Zinc Transporter of Arabidopsis thaliana AtMTP1 is Localized to Vacuolar Membranes and Implicated in Zinc Homeostasis

• DOI: 10.1093/pcp/pci015
• Publication Date: 2005-01-14T21:13:55Z
• Authors: Yoshihiro Kobae; Tomohiro Uemura; Masa H. Sato; Miwa Ohnishi; Tetsuro Mimura; Tsuyoshi Nakagawa; Masayoshi Maeshima
• Keywords: Homeostasis; Protoplast

Cation diffusion facilitator (CDF) proteins belong to a family of heavy metal efflux transporters that might play an essential role in homeostasis and tolerance ions. We investigated the subcellular localization Arabidopsis thaliana AtMTP1, member CDF family, its physiological Zn using MTP1-deficient mutant plants. AtMTP1 was immunochemically detected as 43 kDa protein vacuolar membrane fractioned by sucrose density gradient centrifugation. The expression level suspension-cultured cells not affected concentration medium. When fused with green fluorescent transiently expressed protoplasts prepared from cells, fluorescence clearly observed membrane. A T-DNA insertion line for displays enhanced sensitivity high concentrations ranging 200 500 µM, but Zn-deficient conditions. Mesophyll mtp1-1 plants grown presence µM were degraded, suggesting at causes serious damage leaves plays crucial preventing this Thus we propose is localized involved sequestration excess cytoplasm into vacuoles maintain homeostasis.