Interaction between cyclin-dependent kinases and human papillomavirus replication-initiation protein E1 is required for efficient viral replication
Interaction between cyclin-dependent kinases and human papillomavirus replication-initiation protein E1 is required for efficient viral replication
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DOI：
10.1073/pnas.96.2.382
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发表时间：
1999-01-19
影响因子：
11.1
通讯作者：
Harper, JW
中科院分区：
文献类型：
--
作者：
Ma, TL;Zou, NX;Harper, JW
我们已经确定了人乳头瘤病毒（HPV）的DNA复制起始蛋白E1作为一个紧密结合的底物细胞周期蛋白E/细胞周期蛋白依赖性激酶（Cdk）复合物，通过使用表达克隆。E1是一种DNA解旋酶，在依赖于ori的复制中与HPV E2蛋白协作。在昆虫和哺乳动物细胞中，E1与细胞周期蛋白E形成复合物，不依赖于Cdks和E2。另外的细胞周期蛋白，包括A-、B-和F-型（但不是D型），与E1/E2复合物相互作用，并且A型和E型细胞周期蛋白激酶能够在体外磷酸化E1和E2，与细胞周期蛋白和E1的有效磷酸化的协会需要一个细胞周期蛋白相互作用基序（RXL基序）的存在。缺乏RXL基序的E1在E2依赖的HPV ori体内复制中显示缺陷。与Cdk介导的磷酸化在E1功能中的作用一致，缺乏所有四个候选Cdk磷酸化位点的E1蛋白仍然与E2和细胞周期蛋白E相关，但在体外和体内HPV复制中受损。我们的数据揭示了细胞周期蛋白/Cdk功能和激活HPV DNA复制之间的联系，通过靶向Cdk复合物的E1复制起始蛋白，并建议E1磷酸化的Cdks的功能作用，细胞周期蛋白结合RXL基序的使用，现在正在成为一个主要的机制，细胞周期蛋白靶向的关键基板。
We have identified the human papillomavirus (HPV) DNA replication initiation protein E1 as a tight-binding substrate of cyclin E/cyclin dependent kinase (Cdk) complexes by using expression cloning. E1, a DNA helicase, collaborates with the HPV E2 protein in ori-dependent replication. E1 formed complexes with cyclin E in insect and mammalian cells, independent of Cdks and E2, Additional cyclins, including A-, B-, and F-type (but not D type), interacted with the E1/E2 complex, and A- and E-type cyclin kinases were capable of phosphorylating E1 and E2 in vitro, Association with cyclins and efficient phosphorylation of E1 required the presence of a cyclin interaction motif (the RXL motif). E1 lacking the RXL motif displayed defects in E2-dependent HPV ori replication in vivo. Consistent with a role for Cdk-mediated phosphorylation in E1 function, an E1 protein lacking all four candidate Cdk phosphorylation sites still associated with E2 and cyclin E but was impaired in HPV replication in vitro and in vivo. Our data reveal a link between cyclin/Cdk function and activation of HPV DNA replication through targeting of Cdk complexes to the E1 replication-initiation protein and suggest a functional role for E1 phosphorylation by Cdks, The use of cyclin-binding RXL motifs is now emerging as a major mechanism by which cyclins are targeted to key substrates.