Hydrogen peroxide activates IκB kinases through phosphorylation of serine residues in the activation loops
Hydrogen peroxide activates IκB kinases through phosphorylation of serine residues in the activation loops
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DOI：
10.1016/s0014-5793(02)02712-6
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发表时间：
2002-05-22
期刊：
影响因子：
3.5
通讯作者：
Hirata, H
中科院分区：
文献类型：
--
作者：
Kamata, H;Manabe, T;Hirata, H
细胞氧化还原状态调节核因子-κ B（NF-κ B）信号系统。我们研究了H2 O2对NF-κ B（IkappaB）激酶抑制剂（IKK α和IKK β）的影响，IKK α和IKK β磷酸化IkappaB，导致其降解和NF-κ B活化。肿瘤坏死因子（TNF）刺激HeLa细胞10 min内IKK活性升高，30 min内IKK活性逐渐降低。H2 O2刺激的细胞诱导轻微激活IKK在30分钟内。此外，共刺激与TNF抑制IKK的下调和持续激活超过30分钟。H2 O2也显着激活IKK在细胞中，用TNF或佛波醇肉豆蔻酸酯醋酸酯预处理。电泳迁移率变动分析显示，H2 O2增强TNF诱导的NF-κ B活化。使用IKK突变体和抗磷酸化IKK蛋白的抗体的研究显示，活化环中IKK α的Ser 180和IKK的Ser 181的丝氨酸残基的磷酸化对于H2 O2介导的IKK活化是必需的。IKK β和IKK α激酶阴性突变体分别降低了H2 O2诱导的IKK α和IKK β活化，表明IKK α和IKK β以相互依赖的方式被H2 O2刺激。这些结果表明，氧化自由基应激通过IKK的激活对NF-κ B具有刺激作用，IKK的激活是由激活环中丝氨酸残基的磷酸化介导的。(C)2002年由Elsevier Science B. V.代表欧洲生物化学学会联合会出版。
The cellular redox state regulates nuclear factor-kappaB (NF-kappaB) signaling systems. We investigated the effects of H2O2 on inhibitor of NF-kappaB (IkappaB) kinases (IKKalpha and IKKbeta), which phosphorylate IkappaB leading to its degradation and NF-kappaB activation. Tumor necrosis factor (TNF) stimulation increased IKK activity within 10 min, and then IKK activity decreased gradually within 30 min in HeLa cells. Stimulation of the cells with H2O2 induced a slight activation of IKK within 30 min. Furthermore, co-stimulation with TNF suppressed the down-regulation of IKK and sustained the activation for more than 30 min. H2O2 also markedly activated IKK in cells that were pretreated with TNF or phorbol myristate acetate. Electrophoretic mobility shift assay revealed that H2O2 enhanced TNF-induced NF-kappaB activation. Studies using IKK mutants and an antibody against phosphorylated IKK proteins revealed that phosphorylation of serine residues, Ser180 of IKKalpha and Ser181 of IKK, in the activation loops was essential for the H2O2-mediated activation of IKK. H202-induced activation of IKKalpha and IKKbeta was reduced by IKKbeta and IKKalpha kinase-negative mutants, respectively, indicating that IKKalpha and IKKbeta were stimulated by H2O2 in an interdependent manner. These results suggest that oxidative radical stress has stimulatory effects on NF-kappaB through the activation of IKK, which is mediated by the phosphorylation of serine residues in the activation loops. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.