Cheatham L, Monfar M, Chou M M, Blenis J
Department of Cell Biology, Harvard Medical School, Boston, MA 02130, USA.
Proc Natl Acad Sci U S A. 1995 Dec 5;92(25):11696-700. doi: 10.1073/pnas.92.25.11696.
The pp70/85-kDa S6 kinases, collectively referred to as pp70S6k, are thought to participate in transit through the G1 phase of the cell cycle. pp70S6k regulates the phosphorylation of the 40S ribosomal protein S6 and the transcription factor CREM tau. pp70S6k is regulated by serine/threonine phosphorylation, and although 1-phosphatidylinositol 3-kinase and phospholipase C have been implicated as upstream regulators, the mechanism of activation and identity of the upstream pp70S6k kinases remain unknown. To improve our understanding of how this mitogen-stimulated protein kinase is regulated by growth factors and the immunosuppressant rapamycin, we have initiated a structure/function analysis of pp70S6k. Our results indicate that both the N and C termini participate in the complex regulation of pp70S6k activity.
pp70/85-kDa S6激酶统称为pp70S6k，被认为参与细胞周期G1期的过渡。pp70S6k调节40S核糖体蛋白S6和转录因子CREM tau的磷酸化。pp70S6k受丝氨酸/苏氨酸磷酸化调节，虽然1-磷脂酰肌醇3-激酶和磷脂酶C被认为是上游调节因子，但上游pp70S6k激酶的激活机制和身份仍不清楚。为了更好地理解这种有丝分裂原刺激的蛋白激酶如何受生长因子和免疫抑制剂雷帕霉素调节，我们启动了对pp70S6k的结构/功能分析。我们的结果表明，N端和C端都参与了pp70S6k活性的复杂调节。
