hIscA:: a protein implicated in the biogenesis of iron-sulfur clusters

This article describes the gene called hIscA, its transcription product and protein (hIscA) and its putative function. We screened a human brain cDNA expression library with serum from a patient suffering from the autoimmune Sjogren's syndrome (S5:823/94). One cDNA of 1.6-kbp clone was isolated. This clone contains the entire coding sequence for a protein unknown in human. IscA is ubiquitously expressed and expression levels vary among tissues. The 15.5-kDa predicted protein contains a structural domain named HESB, is located in the mitochondria and is implicated in the biogenesis of iron-sulfur clusters. Since this unknown protein is related to IscA-like protein, we suggest as name for this protein hIscA. The recombinant protein is recognized by a rabbit polyclonal antiserum generated against the carboxyl extreme of the Saccharomyces cerevisiae orthologue Isal. In this article, we demonstrate the functional homology between hIscA and Isal proteins using Isal null mutant S. cerevisiae transformed with hIscA in a yeast functional complementation test. We also describe the rat homologue to this gene. (C) 2004 Elsevier B.V. All rights reserved.