Suppression of src transformation by overexpression of full-length GTPase-activating protein (GAP) or of the GAP C terminus
Suppression of src transformation by overexpression of full-length GTPase-activating protein (GAP) or of the GAP C terminus
复制标题
通过全长 GTP 酶激活蛋白 (GAP) 或 GAP C 末端的过表达来抑制 src 转化
DOI：
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发表时间：
1991
影响因子：
5.3
通讯作者：
D. Lowy
中科院分区：
文献类型：
--
作者：
J. Declue;K. Zhang;P. Redford;W. Vass;D. Lowy
最近，过表达全长GTP酶激活蛋白(GAP)可以抑制NIH3T3细胞的c-ras转化，但不能抑制v-ras转化(36)。在这里，我们表明，c-src诱导的焦点形成被抑制了大约80%，当与编码全长间隙的质粒共转染时。在类似的实验中，激活的c-src(Tyr-527 to Phe)基因的焦点形成被抑制了33%。GAP C末端编码序列(编码GTP酶加速区)与c-src或c-src527F共转染比全长GAP更有效地抑制转化，而GAP N末端编码序列对src转化没有影响。当c-ras、c-src、c-src527F或v-src转化的细胞在存在可选择标记的情况下，将GAP或GAP C末端序列导入细胞时，发现40%~85%的抗性克隆是形态逆转的。GAP C末端比全长GAP更有效地诱导每个src转化细胞系的逆转，但c-ras转化的逆转并非如此。对v-src回复突变亚克隆的生化分析表明，逆转与全长GAP或GAP C末端的过度表达有关。体内pp60src表达水平和蛋白酪氨酸磷酸化水平均未见下降。结论：GAP可通过抑制内源性ras活性抑制src的转化，而不抑制pp60src诱导的细胞蛋白酪氨酸磷酸化，src可能通过负性调节GAP对内源性ras的抑制作用。
Overexpression of the full-length GTPase-activating protein (GAP) has recently been shown to suppress c-ras transformation of NIH 3T3 cells but not v-ras transformation (36). Here, we show that focus formation induced by c-src was inhibited by approximately 80% when cotransfected with a plasmid encoding full-length GAP. In a similar assay, focus formation by the activated c-src (Tyr-527 to Phe) gene was inhibited by 33%. Cotransfection of the GAP C terminus coding sequences (which encode the GTPase-accelerating domain) with c-src or c-src527F inhibited transformation more efficiently than did the full-length GAP, while the GAP N terminus coding sequences had no effect on src transformation. When cells transformed by c-ras, c-src, c-src527F, or v-src were transfected with GAP or the GAP C terminus sequence in the presence of a selectable marker, 40 to 85% of the resistant colonies were found to be morphologically revertant. The GAP C terminus induced reversion of each src-transformed cell line more efficiently than the full-length GAP, but this was not the case for reversion of c-ras transformation. Biochemical analysis of v-src revertant subclones showed that the reversion correlated with overexpression of full-length GAP or the GAP C terminus. There was no decrease in the level of pp60src expression or the level of protein-tyrosine phosphorylation in vivo. We conclude that GAP can suppress transformation by src via inhibition of endogenous ras activity, without inhibiting in vivo tyrosine phosphorylation of cellular proteins induced by pp60src, and that src may negatively regulate GAP's inhibitory action on endogenous ras.
DOI：
10.1073/pnas.85.21.8047
发表时间：
1988-11-01
影响因子：
11.1
作者：
HARTMAN, SC;MULLIGAN, RC
通讯作者：
MULLIGAN, RC
影响因子：
16.6
作者：
M. Barbacid
通讯作者：
M. Barbacid
src 的遗传学：蛋白酪氨酸激酶的结构和功能组织。
影响因子：
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作者：
Parsons,JT;Weber,MJ
通讯作者：
Weber,MJ