Effects of modulators of protein kinase C on human sperm capacitation.
OBJECTIVE
To examine the effects of stimulators or inhibitors of protein kinase C on capacitation and protein phosphorylation in human sperm.


METHODS
Capacitated sperm treated with or without modulators of protein kinase C were monitored by the chlortetracycline fluorescence assay. Capacitation was confirmed by the ability of sperm to undergo the acrosomal reaction in response to mouse zonae pellucidae. 32P-labeled sperm phosphoproteins were analyzed by one-dimensional gel electrophoresis to detect the effect of protein kinase C stimulator, 12-O-tetradecanoyl-phorbol-13-acetate, on protein phosphorylation.


RESULTS
The treatment of sperm with protein kinase C stimulators resulted in the following: [1] the rapid appearance of the clear perimeter pattern, featuring distribution of fluorescence over the entire head exhibiting a bright perimeter and bright midpiece; [2] an accelerated ability to undergo the acrosomal reaction; and [3] an enhanced phosphorylation of 57.5-kd sperm phosphoprotein. Furthermore, these stimulatory effects were inhibited by protein kinase C inhibitors.


CONCLUSIONS
Protein phosphorylation mediated by protein kinase C may be involved in the regulation of human sperm capacitation.
Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
S
S
Furuya
Y
Y
Endo
K
K
Osumi
M
M
Oba
S
S
Suzuki
D000177:Acrosome / Q000187:drug effects; D006801:Humans; D008297:Male; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D013075:Sperm Capacitation / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D011506:Proteins; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate