Qu Zilu, Zhou Jin, Zhou Yidan, Xie Yan, Jiang Yanjing, Wu Jian, Luo Zuoqin, Liu Guanghui, Yin Lei, Zhang Xiao-Lian
Hubei Province Key Laboratory of Allergy and Immunology, Department of Immunology of School of Basic Medical Sciences and Department of Allergy of Zhongnan Hospital, Wuhan University, Wuhan 430071, China.
State Key Laboratory of Virology, Department of Biochemistry and Molecular Biology, College of Life Sciences, Wuhan University, Wuhan 430077, China.
Sci Adv. 2020 Oct 23;6(43). doi: 10.1126/sciadv.aba4733. Print 2020 Oct.
Pyroptosis, an inflammatory form of programmed cell death, has been implicated in eliminating pathogenic infections. However, macrophage pyroptosis-related proteins from () have largely gone unexplored. Here, we identified a cell pyroptosis-inducing protein, Rv1579c, named EST12, secreted from the H37Rv region of difference 3. EST12 binds to the receptor for activated C kinase 1 (RACK1) in macrophages, and the EST12-RACK1 complex recruits the deubiquitinase UCHL5 to promote the K48-linked deubiquitination of NLRP3, subsequently leading to an NLRP3 inflammasome caspase-1/11-pyroptosis gasdermin D-interleukin-1β immune process. Analysis of the crystal structure of EST12 reveals that the amino acid Y80 acts as a critical binding site for RACK1. An EST12-deficient strain (H37RvΔEST12) displayed higher susceptibility to infection in vitro and in vivo. These results provide the first proof that RACK1 acts as an endogenous host sensor for pathogens and that EST12-RACK1-induced pyroptosis plays a pivotal role in -induced immunity.
细胞焦亡是一种程序性细胞死亡的炎症形式，与消除病原体感染有关。然而，来自（）的巨噬细胞焦亡相关蛋白在很大程度上尚未得到探索。在这里，我们鉴定了一种细胞焦亡诱导蛋白Rv1579c，命名为EST12，它由差异3的H37Rv区域分泌。EST12与巨噬细胞中活化C激酶1（RACK1）的受体结合，并且EST12-RACK1复合物招募去泛素化酶UCHL5以促进NLRP3的K48连接去泛素化，随后导致NLRP3炎性小体半胱天冬酶-1/11-细胞焦亡gasdermin D-白细胞介素-1β免疫过程。EST12晶体结构分析表明，氨基酸Y80是RACK1的关键结合位点。EST12缺陷菌株（H37RvΔEST12）在体外和体内对（）感染表现出更高的易感性。这些结果首次证明RACK1作为病原体的内源性宿主传感器，并且EST12-RACK1诱导的细胞焦亡在（）诱导的免疫中起关键作用。
