REGULATION OF CDK4 BY TGF-BETA

解除对细胞增殖的调控，通常是在G1期，是一个共同的特征 在许多人类癌症中。细胞周期蛋白及其受体调控G1期进程 细胞周期蛋白依赖性蛋白激酶(CDKs)伴侣(CDK2、CDK4和CDK6)。几个 一系列证据表明，转化生长因子-β(TGF-β) β)通过下调CDK4的表达诱导G1期停滞 翻译水平。突变型p53使人对细胞因子产生抵抗力。宽 53型还用5‘非翻译区(UTR)抑制CDK4的翻译 CDK4mRNA依赖的方式。我想研究P53在人类基因组中的作用 转化生长因子-β对CDK4的调节及其5‘端非编码区的重要性 进程。具体地说，首先我将确定CDK4mRNA的5‘非翻译区 在转化生长因子-β诱导的CDK4的翻译下调中扮演任何角色。 转化生长因子-β对全长及5‘端非编码区转导细胞的影响 将确定截断。5‘非编码区(二级结构或 特定序列)将是P53翻译调控所必需的 下定决心。将使用各种删除5‘端的方法来研究 P53在翻译下调中的作用。P53在羽绒毛膜病变中的作用 对CDK4的监管也将进行探索。我会确定P53是否 RNAGel Shift分析5‘端非编码区CDK4与P53结合的结构域 信使核糖核酸接下来的问题将是这个领域是否足够 翻译调节能力。如果其他人也很重要，那么 它们的功能与P53的翻译调控能力有关 将会被探索。

Deregulation of cell proliferation, often at G1 phase, is a common feature of many human cancers. G1 progression is regulated by cyclins and their cyclin dependent kinases (cdks) partner (cdk2, cdk4 and cdk6). Several lines of evidence suggested that transforming growth factor-beta (TGF- beta) induces G1 arrest by down regulation of cdk4 expression at translation level. Mutant p53 confers resistance to the cytokine. Wide type 53 also represses cdk4 translation with 5' untranslated region (UTR) of CDK4 mRNA dependent manner. I would like to study the role of p53 in the regulation of cdk4 by TGF-beta and the importance of 5'UTR in this process. Specifically, first I will determine whether 5'UTR of CDK4 mRNA plays any role in TGF-beta-induced translational down regulation of cdk4. The effect of TGF-beta on cell transfected with full length or 5'UTR truncate will be determined. The regions of 5'UTR (secondary structure or specific sequence) necessary for translational regulation by p53 will be determined. Various deletion of the 5'end will be used to study the effect of p53 in translational down regulation. The role of p53 in down regulation of cdk4 will also be explored. I will determine whether p53 binds 5'UTR CDK4 mRNA by RNA gel shift assay and which domain of p53 binds the mRNA. Further question will then be whether this domain is sufficient for translational regulation ability. If others also important, then their functions in relation to translational regulation ability of p53 will be explored.