title: Muscarinic agonists and phorbol esters increase tyrosine phosphorylation of a 40-kilodalton protein in hippocampal slices.
abstract: We have used the hippocampal slice preparation to investigate the regulation of protein tyrosine phosphorylation in brain. After pharmacological treatment of intact slices, proteins were separated by electrophoresis, and levels of protein tyrosine phosphorylation were assessed by immunoblotting with specific anti-phosphotyrosine antibodies. Phorbol esters, activators of the serine- and threonine-phosphorylating enzyme protein kinase C, selectively increase tyrosine phosphorylation of a soluble protein with an apparent molecular mass of approximately 40 kilodaltons. Muscarinic agonists such as carbachol and oxotremorine M that strongly activate the inositol phospholipid system also increase tyrosine phosphorylation of this protein. Neurotransmitter activation of the inositol phospholipid system and protein kinase C appears to trigger a cascade leading to increased tyrosine phosphorylation.
authors.affiliation: Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
authors.forename: K R
authors.initials: KR
authors.lastname: Stratton
authors.forename: P F
authors.initials: PF
authors.lastname: Worley
authors.forename: R L
authors.initials: RL
authors.lastname: Huganir
authors.forename: J M
authors.initials: JM
authors.lastname: Baraban
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D010095:Oxotremorine / Q000494:pharmacology*; D010703:Phorbol Esters / Q000494:pharmacology*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014443:Tyrosine
chemical_list: D009419:Nerve Tissue Proteins; D010703:Phorbol Esters; C053695:phorbol 12,13,20-triacetate; C008874:phorbol-12,13-diacetate; D014443:Tyrosine; D010095:Oxotremorine; D002217:Carbachol; D011505:Protein-Tyrosine Kinases