Bryostatin 1 induces biphasic activation of protein kinase D in intact cells
Bryostatin 1 induces biphasic activation of protein kinase D in intact cells
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DOI：
10.1074/jbc.272.32.20245
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发表时间：
1997-08-08
影响因子：
4.8
通讯作者：
Rozengurt, E
中科院分区：
文献类型：
--
作者：
Matthews, SA;Pettit, GR;Rozengurt, E
苔藓抑素1和佛波醇酯都是蛋白激酶C（PKC）的有效激活剂，尽管它们的特定生物学效应在许多系统中可能不同。在这里，我们报告苔藓抑素1激活蛋白激酶D（PKD），一种新的丝氨酸/苏氨酸蛋白激酶，在完整的瑞士3 T3细胞和二次小鼠胚胎成纤维细胞和COS-7细胞瞬时转染PKD表达构建体。苔藓抑素1诱导的PKD活化的剂量反应遵循显著的双相模式，在10 nM的浓度下达到最大活化。较高浓度的苔藓抑素1（100 nM）将由佛波醇12，13-二丁酸酯诱导的PKD活化降低至仅由苔藓抑素1刺激的水平。苔藓抑素1诱导的PKD活化显着减弱与PKC抑制剂双吲哚马来酰亚胺I和Ro 31-8220的细胞治疗。然而，当直接加入体外激酶试验时，这些药物并不抑制PKD活性，这表明苔藓抑素1通过完整细胞中的PKC依赖性途径刺激PKD活化。我们的结果提高了完整细胞中活化的PKD可能介导苔藓抑素1诱导的多种双相生物反应中的一些的可能性。
Bryostatin 1 and phorbol esters are both potent activators of protein kinase C (PKC), although their specific biological effects can differ in many systems, Here, we report that bryostatin 1 activates protein kinase D (PKD), a novel serine/threonine protein kinase, in intact Swiss 3T3 cells and secondary mouse embryo fibroblasts and in COS-7 cells transiently transfected with a PKD expression construct. The dose response of PKD activation induced by bryostatin 1 follows a striking biphasic pattern with maximal activation achieved at a concentration of 10 nM. Higher concentrations of bryostatin 1 (100 nM) reduced PKD activation induced by phorbol 12,13-dibutyrate to levels stimulated by bryostatin 1 alone. Bryostatin 1-induced PKD activation was markedly attenuated by treatment of cells with the PKC inhibitors bisindolylmaleimide I and Ro 31-8220. However, these agents did not inhibit PKD activity when added directly to in vitro kinase assays, suggesting that bryostatin 1 stimulates PKD activation through a PKC-dependent pathway in intact cells, Our results raise the possibility that activated PKD in intact cells could mediate some of the multiple biphasic biological responses induced by bryostatin 1.