Proteasome subunit alpha type-8(PSMA8) is a member of the peptidase T1A family. PSMA8 is a multicatalytic proteinase complex which is distinguished 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 ATP-dependent proteolytic activity. The PSMA8 subunit may be testis-specific.