Functional expression and photoaffinity labeling of a cloned P2U purinergic receptor

P2U purinergic receptor circular DNA expresses itself for a brief period of time in the K-562 mammalian cell line deficient in the receptor. This expression system serves as a reference frame for biochemical and molecular pharmacological characterization of wildtype and recombinant P2U receptors. Agonist selectivity and signaling characteristics of the cloned P2U receptor is analyzed using 3'-O-(4-benzoylbenzoyl)adenosine 5'-(alpha-32P)triphosphate (alpha-32P)-BzATP, a photoaffinity ATP analog and a polyhistidine coupled P2U receptor. This facilitates the identification of the receptor as a 53-kDa plasma membrane protein.