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 centra l developmental switching from the vegetative to the sporulation state . The level of phosphorylation of SpoOA is regulated by the phosphorel ay, a signal transduction system based on the protein-histidine kinase -response regulator two-component paradigm. To initiate sporulation, t he 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 phospha tases with activity on SpoOF similar to P, a response regulator compon ent of the phosphorelay, that provide a mechanism for signal recogniti on and interpretation. These phosphatases function to drain the phosph orelay, lower SpoOA similar to P levels, and prevent sporulation, The integration of diverse environmental signals that affect the initiatio n of sporulation likely occurs through the competition between opposin g activities of protein kinases and protein phosphatases.