Protein kinase C δ (δPKC)-annexin V interaction -: A required step in δPKC translocation and function
Protein kinase C δ (δPKC)-annexin V interaction -: A required step in δPKC translocation and function
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DOI：
10.1074/jbc.m602075200
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发表时间：
2006-08-11
影响因子：
4.8
通讯作者：
Mochly-Rosen, Daria
中科院分区：
文献类型：
--
作者：
Kheifets, Viktoria;Bright, Rachel;Mochly-Rosen, Daria
蛋白激酶C（PKC）在癌症、中风和心肌缺血等疾病中起关键作用，并参与多种信号转导途径，如细胞凋亡、细胞增殖和肿瘤抑制。虽然对PKC下游信号传导事件了解很多，但PKC激活和随后的易位的调节机制尚未阐明。蛋白质-蛋白质相互作用调节并决定许多细胞信号传导事件的特异性。这样一个特定的蛋白质-蛋白质之间的相互作用在这里描述的δ PKC和膜联蛋白V。我们证明，在生理相关的条件下，膜联蛋白V和δ PKC之间的瞬时相互作用发生在细胞后的δ PKC刺激，但之前的δ PKC易位到颗粒部分。FRET和体外结合研究也提供了δ PKC-膜联蛋白V结合的证据。δ PKC-膜联蛋白V复合物的解离需要ATP和微管的完整性。此外，内源性膜联蛋白V，但不是膜联蛋白IV的消耗，siRNA抑制PKC刺激后的δ PKC易位。合理设计的八个氨基酸肽，对应于膜联蛋白V上的δ PKC的相互作用位点，抑制δ PKC易位和δ PKC介导的功能，如其在心肌梗死模型中的保护作用所证明的。我们的数据表明，δ PKC的易位不是简单的扩散驱动的过程，而是一个多步骤的事件调节蛋白质-蛋白质相互作用。我们发现，细胞活化后，δ PKC-膜联蛋白V结合是一个短暂的和必不可少的步骤，在δ PKC的功能，从而确定一个新的作用膜联蛋白V在PKC信号转导和PKC激活的一个新的步骤。
Protein kinase C (PKC) plays a critical role in diseases such as cancer, stroke, and cardiac ischemia, and participates in a variety of signal transduction pathways such as apoptosis, cell proliferation, and tumor suppression. Though much is known about PKC downstream signaling events, the mechanisms of regulation of PKC activation and subsequent translocation have not been elucidated. Protein-protein interactions regulate and determine the specificity of many cellular signaling events. Such a specific protein-protein interaction is described here between delta PKC and annexin V. We demonstrate, at physiologically relevant conditions, that a transient interaction between annexin V and delta PKC occurs in cells after delta PKC stimulation, but before delta PKC translocates to the particulate fraction. Evidence of delta PKC-annexin V binding is provided also by FRET and by in vitro binding studies. Dissociation of the delta PKC-annexin V complex requires ATP and microtubule integrity. Furthermore, depletion of endogenous annexin V, but not annexin IV, with siRNA inhibits delta PKC translocation following PKC stimulation. A rationally designed eight amino acid peptide, corresponding to the interaction site for delta PKC on annexin V, inhibits delta PKC translocation and delta PKC-mediated function as evidenced by its protective effect in a model of myocardial infarction. Our data indicate that translocation of delta PKC is not simply a diffusion-driven process, but is instead a multi-step event regulated by protein-protein interactions. We show that following cell activation, delta PKC-annexin V binding is a transient and an essential step in the function of delta PKC, thus identifying a new role for annexin V in PKC signaling and a new step in PKC activation.