Hypocretin Receptor 1 (HCRTR1)

Orexin Receptor 1 (OX1R) is one of two receptors that recognize the peptide neurotransmitters orexin A and orexin B. Orexin A and B are 33 and 28 amino acids in length, respectively, and are derived from a common precursor termed prepro-orexin. OX1R binds orexin A with greater affinity than orexin B (a one order of magnitude difference), while OX2R binds both ligands with similar affinities.Both OX1R and OX2R belong to the 7-transmembrane domain, G protein-coupled receptor (GPCR) superfamily. OX1R 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.