Expression patterns of P2X and P2Y receptor subtypes and their affinity for ATP
| Receptor . | Agonists . | Agonist binding affinities EC50, μM . | Main downstream signaling events . | Expression . |
|---|---|---|---|---|
| P2X receptors | ||||
| P2X1 | ATP | 0.05-1 | Ca2+ and Na+ influx | Smooth muscle cells, megakaryocytes, platelets, lymphocytes, DCs, epithelial cells, ventricular myocardium, and neurons |
| P2X2 | ATP | 1-30 | Ca2+ influx | Pancreatic cells, and neurons |
| P2X3 | ATP | 0.3-1 | Cation influx | Neurons, keratinocytes, and CD34+ hematopoietic precursors |
| P2X4 | ATP | 1-10 | Ca2+ influx | Neurons, CD34+ stem cells, lymphocytes, macrophages, MoDCs, fibroblasts, keratinocytes, and placenta |
| P2X5 | ATP | 1-10 | Ion influx | Neurons, keratinocytes, and thyrocytes |
| P2X6 | ATP | 1-12 | Ion influx | Neurons, keratinocytes, and thyrocytes |
| P2X7 | ATP | > 100 | Ca2+ and Na+ influx, K+ efflux pore formation | Neurons, lymphocytes, NK cells, neutrophils, monocytes, macrophages, DCs, and placenta |
| P2Y receptors | ||||
| P2Y1 | ADP | 8 | PLC-β activation | Neurons, heart, skeletal muscle, platelets, liver, and digestive tract |
| P2Y2 | ATP, UTP | 0.1 (ATP), 0.2 (UTP) | PLC-β activation cAMP inhibition | Skeletal muscle, heart, lung, spleen, placenta, kidney, and neutrophils |
| P2Y4 | UTP (ATP, UTP) | 2.5 | PLC-β activation cAMP inhibition | Intestine, lung, and placenta |
| P2Y6 | UDP, UTP | 0.3 (UDP), 6 (UTP) | PLC-β activation | Spleen, thymus, placenta, intestine, lung, and brain |
| P2Y11 | ATP | 17 | cAMP production, PLC-β activation | Corneal epithelia, endothelial cells, pancreatic duct cells, DCs, and lymphocytes |
| P2Y12 | ADP | 0.07 | cAMP inhibition | CD34+ stem cells, mast cells, vascular smooth muscle cells, and platelets |
| P2Y13 | ADP, ATP | 0.06 (ADP), 0.26 (ATP) | cAMP inhibition | Bone marrow, spleen, liver, brain, airway epithelial cells, red blood cells, monocytes, DCs, and T lymphocytes |
| P2Y14 | UDP-glucose | 0.1-0.5 | PLC-β activation | Hematopoietic cells, MoDCs, and human airway epithelial cells |
| Receptor . | Agonists . | Agonist binding affinities EC50, μM . | Main downstream signaling events . | Expression . |
|---|---|---|---|---|
| P2X receptors | ||||
| P2X1 | ATP | 0.05-1 | Ca2+ and Na+ influx | Smooth muscle cells, megakaryocytes, platelets, lymphocytes, DCs, epithelial cells, ventricular myocardium, and neurons |
| P2X2 | ATP | 1-30 | Ca2+ influx | Pancreatic cells, and neurons |
| P2X3 | ATP | 0.3-1 | Cation influx | Neurons, keratinocytes, and CD34+ hematopoietic precursors |
| P2X4 | ATP | 1-10 | Ca2+ influx | Neurons, CD34+ stem cells, lymphocytes, macrophages, MoDCs, fibroblasts, keratinocytes, and placenta |
| P2X5 | ATP | 1-10 | Ion influx | Neurons, keratinocytes, and thyrocytes |
| P2X6 | ATP | 1-12 | Ion influx | Neurons, keratinocytes, and thyrocytes |
| P2X7 | ATP | > 100 | Ca2+ and Na+ influx, K+ efflux pore formation | Neurons, lymphocytes, NK cells, neutrophils, monocytes, macrophages, DCs, and placenta |
| P2Y receptors | ||||
| P2Y1 | ADP | 8 | PLC-β activation | Neurons, heart, skeletal muscle, platelets, liver, and digestive tract |
| P2Y2 | ATP, UTP | 0.1 (ATP), 0.2 (UTP) | PLC-β activation cAMP inhibition | Skeletal muscle, heart, lung, spleen, placenta, kidney, and neutrophils |
| P2Y4 | UTP (ATP, UTP) | 2.5 | PLC-β activation cAMP inhibition | Intestine, lung, and placenta |
| P2Y6 | UDP, UTP | 0.3 (UDP), 6 (UTP) | PLC-β activation | Spleen, thymus, placenta, intestine, lung, and brain |
| P2Y11 | ATP | 17 | cAMP production, PLC-β activation | Corneal epithelia, endothelial cells, pancreatic duct cells, DCs, and lymphocytes |
| P2Y12 | ADP | 0.07 | cAMP inhibition | CD34+ stem cells, mast cells, vascular smooth muscle cells, and platelets |
| P2Y13 | ADP, ATP | 0.06 (ADP), 0.26 (ATP) | cAMP inhibition | Bone marrow, spleen, liver, brain, airway epithelial cells, red blood cells, monocytes, DCs, and T lymphocytes |
| P2Y14 | UDP-glucose | 0.1-0.5 | PLC-β activation | Hematopoietic cells, MoDCs, and human airway epithelial cells |
MoDCs indicates monocyte-derived dendritic cells.