A novel vanadium transporter of the Nramp family expressed at the vacuole of vanadium-accumulating cells of the ascidian Ascidia sydneiensis samea

► A homolog of Nramp, AsNramp, was cloned from a vanadium-rich ascidian. ► AsNramp is a novel VO2+/H+ antiporter on the vacuolar membrane. ► A rat homolog, DCT1, did not transport VO2+ under the same conditions. ► This is the first report on a membrane transporter for vanadium ions.