Retinoblastoma cancer suppressor gene product is a substrate of the cell cycle regulator cdc2 kinase.
Retinoblastoma cancer suppressor gene product is a substrate of the cell cycle regulator cdc2 kinase.
复制标题
视网膜母细胞瘤抑癌基因产物是细胞周期调节因子 cdc2 激酶的底物。
DOI：
10.1002/j.1460-2075.1991.tb08018.x
复制
发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Wang,JY
中科院分区：
文献类型：
--
作者：
Lin,BT;Gruenwald,S;Morla,AO;Lee,WH;Wang,JY
视网膜母细胞瘤基因产物（RB）是一种核蛋白，已被证明具有肿瘤抑制因子的功能。它在细胞周期的 S 期至 M 期被磷酸化，并在 G1 期被去磷酸化。这表明RB的功能是通过其在细胞周期中的磷酸化来调节的。在人类 RB 蛋白中发现了 10 种磷酸胰蛋白酶肽。从细胞周期的 S 期到 M 期，RB 磷酸化模式不会改变。由感染 RB 重组杆状病毒的昆虫细胞制备的低磷酸化 RB 用作体外磷酸化反应的底物。在测试的几种蛋白激酶中，只有 cdc2 激酶能有效磷酸化 RB，所有 10 种肽均可在体外被 cdc2 磷酸化。通过免疫沉淀从有丝分裂细胞提取物中去除 cdc2 会导致 RB 激酶活性随之耗尽。这些结果表明 cdc2 或具有类似底物特异性的激酶参与 RB 蛋白的细胞周期依赖性磷酸化。
The retinoblastoma gene product (RB) is a nuclear protein which has been shown to function as a tumor suppressor. It is phosphorylated from S to M phase of the cell cycle and dephosphorylated in G1. This suggests that the function of RB is regulated by its phosphorylation in the cell cycle. Ten phosphotryptic peptides are found in human RB proteins. The pattern of RB phosphorylation does not change from S to M phases of the cell cycle. Hypophosphorylated RB prepared from insect cells infected with an RB‐recombinant baculovirus is used as a substrate for in vitro phosphorylation reactions. Of several protein kinases tested, only cdc2 kinase phosphorylates RB efficiently and all 10 peptides can be phosphorylated by cdc2 in vitro. Removal of cdc2 from mitotic cell extracts by immunoprecipitation causes a concomitant depletion of RB kinase activity. These results indicate that cdc2 or a kinase with similar substrate specificity is involved in the cell cycle‐dependent phosphorylation of the RB protein.