Figure. Concentration-dependent activation of P2RY6 by UDP. Reporter cells were transfected with either the expression plasmid for pyrimidin­ergic receptor P2Y6 (P2RY6) or the mock plasmid and treated with various concentrations of uridine 5'-di­phos­phate (UDP). Data points shown are the mean ± SEM of an experiment performed in triplicate, and the curve is a fit to Hill equation with an EC50 of 96 nM.