Send to

Choose Destination
Mol Cell. 2001 Oct;8(4):873-83.

Self-reinforcing activation of a cell-specific transcription factor by proteolysis of an anti-sigma factor in B. subtilis.

Author information

Department of Molecular and Cellular Biology, The Biological Laboratories, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.


The transcription factor sigma(F), which is activated in a cell-specific manner during sporulation in B. subtilis, is initially held in an inactive complex by the anti-sigma factor SpoIIAB. The anti-anti-sigma factor SpoIIAA reacts with SpoIIAB.sigma(F) to induce the release of free sigma(F) and free SpoIIAB. We now report that free SpoIIAB is subject to proteolysis and that it is protected from degradation by sigma(F) in the SpoIIAB.sigma(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.sigma(F) and the resulting degradation of newly released SpoIIAB could set up a self-reinforcing cycle that locks on the activation of sigma(F).

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center