SUBUNIT COMPOSITION OF G(O) PROTEINS FUNCTIONALLY COUPLING GALANIN RECEPTORS TO VOLTAGE-GATED CALCIUM CHANNELS

Citation
F. Kalkbrenner et al., SUBUNIT COMPOSITION OF G(O) PROTEINS FUNCTIONALLY COUPLING GALANIN RECEPTORS TO VOLTAGE-GATED CALCIUM CHANNELS, EMBO journal, 14(19), 1995, pp. 4728-4737
Citations number
51
Categorie Soggetti
Biology
Journal title
ISSN journal
02614189
Volume
14
Issue
19
Year of publication
1995
Pages
4728 - 4737
Database
ISI
SICI code
0261-4189(1995)14:19<4728:SCOGPF>2.0.ZU;2-9
Abstract
The neuropeptide galanin is widely expressed in the central nervous sy stem and other tissues and induces different cellular reactions, e.g. hormone release from pituitary and inhibition of insulin release from pancreatic B cells. By microinjection of antisense oligonucleotides we studied the question as to which G proteins mediate the galanin-induc ed inhibition of voltage-gated Ca2+ channels in the rat pancreatic B-c ell line RINm5F and in the rat pituitary cell line GH(3). Injection of antisense oligonucleotides directed against alpha(o1), beta(2), beta( 3), gamma(2), and gamma(4) G protein subunits reduced the inhibition o f Ca2+ channel current which was induced by galanin, whereas no change was seen after injection of cells with antisense oligonucleotides dir ected against alpha(i), alpha(q), alpha(11), alpha(14), alpha(15), bet a(1), beta(4), gamma(1), gamma(3), gamma(5), or gamma(7) G protein sub units or with sense control oligonucleotides. In view of these data an d of previous results, we conclude that the galanin receptors in GH(3) and in RINm5F cells couple mainly to the G(o) protein consisting of a lpha(o1)beta(2) gamma(2), to inhibit Ca2+ channels and use alpha(o1)be ta(3) gamma(4) less efficiently. The latter G protein composition was previously shown to be used by muscarinic M(4) receptors to inhibit Ca 2+ channels.