Group A Streptococcus modulates RAB1- and PIK3C3 complex-dependent autophagy

Autophagy. 2020 Feb;16(2):334-346. doi: 10.1080/15548627.2019.1628539. Epub 2019 Jun 14.

Abstract

Autophagy selectively targets invading bacteria to defend cells, whereas bacterial pathogens counteract autophagy to survive in cells. The initiation of canonical autophagy involves the PIK3C3 complex, but autophagy targeting Group A Streptococcus (GAS) is PIK3C3-independent. We report that GAS infection elicits both PIK3C3-dependent and -independent autophagy, and that the GAS effector NAD-glycohydrolase (Nga) selectively modulates PIK3C3-dependent autophagy. GAS regulates starvation-induced (canonical) PIK3C3-dependent autophagy by secreting streptolysin O and Nga, and Nga also suppresses PIK3C3-dependent GAS-targeting-autophagosome formation during early infection and facilitates intracellular proliferation. This Nga-sensitive autophagosome formation involves the ATG14-containing PIK3C3 complex and RAB1 GTPase, which are both dispensable for Nga-insensitive RAB9A/RAB17-positive autophagosome formation. Furthermore, although MTOR inhibition and subsequent activation of ULK1, BECN1, and ATG14 occur during GAS infection, ATG14 recruitment to GAS is impaired, suggesting that Nga inhibits the recruitment of ATG14-containing PIK3C3 complexes to autophagosome-formation sites. Our findings reveal not only a previously unrecognized GAS-host interaction that modulates canonical autophagy, but also the existence of multiple autophagy pathways, using distinct regulators, targeting bacterial infection.Abbreviations: ATG5: autophagy related 5; ATG14: autophagy related 14; ATG16L1: autophagy related 16 like 1; BECN1: beclin 1; CALCOCO2: calcium binding and coiled-coil domain 2; GAS: group A streptococcus; GcAV: GAS-containing autophagosome-like vacuole; LAMP1: lysosomal associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; Nga: NAD-glycohydrolase; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns4P: phosphatidylinositol-4-phosphate; RAB: RAB, member RAS oncogene GTPases; RAB1A: RAB1A, member RAS oncogene family; RAB11A: RAB11A, member RAS oncogene family; RAB17: RAB17, member RAS oncogene family; RAB24: RAB24, member RAS oncogene family; RPS6KB1: ribosomal protein S6 kinase B1; SLO: streptolysin O; SQSTM1: sequestosome 1; ULK1: unc-51 like autophagy activating kinase 1; WIPI2: WD repeat domain, phosphoinositide interacting 2.

Keywords: Autophagy; NAD-glycohydrolase; PIK3C3; RAB GTPase; group A Streptococcus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autophagosomes / drug effects
  • Autophagosomes / metabolism
  • Autophagy* / drug effects
  • Bacterial Proteins / metabolism
  • Class III Phosphatidylinositol 3-Kinases / metabolism*
  • HeLa Cells
  • Humans
  • Microbial Viability / drug effects
  • Microtubule-Associated Proteins / metabolism
  • NAD+ Nucleosidase / metabolism
  • Protein Aggregates / drug effects
  • Protein Folding / drug effects
  • Puromycin / pharmacology
  • Streptococcus pyogenes / metabolism*
  • Streptolysins / metabolism
  • rab GTP-Binding Proteins / metabolism
  • rab1 GTP-Binding Proteins / metabolism*

Substances

  • Bacterial Proteins
  • MAP1LC3A protein, human
  • Microtubule-Associated Proteins
  • Protein Aggregates
  • Streptolysins
  • streptolysin O
  • Puromycin
  • Class III Phosphatidylinositol 3-Kinases
  • NAD+ Nucleosidase
  • RAB24 protein, human
  • rab GTP-Binding Proteins
  • rab1 GTP-Binding Proteins

Grants and funding

This work was supported by the Japan Agency for Medical Research and Development [18fk0108073h0001]; Japan Agency for Medical Research and Development [18fm0208030h0002]; Japan Society for the Promotion of Science [16K08775]; Japan Society for the Promotion of Science [26462776]; Japan Society for the Promotion of Science [17K19552]; Japan Society for the Promotion of Science [16H05188]; Japan Society for the Promotion of Science [15K15130]; Japan Society for the Promotion of Science [18K07109]; Yakult Bio-Science Foundation [N/A]; Japan Agency for Medical Research and Development [19fk0108073h0002]; Japan Agency for Medical Research and Development [19fm0208030h0003]; Japan Society for the Promotion of Science [19H03471]; Joint Research Project of the Institute of Medical Science, the University of Tokyo [N/A]; Japan Agency for Medical Research and Development [19fk0108044h0203]; Takeda Science Foundation [N/A].