STRUCTURAL AND GENETIC ANALYSIS OF RAS P21 FUNCTION

哺乳动物ras基因编码相关但不同的21千道尔顿血浆 膜蛋白（P21）。 广泛的人类和动物肿瘤细胞系 原发性肿瘤含有结构突变的ras基因， 在DNA介导的基因转移后转化NIH 3T3细胞。 为了 为了确定正常和转化型p21的功能，我们将研究 膜中p21的微环境，此外， 其产物与p21相互作用以引发转化的基因。 具体而言，我们将： (1)确定伴随成熟的翻译后修饰 的p21的质膜，并确定阻断的后果 通过ras基因的适当定点诱变进行修饰。 (2)通过以下方式表征膜中p21的最近邻居： 将用可光活化的交联剂标记的纯化的p21引入 活细胞 (3)使用DNA介导的基因转移来鉴定负责 ras转化的成纤维细胞的形态逆转。 （十）

The mammalian ras genes encode related, but distinct, 21 kilodalton plasma membrane proteins (P21). A wide range of human and animal tumor cell lines and primary tumors contain structurally mutated ras genes capable of transforming NIH 3T3 cells upon DNA-mediated gene transfer. In an attempt to determine the functions of normal and transforming p21, we shall study the microenvironment of p21 in the membrane and, additionally, identify genes whose products interact with p21 to elicit transformation. Specifically, we shall: (1) Determine the post-translational modification accompanying maturation of p21 to the plasma membrane, and determine the consequences of blocking modification by appropriate site-directed mutagenesis of a ras gene. (2) Characterize the nearest neighbors to p21 in the membrane by introducing purified p21 tagged with photoactivatable crosslinker into living cells. (3) Use DNA-mediated gene transfer to identify genes responsible for the morphological reversion of ras-transformed fibroblasts. (X)