Proteasome 26S Subunit, Non ATPase 12 (PSMD12)

The 26S proteasome is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMD12 encodes a non-ATPase subunit of the 19S regulator. A pseudogene has been identified on chromosome 3.The deduced 456-amino acid PSMD12 protein has a calculated molecular mass of 52,903 Da. The authors identified a putative S. cerevisiae homolog, which they named NAS5, that shares 41.1% amino acid sequence identity with PSMD12. Disruption of the NAS5 gene resulted in lethality.