Identification of TRAF6-dependent NEMO polyubiquitination sites through analysis of a new NEMO mutation causing incontinentia pigmenti
Identification of TRAF6-dependent NEMO polyubiquitination sites through analysis of a new NEMO mutation causing incontinentia pigmenti
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DOI：
10.1093/hmg/ddm237
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发表时间：
2007-12-01
影响因子：
3.5
通讯作者：
Courtois, Gilles
中科院分区：
文献类型：
--
作者：
Sebban-Benin, Helene;Pescatore, Alessandra;Courtois, Gilles
调节亚基NEMO参与I κ B激酶（IKK）的活化机制，IKK是控制NF-κ B信号传导途径的激酶复合物。在此过程中，NEMO通过K63连接的多聚泛素化进行后修饰。我们报告了NEMO（A323 P）的一种新的错义突变的分子特征，该突变导致严重形式的色素失禁（OMIM# 308300），这是一种主要以皮肤炎症为特征的遗传性疾病。发现A323 P突变损害TNF-、IL-1-、LPS-和PMA/离子霉素诱导的NF-κ B活化，以及由于NEMO/TRAF 6相互作用缺陷而破坏TRAF 6依赖的NEMO多聚泛素化。突变鉴定出受影响的遍在化位点是位于A323附近的三个赖氨酸残基。出乎意料的是，这些赖氨酸与两个先前鉴定的不与TRAF 6连接的赖氨酸一起被泛素化。所有这些遍在蛋白化位点的突变严重损害了IL-1、LPS、Nod 2/RICK或血清/LPA刺激诱导的NF-κ B活化。与此相反，在所有这些网站的突变只有有限的影响，刺激TNF。这些发现表明，NEMO通过K63连接的多聚泛素化的翻译后修饰是IKK激活的关键事件，这一步骤的扰动可能导致人类病理生理学。
The regulatory subunit NEMO is involved in the mechanism of activation of I kappa B kinase ( IKK), the kinase complex that controls the NF-kappa B signaling pathway. During this process, NEMO is modified post-translationally through K63-linked polyubiquitination. We report the molecular characterization of a new missense mutation of NEMO (A323P) which causes a severe form of incontinentia pigmenti (OMIM# 308300), an inherited disease characterized predominantly by skin inflammation. The A323P mutation was found to impair TNF-, IL-1-, LPS- and PMA/ionomycin-induced NF-kappa B activation, as well as to disrupt TRAF6-dependent NEMO polyubiquitination, due to a defective NEMO/TRAF6 interaction. Mutagenesis identified the affected ubiquitination sites as three lysine residues located in the vicinity of A323. Unexpectedly, these lysines were ubiquitinated together with two previously identified lysines not connected to TRAF6. Mutation of all these ubiquitination sites severely impaired NF-kappa B activation induced by stimulation with IL-1, LPS, Nod2/RICK or serum/LPA. In contrast, mutation at all of these sites had only a limited effect on stimulation by TNF. These findings indicate that post-translational modification of NEMO through K63-linked polyubiquitination is a key event in IKK activation and that perturbation of this step may cause human pathophysiology.