An exported peptide functions intracellularly to contribute to cell density signaling in B. subtilis.
Competence development and sporulation in B. subtilis are partly controlled by peptides that accumulate in culture medium as cells grow to high density. We constructed two genes that encode mature forms of two different signaling molecules, the PhrA peptide that stimulates sporulation, and CSF, the competence- and sporulation-stimulating factor. Both pentapeptides are normally produced by secretion and processing of precursor molecules. The mature pentapeptides were functional when expressed inside the cell, indicating that they normally need to be imported to function. Furthermore, at physiological concentrations (10 nM), CSF was transported into the cell by the oligopeptide permease encoded by spo0K (opp). CSF was shown to have at least three different targets corresponding to its three activities: stimulating competence gene expression at low concentrations, and inhibiting competence gene expression and stimulating sporulation at high concentrations.
Lazazzera
B A
BA
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
Solomon
J M
JM
Grossman
A D
AD
D018528:ATP-Binding Cassette Transporters; D000409:Alanine / Q000235:genetics; D001412:Bacillus subtilis / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D001483:Base Sequence; D002450:Cell Communication / Q000502:physiology*; D002452:Cell Count; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D005838:Genotype; D026901:Membrane Transport Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000502:physiology; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D012808:Sigma Factor; D013171:Spores, Bacterial / Q000502:physiology; D014157:Transcription Factors
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C085800:modF protein, E coli; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; C037230:oligopeptide permease, Bacteria; D010453:Peptide Synthases; C069542:surfactin synthetase; D000409:Alanine