Dorfin is a multi-pass membrane, RING-IBR type, E3 ubiquitin-protein ligase. It is widely expressed with highest levels found in heart and ubiquitous expression throughout the central nervous system. Dorfin functions by accepting ubiquitin in the form of a thioester from UBCH7 and UBC8 and then transferring it to the targeted substrates. Dorfin is responsible for ubiquitylating synphilin-1, CaSR and mutant variants of SOD-1, a protein at fault for familial ALS (amyotrophic lateral sclerosis). Dorfin physically interacts with VCP (Valosin-containing protein) via its C-terminus. Together these two proteins are associated with the formation of ubiquitylated inclusions (UBIs) that characterize many neurodegenerative disorders, such as Parkinson’s disease and ALS. This association with UBIs suggests that Dorfin plays an important role in the disease process.