title: A synthetic peptide of the pseudosubstrate domain of protein kinase C blocks cytoplasmic alkalinization during activation of the sea urchin egg.
abstract: Multiple second messenger pathways have been proposed for transduction of the sperm-egg fusion event during fertilization of sea urchin eggs. Cytoplasmic alkalinization due to increased Na(+)-H+ antiport has been causally linked to many of the metabolic events during fertilization. Two possible second messenger pathways coupling sperm-egg fusion and antiporter activity are activation of protein kinase C (PKC) and Ca2(+)-calmodulin kinase. A selective inhibitor of PKC is PKC(19-36), a synthetic peptide of the pseudosubstrate domain of the kinase. Injection of PKC(19-36) into unfertilized sea urchin eggs blocked cytoplasmic alkalinization during activation by phorbol 12-myristate 13-acetate, a PKC agonist. The rise in pH during fertilization was partially blocked by PKC(19-36), which suggested that multiple pathways regulate the antiporter during fertilization. The use of fluorescein chromophores to measure intracellular pH in sea urchin eggs is also discussed.
authors.affiliation: Department of Zoology, Iowa State University, Ames 50011.
authors.forename: S S
authors.initials: SS
authors.lastname: Shen
authors.forename: W R
authors.initials: WR
authors.lastname: Buck
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization / Q000187:drug effects; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D008297:Male; D010063:Ovum / Q000187:drug effects / Q000502:physiology*; D010455:Peptides / Q000494:pharmacology*; D011480:Protease Inhibitors; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D012617:Sea Urchins; D013050:Spectrometry, Fluorescence; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; D010455:Peptides; D011480:Protease Inhibitors; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate