In vivo effects of sporulation kinases on mutant Spo0A proteins in Bacillus subtilis.
The phosphorylated form of the response regulator Spo0A (Spo0A~P) is required for the initiation of sporulation in Bacillus subtilis. Phosphate is transferred to Spo0A from at least four histidine kinases (KinA, KinB, KinC, and KinD) by a phosphotransfer pathway composed of Spo0F and Spo0B. Several mutations in spo0A allow initiation of sporulation in the absence of spo0F and spo0B, but the mechanisms by which these mutations allow bypass of spo0F and spo0B are not fully understood. We measured the ability of KinA, KinB, and KinC to activate sporulation of five spo0A mutants in the absence of Spo0F and Spo0B. We also determined the effect of Spo0E, a Spo0A~P-specific phosphatase, on sporulation of strains containing the spo0A mutations. Our results indicate that several of the mutations relax the specificity of Spo0A, allowing Spo0A to obtain phosphate from a broader group of phosphodonors. In the course of these experiments, we observed medium-dependent effects on the sporulation of different mutants. This led us to identify a small molecule, acetoin, that can stimulate sporulation of some spo0A mutants.
Quisel
J D
JD
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Burkholder
W F
WF
Grossman
A D
AD
D000093:Acetoin / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D000071677:Histidine Kinase; D009154:Mutation; D010770:Phosphotransferases; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology*; D012808:Sigma Factor; D015398:Signal Transduction; D013171:Spores, Bacterial; D014157:Transcription Factors / Q000235:genetics*
D001426:Bacterial Proteins; D012808:Sigma Factor; C080950:Spo0A protein, Bacillus subtilis; C080951:Spo0F protein, Bacillus subtilis; D014157:Transcription Factors; C075521:kinA protein, Bacillus subtilis; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; D000093:Acetoin; D010770:Phosphotransferases; D011494:Protein Kinases; D000071677:Histidine Kinase; C081245:kinB protein, Bacillus subtilis