Isolation and characterization of Arabidopsis thaliana ISU1 gene.

We describe the isolation of a cDNA encoding Arabidopsis thaliana ISU1 (AtISU1), which regulates iron homeostasis in the mitochondria. The AtISU1 gene contained an open reading frame that encoded 167 amino acid residues. Northern blot analysis demonstrated that AtISU1 gene was ubiquitously expressed in plant tissues examined. The yeast seo5-1, which harbors a single base-pair deletion in ScISU1, is a suppressor of oxidative damage in sod1-deficient mutant. Based on comparative expression analyses using yeast ISU1 gene (ScISU1) in seo5-1 mutant, we found that AtISU1 acts as a counterpart of ScISU1.