Stimulation of ribosomal protein S6 kinase activity by pp60v-src or by serum: dissociation from phorbol ester-stimulated activity.
Stimulation of ribosomal protein S6 kinase activity by pp60v-src or by serum: dissociation from phorbol ester-stimulated activity.
复制标题
通过 pp60v-src 或血清刺激核糖体蛋白 S6 激酶活性：与佛波酯刺激的活性解离。
DOI：
10.1073/pnas.83.6.1733
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发表时间：
1986
影响因子：
11.1
通讯作者：
Erikson,RL
中科院分区：
文献类型：
--
作者：
Blenis,J;Erikson,RL
在用佛波醇 12-肉豆蔻酸酯 13-乙酸酯 (PMA) 处理不同时间的去血清鸡胚成纤维细胞 (CEF) 制备的裂解物中测量核糖体蛋白 S6 激酶活性。 15 分钟内观察到最大活性，并在 4 小时内降至初始水平。初始处理后，将这些细胞与 PMA 一起孵育 4-60 小时，不会导致 S6 蛋白激酶活性进一步增加。这些结果与 PMA 受体、蛋白激酶 C 的下调以及 PMA 刺激的 S6 激酶活性对该酶的依赖性一致。用 PMA 长期预处理 CEF 仅部分减弱了血清或劳斯肉瘤病毒转化基因产物 pp60v-src 表达对 S6 蛋白激酶活性的刺激。用放线菌酮或钒酸钠处理的细胞中也刺激了类似的蛋白激酶活性。 PMA 预处理对此反应影响不大。这些数据表明，可能至少有两种机制可以调节 S6 激酶活性，其中一种明显利用蛋白激酶 C，而另一种则不利用。其他实验表明，PMA 刺激的葡萄糖转运不会因与佛波酯长期孵育而减弱，这表明另一种不依赖于蛋白激酶 C 存在的机制在 PMA 受体下调后维持了这种反应。
Ribosomal protein S6 kinase activity was measured in lysates prepared from serum-deprived chicken embryo fibroblasts (CEF) treated for various times with phorbol 12-myristate 13-acetate (PMA). Maximal activity was observed within 15 min, and it declined to the initial level by 4 hr. Incubation of these cells with PMA 4-60 hr after the initial treatment did not result in an additional increase in S6 protein kinase activity. These results are consistent with down-regulation of the PMA receptor, protein kinase C, and the dependence of PMA-stimulated S6 kinase activity on this enzyme. Long-term pretreatment of CEF with PMA only partially attenuated the stimulation of the S6 protein kinase activity by serum or by expression of the Rous sarcoma virus transforming gene product, pp60v-src. A similar protein kinase activity also was stimulated in cells treated with cycloheximide or sodium vanadate. Pretreatment with PMA had little effect on this response. These data indicate that it is likely that there are at least two mechanisms through which S6 kinase activity can be regulated, one of which apparently utilizes protein kinase C whereas the other(s) does not. Additional experiments show PMA-stimulated glucose transport was not attenuated by long-term incubation with phorbol ester, suggesting that another mechanism, which is not dependent on the presence of protein kinase C, maintains this response after the proposed down-regulation of the PMA receptor.