Use of the Pharmacological Inhibitor BX795 to Study the Regulation and Physiological Roles of TBK1 and IκB Kinase ε A DISTINCT UPSTREAM KINASE MEDIATES SER-172 PHOSPHORYLATION AND ACTIVATION
Use of the Pharmacological Inhibitor BX795 to Study the Regulation and Physiological Roles of TBK1 and IκB Kinase ε A DISTINCT UPSTREAM KINASE MEDIATES SER-172 PHOSPHORYLATION AND ACTIVATION
复制标题
DOI：
10.1074/jbc.m109.000414
复制
发表时间：
2009-05-22
影响因子：
4.8
通讯作者：
Cohen, Philip
中科院分区：
文献类型：
--
作者：
Clark, Kristopher;Plater, Lorna;Cohen, Philip
TANK结合激酶1（TBK 1）和I κ B激酶I（IKK I）在细菌和病毒感染期间调节1型干扰素的产生，但是缺乏有用的药理学抑制剂阻碍了鉴定这些蛋白激酶的其他生理作用以及它们如何被调节的进展。在这里，我们证明，BX 795，一种有效的和相对特异性的抑制剂TBK 1和IKK β，阻断磷酸化，核转位，和干扰素调节因子3的转录活性，因此，在巨噬细胞中的干扰素-β的生产与聚（I：C）或脂多糖（LPS）刺激。相反，BX 795对经典NF κ B信号通路没有影响。尽管BX 795阻断了过度表达的TBK 1和IKK β在Ser-172的自磷酸化，因此阻断了这些蛋白激酶的自活化，但它并不抑制内源性TBK 1和IKK β在Ser-172对LPS、poly（I：C）、白细胞介素-1 α（IL-1 α）或肿瘤坏死因子α，实际上增强了LPS、poly（I：C）和IL-1 α刺激的该残基的磷酸化。这些结果表明，Ser-172的磷酸化以及TBK 1和IKK β的活化在体内由不同的蛋白激酶催化，并且TBK 1和IKK β控制反馈环，该反馈环限制它们被LPS、poly（I：C）和IL-1 α（但不是肿瘤坏死因子α）活化，以防止这些酶的过度活化。
TANK-binding kinase 1 (TBK1) and I kappa B kinase epsilon (IKK epsilon) regulate the production of Type 1 interferons during bacterial and viral infection, but the lack of useful pharmacological inhibitors has hampered progress in identifying additional physiological roles of these protein kinases and how they are regulated. Here we demonstrate that BX795, a potent and relatively specific inhibitor of TBK1 and IKK epsilon, blocked the phosphorylation, nuclear translocation, and transcriptional activity of interferon regulatory factor 3 and, hence, the production of interferon-beta in macrophages stimulated with poly(I: C) or lipopolysaccharide (LPS). In contrast, BX795 had no effect on the canonical NF kappa B signaling pathway. Although BX795 blocked the autophosphorylation of overexpressed TBK1 and IKK epsilon at Ser-172 and, hence, the autoactivation of these protein kinases, it did not inhibit the phosphorylation of endogenous TBK1 and IKK epsilon at Ser-172 in response to LPS, poly(I: C), interleukin-1 alpha (IL-1 alpha), or tumor necrosis factor alpha and actually enhanced the LPS, poly(I: C), and IL-1 alpha-stimulated phosphorylation of this residue. These results demonstrate that the phosphorylation of Ser-172 and the activation of TBK1 and IKK epsilon are catalyzed by a distinct protein kinase(s) in vivo and that TBK1 and IKK epsilon control a feedback loop that limits their activation by LPS, poly(I: C) and IL-1 alpha (but not tumor necrosis factor alpha) to prevent the hyperactivation of these enzymes.