Microinjected GTP-gamma-S inhibits progesterone-induced maturation of Xenopus oocytes.
GTP-gamma-S inhibits progesterone-induced maturation of Xenopus laevis oocytes and induces a rise in their cAMP levels. GTP-gamma-S does not inhibit MPF-induced maturation. Although GTP-gamma-S prevents the progesterone-induced increases in protein synthesis and phosphorylation, it has no effect on the basal rates of either. GTP-gamma-S also prevents the initial DAG drop induced by progesterone. GDP-beta-S effects are ambiguous, but it seems not to affect progesterone-induced maturation. These results suggest that although G-proteins are associated with the pathways affected by progesterone, the effects of progesterone are not mediated by a typical receptor/G-protein/effector interaction.
Cork
R J
RJ
Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
Taylor
M
M
Varnold
R L
RL
Smith
L D
LD
Robinson
K R
KR
D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D007700:Kinetics; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D011374:Progesterone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology; D014982:Xenopus laevis
D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D011374:Progesterone; C023427:guanosine 5'-O-(2-thiodiphosphate); D000242:Cyclic AMP