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
Language
- eng
Conference Location
- United States