CDK11 complexes promote pre-mRNA splicing
CDK11 complexes promote pre-mRNA splicing
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DOI：
10.1074/jbc.m210057200
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发表时间：
2003-03-07
影响因子：
4.8
通讯作者：
Kidd, VJ
中科院分区：
文献类型：
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作者：
Hu, DL;Mayeda, A;Kidd, VJ
PITSLRE蛋白激酶，以下简称CDK11，因为它们与细胞周期蛋白L的调控伙伴有关，属于含有RNA聚合酶II的大分子蛋白质复合体。这些CDK11(P110)复合体被报道影响转录，并与一般的前剪接因子RNPS1相互作用。这些复合体中的一些也可能在前mRNA剪接中发挥作用。利用双杂交交互屏幕，剪接蛋白9G8被鉴定为CDK11(P110)的体内伙伴。一些剪接相关因子作为CDK11(P110)的相互作用因子以及转录与剪接之间的密切关系表明，CDK11(P110)可能直接影响剪接活性。在体外检测系统中，剪接提取物中CDK11(P110)的免疫耗尽大大减少了剪接产物的出现。此外，将这些CDK11(P110)免疫复合物重新添加到CDK11(P110)免疫耗尽的剪接反应中，完全恢复了剪接活性。同样，加入纯化的CDK11(P110)氨基末端结构域蛋白就足以抑制剪接反应。最后，9G8在体内是一种磷酸化蛋白，在体外是CDK11(P110)磷酸化的底物。这些数据是第一批证明CDK活性在功能上与前mRNA剪接事件的调控相耦合的证据之一，并进一步支持了CDK11(P110)处于有助于协调转录和RNA加工事件的信号通路的假设。
The PITSLRE protein kinases, hereafter referred to as CDK11 because of their association with the cyclin L regulatory partner, belong to large molecular weight protein complexes that contain RNA polymerase II. These CDK11(p110) complexes have been reported to influence transcription as well as interact with the general pre-mRNA-splicing factor RNPS1. Some of these complexes may also play a role in pre-mRNA splicing. Using a two-hybrid interactive screen, the splicing protein 9G8 was identified as an in vivo partner for CDK11(p110). The identification of several splicing-related factors as CDK11(P110) interactors along with the close relationship between transcription and splicing indicated that CDK11(p110) might influence splicing activity directly. Immunodepletion of CDK11(p110) from splicing extracts greatly reduced the appearance of spliced products using an in vitro assay system. Moreover, the re-addition of these CDK11(p110) immune complexes to the CDK11(p110)-immunodepleted splicing reactions completely restored splicing activity. Similarly, the addition of purified CDK11(p110) amino-terminal domain protein was sufficient to inhibit the splicing reaction. Finally, 9G8 is a phosphoprotein in vivo and is a substrate for CDK11(p110) phosphorylation in vitro. These data are among the first demonstrations showing that a CDK activity is functionally coupled to the regulation of pre-mRNA-splicing events and further support the hypothesis that CDK11(p110) is in a signaling pathway that may help to coordinate transcription and RNA-processing events.