Protein kinase C beta and delta selectively phosphorylate odorant and metabotropic glutamate receptors

Recombinant protein segments from a metabotropic glutamate receptor and fro m an odorant receptor were used as substrates in protein kinase C phosphory lation assays. Protein kinase C beta and delta phosphorylated an intracellu lar consensus phosphorylation site in the metabotropic glutamate receptor. Only protein kinase C delta phosphorylated a novel extracellular consensus phosphorylation site in the odorant receptor. These results suggest differe ntial regulation of these receptors by protein kinase C isotypes.