Angiotensin II receptor type 2, also known as the AT2 receptor is a protein that in humans is encoded by the AGTR2 gene. [5]
Angiotensin II receptor type 2, also known as the AT2 receptor is a protein that in humans is encoded by the AGTR2 gene. [5]
Angiotensin II is a potent pressor hormone and a primary regulator of aldosterone secretion. It is an important effector controlling blood pressure and volume in the cardiovascular system. It acts through at least two types of receptors termed AT1 and AT2. AGTR2 belongs to a family 1 of G protein-coupled receptors. It is an integral membrane protein. It plays a role in the central nervous system and cardiovascular functions that are mediated by the renin–angiotensin system. This receptor mediates programmed cell death (apoptosis). Consistent with its apoptotic function, angiotensin II receptor type II also opposes cell proliferation, as demonstrated by its antagonism of MAPK activity in cardiac fibroblasts during interstitial fibrosis. [6] In adults, it is highly expressed in myometrium with lower levels in adrenal gland and fallopian tube. It is highly expressed in fetal kidney and intestine. The human AGTR2 gene is composed of three exons and spans at least 5 kb. Exons 1 and 2 encode for 5' untranslated mRNA sequence and exon 3 harbors the entire uninterrupted open reading frame. [5]
Stimulation of AT2 by the selective agonist CGP 42112A increases mucosal nitric oxide production. [7]
| Characteristic | Phenotype |
|---|---|
| Homozygote viability | Normal |
| Fertility | Normal |
| Body weight | Normal |
| Anxiety | Normal |
| Neurological assessment | Normal |
| Grip strength | Normal |
| Hot plate | Normal |
| Dysmorphology | Normal |
| Indirect calorimetry | Normal |
| Glucose tolerance test | Normal |
| Auditory brainstem response | Normal |
| DEXA | Normal |
| Radiography | Normal |
| Body temperature | Normal |
| Eye morphology | Normal |
| Clinical chemistry | Normal |
| Haematology | Normal |
| Peripheral blood lymphocytes | Normal |
| Micronucleus test | Normal |
| Heart weight | Normal |
| Eye Histopathology | Normal |
| All tests and analysis from [8] [9] |
Model organisms have been used in the study of AGTR2 function. A conditional knockout mouse line, called Agtr2tm1a(EUCOMM)Wtsi [10] [11] was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists — at the Wellcome Trust Sanger Institute. [12] [13] [14]
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. [8] [15] Twenty one tests were carried out on mutant mice, but no significant abnormalities were observed. [8]
Angiotensin II receptor type 2 (AGTR2) gene is a protein coding gene responsible for encoding AGTR2, the integral membrane protein that binds to two different G-protein coupled receptors. AGTR2 has recently been discovered to play a role in modifying lung disease. This receptor functions to mediate signaling in lung fibrosis and regulate nitric oxide synthase expression in pulmonary endothelium. [16] AGTR2 has recently been prescribed as a target for lung inflammation therapy in cases of cystic fibrosis (CF). The X-chromosome region associated with CF lung disease is located in a non-coding region 3′ of the AGTR2 gene. The modification effect is likely due to variation in gene regulation rather than a change in protein coding sequence.
Variants at the X-chromosome locus containing AGTR2 gene were identified as significantly associating with lung function in patients with cystic fibrosis. Genetically modified mouse studies determined that absence of the AGTR2 gene normalized pulmonary function indicators in two independent CF mouse models. Furthermore, pharmacological antagonism of AGTR2 signaling improved lung function in CF mice to near wild-type levels. Manipulation of the angiotensin-signaling pathway to reduce AGTR2 signaling may be translatable for the treatment or prevention of CF. [17]
Angiotensin II receptor type 2 has been shown to interact with MTUS1. [18]
Renin, also known as an angiotensinogenase, is an aspartic protease protein and enzyme secreted by the kidneys that participates in the body's renin–angiotensin–aldosterone system (RAAS)—also known as the renin–angiotensin–aldosterone axis—that increases the volume of extracellular fluid and causes arterial vasoconstriction. Thus, it increases the body's mean arterial blood pressure.
Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys.
The angiotensin II receptors, (ATR1) and (ATR2), are a class of G protein-coupled receptors with angiotensin II as their ligands. They are important in the renin–angiotensin system: they are responsible for the signal transduction of the vasoconstricting stimulus of the main effector hormone, angiotensin II.
Angiotensin II receptor blockers (ARBs), formally angiotensin II receptor type 1 (AT1) antagonists, also known as angiotensin receptor blockers, angiotensin II receptor antagonists, or AT1 receptor antagonists, are a group of pharmaceuticals that bind to and inhibit the angiotensin II receptor type 1 (AT1) and thereby block the arteriolar contraction and sodium retention effects of renin–angiotensin system.
Cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein and anion channel in vertebrates that is encoded by the CFTR gene.
