研究揭示caspases靶向GSDMD的結構機制
作者:
小柯機器人發布時間:2020/3/2 13:19:19
中科院生物物理所丁璟珒和清華大學邵峰研究組揭示了細胞焦亡過程中自加工半胱天冬酶(caspases)靶向GSDMD的結構機制。2020年2月27日,《細胞》雜誌發表了這一成果。
他們發現,產生p10產物的位點特異性caspase-4 / 11自動加工,對於裂解GSDMD和誘導細胞焦亡是必要且充分的。p10形式的自動加工caspase-4 / 11以高親和力結合GSDMD-C結構域。自動加工和未加工的capase-11的結構比較可確定自動加工誘導的β摺疊。在caspase-4 / 11-GSDMD-C複合物晶體結構中,β片組織了疏水性GSDMD結合界面,只有p10形式的caspase-4 / 11才可能結合。
結合促進二聚化介導的caspases激活,使得切割不依賴於切割位點四肽序列。Caspase-1-GSDMD-C複合物的晶體結構顯示出相似的GSDMD識別模式。他們的研究揭示了caspases的前所未有的底物靶向機制。疏水界面為開發對細胞焦亡caspases特異性的抑制劑提供了更多的可能性。
研究人員介紹,炎症小體激活的caspase-1和LPS激活的caspase-11 /4/5裂解細胞焦亡執行蛋白GSDMD。從GSMDD-C-末端結構域切割並暴露孔形成結構域。Caspase如何識別GSDMD及其與caspase激活的聯繫尚不清楚。
附:英文原文
Title: Structural Mechanism for GSDMD Targeting by Autoprocessed Caspases in Pyroptosis
Author: Kun Wang, Qi Sun, Xiu Zhong, Mengxue Zeng, Huan Zeng, Xuyan Shi, Zilin Li, Yupeng Wang, Qiang Zhao, Feng Shao, Jingjin Ding
Issue&Volume: 2020-02-27
Abstract: The pyroptosis execution protein GSDMD is cleaved by inflammasome-activated caspase-1and LPS-activated caspase-11/4/5. The cleavage unmasks the pore-forming domain fromGSDMD-C-terminal domain. How the caspases recognize GSDMD and its connection withcaspase activation are unknown. Here, we show site-specific caspase-4/11 autoprocessing,generating a p10 product, is required and sufficient for cleaving GSDMD and inducingpyroptosis. The p10-form autoprocessed caspase-4/11 binds the GSDMD-C domain witha high affinity. Structural comparison of autoprocessed and unprocessed capase-11identifies a β sheet induced by the autoprocessing. In caspase-4/11-GSDMD-C complexcrystal structures, the β sheet organizes a hydrophobic GSDMD-binding interface thatis only possible for p10-form caspase-4/11. The binding promotes dimerization-mediatedcaspase activation, rendering a cleavage independently of the cleavage-site tetrapeptidesequence. Crystal structure of caspase-1-GSDMD-C complex shows a similar GSDMD-recognitionmode. Our study reveals an unprecedented substrate-targeting mechanism for caspases.The hydrophobic interface suggests an additional space for developing inhibitors specificfor pyroptotic caspases.
DOI: 10.1016/j.cell.2020.02.002
Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30146-X
Cell:《細胞》,創刊於1974年。隸屬於細胞出版社,最新IF:36.216