ID 112020
Title Alternative
Studies on the crosstalk between insulin-and G-protein-coupled receptor-mediated signal transduction pathways
インスリン受容体とGq共役受容体シグナル伝達系間の相互作用
Author
Ohnishi, Tetsuo The University of Tokushima
Keywords
insulin receptor
G-protein
crosstalk
glucose transporter
glycogen synthesis
Content Type
Journal Article
Description
Insulin exerts diverse physiological effects, which are mediated by its specific receptor with intrinsic protein tyrosine kinase activity. On the other hand, heterotrimeric G-proteins, consisting of α, β and γ subunits, are coupled to specific receptors for many ligands, and transmit the signal to the downstream effectors. Kishi et al. have already reported that stimulation of Gq-coupled receptors can induce GLUT 4 (glucose transporter type 4) translocation to the cell surface in an insulin-independent manner in CHO cells and 3T3-L1 adipocytes. In this study, we have established CHO (Chinese hamster ovary) cells stably expressing Gq-coupled bradykinin receptors, in order to examine crosstalks between insulin- and G-protein-coupled receptor-mediated signal transduction pathways.
Insulin enhanced insulin receptor kinase activity, IRS-1 (insulin receptor substrate-1) tyrosine phosphorylation, PI 3-kinase and Akt kinase activities, and glycogen synthesis, and induced GLUT 4 translocation in this cell line. Bradykinin treatment inhibited the insulin-stimulated receptor kinase activity, IRS-1 phosphorylation, PI 3-kinase and Akt kinase activities, and glycogen synthesis, while bradykinin itself had no effects on the insulin receptor kinase, IRS-1, PI3-kinase, Akt kinase, and glycogen synthesis. These results showed that Gq signaling interferes insulin receptor signaling at least in the early step (s) including insulin receptor kinase activation. The Gq-mediated inhibition of insulin signal may explain some insulin resistant states appeared in non-insulin-dependent diabetes mellitus.
Journal Title
Shikoku Acta Medica
ISSN
00373699
NCID
AN00102041
Publisher
徳島医学会
Volume
54
Issue
1
Start Page
1
End Page
7
Sort Key
1
Published Date
1998-02-25
FullText File
language
jpn
TextVersion
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