Plk1 docking to GRASP65 phosphorylated by Cdk1 suggests a mechanism for Golgi checkpoint signalling
Plk1 docking to GRASP65 phosphorylated by Cdk1 suggests a mechanism for Golgi checkpoint signalling
复制标题
DOI：
10.1038/sj.emboj.7600569
复制
发表时间：
2005-02-23
期刊：
影响因子：
11.4
通讯作者：
Barr, FA
中科院分区：
文献类型：
--
作者：
Preisinger, C;Körner, R;Barr, FA
GRASP 65是高尔基体的一种结构蛋白，它与高尔基体结构的感知以及这种信息与以高尔基体检查点形式控制有丝分裂进入的整合有关。我们发现Cdk 1-细胞周期蛋白B是有丝分裂中磷酸化GRASP 65的主要激酶，并且磷酸化GRASP 65与波罗样激酶Plk 1的波罗盒结构域相互作用。GRASP 65在其C-末端结构域的四个共有位点被Cdk 1-细胞周期蛋白B磷酸化，这些残基突变为丙氨酸基本上消除了有丝分裂磷酸化和Plk 1结合.在正常大鼠肾细胞中野生型GRASP 65 C-末端而非磷酸化缺陷突变体的表达引起有丝分裂进入的延迟而非阻断，如果这是真正的细胞周期检查点的话。这些发现确定了一个Plk 1依赖的信号机制可能连接高尔基体结构和细胞周期控制，但这可能不是一个细胞周期检查点在经典意义上。
GRASP65, a structural protein of the Golgi apparatus, has been linked to the sensing of Golgi structure and the integration of this information with the control of mitotic entry in the form of a Golgi checkpoint. We show that Cdk1 - cyclin B is the major kinase phosphorylating GRASP65 in mitosis, and that phosphorylated GRASP65 interacts with the polo box domain of the polo- like kinase Plk1. GRASP65 is phosphorylated in its C- terminal domain at four consensus sites by Cdk1 - cyclin B, and mutation of these residues to alanine essentially abolishes both mitotic phosphorylation and Plk1 binding. Expression of the wildtype GRASP65 C- terminus but not the phosphorylation defective mutant in normal rat kidney cells causes a delay but not the block in mitotic entry expected if this were a true cell cycle checkpoint. These findings identify a Plk1- dependent signalling mechanism potentially linking Golgi structure and cell cycle control, but suggest that this may not be a cell cycle checkpoint in the classical sense.