Characterization of cAMP/PKA/CREB signaling cascade in the bonnet monkey corpus luteum: expressions of inhibin-\alpha and StAR during different functional status

Priyanka, S and Medhamurthy, R (2007) Characterization of cAMP/PKA/CREB signaling cascade in the bonnet monkey corpus luteum: expressions of inhibin-\alpha and StAR during different functional status. In: Molecular Human Reproduction, 13 (6). pp. 381-390.

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Abstract

Luteinizing hormone mediates its nuclear action primarily by activating cAMP/Protein kinase A (PKA) pathway leading to phosphorylation of cAMP response element binding (CREB) family of transcription factors. Earlier studies have documented altered cAMP responsiveness of luteal cells during maturation, and in the rhesus monkey, extinction of CREB expression following luteinization and ovulation. In the course of studies aimed at characterizing LH-cAMP signaling pathway, we serendipitously discovered that CREB is after all present in the monkey corpus luteum (CL). The present experiments were carried out to examine the PKA activity, CREB expression and RT–PCR expression of inhibin-a (Inh-a) subunit and steroidogenic acute regulatory protein (StAR) in CL obtained from a variety of model systems. PKA activity in the CL was maintained throughout the luteal phase. Messenger RNA expression by RT–PCR and Northern analyses and protein levels employing antibodies specific to total- and phosphoforms demonstrated presence of CREB in the CL. Additionally, immuno-histo/cytochemical analyses, Electrophoretic mobility shift assays and chromatin immunoprecipitation assays for Inh-a and StAR genes further confirmed the presence of CREB in the CL. The present study, contrary to an earlier report, demonstrates the presence of CREB (both transcript and protein) in the monkey CL. Also, analysis of expression of Inh-\alpha and StAR genes (considered to be cAMP responsive), during different functional status of CL suggests that LH regulates their expression perhaps by cAMP/PKA/CREB pathway.

Item Type:	Journal Article
Publication:	Molecular Human Reproduction
Publisher:	Oxford University Press
Additional Information:	Copyright of this article belongs to Oxford University Press.
Keywords:	bonnet monkey;corpus luteum;CREB;inhibin-a;StAR expressions;PKA
Department/Centre:	Division of Biological Sciences > Molecular Reproduction, Development & Genetics
Date Deposited:	09 Jun 2008
Last Modified:	19 Sep 2010 04:45
URI:	http://eprints.iisc.ac.in/id/eprint/14224

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