Structural Mechanism for GSDMD Targeting by Autoprocessed Caspases in Pyroptosis

Cell. 2020 Mar 5;180(5):941-955.e20. doi: 10.1016/j.cell.2020.02.002. Epub 2020 Feb 27.


The pyroptosis execution protein GSDMD is cleaved by inflammasome-activated caspase-1 and LPS-activated caspase-11/4/5. The cleavage unmasks the pore-forming domain from GSDMD-C-terminal domain. How the caspases recognize GSDMD and its connection with caspase activation are unknown. Here, we show site-specific caspase-4/11 autoprocessing, generating a p10 product, is required and sufficient for cleaving GSDMD and inducing pyroptosis. The p10-form autoprocessed caspase-4/11 binds the GSDMD-C domain with a high affinity. Structural comparison of autoprocessed and unprocessed capase-11 identifies a β sheet induced by the autoprocessing. In caspase-4/11-GSDMD-C complex crystal structures, the β sheet organizes a hydrophobic GSDMD-binding interface that is only possible for p10-form caspase-4/11. The binding promotes dimerization-mediated caspase activation, rendering a cleavage independently of the cleavage-site tetrapeptide sequence. Crystal structure of caspase-1-GSDMD-C complex shows a similar GSDMD-recognition mode. Our study reveals an unprecedented substrate-targeting mechanism for caspases. The hydrophobic interface suggests an additional space for developing inhibitors specific for pyroptotic caspases.

Keywords: caspase; caspase-1; caspase-11; cell death; gasdermin; inflammasome; innate immunity; lipopolysaccharide; pore-forming protein; pyroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caspase 1 / chemistry
  • Caspase 1 / genetics
  • Caspase 1 / ultrastructure
  • Caspases, Initiator / chemistry
  • Caspases, Initiator / genetics
  • Crystallography, X-Ray
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Inflammasomes / genetics
  • Inflammasomes / ultrastructure*
  • Intracellular Signaling Peptides and Proteins / chemistry
  • Intracellular Signaling Peptides and Proteins / genetics
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / ultrastructure*
  • Phosphate-Binding Proteins / chemistry
  • Phosphate-Binding Proteins / genetics
  • Phosphate-Binding Proteins / ultrastructure*
  • Protein Conformation, beta-Strand / genetics
  • Protein Domains / genetics
  • Protein Processing, Post-Translational / genetics
  • Proteolysis
  • Pyroptosis / genetics*


  • GSDMD protein, human
  • Inflammasomes
  • Intracellular Signaling Peptides and Proteins
  • Multiprotein Complexes
  • Phosphate-Binding Proteins
  • CASP4 protein, human
  • Caspases, Initiator
  • Caspase 1