Putative carrier protein indirectly involved in the uptake of malate and fumarate to the vacuole, probably by regulating the energization across the tonoplast. Uptake of malate to vacuoles is inhibited by citrate and by the uncoupler carbonyl-cyanide m-chlorophenylhydrazone, but seems to be not affected by sodium. Critical for pH homeostasis. Tonoplast. Expressed in leaves, stems and flowers. Induced by malate and by acidification of the cytoplasm. Belongs to the SLC13A/DASS transporter (TC 2.A.47) family.