This gene encodes a nuclear protein which is involved in cell cycle regulation. The encoded protein is a ubiquitin ligase capable of ubiquinating PCNP (PEST­containing nuclear protein), and together they may play a role in tumorigenesis. The encoded protein contains an NIRF_N domain, a PHD finger, a set­ and ring associated (SRA) domain, and a RING finger domain and several of these domains have been shown to be essential for the regulation of cell proliferation. This protein may also have a role in intranuclear degradation of polyglutamine aggregates. Alternative splicing results in multiple transcript variants, some of which are non­protein coding. [Provided by RefSeq, Feb 2012].