Tyrosine nitration on p65 -: A novel mechanism to rapidly inactivate nuclear factor-κB
Tyrosine nitration on p65 -: A novel mechanism to rapidly inactivate nuclear factor-κB
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DOI：
10.1074/mcp.m400195-mcp200
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发表时间：
2005-03-01
影响因子：
7
通讯作者：
Wei, LN
中科院分区：
文献类型：
--
作者：
Park, SW;Huq, M;Wei, LN
NO是通过细胞还原和氧化机制（半胱氨酸-亚硝基化或Tyr硝化）诱导蛋白质翻译后修饰的重要因子。核因子(NF)- κ B活性可被硝普钠（NO供体）迅速抑制。这种作用被过氧亚硝酸盐清除剂去铁胺有效逆转，提示Tyr硝化介导的机制。Western blot显示NF-kappa B的p65亚基主要硝化在Tyr残基上。Tyr对p65的硝化诱导其与p50分离，与I κ B α结合，随后通过I κ B α介导的输出将p65隔离在细胞质中。液相色谱耦合纳米电喷雾质谱分析显示p65的tyrr -66和tyrr -152残基具有特定的硝化作用。突变研究证实，Tyr-66和Tyr-152残基对NO对p65的直接影响都很重要，从而导致p65更多的输出和nf - κ B活性的失活。本研究发现了一种新的有效途径，通过诱导p65上的Tyr硝化，NO快速灭活NF-kappa B活性。
NO is an important factor that induces post-translational modifications of proteins by cellular reduction and oxidation mechanism: cysteinyl-nitrosylation or Tyr nitration. Nuclear factor (NF)-kappa B activity can be rapidly suppressed by sodium nitroprusside, a NO donor. This effect was effectively reversed by peroxynitrite scavenger deferoxamine, suggesting a Tyr nitration-mediated mechanism. Western blot with nitrotyrosine- specific antibody demonstrated that the p65 subunit of NF-kappa B was predominantly nitrated on Tyr residues. Tyr nitration of p65 induced its dissociation from p50, its association with I kappa B alpha, and subsequent sequestration of p65 in the cytoplasm by I kappa B alpha-mediated export. Liquid chromatography-coupled nanoelectrospray mass spectrometry revealed specific nitration on Tyr-66 and Tyr-152 residues of p65. Mutation studies confirmed that both Tyr-66 and Tyr-152 residues were important for the direct effects of NO on p65, which resulted in more p65 export and inactivation of NF-kappa B activity. This study identified a novel and efficient pathway where NO rapidly inactivated NF-kappa B activity by inducing Tyr nitration on p65.