Beta-arrestin-2, also known as arrestin beta-2, is an intracellular protein that in humans is encoded by the ARRB2 gene.
Members of arrestin/beta-arrestin protein family are thought to participate in agonist-mediated desensitization of G protein-coupled receptors and cause specific dampening of cellular responses to stimuli such as hormones, neurotransmitters, or sensory signals,[5][6][7] as well as having signalling roles in their own right.[8][9][10][11][12] Arrestin beta 2, like arrestin beta 1, was shown to inhibit beta-adrenergic receptor function in vitro. It is expressed at high levels in the central nervous system and may play a role in the regulation of synaptic receptors. Besides the brain, a cDNA for arrestin beta 2 was isolated from thyroid gland, and thus it may also be involved in hormone-specific desensitization of TSH receptors. Multiple alternatively spliced transcript variants have been found for this gene, but the full-length nature of some variants has not been defined.[13]
The protein may interact with the agonist DOI in 5-HT2A receptor signaling.[14][15]
Arrestin beta 2 is crucial for the development of tolerance to morphine and other opioids.