This gene encodes a subunit of the PA700/19S complex, which is the regulatory component of the 26S proteasome. The 26S proteosome complex is required for ubiquitin-dependent protein degradation. This protein is a non-ATPase subunit that may be involved in protein-protein interactions. Aberrant expression of this gene may paly a role in tumorigenesis. Two transcripts encoding different isoforms have been described. Pseudogenes have been identified on chromosomes 3 and 20.