Identification of G protein a-subunits in RINm5F cells and their selective interaction with galanin receptor

Mireille Cormont, Yannick Le Marchand-Brustel, Emmanuel Van Obberghen, Allen M. Spiegel, Geoffrey W.G. Sharp

Research output: Contribution to journalArticlepeer-review

44 Scopus citations


Galanin, an inhibitor of insulin secretion in pancreatic β-cells, exerts its multiple effects through mechanisms that are sensitive to pertussis toxin (PTX). G proteins have been characterized in RINm5F cells. By ADP ribosylation and immunoblotting, the α-subunits of Gi1, Gi2, Gi3, and two forms of Go were identified, Giα2 being predominant. As expected from a G protein-linked receptor, GTP and its nonhydrolyzable analogue GTP-Y-S decreased tracer galanin binding to cell membranes. This resulted from a change in receptor affinity without any modification in the number of sites. Selective antibodies against the COOH-terminal decapeptide of the á-subunits of the Gi and Go proteins were used to block G protein interaction before we studied galanin binding. Antibody AS, which selectively recognizes Giα1 and Giα2, decreased tracer galanin binding to membranes at concentrations where there were no effects of other antibodies specifically directed against Giα3 or Gαo. These data suggest that Gi1 and/or Gi2 interact with the galanin receptor and probably mediate the effects of galanin in pancreatic β-cells.

Original languageEnglish (US)
Pages (from-to)1170-1176
Number of pages7
Issue number9
StatePublished - Sep 1991
Externally publishedYes

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism


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