Self-Reinforcing Activation of a Cell-Specific Transcription Factor by Proteolysis of an Anti-σ Factor in B. subtilis

• Published in: Molecular cell Vol. 8; no. 4; pp. 873 - 883
• Main Authors: Pan, Qi, Garsin, Danielle A., Losick, Richard
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2001
• Subjects: Amino Acid Sequence; Bacillus subtilis; Bacillus subtilis - physiology; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; DNA-Binding Proteins - metabolism; Gene Expression Regulation; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Macromolecular Substances; Molecular Sequence Data; Mutation; Protein Binding; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Repressor Proteins - metabolism; s@uF factor; Sequence Alignment; sF factor; Sigma Factor - metabolism; SpollAA protein; SpollAB protein; Spores, Bacterial - metabolism; Transcription Factors
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/S1097-2765(01)00362-8

The transcription factor σ F, which is activated in a cell-specific manner during sporulation in B. subtilis, is initially held in an inactive complex by the anti-σ factor SpoIIAB. The anti-anti-σ factor SpoIIAA reacts with SpoIIAB·σ F to induce the release of free σ F and free SpoIIAB. We now report that free SpoIIAB is subject to proteolysis and that it is protected from degradation by σ F in the SpoIIAB·σ F complex and by SpoIIAA in an alternative complex. Proteolysis requires residues located near the extreme C terminus of SpoIIAB and is dependent upon the ClpCP protease. The reaction of SpoIIAA with SpoIIAB·σ F and the resulting degradation of newly released SpoIIAB could set up a self-reinforcing cycle that locks on the activation of σ F.