Picture of mobile phone running fintech app

Fintech: Open Access research exploring new frontiers in financial technology

Strathprints makes available Open Access scholarly outputs by the Department of Accounting & Finance at Strathclyde. Particular research specialisms include financial risk management and investment strategies.

The Department also hosts the Centre for Financial Regulation and Innovation (CeFRI), demonstrating research expertise in fintech and capital markets. It also aims to provide a strategic link between academia, policy-makers, regulators and other financial industry participants.

Explore all Strathclyde Open Access research...

Regulation of bombesin-stimulated inositol 1,4,5-trisphosphate generation in Swiss 3T3 fibroblasts by a guanine-nucleotide-binding protein

Plevin, R and Palmer, S and Gardner, S D and Wakelam, M J (1990) Regulation of bombesin-stimulated inositol 1,4,5-trisphosphate generation in Swiss 3T3 fibroblasts by a guanine-nucleotide-binding protein. Biochemical Journal, 268 (3). pp. 605-610. ISSN 0264-6021

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

The stimulation of inositol phosphate generation by bombesin and GTP analogues was studied in Swiss 3T3 cells permeabilized by electroporation. Bombesin-stimulated inositol phosphate generation is potentiated by guanosine 5'-[gamma-thio]triphosphate (GTP[S]) and inhibited by guanosine 5'-[beta-thio]diphosphate at all peptide concentrations tested, with no change in the EC50 value (concn. giving half-maximal response) for the agonist. Kinetic analysis showed that, although bombesin-stimulated [3H]InsP3 generation in [3H]inositol-labelled cells was rapid (maximal by 5-10 s), the response to GTP[S] alone displayed a distinct lag time of 20-30 s. This lag time was significantly decreased by the addition of bombesin, suggesting that in this system agonist-stimulated GTP/GDP exchange occurs. In addition, bombesin-stimulated generation of Ins(1,4,5)P3 mass at 10 s was enhanced by GTP[S] in the absence of a nucleotide response alone, a result consistent with this proposal. Pretreatment of the cells with phorbol 12-myristate 13-acetate (PMA) resulted in a dose-dependent inhibition of bombesin-, but not GTP[S]-, stimulated inositol phosphate generation. Furthermore, although PMA pretreatment did not affect the lag time for InsP3 formation in response to GTP[S] alone, the degree of synergy between bombesin and the nucleotide was severely decreased at early time points. The results therefore demonstrate that the high-affinity bombesin receptor is coupled via a G-protein to phospholipase C in a manner consistent with a general model for receptor-G-protein interactions and that this coupling is sensitive to phosphorylation by protein kinase C.