Gab1 is an integrator of cell death versus cell survival signals in oxidative stress
Gab1 is an integrator of cell death versus cell survival signals in oxidative stress
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DOI：
10.1128/mcb.23.13.4471-4484.2003
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发表时间：
2003-07-01
影响因子：
5.3
通讯作者：
Wong, AJ
中科院分区：
文献类型：
--
作者：
Holgado-Madruga, M;Wong, AJ
在添加不同的生长因子和细胞因子后，Gab 1对接蛋白被酪氨酸磷酸化，进而激活不同的信号通路。基于大量关于生长因子和氧化应激激活的信号通路之间的串扰的证据，我们决定研究Gab 1在氧化损伤中的作用。我们刺激野生型小鼠胚胎成纤维细胞（MEF）或MEF与纯合删除的Gab 1基因（-/- MEF）与H2 O2。我们的研究结果表明，Gab 1磷酸化的剂量和时间依赖性的方式后，过氧化氢触发。然后，Gab 1招募分子，如SHP 2，磷脂酰肌醇3-激酶（PI 3 K）和Shc。Gab 1磷酸化对Src家族激酶抑制剂PP 2敏感。此外，我们证明Gab 1是H2 O2诱导的c-Jun N-末端激酶（JNK）激活所必需的，但不是ERK 2或p38激活所必需的。Gab 1在-/- MEF中的重建拯救了JNK活化，并且我们发现这依赖于Gab 1中的SHP 2结合位点。细胞活力测定表明，Gab 1在细胞存活中具有双重作用：通过与PI 3 K相互作用的阳性作用和通过与SHP 2相互作用的阴性作用。这是第一份报告确定Gab 1作为氧化应激信号传导的一个组成部分，是JNK激活所必需的。
Upon the addition of different growth factors and cytokines, the Gab1 docking protein is tyrosine phosphorylated and in turn activates different signaling pathways. On the basis of the large body of evidence concerning cross talk between the signaling pathways activated by growth factors and oxidative stress, we decided to investigate the role of Gab1 in oxidative injury. We stimulated wild-type mouse embryo fibroblasts (MEF) or MEF with a homozygous deletion of the Gab1 gene (-/- MEF) with H2O2. Our results show that Gab1 is phosphorylated in a dose- and time-dependent manner after H2O2 triggering. Gab1 then recruits molecules such as SHP2, phosphatidylinositol 3-kinase (PI3K), and Shc. Gab1 phosphorylation is sensitive to the Src family kinase inhibitor PP2. Furthermore, we demonstrate that Gab1 is required for H2O2-induced c-Jun N-terminal kinase (JNK) activation but not for ERK2 or p38 activation. Reconstitution of Gab1 in -/- MEF rescues JNK activation, and we find that this is dependent on the SHP2 binding site in Gab1. Cell viability assays reveal that Gab1 has a dual role in cell survival: a positive one through its interaction with PI3K and a negative one through its interaction with SHP2. This is the first report identifying Gab1 as a component in oxidative stress signaling and one that is required for JNK activation.