細菌效應蛋白揭示異源自噬原理
作者:
小柯機器人發布時間:2019/7/30 13:53:38
細菌效應體揭示了V-ATPase-ATG16L1系統,該系統啟動了異源吞噬,這一成果由清華大學邵峰研究組取得。這一研究成果於2019年7月25日發表在國際學術期刊《細胞》上。
該團隊進行了細菌轉座子篩選,並確定了一個沙門氏菌III型分泌系統(T3SS)效應蛋白SopF,能夠有效阻止沙門氏菌的自噬。SopF是一種不影響經典自噬途徑的常用異源自噬抑制劑。鼠傷寒沙門氏菌ΔSopF與撓曲沙門氏菌ΔvirAΔicsB相似,是大多數細胞內細菌自噬目標,研究者通過CRISPR篩選,發現宿主V-ATPase是自噬的必要因素。當細菌引起液泡損傷時,V-ATPase將ATG16L1引入含有細菌的液泡中,該過程能夠被SopF阻斷。哺乳動物ATG16L1具有與V-ATPase相互作用所需的WD40結構域。通過SopF抑制自噬,可促進鼠傷寒桿菌的體內增殖。SopF以V-ATPase中的ATP6V0C的124位穀氨醯胺為靶點,促使其進行ADP核糖基化。124位穀氨醯胺的突變也能夠阻止異源自噬,但不能阻止經典自噬。因此,SopF的發現揭示了ATPase-ATG16L1這一對細胞內病原體的自噬識別起關鍵性作用的系統。
據悉,異源自噬(xenophagy)是一種重要的宿主防禦手段,但是尚不清楚該過程是如何開始的。
附:英文原文
Title: A Bacterial Effector Reveals the V-ATPase-ATG16L1 Axis that Initiates Xenophagy
Author: Yue Xu, Ping Zhou, Sen Cheng, Jingjin Ding, Michael O.Hottiger, Feng Shao
Issue&Volume: 25 JULY 2019
Abstract: Antibacterial autophagy (xenophagy) is an important host defense, but how it is initiated is unclear. Here, we performed a bacterial transposon screen and identified a T3SS effector SopF that potently blocked Salmonella autophagy. SopF was a general xenophagy inhibitor without affecting canonical autophagy. S. Typhimurium Δ sopF resembled S. flexneri Δ virAΔ icsB with the majority of intracellular bacteria targeted by autophagy, permitting a CRISPR screen that identified host V-ATPase as an essential factor. Upon bacteria-caused vacuolar damage, the V-ATPase recruited ATG16L1 onto bacteria-containing vacuole, which was blocked by SopF. Mammalian ATG16L1 bears a WD40 domain required for interacting with the V-ATPase. Inhibiting autophagy by SopF promoted S. Typhimurium proliferation in vivo. SopF targeted Gln124 of ATP6V0C in the V-ATPase for ADP-ribosylation. Mutation of Gln124 also blocked xenophagy, but not canonical autophagy. Thus, the discovery of SopF reveals the V-ATPase-ATG16L1 axis that critically mediates autophagic recognition of intracellular pathogen.
DOI: https://doi.org/10.1016/j.cell.2019.06.007
Source: https://www.cell.com/cell/fulltext/S0092-8674(19)30635-X
Cell:《細胞》,創刊於1974年。隸屬於細胞出版社,最新IF:36.216