P2Y6 belongs to the family of G-protein coupled receptors. This family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides. This receptor is responsive to UDP, partially responsive to UTP and ADP, and not responsive to ATP. Four transcript variants encoding the same isoform have been identified for this gene. Receptor for extracellular UDP > UTP > ATP. The activity of this receptor is mediated by G proteins which activate a phosphatidylinositol-calcium second messenger system.