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c-ras癌基因及其产物蛋白P21与恶性肿瘤的发生、发展起着重要的作用。c-ras-onc的激活一般有两种机制:(1)基因中第12位或第61位密码子发生点突变,使相应的编码蛋白P21中的氨基酸发生改变;(2)P21的过量表达。C-ras-onc家族的成员均编码分子量为21,000的蛋白质(P21),它们与细胞膜结合具有GTP结合及GTP酶的活性,它们还参与正常细胞的增殖,还可能与信号传递有关。例如在Harvey鼠肉瘤病毒转化的细胞中胰岛素
C-ras oncogene and its product protein P21 play an important role in the occurrence and development of malignant tumors. The activation of c-ras-onc generally has two mechanisms: (1) a point mutation in the 12th or 61st codon in the gene changes the corresponding amino acid in the encoded protein P21; (2) overexpression of P21 . Members of the C-ras-onc family all encode proteins (P21) with a molecular weight of 21,000. They bind to cell membranes and have GTP-binding and GTPase activity. They also participate in the proliferation of normal cells and may also be involved in signal transduction. For example, insulin in cells transformed with Harvey’s murine sarcoma virus