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. 1994 May 1;299(Pt 3):593–596. doi: 10.1042/bj2990593

Suppression of Gi alpha 2 enhances phospholipase C signalling.

D C Watkins 1, C M Moxham 1, A J Morris 1, C C Malbon 1
PMCID: PMC1138062  PMID: 8192647

Abstract

G-proteins mediate transmembrane signalling from a populous group of cell-surface receptors to a smaller group of effectors that includes adenylate cyclase, various ion channels and phospholipase C. Stem cells (F9 teratocarcinoma) or rat osteosarcoma 17/2.8 cells in which Gi alpha 2 expression is abolished by antisense RNA display markedly elevated basal inositol 1,4,5-trisphosphate accumulation and a potentiated phospholipase C response to stimulatory hormones. Expression of the Q205L mutant of Gi alpha 2, which is constitutively active, was found to block persistently hormonally stimulated phospholipase C activity, implicating Gi alpha 2 as an inhibitory regulator of phospholipase C signalling. Analysis using Gi alpha 2-deficient adipocytes of transgenic mice provided further evidence for a role for Gi alpha 2 in phospholipase C regulation, demonstrating in vivo that loss of Gi alpha 2 elevates basal, and markedly potentiates hormonally stimulated, phospholipase C activity. This report demonstrates for the first time that a single G-protein, G12, can regulate two distinct signalling pathways, i.e. adenylate cyclase and phospholipase C.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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