CDK13, a new potential human immunodeficiency virus type 1 inhibitory factor regulating viral mRNA splicing
CDK13, a new potential human immunodeficiency virus type 1 inhibitory factor regulating viral mRNA splicing
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DOI：
10.1128/jvi.02543-07
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发表时间：
2008-07-01
影响因子：
5.4
通讯作者：
Kashanchi, Fatah
中科院分区：
文献类型：
--
作者：
Berro, Reem;Pedati, Caitlin;Kashanchi, Fatah
人类免疫缺陷病毒1型（HIV-1）达特是一种14-kDa病毒蛋白，其通过结合反式激活应答区（位于所有HIV-1转录物5'末端的结构化RNA元件）而充当有效的反式激活因子。达特通过几种Tat活化的激酶诱导RNA聚合酶11的C-末端结构域的磷酸化，并通过将染色质重塑复合物和组蛋白修饰酶募集到HIV-1长末端重复序列来反式激活病毒基因表达。组蛋白乙酰基转移酶，包括p300和hGCN 5，不仅乙酰化组蛋白，而且乙酰化富含丝氨酸的基序中赖氨酸位置50和51处的达特。在位置50和51处的乙酰化达特与专门的蛋白模块（布罗莫结构域）相互作用，并募集具有该特定结构域的新因子，如P/CAF和SWI/SNF。除了对转录有影响外，达特还参与剪接。在这项研究中，我们证明，达特相互作用与细胞周期蛋白依赖性激酶13（CDK 13）在体内和体外。我们还发现CDK 13增加了HIV-1 mRNA的剪接，并有利于双剪接蛋白Nef的产生。此外，我们证明CDK 13作为一个可能的限制因子，因为它的过表达减少了病毒蛋白Gag和Env的产生，随后抑制病毒的产生。使用针对CDK 13的小干扰RNA，我们表明CDK 13的沉默导致病毒产量的显着增加。最后，我们证明了CDK 13通过ASF/SF 2的磷酸化介导其对剪接的影响。
The human immunodeficiency virus type 1 (HIV-1) Tat is a 14-kDa viral protein that acts as a potent transactivator by binding to the transactivation-responsive region, a structured RNA element located at the 5' end of all HIV-1 transcripts. Tat transactivates viral gene expression by inducing the phosphorylation of the C-terminal domain of RNA polymerase 11 through several Tat-activated kinases and by recruiting chromatin-remodeling complexes and histone-modifying enzymes to the HIV-1 long terminal repeat. Histone acetyltransferases, including p300 and hGCN5, not only acetylate histones but also acetylate Tat at lysine positions 50 and 51 in the arginine-rich motif. Acetylated Tat at positions 50 and 51 interacts with a specialized protein module, the bromodomain, and recruits novel factors having this particular domain, such as P/CAF and SWI/SNF. In addition to having its effect on transcription, Tat has been shown to be involved in splicing. In this study, we demonstrate that Tat interacts with cyclin-dependent kinase 13 (CDK13) both in vivo and in vitro. We also found that CDK13 increases HIV-1 mRNA splicing and favors the production of the doubly spliced protein Nef. In addition, we demonstrate that CDK13 acts as a possible restriction factor, in that its overexpression decreases the production of the viral proteins Gag and Env and subsequently suppresses virus production. Using small interfering RNA against CDK13, we show that silencing of CDK13 leads to a significant increase in virus production. Finally, we demonstrate that CDK13 mediates its effect on splicing through the phosphorylation of ASF/SF2.