Regulation of pho regulon gene expression by the carbon control protein A, CcpA, in Bacillus subtilis.
Bacterial regulons involved in carbon, nitrogen and phosphorus metabolism must interact for purposes of coordination, but the mechanisms involved are not understood. We here report that the carbon control pro-tein-A (CcpA) of Bacillus subtilis, primarily concerned with carbon metabolism, influences expression of various phosphorus (pho) regulon genes including the two alkaline phosphatase structural genes, phoA and phoB. The directions and magnitudes of the effects of glucose and the loss of CcpA on these two genes depend on growth conditions, but they always correlate inversely. Absolute expression levels of phoA and phoB depend on a rich nitrogen source, and gene activation by a fermentable substrate such as glucose depends on the presence of a respiratory substrate such as succinate. We show that these CcpA-dependent glucose effects can be explained by the effects of glucose and CcpA acting on the phoPR operon. Although a good CcpA-binding site (CRE) is found in the control region of the phoPR operon, direct regulation of phoPR gene expression by CcpA via this CRE could not account for the effects of glucose and CcpA on phoA and phoB gene expression. We conclude that CcpA exerts indirect control over the pho regulon by a mechanism that involves CcpA and PhoRP but does not involve the phoPR operon CRE.
Choi
Soo-Keun
SK
Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yusong, Taejon, Korea.
Saier
Milton H
MH
D000469:Alkaline Phosphatase; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002244:Carbon / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000096:biosynthesis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D005947:Glucose / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D007763:Lac Operon; D009154:Mutation; D009876:Operon; D018085:Regulon / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013205:Staphylococcal Protein A / Q000235:genetics / Q000378:metabolism*; D019802:Succinic Acid / Q000494:pharmacology; D015533:Transcriptional Activation
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D013205:Staphylococcal Protein A; C069286:catabolite control proteins, bacteria; C061278:PhoB protein, Bacteria; D018698:Glutamic Acid; D002244:Carbon; D019802:Succinic Acid; D018844:Cyclin-Dependent Kinases; D000469:Alkaline Phosphatase; D005947:Glucose