A second PDZ-containing serine protease contributes to activation of the sporulation transcription factor sigmaK in Bacillus subtilis.
Gene expression late during the process of sporulation in Bacillus subtilis is governed by a multistep, signal transduction pathway involving the transcription factor sigma(K), which is derived by regulated proteolysis from the inactive proprotein pro-sigma(K). Processing of pro-sigma(K) is triggered by a signaling protein known as SpoIVB, a serine protease that contains a region with similarity to the PDZ family of protein-protein interaction domains. Here we report the discovery of a second PDZ-containing serine protease called CtpB that contributes to the activation of the pro-sigma(K) processing pathway. CtpB is a sporulation-specific, carboxyl-terminal processing protease and shares several features with SpoIVB. We propose that CtpB acts to fine-tune the regulation of pro-sigma(K) processing, and we discuss possible models by which CtpB influences the sigma(K) activation pathway.
Pan
Qi
Q
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Losick
Richard
R
Rudner
David Z
DZ
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D011498:Protein Precursors / Q000378:metabolism; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013171:Spores, Bacterial / Q000502:physiology; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D011498:Protein Precursors; D014157:Transcription Factors; C084190:sigma K; D012697:Serine Endopeptidases