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Mechanism of membrane pore formation by human gasdermin‐D
Author(s) -
Mulvihill Estefania,
Sborgi Lorenzo,
Mari Stefania A,
Pfreundschuh Moritz,
Hiller Sebastian,
Müller Daniel J
Publication year - 2018
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201798321
Subject(s) - biology , mechanism (biology) , biophysics , microbiology and biotechnology , epistemology , philosophy
Gasdermin‐D ( GSDMD ), a member of the gasdermin protein family, mediates pyroptosis in human and murine cells. Cleaved by inflammatory caspases, GSDMD inserts its N‐terminal domain (GSDMD Nterm ) into cellular membranes and assembles large oligomeric complexes permeabilizing the membrane. So far, the mechanisms of GSDMD Nterm insertion, oligomerization, and pore formation are poorly understood. Here, we apply high‐resolution (≤ 2 nm) atomic force microscopy ( AFM ) to describe how GSDMD Nterm inserts and assembles in membranes. We observe GSDMD Nterm inserting into a variety of lipid compositions, among which phosphatidylinositide ( PI (4,5)P2) increases and cholesterol reduces insertion. Once inserted, GSDMD Nterm assembles arc‐, slit‐, and ring‐shaped oligomers, each of which being able to form transmembrane pores. This assembly and pore formation process is independent on whether GSDMD has been cleaved by caspase‐1, caspase‐4, or caspase‐5. Using time‐lapse AFM , we monitor how GSDMD Nterm assembles into arc‐shaped oligomers that can transform into larger slit‐shaped and finally into stable ring‐shaped oligomers. Our observations translate into a mechanistic model of GSDMD Nterm transmembrane pore assembly, which is likely shared within the gasdermin protein family.