Evidence for a functionally active inhibitory guanine nucleotide-binding regulatory protein in the swine ovary

Johannes D Veldhuis, Erik L. Hewlett

Research output: Contribution to journalArticle

14 Scopus citations


Incubation of particulate fractions of swine granulosa cells or luteal minces with purified pertussis toxin (islet-activitating protein) and [32P]-NAD catalyzed the (32P)-ADP ribosylation of a 41,000 dalton membrane protein. ADP-ribosylation was markedly reduced by prior incubation of intact cells with toxin. The functional relevance of this presumptive inhibitory guanine nucleotide-binding protein in pig granulosa cells was indicated by the ability of prior treatment with pertussis toxin to increase cyclic AMP generation and progesterone production significantly in response to follicle stimulating hormone. Prior cellular intoxication also enhanced cyclic AMP production stimulated by luteinizing hormone and choleratoxin, but not basally or after forskolin. these results demonstrate the presence of an inhibitory guanine nucleotide-binding protein in both the follicular (granulosa cell) and luteal compartments of the mammalian ovary, and indicate its functional relevance in cyclic AMP generation and progesterone secretion.

Original languageEnglish (US)
Pages (from-to)1168-1174
Number of pages7
JournalBiochemical and Biophysical Research Communications
Issue number3
StatePublished - Sep 30 1985
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this