CLONED AND TRANSFECTED P2Y(4) RECEPTORS - CHARACTERIZATION OF A SURAMIN AND PPADS-INSENSITIVE RESPONSE TO UTP

The P2Y family of receptors are G protein-coupled receptors for ATP, A DP, UTP and UDP. Recently several members of this family have been clo ned, including the P2Y(4), which is activated by UTP but not by ATP. I n the present report, using receptors stably transfected into 1321N1 c ells, we show that suramin acts as an antagonist at cloned P2Y(1) and (less potently) P2Y(2) receptors, but not at the cloned P2Y(4) recepto r. Furthermore, PPADS (pyridoxal-phosphate-6-azophenyl-2',4'-disulphon ic acid), a potent antagonist at the P2Y(1) receptor, is a relatively inneffective antagonist at the cloned P2Y(4) receptor. This work moves us closer to the goal of classifying the native P2Y receptors on the basis of agonist and antagonist profiles.