PROTEIN-TYROSINE PHOSPHORYLATION IN STREPTOMYCETES

Using phosphotyrosine-specific antibodies, we demonstrate that in seve ral Streptomyces spp. a variety of proteins are phosphorylated on tyro sine residues. Tyrosine phosphorylation was found in a number of Strep tomyces species including Streptomyces lividans, Streptomyces hygrosco picus and Streptomyces lavendulae. Each species exhibited a unique pat tern of protein tyrosine phosphorylation. Moreover, the patterns of ty rosine phosphorylation varied during the growth phase and were also in fluenced by culture conditions. We suggest that metabolic shifts durin g the complex growth cycle of these filamentous bacteria, and possibly secondary metabolic pathways, may be controlled by the action of prot ein tyrosine kinases and phosphatases, as has been demonstrated in sig nal transduction pathways in eukaryotic organisms.