Cleavage-independent activation of ancient eukaryotic gasdermins and structural mechanisms

作者：Yueyue Li, Yanjie Hou, Qi Sun, Huan Zeng, Fanyi Meng, Xiang Tian, Qun He, Feng Shao, Jingjin Ding · 发表于：Science · 年份：2024 · DOI：10.1126/science.adm9190 · 被引用次数：43 · 研究领域：Inflammasome and immune disorders、Toxin Mechanisms and Immunotoxins、Galectins and Cancer Biology

Gasdermins (GSDMs) are pore-forming proteins that execute pyroptosis for immune defense. GSDMs are two-domain proteins activated by proteolytic removal of the inhibitory domain. In this work, we report two types of cleavage-independent GSDM activation. First, Tricho GSDM, a pore-forming domain–only protein from the basal metazoan Trichoplax adhaerens , is a disulfides-linked autoinhibited dimer activated by reduction of the disulfides. The cryo–electron microscopy (cryo-EM) structure illustrates the assembly mechanism for the 44-mer Tricho GSDM pore. Second, RCD-1-1 and RCD-1-2, encoded by the polymorphic regulator of cell death–1 ( rcd-1 ) gene in filamentous fungus Neurospora crassa , are also pore-forming domain–only GSDMs. RCD-1-1 and RCD-1-2, when encountering each other, form pores and cause pyroptosis, underlying allorecognition in Neurospora . The cryo-EM structure reveals a pore of 11 RCD-1-1/RCD-1-2 heterodimers and a heterodimerization-triggered pore assembly mechanism. This study shows mechanistic diversities in GSDM activation and indicates versatile functions of GSDMs.