Predicted to be involved in proteasome-mediated ubiquitin-dependent protein catabolic process. Predicted to act upstream of or within ubiquitin-dependent protein catabolic process. Predicted to be located in cytoplasm. Predicted to be part of proteasome core complex, alpha-subunit complex. Predicted to be active in cytosol and nucleus. Orthologous to human PSMA4 (proteasome 20S subunit alpha 4).