Blenis J, Spivack J G, Erikson R L
Proc Natl Acad Sci U S A. 1984 Oct;81(20):6408-12. doi: 10.1073/pnas.81.20.6408.
The addition of phorbol 12-myristate 13-acetate (PMA), a potent tumor promoter, to serum-starved quiescent chicken embryo fibroblasts (CEF) or C127 murine cells resulted in increased phosphorylation of 40S ribosomal protein S6. The effect of PMA on S6 phosphorylation in quiescent CEF was half-maximal at approximately equal to 100 nM and was readily observed at 16 nM. In addition, S6 phosphorylation was increased in serum-starved CEF incubated with the diacylglycerol derivative, 1-oleoyl-2-acetylglycerol. S6 phosphorylation in PMA-stimulated, serum-stimulated, and serum-starved Rous sarcoma virus-transformed CEF was analyzed by phospho amino acid analysis, two-dimensional polyacrylamide gel electrophoresis, limited proteolysis with V8 protease, and two-dimensional thin-layer electrophoresis of chymotryptic digests. Comparison of S6 phosphorylation by these methods suggests that phosphorylation of S6 stimulated by PMA, serum, or oncogenic transformation with Rous sarcoma virus occurs through common pathways. This is further supported by the observation that the simultaneous addition of PMA and serum to CEF or of either PMA or serum to Rous sarcoma virus-transformed CEF did not significantly further increase the incorporation of phosphate into S6.
向血清饥饿的静止鸡胚成纤维细胞（CEF）或C127小鼠细胞中添加佛波醇12 - 肉豆蔻酸酯13 - 乙酸酯（PMA，一种强效肿瘤促进剂），会导致40S核糖体蛋白S6的磷酸化增加。PMA对静止CEF中S6磷酸化的作用在约100 nM时达到半数最大效应，在16 nM时即可明显观察到。此外，与二酰基甘油衍生物1 - 油酰基 - 2 - 乙酰甘油一起孵育的血清饥饿CEF中，S6磷酸化也增加。通过磷酸氨基酸分析、二维聚丙烯酰胺凝胶电泳、用V8蛋白酶进行有限蛋白酶解以及胰凝乳蛋白酶消化产物的二维薄层电泳，对PMA刺激、血清刺激和血清饥饿的劳氏肉瘤病毒转化的CEF中的S6磷酸化进行了分析。通过这些方法对S6磷酸化的比较表明，PMA、血清或劳氏肉瘤病毒致癌转化所刺激的S6磷酸化是通过共同途径发生的。CEF同时添加PMA和血清，或劳氏肉瘤病毒转化的CEF添加PMA或血清后，磷酸盐掺入S6并未显著进一步增加，这一观察结果进一步支持了这一点。
