Differential use of signal transduction pathways in the gonadotropin-releasing hormone-mediated regulation of gonadotropin subunit gene expression
Abstract
The regulation of LH and FSH subunit gene expression is under the control of GnRH. Physiological changes in the frequency of pulsatile GnRH release from the hypothalamus result in differential stimulation of alpha-, LHbeta-, and FSHbeta-gene expression. Previous studies indicate that the GnRH receptor couples to G proteins of the G(q/11) family, with phosphoinositide turnover and its resultant increase in intracellular calcium concentration and protein kinase C (PKC) activation, to stimulate secretion of LH and FSH. However, the molecular mechanisms by which GnRH mediates its transcriptional effects remain largely unknown. We used GH3 cells, constitutively expressing the rat GnRH receptor (GGH(3)-1' cells) and transiently transfected with a luciferase reporter gene controlled by either the alpha, LHbeta, or FSHbeta gene regulatory region (alphaLUC, LHbetaLUC, and FSHbetaLUC, respectively), to examine the roles of several signal transduction pathways in the GnRH-mediated stimulation of gonadotropin subunit gene expression. Activation of PKC by phorbol, 12-myristate, 13-acetate resulted in an increase in the luciferase activity of all three gonadotropin subunit gene reporter constructs. Phorbol, 12-myristate, 13-acetate had a gre...Continue Reading
Citations
Molecular biology of gonadotropin-releasing hormone (GnRH)-I, GnRH-II, and their receptors in humans
Related Concepts
Related Feeds
Calcium & Bioenergetics
Bioenergetic processes, including cellular respiration and photosynthesis, concern the transformation of energy by cells. Here is the latest research on the role of calcium in bioenergetics.