Structure of the rat inhibin and activin β(A)-subunit gene and regulation in an ovarian granulosa cell line

Ali M. Ardekani, Joanna C.D. Romanelli, Kelly E. Mayo*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

We have isolated the rat inhibin and activin β(A)-subunit gene, which is composed of three exons, and have characterized a 571-bp region upstream from the transcriptional start site that functions as a promoter in transient transfection studies in an ovarian granulosa cell line, GRMO2. Deletion analysis of the 571-bp promoter region has identified DNA sequences between - 362 bp and -110 bp to be essential in mediating basal promoter activity and activation by forskolin (FSK) and/or 12-O-tetradecanoylphorbol-13-acetate (TPA). Within this region, a variant CRE (cAMP response element) has been identified at -120 bp. Point mutations in the variant CRE substantially reduce the ability of FSK and/or TPA to induce promoter activity in GRMO2 cells. A single nucleotide change in the variant CRE, which converts it to a consensus CRE, does not enhance promoter activity in response to FSK and/or TPA, but rather reduces promoter activity to the same extent as the other inactivating mutation in the variant CRE, suggesting that this element does not act as a classical CRE. Consistent with this, electrophoretic mobility shift assays performed using antibodies to a variety of cAMP and phorbol ester-responsive transcription factors indicate that the AP-1 family proteins jun-B and fos-B are present in the protein complex binding to the variant CRE. Overexpression of jun-B and fos-B in GRMO2 cells resulted in a robust activation of the β(A)-subunit promoter. Our results suggest that this novel variant CRE sequence mediates both cAMP and phorbol ester regulation through its interactions with AP-1 family proteins.

Original languageEnglish (US)
Pages (from-to)3271-3279
Number of pages9
JournalEndocrinology
Volume139
Issue number7
DOIs
StatePublished - 1998

ASJC Scopus subject areas

  • Endocrinology

Fingerprint Dive into the research topics of 'Structure of the rat inhibin and activin β(A)-subunit gene and regulation in an ovarian granulosa cell line'. Together they form a unique fingerprint.

Cite this