The in vitro phosphorylation of actin from rat cerebral cortex.
Actin was phosphorylated by a cyclic AMP-stimulated protein kinase in a lysed synaptosomal fraction incubated with [gamma-32P]ATP, while calcium had no effect on endogenous labeling of the protein. Incubation of an intact synaptosomal fraction with 32P-inorganic phosphate did not lead to any detectable phosphorylation of actin in the presence or absence of dibutyryl-cyclic AMP, or chemical depolarization. It is suggested that actin is not phosphorylated in the physiologically relevant intact synaptosomes but gains access to protein kinases on lysis.
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology*; D000242:Cyclic AMP / Q000494:pharmacology; D007700:Kinetics; D008970:Molecular Weight; D009132:Muscles; D009419:Nerve Tissue Proteins / Q000302:isolation & purification; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013570:Synaptic Membranes / Q000201:enzymology; D013574:Synaptosomes / Q000201:enzymology*
D000199:Actins; D009419:Nerve Tissue Proteins; D000242:Cyclic AMP; D011494:Protein Kinases