Gα 14 links a variety of G i ‐ and G s ‐coupled receptors to the stimulation of phospholipase C

The bovine Gα 14 is a member of the G q subfamily of G proteins that can regulate phospholipase Cβ isoforms but the extent to which Gα 14 recognizes different receptor classes is not known. Gα 14 was cotransfected with a variety of receptors in COS‐7 cells, and agonist‐induced stimulation of phospholipase C was then measured. Activation of the type 2 but not type 1 somatostatin receptor in cells coexpressing Gα 14 stimulated the accumulation of inositol phosphates; functional expression of both subtypes of somatostatin receptors was determined by the ability of somatostatin to inhibit cyclic AMP accumulation. Among the three opioid receptors (μ, δ, and κ), only the δ receptor was capable of stimulating IP formation when coexpressed with Gα 14 in COS‐7 cells. A panel of G i ‐ and G s ‐linked receptors was screened for their ability to stimulate IP accumulation via Gα 14 . The adenosine A 1 , complement C5a, dopamine D 1 , D 2 and D 5 , formyl peptide, luteinizing hormone, secretin, and the three subtypes of melatonin (mt1, MT2, and Xenopus ) receptors were all incapable of activating Gα 14 , while the α 2 ‐ and β 2 ‐adrenoceptors were able to do so. Gα 14 ‐mediated stimulation of phospholipase Cβ was agonist dose‐dependent. These data demonstrate that although Gα 14 can interact with different classes of receptors, it is much less promiscuous than Gα 15 or Gα 16 .British Journal of Pharmacology (2001) 132 , 1431–1440; doi: 10.1038/sj.bjp.0703933