MULTIPLE PROTEIN ASPARTATE PHOSPHATASES PROVIDE A MECHANISM FOR THE INTEGRATION OF DIVERSE SIGNALS IN THE CONTROL OF DEVELOPMENT IN BACILLUS-SUBTILIS

The initiation of sporulation in B. subtilis is regulated by the SpoOA transcription factor, which is activated by phosphorylation to central developmental switching from the vegetative to the sporulation state. The level of phosphorylation of SpoOA is regulated by the phosphorelay, a signal transduction system based on the protein-histidine kinase-response regulator two-component paradigm. To initiate sporulation, the cell must recognize and interpret a large variety of environmental, metabolic, and cell cycle signals that influence the phosphorylation level of SpoOA. We describe here a family of protein-aspartate phosphatases with activity on SpoOF similar to P, a response regulator component of the phosphorelay, that provide a mechanism for signal recognition and interpretation. These phosphatases function to drain the phosphorelay, lower SpoOA similar to P levels, and prevent sporulation, The integration of diverse environmental signals that affect the initiation of sporulation likely occurs through the competition between opposing activities of protein kinases and protein phosphatases.