CELL-TRANSFORMATION BY PP60C-SRC MUTATED IN THE CARBOXY-TERMINAL REGULATORY DOMAIN
CELL-TRANSFORMATION BY PP60C-SRC MUTATED IN THE CARBOXY-TERMINAL REGULATORY DOMAIN
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DOI：
10.1016/0092-8674(87)90758-6
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发表时间：
1987-04-10
期刊：
影响因子：
64.5
通讯作者：
KAPLAN, PL
中科院分区：
文献类型：
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作者：
CARTWRIGHT, CA;ECKHART, W;KAPLAN, PL
我们在鸡pp60c-src的羧基末端调控区引入了两个突变。一种是F527，它用苯丙氨酸取代酪氨酸527。另一种是Am517，它产生一个截短的pp60c-src蛋白，缺少17个羧基末端氨基酸。两种突变蛋白均在体内酪氨酸416位发生磷酸化。Am517突变体的比活力与野生型pp60c-src相似，而F527突变体的比活力高5~10倍。两种突变的c-src基因均可诱导NIH3T3细胞形成病灶，但病灶出现频率较低，且小于多瘤中瘤抗原(MT)诱导的病灶。野生型或F527 pp60c-src与mt形成复合体，而Am517 pp60c-src不与mt形成复合体。结果表明：第一，不能磷酸化酪氨酸527会增加pp60c-src蛋白激酶的活性和转化能力；第二，mt的转化除了缺乏pp60c-src酪氨酸527的磷酸化外，还涉及其他事件；第三，Am517突变体可能不需要激活pp60c-src蛋白激酶；第四，pp60c-src的羧基末端似乎是与mt结合所必需的。
We introduced two mutations into the carboxy-terminal regulatory region of chicken pp60c-src. One, F527, replaces tyrosine 527 with phenylalanine. The other, Am517, produces a truncated pp60c-src protein lacking the 17 carboxy-terminal amino acids. Both mutant proteins were phosphorylated at tyrosine 416 in vivo. The specific activity of the Am517 mutant protein kinase was similar to that of wild-type pp60c-src whereas that of the F527 mutant was 5- to 10-fold higher. Both mutant c-src genes induced focus formation on NIH 3T3 cells, but the foci appeared at lower frequency, and were smaller than foci induced by polyoma middle tumor antigen (mT). The wild-type or F527 pp60c-src formed a complex with mT, whereas the Am517 pp60c-src did not. The results suggest that one, inability to phosphorylate tyrosine 527 increases pp60c-src protein kinase activity and transforming ability; two, transformation by mT involves other events besides lack of phosphorylation at tyrosine 527 of pp60c-src; three, activation of the pp60c-src protein kinase may not be required for transformation by the Am517 mutant; and four, the carboxyl terminus of pp60c-src appears to be required for association with mT.