Vasopressin receptor 2 (V2R), or arginine vasopressin receptor 2, is a protein that acts as receptor for vasopressin. AVPR2 belongs to the subfamily of G-protein-coupled receptors. Its activity is mediated by the Gs type of G proteins, which stimulate adenylate cyclase.
The epithelial sodium channel(ENaC), (also known as amiloride-sensitive sodium channel) is a membrane-bound ion channel that is selectively permeable to sodium ions (Na+). It is assembled as a heterotrimer composed of three homologous subunits α or δ, β, and γ, These subunits are encoded by four genes: SCNN1A, SCNN1B, SCNN1G, and SCNN1D. The ENaC is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney's nephrons. In addition to being implicated in diseases where fluid balance across epithelial membranes is perturbed, including pulmonary edema, cystic fibrosis, COPD and COVID-19, proteolyzed forms of ENaC function as the human salt taste receptor.
The Apelin Receptor is a G protein-coupled receptor. APLNR possesses two endogenous ligands which are APELIN and ELABELA. The structure of APLNR was resolved in 2017
Angiotensin II receptor type 1(AT1) is the best characterized angiotensin receptor. It is encoded in humans by the AGTR1 gene. AT1 has vasopressor effects and regulates aldosterone secretion. It is an important effector controlling blood pressure and volume in the cardiovascular system. Angiotensin II receptor blockers are drugs indicated for hypertension, diabetic nephropathy and congestive heart failure.
Interleukin 8 receptor, alpha is a chemokine receptor. This name and the corresponding gene symbol IL8RA have been replaced by the HGNC approved name C-X-C motif chemokine receptor 1 and the approved symbol CXCR1. It has also been designated as CD181. The IUPHAR Committee on Receptor Nomenclature and Drug Classification use the HGNC recommended name, CXCR1.
Bradykinin receptor B2 is a G-protein coupled receptor for bradykinin, encoded by the BDKRB2 gene in humans.
P2Y purinoceptor 1 is a protein that in humans is encoded by the P2RY1 gene.
Metabotropic glutamate receptor 8 is a protein that in humans is encoded by the GRM8 gene.
The Prostacyclin receptor, also termed the prostaglandin I2 receptor or just IP, is a receptor belonging to the prostaglandin (PG) group of receptors. IP binds to and mediates the biological actions of prostacyclin (also termed Prostaglandin I2, PGI2, or when used as a drug, epoprostenol). IP is encoded in humans by the PTGIR gene. While possessing many functions as defined in animal model studies, the major clinical relevancy of IP is as a powerful vasodilator: stimulators of IP are used to treat severe and even life-threatening diseases involving pathological vasoconstriction.
G protein-coupled receptor kinase 5 is a member of the G protein-coupled receptor kinase subfamily of the Ser/Thr protein kinases, and is most highly similar to GRK4 and GRK6. The protein phosphorylates the activated forms of G protein-coupled receptors to regulate their signaling.
Type-1 angiotensin II receptor-associated protein is a protein that in humans is encoded by the AGTRAP gene.
In molecular cloning and biology, a gene knock-in refers to a genetic engineering method that involves the one-for-one substitution of DNA sequence information in a genetic locus or the insertion of sequence information not found within the locus. Typically, this is done in mice since the technology for this process is more refined and there is a high degree of shared sequence complexity between mice and humans. The difference between knock-in technology and traditional transgenic techniques is that a knock-in involves a gene inserted into a specific locus, and is thus a "targeted" insertion. It is the opposite of gene knockout.
Mitochondrial tumor suppressor 1 (MTSG1) or Microtubule-Associated Scaffold Protein 1 (MTUS1) is a candidate tumor suppressor protein encoded by the MTUS1 gene in humans. Expression levels of MTUS1 was reported to be lost in various types of human malignancies such as colon, ovarian, head-and-neck, pancreas, breast cancers, bladder, gastric, and lung cancers.
G-protein-coupled receptor kinase 3 (GRK3) is an enzyme that in humans is encoded by the ADRBK2 gene. GRK3 was initially called Beta-adrenergic receptor kinase 2 (βARK-2), and is a member of the G protein-coupled receptor kinase subfamily of the Ser/Thr protein kinases that is most highly similar to GRK2.
EMA401 is a drug under development for the treatment of peripheral neuropathic pain. Trials were discontinued in 2015, with new trials scheduled to begin March, 2018. It was initially established as a potential drug option for patients suffering pain caused by postherpetic neuralgia. It may also be useful for treating various types of chronic neuropathic pain EMA401 has shown efficacy in preclinical models of shingles, diabetes, osteoarthritis, HIV and chemotherapy. EMA401 is a competitive antagonist of angiotensin II type 2 receptor (AT2R) being developed by the Australian biotechnology company Spinifex Pharmaceuticals. EMA401 target angiotensin II type 2 receptors, which may have importance for painful sensitisation.