High-affinity permease involved in the transport of the cationic amino acids (e.g. arginine, and, to a lower extent, citrulline and glutamate). Transport mostly basic amino acids, and, to a lower extent neutral and acidic amino acids. Optimal transport of arginine at pH 5. Expressed in roots, stems, flowers, seeds, and leaves. Mostly present in leaf rims and cotyledons of developing seedlings. Belongs to the amino acid-polyamine-organocation (APC) superfamily. Cationic amino acid transporter (CAT) (TC 2.A.3.3) family.