%0 Journal Article
%T Dual-Specificity Anti-sigma Factor Reinforces Control of Cell-Type Specific Gene Expression in Bacillus subtilis
%A Adriano O. Henriques
%A Ashley R. Bate
%A Charles P. Moran Jr.
%A Jeffrey Meisner
%A JinXin Gao
%A Joˋo Bota
%A M車nica Serrano
%A Patrick Eichenberger
%J -
%D 2015
%R 10.1371/journal.pgen.1005104
%X Gene expression during spore development in Bacillus subtilis is controlled by cell type-specific RNA polymerase sigma factors. 考Fand 考E control early stages of development in the forespore and the mother cell, respectively. When, at an intermediate stage in development, the mother cell engulfs the forespore, 考F is replaced by 考G and 考E is replaced by 考K. The anti-sigma factor CsfB is produced under the control of 考F and binds to and inhibits the auto-regulatory 考G, but not 考F. A position in region 2.1, occupied by an asparagine in 考G and by a glutamate in 羊F, is sufficient for CsfB discrimination of the two sigmas, and allows it to delay the early to late switch in forespore gene expression. We now show that following engulfment completion, csfB is switched on in the mother cell under the control of 考K and that CsfB binds to and inhibits 考E but not 考K, possibly to facilitate the switch from early to late gene expression. We show that a position in region 2.3 occupied by a conserved asparagine in 考E and by a conserved glutamate in 考K suffices for discrimination by CsfB. We also show that CsfB prevents activation of 考G in the mother cell and the premature 考G-dependent activation of 考K. Thus, CsfB establishes negative feedback loops that curtail the activity of 考E and prevent the ectopic activation of 考G in the mother cell. The capacity of CsfB to directly block 考E activity may also explain how CsfB plays a role as one of the several mechanisms that prevent 考E activation in the forespore. Thus the capacity of CsfB to differentiate between the highly similar 考F/考G and 考E/考K pairs allows it to rinforce the cell-type specificity of these sigma factors and the transition from early to late development in B. subtilis, and possibly in all sporeformers that encode a CsfB orthologue
%K Cell cycle and cell division
%K Bacillus subtilis
%K Bacterial sporulation
%K RNA polymerase
%K Gene expression
%K Bacterial spores
%K DNA transcription
%K Fluorescence microscopy
%U https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1005104