Implication of phospholipase D2 in oxidant-induced phosphoinositide 3-kinase signaling via Pyk2 activation in PC12 cells
Implication of phospholipase D2 in oxidant-induced phosphoinositide 3-kinase signaling via Pyk2 activation in PC12 cells
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DOI：
10.1074/jbc.m410903200
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发表时间：
2005-04-22
影响因子：
4.8
通讯作者：
Nozawa, Y
中科院分区：
文献类型：
--
作者：
Banno, Y;Ohguchi, K;Nozawa, Y
磷脂酶D（PLD）激活在过氧化氢（H2 O2）诱导的信号转导和细胞反应中的作用尚未完全了解。在这里，我们提出的证据表明，钙依赖性酪氨酸激酶，Pyk 2，需要PLD激活介导的生存途径在大鼠嗜铬细胞瘤PC 12细胞在氧化应激。H2 O2诱导的两个Pyk 2位点（Tyr（580）和Tyr（881））的磷酸化被1-丁醇抑制，1-丁醇是PLD转磷脂酰化的抑制剂，并且也被催化阴性小鼠PLD 2K 758 R（PLD 2KR）的转染抑制。此外，我们发现PLD 2与Pyk 2和Src相关，并且PLD 2的激活是H2 O2增强Src与Pyk 2的关联导致Pyk 2完全激活所必需的。H2 O2诱导的Akt和p70 S6 K的磷酸化依赖于磷脂酰肌醇3-激酶（PI 3 K）的活性，并取消1-丁醇，但不是叔丁醇。此外，通过转染PLD 2KR或显性负性Pyk 2DN，响应于H2 O2的PI 3 K/Akt活化降低。本研究首次证明，PLD 2活化通过促进暴露于H2 O2的PC 12细胞中Pyk 2和活化Src之间的复合物形成，从而导致存活信号通路PI 3 K/Akt/p70 S6 K的活化，参与Pyk 2（Tyr（580）和Tyr（881））的Src依赖性磷酸化。
The role of phospholipase D (PLD) activation in hydrogen peroxide (H2O2)-induced signal transduction and cellular responses is not completely understood. Here we present evidence that Ca2+-dependent tyrosine kinase, Pyk2, requires PLD activation to mediate survival pathways in rat pheochromocytoma PC12 cells under oxidative stress. The H2O2-induced phosphorylation of two Pyk2 sites (Tyr(580), and Tyr(881)) was suppressed by 1-butanol, an inhibitor of transphosphatidylation by PLD, and also by transfection of catalytically negative mouse PLD2K758R (PLD2KR). Furthermore, we found that PLD2 was associated with Pyk2 and Src, and that activation of PLD2 was required for H2O2-enhanced association of Src with Pyk2 leading to full activation of Pyk2. H2O2-induced phosphorylation of Akt and p70S6K was dependent on phosphatidylinositol 3-kinase (PI3K) activity and was abolished by 1-butanol but not t-butanol. Furthermore, the PI3K/Akt activation in response to H2O2 was reduced by transfection of either PLD2KR or the dominant negative Pyk2DN. This study is the first demonstration that PLD2 activation is implicated in Src-dependent phosphorylation of Pyk2 (Tyr(580) and Tyr(881)) by promoting the complex formation between Pyk2 and activated Src in PC12 cells exposed to H2O2, thereby resulting in activation of the survival signaling pathway PI3K/Akt/p70S6K.