This gene encodes a component of the 26S proteasome. The 26S proteasome is a large multiprotein complex that catalyzes the degradation of ubiquitinated intracellular proteins. The encoded protein is a component of the 19S regulatory cap complex of the 26S proteasome and mediates substrate deubiquitination. A pseudogene of this gene is also located on the long arm of chromosome 2. [provided by RefSeq, Feb 2012].