NINJ1 mediates plasma membrane rupture by cutting and releasing membrane disks

Cell. 2024 Apr 25;187(9):2224-2235.e16. doi: 10.1016/j.cell.2024.03.008. Epub 2024 Apr 12.


The membrane protein NINJ1 mediates plasma membrane rupture in pyroptosis and other lytic cell death pathways. Here, we report the cryo-EM structure of a NINJ1 oligomer segmented from NINJ1 rings. Each NINJ1 subunit comprises amphipathic (⍺1, ⍺2) and transmembrane (TM) helices (⍺3, ⍺4) and forms a chain of subunits, mainly by the TM helices and ⍺1. ⍺3 and ⍺4 are kinked, and the Gly residues are important for function. The NINJ1 oligomer possesses a concave hydrophobic side that should face the membrane and a convex hydrophilic side formed by ⍺1 and ⍺2, presumably upon activation. This structural observation suggests that NINJ1 can form membrane disks, consistent with membrane fragmentation by recombinant NINJ1. Live-cell and super-resolution imaging uncover ring-like structures on the plasma membrane that are released into the culture supernatant. Released NINJ1 encircles a membrane inside, as shown by lipid staining. Therefore, NINJ1-mediated membrane disk formation is different from gasdermin-mediated pore formation, resulting in membrane loss and plasma membrane rupture.

Keywords: NINJ1; NINJ2; Ninjurin1; Ninjurin2; cryo-EM; inflammasome; inflammation; lytic cell death; plasma membrane rupture; pyroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Adhesion Molecules, Neuronal* / chemistry
  • Cell Adhesion Molecules, Neuronal* / metabolism
  • Cell Membrane* / metabolism
  • Cryoelectron Microscopy*
  • HEK293 Cells
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism
  • Mice
  • Models, Molecular
  • Phosphate-Binding Proteins / metabolism
  • Pyroptosis


  • Cell Adhesion Molecules, Neuronal
  • Membrane Proteins
  • Phosphate-Binding Proteins