Angiotensin receptor

Angiotensin receptors are "cell surface proteins that bind angiotensins and trigger intracellular changes influencing the behavior of cells.

The angiotensin receptors are G protein-coupled cell surface receptors responsible for the signal transduction of the main effector hormone. The AT₁ and AT₂ receptors have a sequence identity of ~30%, but have a similar affinity for angiotensin II, their main ligand.

Classification

angiotensin II receptor, type 1
Identifiers
Symbol(s)	AGTR1 AGTR1B
Entrez	185
OMIM	106165
RefSeq	NM_000685
UniProt	P30556
Other data
Locus	Chr. 3 q21-q25

angiotensin II receptor, type 2
Identifiers
Symbol(s)	AGTR2
Entrez	186
OMIM	300034
RefSeq	NM_000686
UniProt	P50052
Other data
Locus	Chr. X q22-q23

The AT₁ receptor is the best elucidated angiotensin receptor. It is coupled to phospholipase C and angiotensin II increases the cytosolic Ca²⁺ level. It also inhibits adenylate cyclase and activate various tyrosine kinases. Effects mediated by the AT₁ receptor include vasoconstriction, aldosterone synthesis and secretion, increased vasopressin secretion, cardiac hypertrophy, augmentation of peripheral noradrenergic activity, vascular smooth muscle cells proliferation, decreased renal blood flow, renal renin inhibition, renal tubular sodium reuptake, modulation of central sympathetic nervous system activity, cardiac contractility, central osmocontrol and extracellular matrix formation.

AT₂ receptors are more plentiful in the foetus and neonate. Effects mediated by the AT₂ receptor include inhibition of cell growth, fetal tissue development, modulation of extracellular matrix, neuronal regeneration, apoptosis, cellular differentiation and maybe vasodilation.

Other poorly characterized subtypes include AT₃ receptor and AT₄ receptor. The AT₄ receptor is activated by angiotensin IV, and may play a role in regulating the CNS extracellular matrix.

External links

• IUPHAR GPCR Database - Angiotensin Receptors