IN-VITRO PROTEIN-PHOSPHORYLATION ASSOCIATED WITH CELLULAR-DIFFERENTIATION OF STREPTOMYCES-GRISEUS

In vitro phosphorylation reactions with crude cellular extracts reveal ed that phosphorylation of a 17-kDa protein is associated with the ons et of aerial mycelium formation in solid culture (but not submerged sp ore formation in liquid culture) of Streptomyces griseus. The possible importance of the 17-kDa protein phosphorylation in cellular differen tiation was further indicated by inducing aerial mycelium formation in the presence of decoyinine and in studies using certain developmental mutants (relC, afsA, and M-1). It is proposed that the 17-kDa protein may play a role in cellular differentiation of S. griseus via its pho sphorylation.