Isoenzyme-specific translocation of protein kinase C (PKC) βII and not PKCβI to a juxtanuclear subset of recycling endosomes -: Involvement of phospholipase D
Isoenzyme-specific translocation of protein kinase C (PKC) βII and not PKCβI to a juxtanuclear subset of recycling endosomes -: Involvement of phospholipase D
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DOI：
10.1074/jbc.m400770200
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发表时间：
2004-07-02
影响因子：
4.8
通讯作者：
Hannun, YA
中科院分区：
文献类型：
--
作者：
Becker, KP;Hannun, YA
阐明单个蛋白激酶 C (PKC) 同工酶的同工酶特异性功能已成为该激酶家族研究的一个重要目标，但由于每个 PKC 亚家族各个成员之间的底物特异性适中和高度同源性，这项任务变得复杂。经典的 PKCbetaI 和 PKCbetaII 同工酶提供了独特的机会，因为它们是 β 基因的选择性剪接产物，除了 52 个氨基酸中的最后 50 个氨基酸外，它们 100% 相同。在这项研究中，表明绿色荧光蛋白标记的 PKCbetaII 而不是 PKCbetaI 易位到最近描述的 PKCα 和 PKCbetaII 同工酶的近核定位位点，该位点随着 PKC 的持续刺激而出现。从机制上讲，PKCbetaII 易位至核旁区域需要激酶活性。发现 PKCbetaII（而非 PKCbetaI）在此时间范围内激活磷脂酶 D。磷脂酶 D 抑制剂（1-丁醇和显性失活构建体）可阻止 PKCbetaII 转位至核旁区域，但不能转位至质膜，从而证明磷脂酶 D 在 PKCbetaII 核旁转位中的作用。总而言之，这些结果定义了 PKCbetaII 与 PKCbetaI 相比的特定生化和细胞作用。
Elucidation of isoenzyme-specific functions of individual protein kinase C (PKC) isoenzymes has emerged as an important goal in the study of this family of kinases, but this task has been complicated by modest substrate specificity and high homology among the individual members of each PKC subfamily. The classical PKCbetaI and PKCbetaII isoenzymes provide a unique opportunity because they are the alternatively spliced products of the beta gene and are 100% identical except for the last 50 of 52 amino acids. In this study, it is shown that green fluorescent protein-tagged PKCbetaII and not PKCbetaI translocates to a recently described juxtanuclear site of localization for PKCalpha and PKCbetaII isoenzymes that arises with sustained stimulation of PKC. Mechanistically, translocation of PKCbetaII to the juxtanuclear region required kinase activity. PKCbetaII, but not PKCbetaI, was found to activate phospholipase D within this time frame. Inhibitors of phospholipase D (1-butanol and a dominant negative construct) prevented the translocation of PKCbetaII to the juxtanuclear region but not to the plasma membrane, thus demonstrating a role for phospholipase D in the juxtanuclear translocation of PKCbetaII. Taken together, these results define specific biochemical and cellular actions of PKCbetaII when compared with PKCbetaI.