Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Our recent studies have identified a new gene family, the ZIP family, of metal ion transport proteins. The members of this family share significant sequence similarity and predicted topology. These proteins are ubiquitous among eukaryotes; closely related genes are found in the genomes of organisms as diverse as fungi, protozoa, plants, nematodes, and humans. The members of this family that have been examined experimentally have been shown to encode metal ion transport proteins. The IRT1 (iron-regulated transporter) gene of the plant Arabidopsis thaliana encodes an Fe(II) transporter. This gene was cloned by functional expression in a yeast strain defective for iron uptake and yeast expressing IRT1 possess a novel Fe(II) uptake activity. 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. The ZRT1 and ZRT2 (zinc-regulated transporter) genes of the yeast Saccharomyces cerevisiae encode zinc transporters. Moreover, the newly-isolated ZIP1, ZIP2, and ZIP3 genes of A. thaliana also encode zinc transporters. Given the role of these genes in metal ion uptake, it is likely that other genes in this family play similar roles in the organisms in which they are found.

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Presentation Number SAeide0217
Keywords: yeast, transporter, uptake, eukaryotes