TY - JOUR
T1 - A nutrient-regulated cyclic diguanylate phosphodiesterase controls Clostridium difficile biofilm and toxin production during stationary phase
AU - Purcell, Erin B.
AU - McKee, Robert W.
AU - Courson, David S.
AU - Garrett, Elizabeth M.
AU - McBride, Shonna M.
AU - Cheney, Richard E.
AU - Tamayo, Rita
N1 - Funding Information:
We thank Abraham Sonenshein for the JIR8094/pSD21 strain and for pEAV1. This research was supported by NIH grants U54-AI057157 and R01-AI107029 to R.T., R01-DC003299 to R.E.C., and K01-DK087763 to S.M.M. E.B.P. was supported by T32-DK007737 to the Center for Gastrointestinal Biology and Disease, and D.S.C. was supported by T32-CA009156 to the Lineberger Comprehensive Cancer Center. UPLC-MS was performed at the University of North Carolina Environmental Sciences and Engineering Biomarker Mass Spectrometry Core Facility, which is supported in part by a grant from the National Institute of Environmental Health Sciences (P30ES010126). The contents of this report are solely the responsibility of the authors and do not necessarily represent the official views of the funding bodies.
Publisher Copyright:
© 2017 American Society for Microbiology.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - The signaling molecule cyclic diguanylate (c-di-GMP) mediates physiological adaptation to extracellular stimuli in a wide range of bacteria. The complex metabolic pathways governing c-di-GMP synthesis and degradation are highly regulated, but the specific cues that impact c-di-GMP signaling are largely unknown. In the intestinal pathogen Clostridium difficile, c-di-GMP inhibits flagellar motility and toxin production and promotes pilus-dependent biofilm formation, but no specific biological functions have been ascribed to any of the individual c-di-GMP synthases or phosphodiesterases (PDEs). Here, we report the functional and biochemical characterization of a c-di-GMP PDE, PdcA, 1 of 37 confirmed or putative c-di-GMP metabolism proteins in C. difficile 630. Our studies reveal that pdcA transcription is controlled by the nutrient-regulated transcriptional regulator CodY and accordingly increases during stationary phase. In addition, PdcA PDE activity is allosterically regulated by GTP, further linking c-di-GMP levels to nutrient availability. Mutation of pdcA increased biofilm formation and reduced toxin biosynthesis without affecting swimming motility or global intracellular c-di-GMP. Analysis of the transcriptional response to pdcA mutation indicates that PdcA-dependent phenotypes manifest during stationary phase, consistent with regulation by CodY. These results demonstrate that inactivation of this single PDE gene is sufficient to impact multiple c-di-GMPdependent phenotypes, including the production of major virulence factors, and suggest a link between c-di-GMP signaling and nutrient availability.
AB - The signaling molecule cyclic diguanylate (c-di-GMP) mediates physiological adaptation to extracellular stimuli in a wide range of bacteria. The complex metabolic pathways governing c-di-GMP synthesis and degradation are highly regulated, but the specific cues that impact c-di-GMP signaling are largely unknown. In the intestinal pathogen Clostridium difficile, c-di-GMP inhibits flagellar motility and toxin production and promotes pilus-dependent biofilm formation, but no specific biological functions have been ascribed to any of the individual c-di-GMP synthases or phosphodiesterases (PDEs). Here, we report the functional and biochemical characterization of a c-di-GMP PDE, PdcA, 1 of 37 confirmed or putative c-di-GMP metabolism proteins in C. difficile 630. Our studies reveal that pdcA transcription is controlled by the nutrient-regulated transcriptional regulator CodY and accordingly increases during stationary phase. In addition, PdcA PDE activity is allosterically regulated by GTP, further linking c-di-GMP levels to nutrient availability. Mutation of pdcA increased biofilm formation and reduced toxin biosynthesis without affecting swimming motility or global intracellular c-di-GMP. Analysis of the transcriptional response to pdcA mutation indicates that PdcA-dependent phenotypes manifest during stationary phase, consistent with regulation by CodY. These results demonstrate that inactivation of this single PDE gene is sufficient to impact multiple c-di-GMPdependent phenotypes, including the production of major virulence factors, and suggest a link between c-di-GMP signaling and nutrient availability.
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U2 - 10.1128/IAI.00347-17
DO - 10.1128/IAI.00347-17
M3 - Article
C2 - 28652311
AN - SCOPUS:85027517518
SN - 0019-9567
VL - 85
JO - Infection and Immunity
JF - Infection and Immunity
IS - 9
M1 - e00347-17
ER -