Anti-Orexin Receptor 2

Orexin Receptor 2 (OX2R) (also known as hypocretin receptor 2) is one of two receptors that recognize the peptide neurotransmitters orexin A and orexin B.1 Orexin A and B are 33 and 28 amino acids in length, respectively, and are derived from a common precursor termed prepro-orexin. OX2R binds both orexin A and B with similar affinities while OX1R binds orexin A with greater affinity than orexin B (a one order of magnitude difference).2,3 Both OX2R and OX1R belong to the 7-transmembrane domain, G protein-coupled receptor (GPCR) superfamily. OX2R is thought to transmit signals through the Ga11 class of G proteins, resulting in the activation of phospholipase C with subsequent triggering of the phosphatidylinositol cascade and an influx of extracellular Ca2 , probably through transient receptor potential (TRP) channels. OX2R can also transmit signals through inhibitory Gi G proteins, although the mechanism is less well understood.2,3 The physiological functions of the orexin system (OX1R, OX2R, and their ligands) have been a matter of intense research over the last few years. OX2R is expressed in both the central nervous system and peripheral locations such as gastrointestinal tissues, pancreas, and testis.2 The best studied physiological role of OX2R is its involvement in the regulation of sleep and wakefulness states. Studies in mice lacking the orexin gene and dogs expressing a null mutation of the OX2R show a remarkably similar phenotype to human narcolepsy, a condition characterized by excessive daytime sleepiness, inability to maintain vigilant states, and defects in the regulation of rapid eye movement (REM) sleep.4 In addition, the orexin system is involved in regulating autonomic functions such as blood pressure and heart rate, as well as in mechanisms that regulate the reward response in the brain.4 We are pleased to offer a highly specific antibody directed against an epitope located in the intracellular C-terminal domain of rat Orexin Receptor 2. Anti-OX2R antibody can be used in Western blot, immunocytochemical, and immunohistochemical applications and recognizes OX2R from rat, mouse, and human samples.