title: Extracellular signal protein triggering the proteolytic activation of a developmental transcription factor in B. subtilis.
abstract: We present biochemical evidence for an intercellular signal transduction pathway in B. subtilis. This pathway governs the conversion of the proprotein pro-sigma E to mature transcription factor sigma E. Proteolytic processing is mediated by the membrane protein SpollGA and is triggered by the inferred extracellular signal protein SpollR. A factor in conditioned medium from B. subtilis cells engineered to produce SpollR during growth triggered processing in protoplasts of B. subtilis cells that had been engineered to produce SpollGA and pro-sigma E. The factor was also detected in, and partially purified from, extracts of SpollR-producing cells of E. coli. We speculate that SpollGA is both a receptor and a protease and the SpollR interacts with SpollGA on the outside of the cytoplasmic membrane, activating the intracellular protease domain of SpollGA.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Hofmeister
authors.forename: A
authors.initials: A
authors.lastname: Londoño-Vallejo
authors.forename: E
authors.initials: E
authors.lastname: Harry
authors.forename: P
authors.initials: P
authors.lastname: Stragier
authors.forename: R
authors.initials: R
authors.lastname: Losick
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases; D011498:Protein Precursors / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012808:Sigma Factor / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C064971:FliA protein, Bacteria; D008565:Membrane Proteins; D011498:Protein Precursors; D012808:Sigma Factor; D014157:Transcription Factors; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; C063202:sporulation-specific sigma factors; D010450:Endopeptidases; D010447:Peptide Hydrolases; C071976:SpoIIGA protein, Bacillus subtilis