The Salmonella Secreted Effector SarA/SteE Mimics Cytokine Receptor Signaling to Activate STAT3.

Journal Article (Journal Article)

Bacteria masterfully co-opt and subvert host signal transduction. As a paradigmatic example, Salmonella uses two type-3 secretion systems to inject effector proteins that facilitate Salmonella entry, establishment of an intracellular niche, and modulation of immune responses. We previously demonstrated that the Salmonella anti-inflammatory response activator SarA (Stm2585, GogC, PagJ, SteE) activates the host transcription factor STAT3 to drive expression of immunomodulatory STAT3-targets. Here, we demonstrate-by sequence, function, and biochemical measurement-that SarA mimics the cytoplasmic domain of glycoprotein 130 (gp130, IL6ST). SarA is phosphorylated at a YxxQ motif, facilitating binding to STAT3 with greater affinity than gp130. Departing from canonical gp130 signaling, SarA function is JAK-independent but requires GSK-3, a key regulator of metabolism and development. Our results reveal that SarA undergoes host phosphorylation to recruit a STAT3-activating complex, circumventing cytokine receptor activation. Effector mimicry of gp130 suggests GSK-3 can regulate normal cytokine signaling, potentially enabling metabolic and immune crosstalk.

Full Text

Duke Authors

Cited Authors

  • Gibbs, KD; Washington, EJ; Jaslow, SL; Bourgeois, JS; Foster, MW; Guo, R; Brennan, RG; Ko, DC

Published Date

  • January 8, 2020

Published In

Volume / Issue

  • 27 / 1

Start / End Page

  • 129 - 139.e4

PubMed ID

  • 31901521

Pubmed Central ID

  • PMC6952535

Electronic International Standard Serial Number (EISSN)

  • 1934-6069

Digital Object Identifier (DOI)

  • 10.1016/j.chom.2019.11.012


  • eng

Conference Location

  • United States