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ClpC regulates the fate of a sporulation initiation sigma factor, σ H protein, in Bacillus subtilis at elevated temperatures
Author(s) -
Nanamiya Hideaki,
Ohashi Yoshiaki,
Asai Kei,
Moriya Shigeki,
Ogasawara Naotake,
Fujita Masaya,
Sadaie Yoshito,
Kawamura Fujio
Publication year - 1998
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1998.00943.x
Subject(s) - mutant , biology , bacillus subtilis , wild type , sigma factor , transcription (linguistics) , operon , microbiology and biotechnology , gene , lac operon , overproduction , locus (genetics) , gene product , transcription factor , gene expression , genetics , promoter , linguistics , philosophy , bacteria
Using a strain carrying a clpC–bgaB transcriptional fusion at the amyE locus, we found that the expression of a clpC operon was induced at the end of exponential growth in a σ B ‐independent manner and ceased around T 3.5 in the wild type but not in a spo0H mutant. This suggests that some gene product(s) whose expression is dependent on σ H function is required for the turn‐off of clpC transcription during an early stage of sporulation. A clpC deletion mutant showed a temperature‐sensitive sporulation phenotype and exhibited an abnormally large accumulation of σ H in the cell at 45°C after T 2 , at which time the σ H level in the wild type had begun to decrease. These results, together with the fact that spo0H transcription in the clpC deletion mutant was similar to that of the wild type, suggested that ClpC may be responsible for the degradation of σ H after the accomplishment of its role in sporulation. Moreover, as expected from these results, overproduction of Spo0A was also observed after the initiation of sporulation in the clpC deletion mutant at 45°C.