F
IPR000332

Beta 2 adrenoceptor

InterPro entry
Short nameADRB2_rcpt
family relationships

Description

This entry represents the beta 2 receptor; it mediates relaxation of smooth muscle including vascular beds, bronchus, intestine and uterus
[4, 2]
. Beta 2 adrenoceptors, also mediate glycogenlysis and glucogenesis in the liver
[5]
, regulate cell metabolism in skeletal muscle
[6]
and inhibit the activity of leukocytes and other blood cells. The receptors are found in the heart, where they are involved in increased cardiac output, although to a lesser extent than beta 1 adrenoceptor. The receptors are located presynaptically in nerves, where they facilitate neurotransmitter release, and in the brain, where they regulate a variety of physiological processes
[1]
.

The adrenoceptors (or adrenergic receptors) are rhodopsin-like G protein-coupled receptors that are targets of the catecholamines, especially norepinephrine (noradrenaline) and epinephrine (adrenaline). Many cells possess these receptors, and the binding of a catecholamine to the receptor will generally stimulate the sympathetic nervous system, effect blood pressure, myocardial contractile rate and force, airway reactivity, and a variety of metabolic and central nervous system functions. The clinical uses of adrenergic compounds are vast. Agonists and antagonists interacting with adrenoceptors have proved useful in the treatment of a variety of diseases, including hypertension, angina pectoris, congestive heart failure, asthma, depression, benign prostatic hypertrophy, and glaucoma. These drugs are also useful in several other therapeutic situations including shock, premature labour and opioid withdrawal, and as adjuncts to general anaesthetics.

There are three classes of adrenoceptors, based on their sequence similarity, receptor pharmacology and signalling mechanisms
[3]
. These three classes are alpha 1 (a Gq coupled receptor), alpha 2 (a Gi coupled receptor) and beta (a Gs coupled receptor), and each can be further divided into subtypes
[9]
. The different subtypes can coexist in some tissues, but one subtype normally predominates.

There are three subtypes of beta adrenoceptors (beta 1-3), the division is mainly based on their affinities to adrenergic agonists and antagonists. All three subtypes act in the main by activating a Gs protein
[8]
, activating adenylate cyclase activity. The beta 2 subtype also couples to Gi/o protein
[8, 10]
. Beta adrenoceptor selective agonists (beta blockers) are used in the treatment of asthma, angina, cardiac conditions and have proven useful in the treatment of migraine, anxiety disorders and hyperthyroidism, and, when applied topically, are useful in the treatment of glaucoma
[7]
.

References

1.The sympathetic nerve--an integrative interface between two supersystems: the brain and the immune system. Elenkov IJ, Wilder RL, Chrousos GP, Vizi ES. Pharmacol. Rev. 52, 595-638, (2000). PMID: 11121511

2.Role of adenylate and guanylate cyclases in beta1-, beta2-, and beta3-adrenoceptor-mediated relaxation of internal anal sphincter smooth muscle. Li F, De Godoy M, Rattan S. J. Pharmacol. Exp. Ther. 308, 1111-20, (2004). View articlePMID: 14711933

3.A study of the adrenotropic receptors. AHLQUIST RP. Am. J. Physiol. 153, 586-600, (1948). PMID: 18882199

4.Effects of acute and chronic administration of beta-adrenoceptor ligands on airway function in a murine model of asthma. Callaerts-Vegh Z, Evans KL, Dudekula N, Cuba D, Knoll BJ, Callaerts PF, Giles H, Shardonofsky FR, Bond RA. Proc. Natl. Acad. Sci. U.S.A. 101, 4948-53, (2004). View articlePMID: 15069206

5.Antibiotic treatment of spontaneous bacterial peritonitis: don't forget enterococci! Pariente EA. Gastroenterology 102, 375-6, (1992). PMID: 1558559

6.Functional expression of beta2 adrenergic receptors responsible for protection against oxidative stress through promotion of glutathione synthesis after Nrf2 upregulation in undifferentiated mesenchymal C3H10T1/2 stem cells. Takahata Y, Takarada T, Iemata M, Yamamoto T, Nakamura Y, Kodama A, Yoneda Y. J. Cell. Physiol. 218, 268-75, (2009). View articlePMID: 18814142

7.The selectivity of beta-adrenoceptor antagonists at the human beta1, beta2 and beta3 adrenoceptors. Baker JG. Br. J. Pharmacol. 144, 317-22, (2005). View articlePMID: 15655528

8.G(i)-dependent localization of beta(2)-adrenergic receptor signaling to L-type Ca(2+) channels. Chen-Izu Y, Xiao RP, Izu LT, Cheng H, Kuschel M, Spurgeon H, Lakatta EG. Biophys. J. 79, 2547-56, (2000). View articlePMID: 11053129

9.Subtypes of alpha 2-adrenoceptors: pharmacological and molecular biological evidence converge. Bylund DB. Trends Pharmacol. Sci. 9, 356-61, (1988). View articlePMID: 2855960

10.Protein kinase A-mediated phosphorylation of the beta 2-adrenergic receptor regulates its coupling to Gs and Gi. Demonstration in a reconstituted system. Zamah AM, Delahunty M, Luttrell LM, Lefkowitz RJ. J. Biol. Chem. 277, 31249-56, (2002). View articlePMID: 12063255

GO terms

Cross References

  • IUPHAR receptor code
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