Cleaves proteins C-terminally to mono- and paired-basic residues. Involved in the shedding of a subset of GPI-anchored plasma membrane proteins from the cell surface, including itself, GAS1 and MSB2. May also play a role in the maturation of GPI-mannoproteins associated with the cell wall. Can process the alpha-mating factor precursor. Required for cell wall integrity. Hydrolyzes various precursor proteins with Arg or Lys in P1, and commonly Arg or Lys also in P2. The P3 amino acid is usually non-polar, but otherwise additional basic amino acids are favorable in both non-prime and prime positions. Optimum pH is 4.0. Consists of an alpha and a beta subunit, which are maintained together by a disulfide bond. GPI-anchored plasma membrane protein (GPI-PMP), peripherally distributed over the entire cell surface. Positively regulated by cell integrity signaling through MPK1 in response to cell wall perturbation. The zymogen is transported to the periplasm, where the propeptide is removed and the enzyme is further subjected to an internal, autocatalytic cleavage to generate an alpha/beta two-subunit endopeptidase. The proteolytic processing at the cell surface is regulated by the environmental pH. Extensively N-glycosylated. Present with 5000 molecules/cell in log phase SD medium. Belongs to the peptidase A1 family.