Proteasome (prosome, macropain) subunit, alpha type, 2 (PSMA2) is a component of the proteasome, a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. 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. PSMA2 is a member of the peptidase T1A family, that is a 20S core alpha subunit [taken from NCBI Entrez Gene (Gene ID: 5683)].