Arabidopsis thaliana MTP1 is a Zn transporter in the vacuolar membrane which mediates Zn detoxification and drives leaf Zn accumulation

The Arabidopsis thaliana metal tolerance protein I (MTP1) of the cation diffusion facilitator family of membrane transport proteins can mediate the detoxification of Zn in Arabidopsis and yeast. Xenopus laevis oocytes expressing AtMTP1 accumulate more Zn than oocytes expressing the AtMTP1(D94A) mutant or water-injected oocytes. An AtMTP1(D94A) fusion protein localizes to the vacuolar membrane in root and leaf cells. The analysis of Arabidopsis transformed with a promoter-GUS construct suggests that AtMTP1 is not produced throughout the plant, but primarily in the subpopulation of dividing, differentiating and expanding cells. RNA interference-mediated silencing of AtMTP1 causes Zn hypersensitivity and a reduction in Zn concentrations in vegetative plant tissues. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved