High affinity gamma-aminobutyric acid (GABA) transporter probably involved in GABA uptake into cells. When expressed in a heterologous system (Xenopus oocytes), imports GABA, butylamine, beta- and L-Alanine, 5-aminovaleric acid, 6-aminocaproic acid and 8-aminocaprylic acid, but does not mediate the transport of proline or glycine betaine. Optimum pH is 4.5-5.5. Plasma membrane. Highly expressed in flowers and at lower levels in roots, leaves and stems. By wounding and senescence. Belongs to the amino acid/polyamine transporter 2 family. Amino acid/auxin permease (AAAP) (TC 2.A.18.2) subfamily.