Protein phosphorylation in pancreatic islets induced by 3-phosphoglycerate and 2-phosphoglycerate.
Protein phosphorylation in pancreatic islets induced by 3-phosphoglycerate and 2-phosphoglycerate.
复制标题
3-磷酸甘油酸和 2-磷酸甘油酸诱导胰岛中的蛋白质磷酸化。
DOI：
10.1073/pnas.87.11.4294
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发表时间：
1990
影响因子：
11.1
通讯作者：
Ueda,T
中科院分区：
文献类型：
--
作者：
Pek,SB;Usami,M;Bilir,N;Fischer-Bovenkerk,C;Ueda,T
我们之前已经证明，3-磷酸甘油酸是葡萄糖的糖酵解代谢物，可诱导牛和大鼠大脑以及大鼠心脏、肾脏、肝脏、肺和整个胰腺中的蛋白质磷酸化。由于葡萄糖的糖酵解代谢在胰岛素释放中至关重要，因此我们考虑了3-磷酸甘油酸可能充当偶联因子的可能性，并且我们在新鲜分离的正常大鼠胰岛中寻找3-磷酸甘油酸依赖性蛋白磷酸化系统存在的证据。将膜和细胞质级分与[gamma-32P]ATP和适当的测试物质一起孵育，并进行NaDodSO4/PAGE和放射自显影。低至 0.005 mM 3-磷酸甘油酸或 2-磷酸甘油酸即可在 0.25 分钟内刺激 65-kDa 胞质蛋白的磷酸化。 65-kDa 磷蛋白的磷酸键足够稳定，可以承受透析；随后暴露于 ATP、ADP、3-磷酸甘油酸或 2,3-二磷酸甘油酸中无法消除放射性。此外，cAMP、cGMP、佛波醇12-肉豆蔻酸酯13-乙酸酯或钙未能刺激65-kDa蛋白的磷酸化。胰岛中磷酸甘油依赖的蛋白质磷酸化可能与刺激胰岛素分泌有关。
We have shown previously that 3-phosphoglycerate, which is a glycolytic metabolite of glucose, induces protein phosphorylation in bovine and rat brain and in rat heart, kidney, liver, lung, and whole pancreas. Since glycolytic metabolism of glucose is of paramount importance in insulin release, we considered the possibility that 3-phosphoglycerate may act as a coupling factor, and we searched for evidence for the existence of 3-phosphoglycerate-dependent protein phosphorylation systems in freshly isolated normal rat pancreatic islets. Membrane and cytosol fractions were incubated with [gamma-32P]ATP and appropriate test substances and were subjected to NaDodSO4/PAGE and autoradiography. As little as 0.005 mM 3-phosphoglycerate or 2-phosphoglycerate stimulated the phosphorylation of a 65-kDa cytosol protein by as early as 0.25 min. The phosphate bond of the 65-kDa phosphoprotein was sufficiently stable to withstand dialysis; the radioactivity could not be chased out by subsequent exposure to ATP, ADP, 3-phosphoglycerate, or 2,3-bisphosphoglycerate. Moreover, cAMP, cGMP, phorbol 12-myristate 13-acetate, or calcium failed to stimulate the phosphorylation of the 65-kDa protein. Phosphoglycerate-dependent protein phosphorylation in islets may have relevance to stimulation of insulin secretion.