Non-canonical autophosphorylation of RIPK1 drives timely pyroptosis to control Yersinia infection
David Jetton,
Hayley I. Muendlein,
Wilson M. Connolly,
Zoie Magri,
Irina Smirnova,
Rebecca Batorsky,
Joan Mecsas,
Alexei Degterev,
Alexander Poltorak
Affiliations
David Jetton
Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, MA 02111, USA
Hayley I. Muendlein
Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
Wilson M. Connolly
Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
Zoie Magri
Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, MA 02111, USA
Irina Smirnova
Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
Rebecca Batorsky
Data Intensive Studies Center, Tufts University, Medford, MA 02155, USA
Joan Mecsas
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
Alexei Degterev
Department of Cell, Molecular & Developmental Biology, Tufts University School of Medicine, Boston, MA 02111, USA
Alexander Poltorak
Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, MA 02111, USA; Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA; Corresponding author
Summary: Caspase-8-dependent pyroptosis has been shown to mediate host protection from Yersinia infection. For this mode of cell death, the kinase activity of receptor-interacting protein kinase 1 (RIPK1) is required, but the autophosphorylation sites required to drive caspase-8 activation have not been determined. Here, we show that non-canonical autophosphorylation of RIPK1 at threonine 169 (T169) is necessary for caspase-8-mediated pyroptosis. Mice with alanine in the T169 position are highly susceptible to Yersinia dissemination. Mechanistically, the delayed formation of a complex containing RIPK1, ZBP1, Fas-associated protein with death domain (FADD), and caspase-8 abrogates caspase-8 maturation in T169A mice and leads to the eventual activation of RIPK3-dependent necroptosis in vivo; however, this is insufficient to protect the host, suggesting that timely pyroptosis during early response is specifically required to control infection. These results position RIPK1 T169 phosphorylation as a driver of pyroptotic cell death critical for host defense.
