[期刊论文][Articles]

出版年：1993

Muscarinic acetylcholine receptor (mAChR) activation in isolated cells from the nasal salt gland of the domestic duck ( Anas platyrhynchos ) results in a rapid increase in the rate of phosphatidylinositol hydrolysis and pronounced intracellular calcium signals. Both responses can be elicited by treating these cells with fluoroaluminate (AlF₄^-) indicating the involvement of a heterotrimeric G protein in the transmembrane signaling process. To characterize this G protein, electrophoretically separated membrane proteins were blotted onto nitrocellulose filters and probed with peptide-antibodies raised against portions of different a-subunits of mammalian G proteins. We could demonstrate the presence of at least four different G proteins in salt gland cell membranes. Two of these proteins (40 and 41 kD) were ADP-ribosylated by pertussis toxin and were recognized by an antiserum against a common sequence in all G protein a-subunits. One protein (46 kD) was a cholera toxin-substrate and was recognized by a G_s-specific antiserum; the other (42 kD) was recognized by G_q-specific antisera and was resistant to ADP-ribosylation. Since the initial inositol phosphate production upon receptor activation with carbachol and the resulting calcium signals were not affected by pertussis toxin-pretreatment of salt gland cells, we conclude that muscarinic receptors are coupled to phospholipase C by a G_q-type G protein.

signal transduction; Gq-type G protein; intracellular calcium signals; inositol phosphates; avian salt gland; Industry SectorsBiotechnology ; Pharma ;