Vacuolar membrane transporter for lysine; exporter necessary for lysine mobilization from the vacuole under conditions of lysine starvation and for rapid exchange between the vacuole and cytosol during active growth; member of the PQ-loop family, with seven transmembrane domains; similar to mammalian PQLC2 vacuolar transporter; YPQ1 has a paralog, RTC2, that arose from the whole genome duplication