Regulatory interactions between the Pho and sigma(B)-dependent general stress regulons of Bacillus subtilis.
When Bacillus subtilis is subjected to phosphate starvation, the Pho and sigma(B)-dependent general stress regulons are activated to elicit, respectively, specific and non-specific responses to this nutrient-limitation stress. A set of isogenic mutants, with a beta-galactosidase reporter gene transcriptionally fused to the inactivated target gene, was used to identify genes of unknown function that are induced or repressed under phosphate limitation. Nine phosphate-starvation-induced (psi) genes were identified: yhaX, yhbH, ykoL and yttP were regulated by the PhoP-PhoR two-component system responsible for controlling the expression of genes in the Pho regulon, while ywmG (renamed csbD), yheK, ykzA, ysnF and yvgO were dependent on the alternative sigma factor sigma(B), which controls the expression of the general stress genes. Genes yhaX and yhbH are unique members of the Pho regulon, since they are phosphate-starvation induced via PhoP-PhoR from a sporulation-specific sigma(E) promoter or a promoter that requires the product of a sigma(E)-dependent gene. Null mutations in key regulatory genes phoR and sigB showed that the Pho and sigma(B)-dependent general stress regulons of Bacillus subtilis interact to modulate the levels at which each are activated.
Prágai
Zoltán
Z
Department of Microbiology and Immunology, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne NE2 4HH, UK1.
Harwood
Colin R
CR
Department of Microbiology and Immunology, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne NE2 4HH, UK1.
D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial / Q000235:genetics*; D017930:Genes, Reporter; D010710:Phosphates / Q000172:deficiency* / Q000378:metabolism; D018085:Regulon / Q000235:genetics; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
D001426:Bacterial Proteins; D010710:Phosphates; C079011:SigB protein, Bacteria; D012808:Sigma Factor; C061279:PhoR protein, Bacteria