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Coupling of bradykinin receptors to phospholipase C in cultured fibroblasts is mediated by a G‐protein
Author(s) -
Etscheid Beth G.,
Villereal Mitchel L.
Publication year - 1989
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041400211
Subject(s) - bradykinin , phospholipase c , inositol phosphate , bradykinin receptor , pertussis toxin , receptor , gtp' , g protein , cholera toxin , inositol trisphosphate , stimulation , inositol , phosphatidylinositol , chemistry , biochemistry , microbiology and biotechnology , biology , endocrinology , signal transduction , enzyme
In cultured foreskin fibroblasts, bradykinin stimulates inositol phosphate generation, arachidonic acid release, and Na + /H + exchange, with doses of 1‐3 nM yielding half‐maximal stimulation. Binding of 3 H‐bradykinin to these cells demonstrates a single receptor site with a K d of 2.0 nM and a B max of 91 fmoles/mg protein. Bradykinin analogs of the B2 type inhibit this binding. GTP synergizes with bradykinin to stimulate phosphatidylinositol turnover in permeabilized fibroblasts and GTP‐γ‐S decreases the B max of bradykinin binding to fibroblast membranes, indicating that a G‐protein couples the receptor to phospholipase C. Pretreatment of fibroblasts with either cholera or pertussis toxin enhances bradykinin stimulation of inositol phosphate accumulation.