May catalyze the decarboxylation of L-aspartate, 3-sulfino-L- alanine (cysteine sulfinic acid), and L-cysteate to beta-alanine, hypotaurine and taurine, respectively. Does not exhibit any decarboxylation activity toward glutamate. . This is the function of GADL1 (GAD like acidic amino acid decarboxylase 1, ENSG00000144644).