蛋白激酶A抑制剂对HeLa细胞S期进程的影响  

Primary Studies on the Progression of S Phase and its Molecular Mechanism by Protein Kinase A Inhibitor in the HeLa Cell

作　　者：孙霞[1] 柳惠图[1] 童迎凯[1] 王端顺[1] 

机构地区：[1]北京师范大学生命科学学院

出　　处：《生物化学与生物物理进展》2001年第2期232-235,共4页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金!资助项目 (39430 0 80 )&&

摘　　要：以同步化的HeLa细胞为实验材料 ,研究了蛋白激酶A (PKA)抑制剂对HeLa细胞S期进程的影响及其作用的分子机理 .通过TdR双阻断法 ,获得了同步化的S期细胞 ,3H TdR掺入实验表明PKA抑制剂typeⅢ(80mg/L)明显提高了S期3H TdR的掺入水平 ,提示了PKA在S期进程中起阻抑作用 .进一步实验表明 ,在PKA抑制剂typeⅢ作用下胸苷激酶 (TK)活性和PCNA蛋白水平均有所提高 ,同时明显促进了CyclinA蛋白的表达 ,并抑制了周期负调因子 p2 1蛋白的水平 ,但对CDK2表达几乎无影响 .结果表明 ,PKA可通过作用于PCNA和引擎分子CyclinA的水平和通过影响 p2 1的表达负调于S期进程 .这可能是PKA负调HeLa细胞S期进程的分子机理之一 .The synchronized HeLa cells were used to study the effect of protein kinase A (PKA) inhibitor on the progression of S phase. Synchronized cells in S phase were obtained by the method of TdR double block through H-3-TdR incorporation assay. The PKA inhibitor type III obviously increased the level of 3H-TdR incorporation of S phase in HeLa cells. In contrast with control, the activity of thymidine kinase (TK) in S phase increased, too. It indicated that PKA played an inhibitory role in S phase progression of HeLa cells. With the method of Western blotting, the PKA inhibitor type III enhanced the level of CyclinA and PCNA, inhibited the expression of p21, which is a negative regulator of cell cycle, but had no effect on the expression of CDK2. The results showed that PKA could negatively regulate the S phase progression by affecting the level of CyclinA, PCNA and influencing the expression of p21 protein. This may be one of the molecular mechanisms which is involved in the negative regulation of S phase progression by PKA in HeLa cells.

关 键 词：蛋白激酶A 蛋白激酶A抑制剂 S期 HELA细胞 

分 类 号：Q26[生物学—细胞生物学] Q279