Activation of atypical protein kinase C by sphingosine 1-phosphate revealed by an aPKC-specific activity reporter
Activation of atypical protein kinase C by sphingosine 1-phosphate revealed by an aPKC-specific activity reporter
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DOI：
10.1126/scisignal.aat6662
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发表时间：
2019-01-01
影响因子：
7.3
通讯作者：
Newton, Alexandra C.
中科院分区：
文献类型：
--
作者：
Kajimoto, Taketoshi;Caliman, Alisha D.;Newton, Alexandra C.
非典型蛋白激酶C （aPKC）同工酶在PKC超家族中是独特的，因为它们不受脂质第二信使二酰基甘油的调节，这导致人们猜测是否有不同的第二信使急性控制它们的功能。本研究使用我们设计的基因编码报告基因，aPKC特异性C激酶活性报告基因（aCKAR），我们发现脂质介质鞘氨醇1-磷酸（S1P）促进了aPKC的细胞活性。胞内S1P直接与纯化的aPKC激酶结构域结合，解除了自身抑制约束，从而激活了激酶。计算机研究确定了激酶结构域的潜在结合位点，其中一个得到了生化验证。在HeLa细胞中，s1p依赖性的aPKC激活抑制细胞凋亡。总之，我们的发现确定了先前未描述的aPKC调控的分子机制，S1P在细胞存活调控中的分子靶点，并为进一步探索aPKC的生化和生物学功能提供了工具。
Atypical protein kinase C (aPKC) isozymes are unique in the PKC superfamily in that they are not regulated by the lipid second messenger diacylglycerol, which has led to speculation about whether a different second messenger acutely controls their function. Here, using a genetically encoded reporter that we designed, aPKC-specific C kinase activity reporter (aCKAR), we found that the lipid mediator sphingosine 1-phosphate (S1P) promoted the cellular activity of aPKC. Intracellular S1P directly bound to the purified kinase domain of aPKC and relieved autoinhibitory constraints, thereby activating the kinase. In silico studies identified potential binding sites on the kinase domain, one of which was validated biochemically. In HeLa cells, S1P-dependent activation of aPKC suppressed apoptosis. Together, our findings identify a previously undescribed molecular mechanism of aPKC regulation, a molecular target for S1P in cell survival regulation, and a tool to further explore the biochemical and biological functions of aPKC.