SLC66 Lysosomal amino acid transporters in GtoPdb v.2021.2

This is a family of 5 evolutionarily related proteins. Their structural similarities suggest that they are transporters. Biochemical evidence supports transporter activity for SLC66A1 (LAAT1) and SLC66A4 (CTNS; Cystinosin). The functions of the 3 remaining members of the family are undetermined.