This gene encodes a member of the ring between ring fingers (RBR) protein family, and the encoded protein contains two RING-finger motifs and an in between RING fingers motif. This protein is an E3 ubiquitin ligase that is localized to Lewy bodies, and ubiquitylates synphilin-1, which is an interacting protein of alpha synuclein in neurons. The encoded protein may be involved in amyotrophic lateral sclerosis and Parkinson's disease. Alternative splicing results in multiple transcript variants.