A novel iron-regulated metal transporter from plants identified by functional expression in yeast.
Iron is an essential nutrient for virtually all organisms. The IRT1 (iron-regulated transporter) gene of the plant Arabidopsis thaliana, encoding a probable Fe(II) transporter, was cloned by functional expression in a yeast strain defective for iron uptake. Yeast expressing IRT1 possess a novel Fe(II) uptake activity that is strongly inhibited by Cd. IRT1 is predicted to be an integral membrane protein with a metal-binding domain. Data base comparisons and Southern blot analysis indicated that IRT1 is a member of a gene family in Arabidopsis. Related sequences were also found in the genomes of rice, yeast, nematodes, and humans. In Arabidopsis, IRT1 is expressed in roots, is induced by iron deficiency, and has altered regulation in plant lines bearing mutations that affect the iron uptake system. These results provide the first molecular insight into iron transport by plants.
Eide
D
D
Department of Biochemistry and Molecular Biology, University of Minnesota School of Medicine, Duluth, 55812, USA.
Broderius
M
M
Fett
J
J
Guerinot
M L
ML
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins; D002352:Carrier Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D027682:Cation Transport Proteins; D003001:Cloning, Molecular; D004926:Escherichia coli; D015870:Gene Expression; D015723:Gene Library; D017343:Genes, Plant; D006801:Humans; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D009348:Nematoda / Q000378:metabolism; D012275:Oryza / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots; D021382:Protein Sorting Signals / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D027682:Cation Transport Proteins; C099651:IRT1 protein, Arabidopsis; D010940:Plant Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D011994:Recombinant Proteins; D007501:Iron