STING induces LC3B lipidation onto single-membrane vesicles via the V-ATPase and ATG16L1-WD40 domain

J Cell Biol. 2020 Dec 7;219(12):e202009128. doi: 10.1083/jcb.202009128.

Abstract

Following the detection of cytosolic double-stranded DNA from viral or bacterial infection in mammalian cells, cyclic dinucleotide activation of STING induces interferon β expression to initiate innate immune defenses. STING activation also induces LC3B lipidation, a classical but equivocal marker of autophagy, that promotes a cell-autonomous antiviral response that arose before evolution of the interferon pathway. We report that STING activation induces LC3B lipidation onto single-membrane perinuclear vesicles mediated by ATG16L1 via its WD40 domain, bypassing the requirement of canonical upstream autophagy machinery. This process is blocked by bafilomycin A1 that binds and inhibits the vacuolar ATPase (V-ATPase) and by SopF, a bacterial effector that catalytically modifies the V-ATPase to inhibit LC3B lipidation via ATG16L1. These results indicate that activation of the cGAS-STING pathway induces V-ATPase-dependent LC3B lipidation that may mediate cell-autonomous host defense, an unanticipated mechanism that is distinct from LC3B lipidation onto double-membrane autophagosomes.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy
  • Autophagy-Related Proteins / genetics
  • Autophagy-Related Proteins / metabolism*
  • Cell-Derived Microparticles / genetics
  • Cell-Derived Microparticles / metabolism*
  • HeLa Cells
  • Humans
  • Lipoylation*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Nucleotidyltransferases / genetics
  • Nucleotidyltransferases / metabolism
  • Protein Domains
  • Signal Transduction
  • Vacuolar Proton-Translocating ATPases / genetics
  • Vacuolar Proton-Translocating ATPases / metabolism*

Substances

  • ATG16L1 protein, human
  • Atg16l1 protein, mouse
  • Autophagy-Related Proteins
  • MAP1LC3B protein, human
  • Map1lc3b protein, mouse
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • STING1 protein, human
  • Sting1 protein, mouse
  • Nucleotidyltransferases
  • cGAS protein, human
  • cGAS protein, mouse
  • Vacuolar Proton-Translocating ATPases