Cell Reports (Sep 2024)

Starvation-induced phosphorylation activates gasdermin A to initiate pyroptosis

  • Xinran Li,
  • Xiao Li,
  • Cong Xiang,
  • Jin Cao,
  • Jiansheng Guo,
  • Shilei Zhu,
  • Jingyi Tan,
  • Lijing Wang,
  • Chun Gao,
  • Shengduo Liu,
  • Lifeng Zhao,
  • Bo Yuan,
  • Pinglong Xu,
  • Bing Yang,
  • Dali Li,
  • Bin Zhao,
  • Xin-Hua Feng

Journal volume & issue
Vol. 43, no. 9
p. 114728

Abstract

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Summary: Pyroptosis, a pro-inflammatory form of programmed cell death, is crucial for host defense against pathogens and danger signals. Proteolytic cleavage of gasdermin proteins B–E (GSDMB–GSDME) is well established as a trigger for pyroptosis, but the intracellular activation mechanism of GSDMA remains elusive. Here, we demonstrate that severe starvation induces pyroptosis through phosphorylation-induced activation of GSDMA. Nutrient stresses stimulate GSDMA activation via phosphorylation mediated by Unc-51-like autophagy-activating kinase 1 (ULK1). Phosphorylation of Ser353 on human GSDMA by ULK1 or the phospho-mimetic Ser353Asp mutant of GSDMA liberates GSDMA from auto-inhibition, facilitating its membrane targeting and initiation of pyroptosis. To further validate the significance of GSDMA phosphorylation, we generated a constitutively active mutant Ser354Asp of mouse Gsdma, which induced skin inflammation and hyperplasia in mice, reminiscent of phenotypes with activated Gsdma. This study uncovers phosphorylation of GSDMA as a mechanism underlying pyroptosis initiation and cellular response to nutrient stress.

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