Protein kinase C phosphorylates a 47 M sub(r) protein (F1) directly related to synaptic plasticity

Ca super(2+)-phospholipid-dependent protein kinase C, and activators of protein kinase C (phosphatidylserine, phorbol esters) stimulate the in vitro phosphorylation of a 47 kdalton phosphoprotein (protein F1) previously shown to be directly related to the plasticity of long-term potentiation. The data indicate that protein F1 serves as a protein kinase C substrate, and suggest the hypothesis that protein kinase C is involved in processes of long-term potentiation.