Activation of spo0A transcription by sigma H is necessary for sporulation but not for competence in Bacillus subtilis

Abstract

spoOA and spoOH are needed for the initiation of sporulation and for the development of genetic competence in Bacillus subtilis. Transcription of spoOA initiates from two promoters, Pv and Ps. Pv is active during vegetative growth and is recognized by RNA polymerase containing oA. Expression from Ps increases during sporulation and depends on cH, the spoOH gene product. A deletion mutation, spoOAAPs, that removes the promoter controlled by frH blocked sporulation but had no detectable elfect on competence. These results indicate that expression of spoOA from Ps is necessary for sporulation and that the requirement for spoOH in competence development is not due to its role in expression of spoOA.Under conditions of nutrient deprivation, cells of Bacillus subtilis enter into a developmental pathway that leads to the production of dormant, heat-resistant endospores. Sporulation involves the production of two distinct cell types with different developmental fates (reviewed in reference 11). Sporulation is not the only form of development in B. subtilis. When cells are grown in minimal glucose medium, a fraction of the cells in a culture differentiate to become competent to take up exogenous DNA (reviewed in reference 9).Both sporulation and competence development are controlled in part by the spoOA gene product, a transcription factor that functions as an activator and a repressor, depending on the location of the target binding site. SpoOA is a response regulator of the large family of two-component regulatory systems (23). The activity of SpoOA is controlled by phosphorylation (6), and the phosphorylated (activated) form has a higher affinity for DNA than does the nonphosphorylated form (4,5,31,32). Several proteins are required for the phosphorylation of SpoOA, including the histidine protein kinases KinA (3, 24), KinB (33), and KinC (19) and the phosphotransfer proteins SpoOF and SpoOB. One or more kinases autophosphorylate on a histidine residue and serve as substrate to donate phosphate to SpoOF. SpoOB then acquires the phosphate from SpoOF-P, and finally phosphate is transferred from SpoOB-P to SpoOA (6). A threshold concentration of SpoOA-P appears to be necessary for the initiation of sporulation (8).Transcription of spoOA is controlled by two promoters, Pv and Ps (7). Pv is expressed during vegetative growth and is transcribed by RNA polymerase containing the major sigma factor OA. Ps is induced during sporulation and requires (u as well as SpoOA-P for expression (26,30). ( H, the spoOH gene product, is also needed for the development of competence and the expression of competence genes (2, 17).Previous work had characterized the role of Pv in sporulation (7). Pv is not needed for sporulation under normal conditions in the absence of glucose. However, mutations that * Corresponding author. Phone: (617) Construction of spoOAAPs. To test the role of spoOAPs in competence and sporulation, we constructed a deletion mutation that removed the sporulation promoter, Ps. This mutation is contained in plasmid pSK5 ...

Compartmentalization of Gene Expression duringBacillus subtilisSpore Formation

“…H -dependent transcription of spo0A is essential for sporulation (270), and kinA, kinE, and spo0F also have H -dependent promoters (23,236). In addition, transcription of several phr genes encoding peptide precursors, some of which function to reverse phosphorelay inhibition by Rap phosphatases, is also dependent upon H (197).…”

The Clostridium Sporulation Programs: Diversity and Preservation of Endospore Differentiation

“…For B. subtilis, initiation of sporulation begins with the activation, via phosphorylation, of the master transcriptional regulator of all endospore formers, Spo0A, which is initially transcribed from a H -dependent promoter, the first sigma factor activated at the onset of sporulation ( Fig. 2A) (27,28). Once Spo0A is phosphorylated (Spo0AϳP), it regulates the expression of upwards of 100 genes or operons (27,29,30).…”

Postexponential Regulation of sin Operon Expression in Bacillus subtilis

“…Spo0AϳP is a repressor of abrB transcription and an activator of spoIIA, spoIIG, and spoIIE operon expression (4,45,51,57,63). spo0A expression is controlled by A and H promoters (9,44,49). Vegetative spo0A expression originates from the A promoter, and catabolite-regulated postexponential expression is controlled from the H promoter.…”