Identification and Functional Analysis of a Novel Cyclin E/Cdk2 Substrate Ankrd17
Identification and Functional Analysis of a Novel Cyclin E/Cdk2 Substrate Ankrd17
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新型 Cyclin E/Cdk2 底物 Ankrd17 的鉴定和功能分析
DOI：
10.1074/jbc.m807827200
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发表时间：
2009-03-20
影响因子：
4.8
通讯作者：
Ye, Xin
中科院分区：
文献类型：
--
作者：
Deng, Min;Li, Fahui;Ye, Xin
Cyclin E/Cdk2是G1-S转变的关键调节因子。我们使用TAP标签纯化技术鉴定了一种新的周期蛋白E/Cdk2底物，称为Ankrd17（锚蛋白重复蛋白17）。Ankrd17蛋白在其N端包含两簇共25个锚蛋白重复序列，中间包含一个NES（核输出信号）和一个NLS（核定位信号），在其C端包含一个RXL基序。Ankrd17在多种组织中表达，并以rxl依赖的方式与cyclin E/Cdk2相关。它可以被cyclin E/Cdk2磷酸化3个磷酸化位点（Ser1791， Ser1794和Ser2150）。Ankrd17的过表达促进S期进入，而通过小干扰RNA抑制Ankrd17的表达抑制DNA复制，阻断细胞周期进程，上调p53和p21的表达。Ankrd17定位于细胞核，与MCM家族成员、Cdc6和PCNA等DNA复制因子相互作用。Ankrd17的缺失导致Cdc6和PCNA在DNA上的负载减少，这表明Ankrd17可能直接参与DNA复制过程。综上所述，这些数据表明Ankrd17是cyclin E/Cdk2的重要下游效应因子，并积极调节G1/S转变。
Cyclin E/Cdk2 is a key regulator in G1-S transition. We have identified a novel cyclin E/Cdk2 substrate called Ankrd17 (ankyrin repeat protein 17) using the TAP tag purification technique. Ankrd17 protein contains two clusters of a total 25 ankyrin repeats at its N terminus, one NES (nuclear exporting signal) and one NLS (nuclear localization signal) in the middle, and one RXL motif at its C terminus. Ankrd17 is expressed in various tissues and associates with cyclin E/Cdk2 in an RXL-dependent manner. It can be phosphorylated by cyclin E/Cdk2 at 3 phosphorylation sites (Ser1791, Ser1794, and Ser2150). Overexpression of Ankrd17 promotes S phase entry, whereas depletion of Ankrd17 expression by small interfering RNA inhibits DNA replication and blocks cell cycle progression as well as up-regulates the expression of p53 and p21. Ankrd17 is localized to the nucleus and interacts with DNA replication factors including MCM family members, Cdc6 and PCNA. Depletion of Ankrd17 results in decreased loading of Cdc6 and PCNA onto DNA suggesting that Ankrd17 may be directly involved in the DNA replication process. Taken together, these data indicate that Ankrd17 is an important downstream effector of cyclin E/Cdk2 and positively regulates G1/S transition.