Receptor crosstalk

Passing signals by sharing subunits

Science's STKE  28 Sep 1999:
Vol. 1999, Issue 1, pp. tw6
DOI: 10.1126/stke.1999.1.tw6

Although the Gα subunits of heterotrimeric G-proteins exhibit specificity for the receptors to which they couple, receptor interaction with Gβγ subunits appears to be less selective. Quitterer and Lohse now report that two different G-protein coupled receptors (GPCRs) appear to communicate with each other by sharing the same Gβγ. Activation of the Gαi-coupled receptor for adenosine A1 or the α2C adrenergic receptor stimulated signals that are propagated by Gαq-coupled receptors for bradykinin or UTP. The authors suggest that upon receptor stimulation, the Gαi -coupled receptor releases its Gβγ to the Gαq -coupled receptor. Once docked in its new home, Gβγ stimulates Gαq activation. Subunit exchange may therefore be one mechanism for crosstalk between GPCRs.

Quittere, U. and Lohse, M.J. (1999) Crosstalk between Gαi - and Gαq -coupled receptors is mediated by Gβγ exhange. Proc. Natl. Acad. Sci. U.S.A. 96:378-381. [Abstract] [Full Text]