Covalent modification of proteins in Bacillus subtilis during the process of sporulation, germination and outgrowth

Cells of Bacillus subtilis 168+ were labeled with 32P-orthophosphate during the process of sporulation, germination and outgrowth. By two-dimensional gel electrophoresis, at least 30 protein species were found to be radioactively labeled; 30% of these were modified by phosphorylation. Significant changes in the protein phosphorylation pattern during growth and cellular differentiation could be demonstrated. Using γ-32P-ATP evidence for an ATP-dependent protein kinase was also obtained. Under these conditions 4 proteins with a molecular mass of 109 600; 103 100; 73 300 and 32 200 Da were found to be phosphorylated.