboxy-Terminally Truncated Human CPSF6 Lacking Residues Encoded by Exon 6 Inhibits HIV-1 cDNA Synthesis and Promotes Capsid Disassembly
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DOI：
10.1128/jvi.00124-13
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发表时间：
2013-07-01
影响因子：
5.4
通讯作者：
Yamaoka, Shoji
中科院分区：
文献类型：
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作者：
Hori, Takanori;Takeuchi, Hiroaki;Yamaoka, Shoji
由于HIV-1复制在多个阶段由宿主细胞因子调节，因此这些宿主细胞因子的鉴定和表征有望有助于开发新的抗HIV治疗剂。先前的研究表明，C-末端截短的胞质形式的裂解和多聚腺苷酸化特异性因子6（CPSF 6 -358）通过干扰HIV-1向细胞核的运输来抑制HIV-1感染。在这里，我们确定和特点的C-末端截短的人CPSF 6（hCPSF 6 -375）通过cDNA表达克隆结合更昔洛韦介导的致死选择的不同配置。值得注意的是，hCPSF 6 -375，而不是小鼠CPSF 6 -358（mCPSF 6 -358），如先前报道的，显着干扰HIV-1感染后的病毒cDNA合成。此外，我们发现hCPSF 6 -375异常地加速了靶细胞中病毒衣壳的解体，而CPSF 6 -358没有。CPSF 6 -375和CPSF 6 -358 cDNA的序列比较显示，hCPSF 6 -375的C末端缺少外显子6和另外的54个氨基酸残基的编码序列。突变分析显示，hCPSF 6 -375中由外显子6编码的残基，而不是C-末端54个残基，是导致hCPSF 6 - 375的病毒cDNA合成受损的原因。这是第一份报告，证明了一种新的模式，HIV-1抑制截断形式的CPSF 6，涉及快速衣壳解体和抑制病毒cDNA的合成。这些发现可能有助于增加理解的病毒衣壳解体的病毒cDNA合成。
Since HIV-1 replication is modulated at multiple stages by host cell factors, identification and characterization of those host cell factors are expected to contribute to the development of novel anti-HIV therapeutics. Previous studies showed that a C-terminally truncated cytosolic form of cleavage and polyadenylation-specific factor 6 (CPSF6-358) inhibits HIV-1 infection through interference with HIV-1 trafficking to the nucleus. Here we identified and characterized a different configuration of C-terminally truncated human CPSF6 (hCPSF6-375) through cDNA expression cloning coupled with ganciclovir-mediated lethal selection. Notably, hCPSF6-375, but not mouse CPSF6-358 (mCPSF6-358) as previously reported, remarkably interfered with viral cDNA synthesis after HIV-1 infection. Moreover, we found that hCPSF6-375 aberrantly accelerated the disassembly of the viral capsid in target cells, while CPSF6-358 did not. Sequence comparison of CPSF6-375 and CPSF6-358 cDNAs showed a lack of exon 6 and additional coding sequence for 54 amino acid residues in the C terminus of hCPSF6-375. Mutational analyses revealed that the residues encoded by exon 6, but not the C-terminal 54 residues in hCPSF6-375, is responsible for impaired viral cDNA synthesis by hCPSF6-375. This is the first report demonstrating a novel mode of HIV-1 inhibition by truncated forms of CPSF6 that involves rapid capsid disassembly and inhibition of viral cDNA synthesis. These findings could facilitate an increased understanding of viral cDNA synthesis in light of the viral capsid disassembly.