Receptor for extracellular ATP > UTP and ADP. The activity of this receptor is mediated by G proteins which activate a phosphatidylinositol-calcium second messenger system. May be the cardiac P2Y receptor involved in the regulation of cardiac muscle contraction through modulation of L-type calcium currents. Is a receptor for leukotriene B4, a potent chemoattractant involved in inflammation and immune response (By similarity). Phosphorylated by GRK6 upon leukotriene B4 binding; which promotes desensitization. Belongs to the G-protein coupled receptor 1 family.