The tyrosine kinase Src promotes phosphorylation of the kinase TBK1 to facilitate type I interferon production after viral infection
The tyrosine kinase Src promotes phosphorylation of the kinase TBK1 to facilitate type I interferon production after viral infection
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酪氨酸激酶 Src 促进激酶 TBK1 磷酸化，以促进病毒感染后 I 型干扰素的产生
DOI：
10.1126/scisignal.aae0435
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发表时间：
2017-01-03
影响因子：
7.3
通讯作者：
Chen, Taoyong
中科院分区：
文献类型：
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作者：
Li, Xuelian;Yang, Mingjin;Chen, Taoyong
酪氨酸激酶Src将多种模式识别受体的激活与I型干扰素的产生结合起来。Src和干扰素细胞具有多种模式识别受体（PRRs），可感知病毒感染。尽管PRRs通过不同的接头蛋白介导信号传导，但它们主要集中在TBK1激酶的激活上，TBK1激酶磷酸化并激活转录因子IRF3，促进编码I型干扰素（ifn）的基因的表达。Li等人发现TBK1经过丝氨酸自磷酸化激活，同时也被酪氨酸磷酸化，这依赖于激酶Src。尽管Src不直接与TBK1结合并磷酸化，但它被招募到含有TBK1的多个prr相关的含接头复合物中。此外，Src的缺失或其活性的抑制会损害病毒感染的巨噬细胞产生I型ifn，这表明Src在对病毒的先天免疫反应中起着中心调节作用。各种模式识别受体（PRRs）在病毒感染的反应中被激活，以刺激I型干扰素（ifn）的产生。然而，所有这些受体反应的核心是它们对TBK1激酶的激活，TBK1激酶通过IFN调节因子3 （IRF3）刺激转录。我们研究了病毒感染刺激TBK1激酶活性的机制。我们发现，在病毒感染RAW264.7巨噬细胞时，酪氨酸激酶Src促进Tyr179上TBK1的磷酸化。Tyr179到丙氨酸的突变导致TBK1在Ser172处的自磷酸化受损，这是TBK1激活所必需的。TBK1 Y179A突变体未能挽救TBK1缺陷的病毒感染RAW264.7巨噬细胞产生I型IFN。AZD0530对Src的药理学抑制和聚集规律间隔的短回语重复序列/ cas9介导的Src敲除表明，Src对于激活TBK1-IRF3通路和刺激I型IFN的产生至关重要。然而，Src在体外并没有直接与重组TBK1结合，而是与PRR关键衔接蛋白（如TRIF、MAVS和STING）中的脯氨酸- x - x -脯氨酸基基结合，这些蛋白在PRR结合后与TBK1形成复合物。总之，我们的数据表明，Src是启动TBK1自磷酸化和激活的主要酪氨酸激酶，从而为各种PRRs作为先天抗病毒反应的一部分调节TBK1活性提供了机制见解。
The tyrosine kinase Src couples activation of multiple pattern recognition receptors to the production of type I interferon. Src and interferon Cells are armed with multiple pattern recognition receptors (PRRs) that sense viral infection. Although PRRs mediate signaling through different adaptor proteins, they mostly converge on activation of the kinase TBK1, which phosphorylates and activates the transcription factor IRF3 to promote expression of genes encoding type I interferons (IFNs). Li et al. found that TBK1, which undergoes serine autophosphorylation to become activated, was also tyrosine-phosphorylated, which was dependent on the kinase Src. Although Src did not directly associate with and phosphorylate TBK1, it was recruited to multiple PRR-associated adaptor-containing complexes that contained TBK1. Furthermore, loss of Src or inhibition of its activity impaired the production of type I IFNs by virally infected macrophages, suggesting that Src acts as a central regulator of the innate immune response to viruses. Various pattern recognition receptors (PRRs) are activated in response to viral infection to stimulate the production of type I interferons (IFNs). However, central to the responses of all of these receptors is their activation of the kinase TBK1, which stimulates transcription by IFN regulatory factor 3 (IRF3). We investigated the mechanism by which the kinase activity of TBK1 is stimulated in response to viral infection. We found that the tyrosine kinase Src promoted the phosphorylation of TBK1 on Tyr179 upon viral infection of RAW264.7 macrophages. Mutation of Tyr179 to alanine resulted in impaired autophosphorylation of TBK1 at Ser172, which is required for TBK1 activation. The TBK1 Y179A mutant failed to rescue type I IFN production by virally infected RAW264.7 macrophages deficient in TBK1. Pharmacological inhibition of Src with AZD0530 and clustered regularly interspaced short palindromic repeats/Cas9–mediated knockout of Src demonstrated that Src was critical for activating the TBK1-IRF3 pathway and stimulating type I IFN production. However, Src did not directly bind to recombinant TBK1 in vitro but instead bound to the proline-X-X-proline motifs within key PRR adaptor proteins, such as TRIF, MAVS, and STING, which formed complexes with TBK1 after PRR engagement. Together, our data suggest that Src is the major tyrosine kinase that primes TBK1 for autophosphorylation and activation, thus providing mechanistic insights into the regulation of TBK1 activity by various PRRs as part of the innate antiviral response.