Protein kinase C regulates ionic conductance in hippocampal pyramidal neurons: electrophysiological effects of phorbol esters.
The vertebrate central nervous system contains very high concentrations of protein kinase C, a calcium- and phospholipid-stimulated phosphorylating enzyme. Phorbol esters, compounds with inflammatory and tumor-promoting properties, bind to and activate this enzyme. To clarify the role of protein kinase C in neuronal function, we have localized phorbol ester receptors in the rat hippocampus by autoradiography and examined the electrophysiological effects of phorbol esters on hippocampal pyramidal neurons in vitro. Phorbol esters blocked a calcium-dependent potassium conductance. In addition, phorbol esters blocked the late hyperpolarization elicited by synaptic stimulation even though other synaptic potentials were not affected. The potencies of several phorbol esters in exerting these actions paralleled their affinities for protein kinase C, suggesting that protein kinase C regulates membrane ionic conductance.
Baraban
J M
JM
Snyder
S H
SH
Alger
B E
BE
D000818:Animals; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004594:Electrophysiology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000502:physiology; D010703:Phorbol Esters / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D011493:Protein Kinase C; D011494:Protein Kinases / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011955:Receptors, Drug; D011971:Receptors, Immunologic / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D010703:Phorbol Esters; D010704:Phorbols; D011955:Receptors, Drug; D011971:Receptors, Immunologic; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D011494:Protein Kinases; D011493:Protein Kinase C