Dominant inhibitory Ras mutants demonstrate the requirement for Ras activity in the action of tyrosine kinase oncogenes.
Dominant inhibitory Ras mutants demonstrate the requirement for Ras activity in the action of tyrosine kinase oncogenes.
复制标题
显性抑制性 Ras 突变体证明酪氨酸激酶癌基因的作用需要 Ras 活性。
作者：
Dennis W. Stacey;Margaret M. Roudebush;Regina M. Day;S. Mosser;Jackson B. Gibbs;Larry A. Feig
将两种抑制性RAS突变体蛋白[(ASN 17)RAS和RAST]显微注射到NIH3T3细胞中，以比较它们与中和抗ras抗体的抑制活性。两个突变体都能有效地阻断血清对静止的NIH3T3细胞的促分裂作用。此外，就在新一轮DNA合成开始之前，每种抑制剂都在注射抗ras抗体的同一时间点阻止了细胞周期的进展。最后，与注射的抗ras抗体一样，每种抑制剂都能有效地阻止酪氨酸激酶癌基因转化的细胞的增殖并逆转转化的形态，而丝氨酸激酶癌基因转化的细胞不受影响。因此，所有三种试剂的结果都清楚地表明，细胞RAS活性在细胞周期的晚期是必需的，并且对于维持由酪氨酸而不是丝氨酸激酶癌基因诱导的转化表型是必不可少的。这些研究证明了显性抑制突变体作为干扰细胞癌基因活性的一种手段的实用性。
Two inhibitory Ras mutant proteins [(Asn 17) Ras and RAST] were microinjected into NIH3T3 cells in order to compare their inhibitory activity with that of a neutralizing anti-ras antibody. Both mutants were able to block efficiently the mitogenic effects of serum added to quiescent NIH3T3 cells. Furthermore, each of the inhibitors blocked cell cycle progression at the same point as the injected anti-ras antibody, just prior to the initiation of a new round of DNA synthesis. Finally, as with the injected anti-ras antibody, each of the inhibitors was efficiently able to block proliferation and reverse the transformed morphology of cells transformed by tyrosine kinase oncogenes, while cells transformed by serine kinase oncogenes were unaffected. Therefore, results with all three reagents clearly indicate that cellular Ras activity is required in the late G1 phase of the cell cycle and is essential for the maintenance of the transformed phenotype induced by tyrosine but not serine kinase oncogenes. These studies demonstrate the utility of dominant inhibitory mutants as a means of interfering with the activity of cellular oncogenes.