Cloning and expression of the alpha 2C-adrenergic receptor from the OK cell line

The alpha 2-adrenergic receptors have been divided into four pharmacological subtypes, alpha 2A, alpha 2B, alpha 2C, and alpha 2D. The OK cell line, a cell line derived from an opossum kidney, expresses the alpha 2C-adrenergic receptor and is the prototypical cell line for the alpha 2C receptor subtype. The cloned human alpha 2C-C4 and rat RG10 receptors have been shown to express alpha 2C pharmacology. Here we report the cloning and expression of the OK alpha 2C-adrenergic receptor, OKc2. The receptor has 64% deduced amino acid identity and 21% similarity to the alpha 2-C4 receptor, giving an overall similarity of 85%. The clone, expressed in Chinese hamster ovary cells, has a pharmacology that correlates very well (r = 0.97) with that of the native OK cell alpha 2C-adrenergic receptor, and it is negatively coupled to adenylyl cyclase.