Plays an important role in deacetylating mercapturic acids in kidney proximal tubules. Also acts on N-acetyl-aromatic amino acids (By similarity). an N-acyl-aromatic L-alpha-amino acid + H2O = a carboxylate + an aromatic L-alpha-amino acid an N-acetyl-L-cysteine-S-conjugate + H2O = acetate + an S-substituted L-cysteine Binds 1 zinc ion per subunit. Exists as a mixture of homodimers and homotetramer, both catalytically active. (Microbial infection) Interacts with hepatitis C virus/HCV core protein. Predominantly localized in the apical membrane of cells in the S1 segment. In the proximal straight tubules (S2 and S3 segments) is expressed diffusely throughout the cytoplasm. Belongs to the AspA/AstE family. Aspartoacylase subfamily.