Signal transduction of the gonadotropin releasing hormone (GnRH) receptor: Cross-talk of calcium, protein kinase C (PKC), and arachidonic acid

1995 ◽  
Vol 15 (5) ◽  
pp. 527-544 ◽  
Author(s):  
Zvi Naor ◽  
Sharon Shacham ◽  
Dagan Harris ◽  
Rony Seger ◽  
Nachum Reiss
Keyword(s):  
Signal Transduction ◽  
Arachidonic Acid ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cross Talk ◽  
Gnrh Receptor ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Kinase C ◽  
Receptor Cross Talk

scholarly journals Absence of rapid desensitization of the mouse gonadotropin-releasing hormone receptor

1994 ◽  
Vol 300 (2) ◽  
pp. 299-302 ◽  
Author(s):  
J S Davidson ◽  
I K Wakefield ◽  
R P Millar
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Ester ◽  
Inositol Phosphate ◽  
Gnrh Receptor ◽  
Gonadotropin Releasing Hormone ◽  
Gonadal Hormone ◽  
Releasing Hormone ◽  
Kinase C ◽  
Homologous Desensitization

Desensitization of gonadotropin release by the pituitary gland in response to gonadotropin-releasing hormone (GnRH) agonists has clinical applications in the treatment of gonadal-hormone-dependent disorders. We therefore investigated possible desensitization of inositol phosphate (IP) responses of GNRH receptors. No short-term homologous desensitization of the IP response to GnRH was observed in either alpha T3 gonadotrope cells line or GH3 cells transfected with GnRH receptor cDNA. The absence of homologous desensitization is unusual among G-protein-coupled receptors, and may be due to the absence of a C-terminal cytoplasmic tail, a unique feature of the GnRH receptor. Several potential protein kinase C phosphorylation sites which might mediate heterologous desensitization are present on the GnRH receptor. In both alpha T3 cells and GnRH-receptor-transfected Cos-1 cells, activation of protein kinase C by pretreatment with phorbol ester caused a 35-53% decrease in the IP response to GnRH. However, phorbol ester also inhibited guanosine 5′-[gamma-thio]triphosphate-stimulated IP production in permeabilized Cos-1 cells, suggesting that this inhibition is mediated at a post-receptor site.

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