Phosphofurin acidic cluster sorting protein 1 is a protein with a putative role in the localization of trans-Golgi network (TGN) membrane proteins. Mouse and rat homologs have been identified and studies of the homologous rat protein indicate a role in directing TGN localization of furin by binding to the protease's phosphorylated cytosolic domain.

Coat protein that is involved in the localization of trans-Golgi network (TGN) membrane proteins that contain acidic cluster sorting motifs. Controls the endosome-to-Golgi trafficking of furin and mannose-6-phosphate receptor by connecting the acidic-cluster-containing cytoplasmic domain of these molecules with the adapter-protein complex-1 (AP-1) of endosomal clathrin- coated membrane pits.