Insulin-stimulated microtubule associated protein kinase is detectable by analytical gel chromatography as a 35-kDa protein in myocytes, adipocytes, and hepatocytes.
Insulin-stimulated microtubule associated protein kinase is detectable by analytical gel chromatography as a 35-kDa protein in myocytes, adipocytes, and hepatocytes.
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胰岛素刺激的微管相关蛋白激酶可通过分析凝胶色谱检测为肌细胞、脂肪细胞和肝细胞中的 35 kDa 蛋白。
DOI：
10.1016/0003-9861(88)90193-2
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发表时间：
1988
影响因子：
3.9
通讯作者：
Sturgill,TW
中科院分区：
文献类型：
--
作者：
Ray,LB;Sturgill,TW
胰岛素刺激一种新的丝氨酸苏氨酸激酶，在体外使微管相关蛋白-2(MAP-2)磷酸化。在主要的胰岛素反应组织的细胞模型中，使用分析性快速蛋白质液相色谱对MAP激酶进行了部分纯化。在BC3H1和23A2骨骼肌细胞、3T3-L1脂肪细胞以及分离的大鼠肝细胞和脂肪细胞中，胰岛素容易检测到MAPK的激活(1.3~2倍)。在所用的测定条件下未检测到磷酸酶活性，证明胰岛素处理的3T3-L1细胞上清液催化的32PO4掺入增加是由于对激酶的刺激，而不是对磷酸酶的抑制。在H4肝癌细胞中，与其他类型的细胞相比，凝胶过滤后对MAP激酶的刺激作用要小得多。胰岛素处理细胞上清液中存在的激活酶以~35 kDa表观分子质量的单峰迁移(除有肩部的分离肝细胞外)。这些结果表明，胰岛素刺激的MAPK可能在胰岛素反应细胞中普遍存在。
Insulin stimulates a novel Ser Thr kinase, which phosphorylates microtubule associated protein-2 (MAP-2) in vitro. MAP kinase was studied in cell models of the principal insulin responsive tissues using analytical fast-protein liquid chromatography for partial purification of the enzyme. Stimulation of MAP kinase (1.3-to 2-fold) by insulin was readily detected in BC 3 H1 smooth and 23A2 skeletal muscle cells; 3T3-L1 adipocytes; and isolated rat hepatocytes and adipocytes. No phosphatase activity was detectable under the assay conditions used, proving that stimulation of a kinase, not inhibition of a phosphatase, is responsible for the increased incorporation of 32 PO 4 catalyzed by supernatants from insulin-treated 3T3-L1 cells. In H4 hepatoma cells, stimulation of MAP kinase was much less evident after gel filtration in comparison to the other cell types. The activated enzyme present in supernatants from insulin-treated cells migrated as a single peak of~ 35 kDa apparent molecular mass (except in the case of isolated hepatocytes in which a shoulder was present). These results suggest that the insulin-stimulatable MAP kinase may be ubiquitous in insulin responsive cells.