title: Cloning and functional characterization of the Rhizopus oryzae high affinity iron permease (rFTR1) gene.
abstract: Rhizopus oryzae is the most common etiologic agent of mucormycosis. Clinical and animal model data clearly demonstrate that the presence of elevated available serum iron predisposes the host to develop mucormycosis. Therefore, the high affinity iron permease (rFTR1) which encodes a protein required to scavenge iron from the environment, is highly likely to be a critical determinant of virulence for R. oryzae. We have cloned rFTR1 by using a PCR approach relying on degenerate primers designed from the conserved regions of Saccharomyces cerevisiae high affinity iron permease. Sequence analysis of a 2.0 kb EcoRI genomic clone revealed a single open reading frame of 1107 bp that lacked introns. The putative rFtr1p had significant homology to known fungal high affinity iron permeases from Candida albicans (46% identity) and S. cerevisiae (44% identity). In R. oryzae, rFTR1 was expressed in iron-depleted and not in iron-rich media. Finally, rFTR1 restored the ability of an ftr1 null mutant of S. cerevisiae to grow on iron-limited medium and to take up radiolabeled iron, whereas S. cerevisiae transformed with the empty vector did not. These data demonstrate that we have cloned the gene encoding a R. oryzae high affinity iron permease and the putative rFtr1p is involved in assimilation of iron from iron-depleted environments.
authors.affiliation: Harbor-UCLA Research and Education Institute, Torrance, CA 90502, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Fu
authors.forename: Helen
authors.initials: H
authors.lastname: Lee
authors.forename: Mary
authors.initials: M
authors.lastname: Collins
authors.forename: Huei-Fung
authors.initials: HF
authors.lastname: Tsai
authors.forename: Brad
authors.initials: B
authors.lastname: Spellberg
authors.forename: John E
authors.initials: JE
authors.lastname: Edwards
authors.forename: Kyung J
authors.initials: KJ
authors.lastname: Kwon-Chung
authors.forename: Ashraf S
authors.initials: AS
authors.lastname: Ibrahim
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport; D002455:Cell Division; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology*; D007501:Iron / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000502:physiology*; D008969:Molecular Sequence Data; D012233:Rhizopus / Q000201:enzymology* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D016415:Sequence Alignment
chemical_list: C098723:FTR1 protein, S cerevisiae; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D007501:Iron