Phorbol esters and neurotransmitter release: more than just protein kinase C?
This review focuses on the effects of phorbol esters and the role of phorbol ester receptors in the secretion of neurotransmitter substances. We begin with a brief background on the historical use of phorbol esters as tools to decipher the role of the enzyme protein kinase C in signal transduction cascades. Next, we illustrate the structural differences between active and inactive phorbol esters and the mechanism by which the binding of phorbol to its recognition sites (C1 domains) on a particular protein acts to translocate that protein to the membrane. We then discuss the evidence that the most important nerve terminal receptor for phorbol esters (and their endogenous counterpart diacylglycerol) is likely to be Munc13. Indeed, Munc13 and its invertebrate homologues are the main players in priming the secretory apparatus for its critical function in the exocytosis process.
Silinsky
Eugene M
EM
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611, U.S.A. e-silinsky@northwestern.edu
Searl
Timothy J
TJ
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004330:Drosophila / Q000235:genetics; D008954:Models, Biological; D018377:Neurotransmitter Agents / Q000494:pharmacology* / Q000502:physiology*; D010703:Phorbol Esters / Q000494:pharmacology*; D011493:Protein Kinase C / Q000235:genetics* / Q000494:pharmacology* / Q000502:physiology*; D011955:Receptors, Drug / Q000235:genetics* / Q000502:physiology*
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D018377:Neurotransmitter Agents; D010703:Phorbol Esters; D011955:Receptors, Drug; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D011493:Protein Kinase C