Proteasome subunit alpha type-8, also known as PSMA8, belongs to the peptidase T1A family. PSMA8 is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATPdependent proteolytic activity.