ScoC mediates catabolite repression of sporulation in Bacillus subtilis.
Sporulation in Bacillus subtilis can be triggered by carbon catabolite limitation. Conversely, carbon source excess can repress the production of extracellular enzymes, motility, and sporulation. Recent studies have implicated a pH-sensing mechanism, involving AbrB, the TCA cycle, Spo0K, and sigmaH in controlling the catabolite repression of sporulation gene expression. In an accompanying paper, we demonstrate that the AbrB-dependent pH-sensing mechanism may not be the only means by which carbon catabolites affect sporulation. In the studies reported here, we have examined the molecular basis underlying the catabolite repression phenotype of mutations in the hpr (scoC), rpoD (crsA47), and spo0A (rvtA11) loci. Loss of function mutations in hpr (scoC) restored sporulation gene expression and sporulation in the presence of excess catabolite(s), suggesting that Hpr (ScoC) has a pivotal role in mediating catabolite repression. Moreover, hpr gene expression increased substantially in the presence of excess catabolite(s), further supporting the involvement of Hpr (ScoC) in the carbon catabolite response system. We suggest that alterations in the phosphorelay response to catabolites may be one mechanism by which catabolite-resistant mutants such as crsA and rvtA are able to sporulate in the presence of excess glucose.
Shafikhani
Sasha H
SH
Department of Molecular and Cellular Biology, Division of Biochemistry and Molecular Biology, University of California, Berkeley, California 94720, USA.
Núñez
Esperanza
E
Leighton
Terrance
T
D019677:Artificial Gene Fusion; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D017930:Genes, Reporter; D005947:Glucose / Q000378:metabolism; D007763:Lac Operon; D016254:Mutagenesis, Insertional; D009154:Mutation; D014176:Protein Biosynthesis; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D012808:Sigma Factor / Q000235:genetics; D013171:Spores, Bacterial / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D001426:Bacterial Proteins; C442131:ScoC protein, Bacillus subtilis; D012808:Sigma Factor; C097712:SinI protein, Bacillus subtilis; C080950:Spo0A protein, Bacillus subtilis; D014157:Transcription Factors; C075521:kinA protein, Bacillus subtilis; D011494:Protein Kinases; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; D001616:beta-Galactosidase; D005947:Glucose