Alpha-2-adrenergic receptors are members of the G protein-coupled receptor superfamily. They include 3 highly homologous subtypes: alpha2A, alpha2B, and alpha2C. These receptors have a critical role in regulating neurotransmitter release from sympathetic nerves and from adrenergic neurons in the central nervous system. This intronless gene encodes the alpha2B subtype, which was observed to associate with eIF-2B, a guanine nucleotide exchange protein that functions in regulation of translation. A polymorphic variant of the alpha2B subtype, which lacks 3 glutamic acids from a glutamic acid repeat element, was identified to have decreased G protein-coupled receptor kinase-mediated phosphorylation and desensitization; this polymorphic form is also associated with reduced basal metabolic rate in obese subjects and may therefore contribute to the pathogenesis of obesity. [provided by RefSeq, Aug 2011]