p38 kinase mediates nitric oxide-induced apoptosis of chondrocytes through the inhibition of protein kinase C ζ by blocking autophosphorylation
p38 kinase mediates nitric oxide-induced apoptosis of chondrocytes through the inhibition of protein kinase C ζ by blocking autophosphorylation
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DOI：
10.1038/sj.cdd.4401511
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发表时间：
2005-03-01
影响因子：
12.4
通讯作者：
Chun, JS
中科院分区：
文献类型：
--
作者：
Kim, JS;Park, ZY;Chun, JS
本研究探讨了一氧化氮（NO）诱导软骨细胞凋亡过程中p38激酶抑制蛋白激酶C（PKC）zeta的分子机制。免疫共沉淀实验表明，激活p38激酶后，添加一氧化氮供体导致PKCzeta和p38激酶之间的物理关联。使用p38激酶和PKCzeta重组蛋白在体外证实了p38激酶与PKCzeta的直接相互作用。p38激酶与PKCzeta的调节结构域相互作用，其结合阻断PKCzeta自身磷酸化。使用重组蛋白的Micro LC-MS/MS分析表明，p38激酶与PKCzeta的相互作用阻断了PKCzeta在Thr-560上的自磷酸化，这是PKCzeta活化所必需的。总的来说，我们的研究结果证明了PKCzeta调节的一种新机制：通过产生NO激活后，p38激酶直接与PKCzeta调节结构域结合，阻止PKCzeta在Thr-560上的自磷酸化，从而抑制PKCzeta激活。
This study investigated the molecular mechanisms underlying inhibition of protein kinase C (PKC) zeta by p38 kinase during nitric oxide (NO)-induced apoptosis of chondrocytes. Coimmunoprecipitation experiments showed that activation of p38 kinase following addition of an NO donor resulted in a physical association between PKCzeta and p38 kinase. Direct interaction of p38 kinase with PKCzeta was confirmed in vitro using p38 kinase and PKCzeta recombinant proteins. p38 kinase interacts with the regulatory domain of PKCzeta and its association blocked PKCzeta autophosphorylation. Micro LC-MS/MS analysis using recombinant proteins indicated that the interaction of p38 kinase with PKCzeta blocked autophosphorylation of PKCzeta on Thr-560, which is required for PKCzeta activation. Collectively, our results demonstrate a novel mechanism of PKCzeta regulation: following activation by the production of NO, p38 kinase binds directly to the PKCzeta regulatory domain, preventing PKCzeta autophosphorylation on Thr-560, thereby inhibiting PKCzeta activation.