RAPID STIMULATION BY INSULIN OF A SERINE THREONINE KINASE IN 3T3-L1 ADIPOCYTES THAT PHOSPHORYLATES MICROTUBULE-ASSOCIATED PROTEIN-2 INVITRO
RAPID STIMULATION BY INSULIN OF A SERINE THREONINE KINASE IN 3T3-L1 ADIPOCYTES THAT PHOSPHORYLATES MICROTUBULE-ASSOCIATED PROTEIN-2 INVITRO
复制标题
DOI：
10.1073/pnas.84.6.1502
复制
发表时间：
1987-03-01
影响因子：
11.1
通讯作者：
STURGILL, TW
中科院分区：
文献类型：
--
作者：
RAY, LB;STURGILL, TW
胰岛素治疗（Kact， 5次）。10-9 M)的血清饥饿3T3-L1脂肪细胞刺激可溶性丝氨酸/苏氨酸激酶，催化微管相关蛋白2 （MAP-2）的磷酸化。80 nM胰岛素对MAP-2激酶活性的最大激活在激素刺激10分钟后观察到，在S6激酶活性的最大刺激（20分钟）之前。胰岛素刺激的MAP-2激酶活性不被吸附到磷酸纤维素上，而主要的S6激酶活性被保留并在.simeq被洗脱。5 M NaCl。胰岛素刺激的MAP-2激酶在30℃的孵育期间比S6激酶活性更不稳定。磷酸酶抑制剂的加入降低了在30℃下培养的提取液上清中受刺激的MAP-2激酶活性丧失的速率。对硝基苯磷酸比dl -磷酸酪氨酸更有效，而dl -磷酸丝氨酸在使用的浓度（40 mM）下没有效果。在Sephadex G-25快速层析后，对照和胰岛素处理细胞的提取上清液中MAP-2激酶活性的差异也得以保存。这些结果表明可溶性丝氨酸/苏氨酸激酶被胰岛素迅速激活，可能是通过激酶本身的磷酸化或相互作用的调节剂。
Insulin treatment (Kact, 5 .times. 10-9 M) of serum-starved 3T3-L1 adipocytes stimulates a soluble serine/threonine kinase that catalyzes phosphorylation of microtubule-associated protein 2 (MAP-2) in vitro. Maximal activation of MAP-2 kinase activity by 80 nM insulin was observed after 10 min of hormonal stimulation, prior to maximal stimulation of S6 kinase activity (20 min). The insulin-stimulatable MAP-2 kinase activity is not adsorbed to phosphocellulose, whereas the principal S6 kinase activity is retained and eluates at .simeq. 5 M NaCl. The insulin-stimulatable MAP-2 kinase is less stable during incubation ats 30.degree.C than S6 kinase activity. Inclusion of phosphatase inhibitors decreases the rate at which the stimulated MAP-2 kinase activity is lost from extract supernatants incubated at 30.degree.C. p-Nitrophenyl phosphate is more effective than DL-phosphotyrosine, whereas DL-phosphoserine is without effect at the concentration used (40 mM). The difference in MAP-2 kinase activity in extract supernatants from control and insulin-treated cells is also preserved after rapid chromatography on Sephadex G-25. These results show that a soluble serine/threonine kinase is rapidly activated by insulin, possibly by phosphorylation of either the kinase itself or an interacting modulator.