Endosomal trafficking of the G protein-coupled receptor somatostatin receptor 3

► A number of human diseases are caused by mutations in GPCR. ► SSTR3 traffics through distinct Rab domains. ► SSTR3 sorting in early endosomes is regulated by Rab21 and Rab4. ► SSTR3 traffic in recycling endosomes is regulated by Rab11.