Mechanism of GnRH receptor signaling: from the membrane to the nucleus

The purpose of this review is to update the information concerning the intr acellular effect of GnRH. Binding of GnRH to a G-protein coupled receptor l eads to stimulation of Gq and/or G(11) protein and to activation of phospho lipase C beta. Inositol 1-4-5-triphosphate and early diacylylycerol are the second messengers required for conventional protein kinase C activation. A ctivation of phospholipase A(2) and phospholipase D are also involved, as d emonstrated by the liberation of Arachidonic Acid and Phosphatidic Acid. Pi tuitary cells also express atypical protein kinase C isoforms which mode of activation is not known. Hypothesis concerning transcriptional regulation are presented.