Characteristics of AT1 and AT2 angiotensin receptor subtypes
| Angiotensin Receptors | ||
|---|---|---|
| AT1 | AT2 | |
| Gene | at 1 | at 2 |
| Chromosome | Chromosome 3 | Chromosome X |
| Structure | Seven transmembrane spanning 359 amino acids (rat, human) | Seven transmembrane spanning 363 amino acids (rat, human) |
| Amino acid site for Ang II binding | N-terminal extension extracellular loop 1, extracellular loop 3 | |
| Molecular mass | ∼50 kDa | ∼44 kDa |
| Potency order | Ang II > Ang III | Ang II = Ang III |
| Agonists | None known | CGP42112A (high concentrations) |
| Antagonists | Losartan, irbesartan, valsartan, candesartan, tasosartan, telmisartan, eprosartan | PD123319, PD123177 |
| Effector | Gq/11 | G protein |
| Signal transduction mediators | PLC, Ca2+ channels, tyrosine kinases, MAP kinases, PLD, PLA2 | cGMP, phosphatases |
| Location | Mainly in VSMC, lung, liver, brain, kidney | Mainly in fetal tissues, brain, reproductive tissues |
VSMC, vascular smooth muscle cells.