RNAi screen in mouse astrocytes identifies phosphatases that regulate NF-κB signaling
RNAi screen in mouse astrocytes identifies phosphatases that regulate NF-κB signaling
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DOI：
10.1016/j.molcel.2006.10.015
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发表时间：
2006-11-17
期刊：
影响因子：
16
通讯作者：
Dorf, Martin E.
中科院分区：
文献类型：
--
作者：
Li, Shitao;Wang, Lingyan;Dorf, Martin E.
NF-κ B活化的调节由一系列激酶控制;然而，磷酸酶在调节该途径中的作用知之甚少。我们报告了一个系统的RNAi筛选磷酸酶调节NF-κ B活性。250个磷酸酶基因中的19个被鉴定为星形胶质细胞中NF-κ B信号传导的调节因子。RNAi选择性调节内源性趋化因子和细胞因子表达。免疫共沉淀鉴定了不同蛋白磷酸酶2A核心或全酶与IKK、NF-κ B和TRAF 2复合物的关联。这些复合物的去磷酸化导致NF-κ B转录活性的调节。与IKK和NF-κ B相反，TRAF 2磷酸化尚未得到很好的阐明。我们表明，在TRAF 2的Thr 117残基是磷酸化后TNF α刺激。该磷酸化过程由PP 2A调节，并且是TRAF 2功能活性所需的。这些结果为TNF诱导的TRAF 2磷酸化提供了直接证据，并证明在NF-κ B通路中磷酸化在多个水平上受到调节。
Regulation of NF-kappa B activation is controlled by a series of kinases; however, the roles of phosphatases in regulating this pathway are poorly understood. We report a systematic RNAi screen of phosphatases that modulate NF-kappa B activity. Nineteen of 250 phosphatase genes were identified as regulators of NF-kappa B signaling in astrocytes. RNAi selectively regulates endogenous chemokine and cytokine expression. Coimmunoprecipitation identified associations of distinct protein phosphatase 2A core or holoenzymes; with the IKK, NF-kappa B, and TRAF2 complexes. Dephosphorylation of these complexes leads to modulation of NF-kappa B transcriptional activity. In contrast to IKK and NF-kappa B, TRAF2 phosphorylation has not been well elucidated. We show that the Thr117 residue in TRAF2 is phosphorylated following TNF alpha stimulation. This phosphorylation process is modulated by PP2A and is required for TRAF2 functional activity. These results provide direct evidence for TNF-induced TRAF2 phosphorylation and demonstrate that phosphorylation is regulated at multiple levels in the NF-kappa B pathway.