Role of CcpA in regulation of the central pathways of carbon catabolism in Bacillus subtilis - PubMed (original) (raw)

Role of CcpA in regulation of the central pathways of carbon catabolism in Bacillus subtilis

S Tobisch et al. J Bacteriol. 1999 Nov.

Abstract

The Bacillus subtilis two-dimensional (2D) protein index contains almost all glycolytic and tricarboxylic acid (TCA) cycle enzymes, among them the most abundant housekeeping proteins of growing cells. Therefore, a comprehensive study on the regulation of glycolysis and the TCA cycle was initiated. Whereas expression of genes encoding the upper and lower parts of glycolysis (pgi, pfk, fbaA, and pykA) is not affected by the glucose supply, there is an activation of the glycolytic gap gene and the pgk operon by glucose. This activation seems to be dependent on the global regulator CcpA, as shown by 2D polyacrylamide gel electrophoresis analysis as well as by transcriptional analysis. Furthermore, a high glucose concentration stimulates production and excretion of organic acids (overflow metabolism) in the wild type but not in the ccpA mutant. Finally, CcpA is involved in strong glucose repression of almost all TCA cycle genes. In addition to TCA cycle and glycolytic enzymes, the levels of many other proteins are affected by the ccpA mutation. Our data suggest (i) that ccpA mutants are unable to activate glycolysis or carbon overflow metabolism and (ii) that CcpA might be a key regulator molecule, controlling a superregulon of glucose catabolism.

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Figures

FIG. 1

FIG. 1

Main pathways of carbohydrate metabolism. (A) Silver-stained 2D gel showing identified proteins which are involved in glycolysis (Pgi, Pfk, FbaA, Tpi, Gap, Pgk, Pgm, Eno), pyruvate dehydrogenesis (PdhA, PdhB, PdhC, PdhD), the TCA cycle (CitZ, CitB, CitC, OdhA, PdhD, SucC, SucD, SdhA, CitG, CitH), and overflow metabolism (Pta, AckA). (B) Schematic representation of glycolysis and the TCA cycle. Enzymes and metabolites are indicated. Note that not all the proteins of these pathways are identified on 2D gels.

FIG. 2

FIG. 2

Comparison of CcpA-dependent expression of proteins involved in glycolysis (□), the TCA cycle (○), and overflow metabolism (◊) in B. subtilis. The spots correspond to enzymes of central carbon metabolism. They are derived from silver-stained 2D electrophoretograms of B. subtilis IS58 and the ccpA mutant strain BGW2, which were grown in pure ASM without any additional carbon source or with 1% glucose.

FIG. 3

FIG. 3

Northern blot analysis of genes encoding glycolytic enzymes. RNA of exponentially growing B. subtilis cells was hybridized with probes specific for gap (A), pgk (B), and eno (C). Sizes of transcripts are indicated, and possible interpretations are illustrated (D); thicknesses of arrows correspond with the amount of transcript.

FIG. 4

FIG. 4

Quantitative analysis of mRNAs of glycolytic and TCA cycle enzymes. Different concentrations of RNA (1 and 0.5 μg) from B. subtilis IS58 and BGW2 were blotted onto nylon membranes and hybridized with probes specific for the genes indicated. The mRNA amount obtained for IS58 in the presence of 0.1% ribose was set at 1.

FIG. 5

FIG. 5

CcpA- and carbon source-dependent acidification of growth medium. Measurement of pH (□) during growth (⧫) was carried out as described in Materials and Methods for the B. subtilis IS58 wild-type strain in ASM containing 1% glucose (A) or 0.1% ribose (B), as well as for the B. subtilis BGW2 ccpA mutant strain in ASM containing 1% glucose (C) or 0.1% ribose (D).

FIG. 6

FIG. 6

Silver-stained 2D gels of B. subtilis wild-type strain IS58 (A) and isogenic ccpA mutant strain BGW2 (B) protein extracts. Glycolytic enzymes (□), enzymes of the TCA cycle (○), and enzymes of overflow metabolism (◊) are indicated, as are proteins which are repressed (formula image) or induced (formula image) in the absence of CcpA.

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References

    1. Antelmann H, Bernhardt J, Schmid R, Mach H, Völker U, Hecker M. First steps from a two-dimensional protein index towards a response-regulation map for Bacillus subtilis. Electrophoresis. 1997;18:1451–1463. - PubMed
    1. Aymerich, S. Personal communication.
    1. Behari J, Youngman P. A homolog of CcpA mediates catabolite control in Listeria monocytogenes but not carbon source regulation of virulence genes. J Bacteriol. 1998;180:6316–6324. - PMC - PubMed
    1. Bernhardt J, Völker U, Völker A, Antelmann H, Schmid R, Mach H, Hecker M. Specific and general stress proteins in Bacillus subtilis—a two dimensional protein electrophoresis study. Microbiology. 1997;143:999–1017. - PubMed
    1. Berhardt J, Werner H. revision date. The 2D protein index of Bacillus subtilis—Sub2D. 19 August 1999. http://microbiol.biologie.uni-greifswald.de::88801 [Online.] http://microbiol.biologie.uni-greifswald.de::88801. Ernst-Moritz-Arndt-Universität Greifswald, Griefswald, Germany. . Ernst-Moritz-Arndt-Universitt Greifswald, Griefswald, Germany.

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