Background：

This gene encodes a member of the GPRASP (G protein-coupled receptor associated sorting protein) family. The protein may modulate lysosomal sorting and functional down-regulation of a variety of G-protein coupled receptors. It targets receptors for degradation in lysosomes. The receptors interacting with this sorting protein include D2 dopamine receptor (DRD2)， delta opioid receptor (OPRD1)， beta-2 adrenergic receptor (ADRB2)， D4 dopamine receptor (DRD4) and cannabinoid 1 receptor (CB1R). Multiple alternatively spliced transcript variants encoding the same protein have been identified.