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CRP-Mediated Carbon Catabolite Regulation of Yersinia pestis Biofilm Formation Is Enhanced by the Carbon Storage Regulator Protein, CsrA.

Willias SP, Chauhan S, Lo CC, Chain PS, Motin VL - PLoS ONE (2015)

Bottom Line: Media supplementation with cAMP, a small-molecule activator of CRP, did not significantly alter Y. pestis biofilm production.Therefore, our findings indicate CRP does not confer a direct stimulatory effect, but may indirectly promote Y. pestis biofilm production by facilitating the alternate carbon source expression profile.Loss of csrA did not significantly alter relative hmsH, hmsP, or hmsT mRNA abundance.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America.

ABSTRACT
The natural transmission of Yersinia pestis is reliant upon biofilm blockage of the flea vector. However, the environmentally-responsive adaptive regulators which facilitate Y. pestis biofilm production in accordance with the flea midgut milieu are not well understood. We seek to establish the impact of available carbon source metabolism and storage upon Y. pestis biofilm production. Our findings demonstrate that Y. pestis biofilm production is subject to carbon catabolite regulation in which the presence of glucose impairs biofilm production; whereas, the sole metabolism of alternate carbon sources promotes robust biofilm formation. This observation is facilitated by the cAMP receptor protein, CRP. In accordance with a stark growth defect, deletion of crp in both CO92 and KIM6+ Y. pestis strains significantly impaired biofilm production when solely utilizing alternate carbon sources. Media supplementation with cAMP, a small-molecule activator of CRP, did not significantly alter Y. pestis biofilm production. Furthermore, CRP did not alter mRNA abundance of previously-characterized hms biofilm synthesis and regulation factors. Therefore, our findings indicate CRP does not confer a direct stimulatory effect, but may indirectly promote Y. pestis biofilm production by facilitating the alternate carbon source expression profile. Additionally, we assessed the impact of the carbon storage regulator protein, CsrA, upon Y. pestis biofilm production. Contrary to what has been described for E. coli, Y. pestis biofilm formation was found to be enhanced by CsrA. Regardless of media composition and available carbon source, deletion of csrA significantly impaired Y. pestis biofilm production. CsrA was found to promote Y. pestis biofilm production independent of glycogen regulation. Loss of csrA did not significantly alter relative hmsH, hmsP, or hmsT mRNA abundance. However, deletion of hmsP in the csrA-deficient mutant enabled excessive biofilm production, suggesting CsrA enables potent Y. pestis biofilm production through cyclic diguanylate regulation.

No MeSH data available.


Related in: MedlinePlus

CRP Enables Robust Y. pestis Biofilm Production.Relative biofilm production of CO92, CO92Δcrp, and plasmid complemented CO92Δcrp: pBluescript/crp when cultured in HIB medium or BCS medium supplemented with either 0.2% K-gluconate or 0.2% glucose. (A) Following 24 hours post-inoculation. (B) After 72 hours post-inoculation. Error bars reflect standard deviation from the mean derived from two independent experiments, each consisting of 6 technical replicates. * P-value <0.005 determined by Tukey’s HSD post-hoc analysis.
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pone.0135481.g004: CRP Enables Robust Y. pestis Biofilm Production.Relative biofilm production of CO92, CO92Δcrp, and plasmid complemented CO92Δcrp: pBluescript/crp when cultured in HIB medium or BCS medium supplemented with either 0.2% K-gluconate or 0.2% glucose. (A) Following 24 hours post-inoculation. (B) After 72 hours post-inoculation. Error bars reflect standard deviation from the mean derived from two independent experiments, each consisting of 6 technical replicates. * P-value <0.005 determined by Tukey’s HSD post-hoc analysis.

Mentions: The metabolism of alternate carbon sources is facilitated by CRP. Thus, the biofilm production of scarless crp deletion mutants constructed in both CO92 and KIM6+ backgrounds was characterized (Fig 4 and S2 Fig). When grown in the presence of glucose, deletion of crp had no impact upon Y. pestis biofilm production. However, biofilm formation of the crp-deficient mutant was significantly reduced after 24 hours post-inoculation in BCS medium solely supplemented with alternate carbon sources (Fig 4A). In order to account for the aforementioned growth defect of the crp-deficient mutants, biofilm production was determined at 72 hours post-inoculation biofilm production (Fig 4B). The biofilm formation of the crp deletion mutant was significantly impaired after 72 hours of growth in BCS medium solely supplemented with alternate carbon sources.


CRP-Mediated Carbon Catabolite Regulation of Yersinia pestis Biofilm Formation Is Enhanced by the Carbon Storage Regulator Protein, CsrA.

Willias SP, Chauhan S, Lo CC, Chain PS, Motin VL - PLoS ONE (2015)

CRP Enables Robust Y. pestis Biofilm Production.Relative biofilm production of CO92, CO92Δcrp, and plasmid complemented CO92Δcrp: pBluescript/crp when cultured in HIB medium or BCS medium supplemented with either 0.2% K-gluconate or 0.2% glucose. (A) Following 24 hours post-inoculation. (B) After 72 hours post-inoculation. Error bars reflect standard deviation from the mean derived from two independent experiments, each consisting of 6 technical replicates. * P-value <0.005 determined by Tukey’s HSD post-hoc analysis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549057&req=5

pone.0135481.g004: CRP Enables Robust Y. pestis Biofilm Production.Relative biofilm production of CO92, CO92Δcrp, and plasmid complemented CO92Δcrp: pBluescript/crp when cultured in HIB medium or BCS medium supplemented with either 0.2% K-gluconate or 0.2% glucose. (A) Following 24 hours post-inoculation. (B) After 72 hours post-inoculation. Error bars reflect standard deviation from the mean derived from two independent experiments, each consisting of 6 technical replicates. * P-value <0.005 determined by Tukey’s HSD post-hoc analysis.
Mentions: The metabolism of alternate carbon sources is facilitated by CRP. Thus, the biofilm production of scarless crp deletion mutants constructed in both CO92 and KIM6+ backgrounds was characterized (Fig 4 and S2 Fig). When grown in the presence of glucose, deletion of crp had no impact upon Y. pestis biofilm production. However, biofilm formation of the crp-deficient mutant was significantly reduced after 24 hours post-inoculation in BCS medium solely supplemented with alternate carbon sources (Fig 4A). In order to account for the aforementioned growth defect of the crp-deficient mutants, biofilm production was determined at 72 hours post-inoculation biofilm production (Fig 4B). The biofilm formation of the crp deletion mutant was significantly impaired after 72 hours of growth in BCS medium solely supplemented with alternate carbon sources.

Bottom Line: Media supplementation with cAMP, a small-molecule activator of CRP, did not significantly alter Y. pestis biofilm production.Therefore, our findings indicate CRP does not confer a direct stimulatory effect, but may indirectly promote Y. pestis biofilm production by facilitating the alternate carbon source expression profile.Loss of csrA did not significantly alter relative hmsH, hmsP, or hmsT mRNA abundance.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America.

ABSTRACT
The natural transmission of Yersinia pestis is reliant upon biofilm blockage of the flea vector. However, the environmentally-responsive adaptive regulators which facilitate Y. pestis biofilm production in accordance with the flea midgut milieu are not well understood. We seek to establish the impact of available carbon source metabolism and storage upon Y. pestis biofilm production. Our findings demonstrate that Y. pestis biofilm production is subject to carbon catabolite regulation in which the presence of glucose impairs biofilm production; whereas, the sole metabolism of alternate carbon sources promotes robust biofilm formation. This observation is facilitated by the cAMP receptor protein, CRP. In accordance with a stark growth defect, deletion of crp in both CO92 and KIM6+ Y. pestis strains significantly impaired biofilm production when solely utilizing alternate carbon sources. Media supplementation with cAMP, a small-molecule activator of CRP, did not significantly alter Y. pestis biofilm production. Furthermore, CRP did not alter mRNA abundance of previously-characterized hms biofilm synthesis and regulation factors. Therefore, our findings indicate CRP does not confer a direct stimulatory effect, but may indirectly promote Y. pestis biofilm production by facilitating the alternate carbon source expression profile. Additionally, we assessed the impact of the carbon storage regulator protein, CsrA, upon Y. pestis biofilm production. Contrary to what has been described for E. coli, Y. pestis biofilm formation was found to be enhanced by CsrA. Regardless of media composition and available carbon source, deletion of csrA significantly impaired Y. pestis biofilm production. CsrA was found to promote Y. pestis biofilm production independent of glycogen regulation. Loss of csrA did not significantly alter relative hmsH, hmsP, or hmsT mRNA abundance. However, deletion of hmsP in the csrA-deficient mutant enabled excessive biofilm production, suggesting CsrA enables potent Y. pestis biofilm production through cyclic diguanylate regulation.

No MeSH data available.


Related in: MedlinePlus