[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.

CONCLUSION:

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 Xu, Yong Liang, Xinxin Cheng, Kefan Qian, Qilin Yu, Mingchun Li
• Journal: Wei sheng wu xue bao = Acta microbiologica Sinica (Wei Sheng Wu Xue Bao) Vol. 54 Issue 10 Pg. 1185-92 (Oct 04 2014) ISSN: 0001-6209 [Print] China
• PMID: 25803896 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Fungal Proteins
• Iron
• FMN Reductase
• ferric citrate iron reductase

Topics

• Candida albicans (chemistry, enzymology, genetics, growth & development)
• Enzyme Stability
• FMN Reductase (chemistry, genetics, metabolism)
• Fungal Proteins (chemistry, genetics, metabolism)
• Gene Deletion
• Gene Expression Regulation, Fungal
• Hydrogen-Ion Concentration
• Iron (metabolism)
• Protein Transport