Phorbol ester treatment stimulates tyrosine phosphorylation of a sea urchin egg cortex protein.
Fertilization of the sea urchin egg results in the phosphorylation, on tyrosine, of a high molecular weight protein localized in the egg cortex. In the present study, treatment of unfertilized eggs with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate stimulated tyrosine phosphorylation of the high molecular weight cortical protein to levels three- to fivefold higher than that occurring in response to fertilization. Experiments using agents that inhibit the egg Na+/H+ exchange system or mimic the fertilization-induced shift in cytoplasmic pHi, suggest a signal transduction pathway in which protein kinase C activates the egg Na+/H+ exchange system and the resultant cytoplasmic pHi shift promotes tyrosine phosphorylation of the high molecular weight cortical protein.
Jiang
W P
WP
Department of Cell Biology and Anatomy, University of Miami School of Medicine, Florida 33101.
Gottlieb
R A
RA
Lennarz
W J
WJ
Kinsey
W H
WH
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000584:Amiloride / Q000494:pharmacology; D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002352:Carrier Proteins / Q000037:antagonists & inhibitors; D004527:Egg Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D006863:Hydrogen-Ion Concentration; D007546:Isoquinolines / Q000494:pharmacology; D008970:Molecular Weight; D010063:Ovum / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000302:isolation & purification; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D012617:Sea Urchins; D015398:Signal Transduction; D017923:Sodium-Hydrogen Exchangers; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014443:Tyrosine
D002352:Carrier Proteins; D004527:Egg Proteins; D007546:Isoquinolines; D010750:Phosphoproteins; D010879:Piperazines; D017923:Sodium-Hydrogen Exchangers; D000643:Ammonium Chloride; D014443:Tyrosine; D000584:Amiloride; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate