Synapsin I in PC12 cells. II. Evidence for regulation by NGF of phosphorylation at a novel site.
NGF treatment of PC12 cells caused a rapid increase in the state of phosphorylation of synapsin I. This phosphorylation of synapsin I is accompanied by a decrease in its electrophoretic mobility on SDS-PAGE. Phosphopeptide fingerprint analysis of the synapsin I revealed that this phosphorylation occurred on a particular phosphopeptide, designated peptide N. Phosphoserine was the only phosphoamino acid detected in peptide N. Partially purified PC12 synapsin I was a substrate for several protein kinases known to be capable of phosphorylating brain synapsin I, but none of these kinases phosphorylated synapsin I on peptide N. The results suggest that the NGF-stimulated phosphorylation of synapsin I may be mediated by a novel protein kinase.
D000310:Adrenal Gland Neoplasms / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D007158:Immunologic Techniques; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D010449:Peptide Mapping; D010673:Pheochromocytoma / Q000378:metabolism; D010766:Phosphorylation; D013379:Substrate Specificity; D016704:Synapsins
D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D016704:Synapsins; D003994:Bucladesine