Cleavage-independent activation of ancient eukaryotic gasdermins and structural mechanisms.
Li, Y., Hou, Y., Sun, Q., Zeng, H., Meng, F., Tian, X., He, Q., Shao, F., Ding, J.(2024) Science 384: adm9190-adm9190
- PubMed: 38662913 
- DOI: https://doi.org/10.1126/science.adm9190
- Primary Citation of Related Structures:  
8JYV, 8JYW, 8JYX, 8JYY, 8JYZ - PubMed Abstract: 
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. Here 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. Cryo-electron microscopy (cryo-EM) structure illustrates assembly mechanism for the 44-mer Tricho GSDM pore. Second, RCD-1-1/RCD-1-2, encoded by polymorphic rcd-1 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 . Cryo-EM structure reveals a pore of 11 RCD-1-1/RCD-1-2 heterodimers and heterodimerization-triggered pore assembly mechanism. This study shows mechanistic diversities in GSDM activation and indicates versatile functions of GSDMs.
Organizational Affiliation: 
Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.