Hydrolyzes the N-acetamido groups of N-acetyl-D-glucosamine residues in chitin to form chitosan and acetate (PubMed:17400891, PubMed:22354955). Chitosan is required to anchor melanin to the cell wall, for maintenance of cell wall integrity, and for proper cytokinesis (PubMed:17400891). Chitosan offers an advantage during infection as it is less readily detected than chitin by host immunosurveillance mechanisms (PubMed:21784998, PubMed:32071275, PubMed:27165801). [(1->4)-N-acetyl-beta-D-glucosaminyl](n) + n H2O = n acetate + chitosan GPI-anchored cell membrane protein (GPI-PMP) (PubMed:22354955). Non-covalently associated to the cell wall independently of both its GPI-anchor and beta-1,6-glucan (PubMed:22354955). Cell membrane localization is critical for effective deacetylase activity (PubMed:22354955). Expressed during unicellular vegetative growth. Repressed by the antifungal agent caspofungin. The GPI anchor is required for the attachment to the cell membrane but not for cell surface targeting. Triple knockout of CDA1, CDA2 and CDA3 results in an absence of cell wall chitosan, melanization of surrounding media, an increase in capsule size, sensitivity to cell wall (sodium dodecyl sulfate), osmotic (NaCl) and heat stress, and avirulence in a mouse intranasal infection model. Recombinant CDA2 is a potential vaccine candidiate; induces protective immunity in mice against infection (PubMed:29184017). A strain lacking CDA1, CDA2, and CDA3 is a potential vaccine candidate; inoculation with heat-killed CDA1-CDA2-CDA3 knockout cells in mouse induces protective immunity to subsequent virulent fungal infection (PubMed:27165801). Belongs to the polysaccharide deacetylase family.