title: [Characterization of Candida albicans ferric reductase genes in response to environmental stresses].
abstract: OBJECTIVE
  Ferric reductases play a central role in iron acquisition and mobilization in C. albicans. This study focuses on stress response strategies exhibited by several ferric reductase genes through function and expression analyses.
  
  
  METHODS
  Northern blot analysis was used to examine ferric reductase genes expression levels in different iron deficiency. We constructed ferric reductase-null mutants by a PCR-based homologous recombination, and examined the effects of gene deletion on cell-surface ferric reductase activity and growth ability under different conditions. Sub-cellular localization of Frpl-GFP fusion was imaged and analyzed by confocal laser scanning fluorescence microscopy.
  
  
  RESULTS
  FRE10 was highly expressed at acidic pH, compared to that at alkaline pH, whereas the expression of FRE2 was just the opposite. Deletion of FRE10 resulted in a significant decreased surface reductase activity at acidic pH, with 75.5% down-regulation compared to wild-type levels. The fre2delta/delta mutant showed significantly attenuated growth ability and cell-surface ferric reductase activity at alkaline pH. Sub-cellular localization revealed that the green fluorescence was accumulated in the vacuoles.
  
  
  CONCLUSIONS
  The expression of both FRE10 and FRE2 is induced in a pH-dependent manner. FRE2 encodes a major cell surface ferric reductase under alkaline pH condition. Frp1 localizes to the vacuole, and might support mobilization and transport of vacuolar ferric iron stores.
authors: Ning
authors: N
authors: Xu
authors: Yong
authors: Y
authors: Liang
authors: Xinxin
authors: X
authors: Cheng
authors: Kefan
authors: K
authors: Qian
authors: Qilin
authors: Q
authors: Yu
authors: Mingchun
authors: M
authors: Li
mesh_terms: D002176:Candida albicans / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D004795:Enzyme Stability; D038181:FMN Reductase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D021381:Protein Transport
chemical_list: D005656:Fungal Proteins; D007501:Iron; D038181:FMN Reductase; C023903:ferric citrate iron reductase