p16蛋白的磷酸化与精氨酸甲基化修饰影响其功能的相互关系及其分子机制研究

项目名称： p16蛋白的磷酸化与精氨酸甲基化修饰影响其功能的相互关系及其分子机制研究

项目编号： No.31271442

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 王秀莉

作者单位： 东北师范大学

项目金额： 60万元

中文摘要： p16是目前已知的抑癌基因中唯一通过直接抑制细胞周期而抑制细胞生长的基因，在肿瘤基因治疗中极具潜力。有研究表明p16蛋白的152位丝氨酸的磷酸化能促进p16与CDK4的结合，而8位丝氨酸磷酸化作用刚好相反，p16蛋白是否还存在其他翻译后修饰参与其功能的调控未见报道。我们的前期研究证实p16蛋白的甲基化存在于多种细胞系中，p16蛋白的22位、131位、138位精氨酸受到甲基化修饰。此外，p16蛋白精氨酸甲基化水平下降会促进p16与CDK4的结合并有效地抑制细胞周期进行。本项目拟在现有工作的基础上，进一步确定哪个信号通路或激酶参与p16的磷酸化修饰，探索p16的磷酸化和精氨酸甲基化修饰之间的关系，阐明磷酸化修饰与精氨酸甲基化对p16诱导的细胞衰老与细胞凋亡的影响及其分子机制，为p16抑制肿瘤提供新的理论依据，并为以后利用p16进行基因治疗肿瘤提供新的实验证据。

中文关键词： p16；精氨酸甲基化；丝氨酸磷酸化；细胞凋亡；细胞衰老

英文摘要： p16 has been known as a tumor suppressor gene, which suppresses proliferation of cells via direct inhibition of cell cycle progression. The p16 protein binds specifically to CDK4 and CDK6 to prevent them from interacting with cyclin D, which prevents G1/S cell cycle progression and cell proliferation. Accordingly, p16 is a potential target for cancer gene therapy. Previous studies have demonstrated that the phosphorylation of Ser152 of p16 protein promotes the interaction of p16 with CDK4,however,the phosphorylation of Ser8 abolishes its CDK4-inhibitory activity, suggesting that the post-translational modification of p16 participates in the regulation of p16 function. Whether other modification of p16 protein participates in its functionis unclear. In our previous study, we found that the p16 protein was methylated in various cell lineages. We then determined that the arginine 22, 131 and 138 of p16 were the methylation sites, because mutations of these arginine residues to lysine resulted in hypomethylation of p16. Furthermore, decrease of the p16 arginine methylation level promoted the association of p16 with CDK4 and exhibited a reinforced function in preventing cell proliferation. In this study, we plan to explore which pathway or kinase participate in phosphorylation of p16, the crosstalk between phosphoryl

英文关键词： p16；arginine methylation；serine phosphorylation；apoptosis；senescence