Characterization of a salt-induced DhAHP, a gene coding for alkyl hydroperoxide reductase, from the extremely halophilic yeast Debaryomyces hansenii
Open Access
- 28 August 2009
- journal article
- Published by Springer Science and Business Media LLC in BMC Microbiology
- Vol. 9 (1), 182
- https://doi.org/10.1186/1471-2180-9-182
Abstract
Debaryomyces hansenii is one of the most salt tolerant species of yeast and has become a model organism for the study of tolerance mechanisms against salinity. The goal of this study was to identify key upregulated genes that are involved in its adaptation to high salinity. By using forward subtractive hybridization we have cloned and sequenced DhAHP from D. hansenii that is significantly upregulated during salinity stress. DhAHP is orthologous to the alkly hydroperoxide reductase of the peroxiredoxin gene family, which catalyzes the reduction of peroxides at the expense of thiol compounds. The full-lengthed cDNA of DhAHP has 674 bp of nucleotide and contains a 516 bp open reading frame (ORF) encoding a deduced protein of 172 amino acid residues (18.3 kDa). D. hansenii Ahp is a cytosolic protein that belongs to the Ahp of the 1-Cys type peroxiredoxins. Phylogentically, the DhAhp and Candida albicans Ahp11 (Swiss-Prot: Q5AF44) share a common ancestry but show divergent evolution. Silence of its expression in D. hansenii by RNAi resulted in decreased tolerance to salt whereas overexpression of DhAHP in D. hansenii and the salt-sensitive yeasts Saccharomyces cereviasiae and Pichia methanolica conferred a higher tolerance with a reduced level of reactive oxygen species. In conclusion, for the first time our study has identified alkly hydroperoxide reductase as a key protein involved in the salt tolerance of the extremely halophilic D. hansenii. Apparently, this enzyme plays a multi-functional role in the yeast's adaptation to salinity; it serves as a peroxidase in scavenging reactive oxygen species, as a molecular chaperone in protecting essential proteins from denaturation, and as a redox sensor in regulating H2O2-mediated cell defense signaling.Keywords
This publication has 47 references indexed in Scilit:
- Characterization ofDhKHA1, a gene coding for a putative Na+transporter fromDebaryomyces hanseniiFEMS Yeast Research, 2007
- Polyamine deficiency leads to accumulation of reactive oxygen species in a spe2Δ mutant of Saccharomyces cerevisiaeYeast, 2006
- DhARO4, an amino acid biosynthetic gene, is stimulated by high salinity in Debaryomyces hanseniiYeast, 2006
- Yeast oxidative stress responseThe FEBS Journal, 2006
- Compensatory increase in ahpC gene expression and its role in protecting Burkholderia pseudomallei against reactive nitrogen intermediatesArchiv für Mikrobiologie, 2003
- Comparison Between NaCl Tolerance Response and Acclimation to Cold Temperature in Shewanella putrefaciensCurrent Microbiology, 2003
- PeroxiredoxinsBiological Chemistry, 2002
- Purification and Characterization of a Second Type Thioredoxin Peroxidase (Type II TPx) from Saccharomyces cerevisiaeBiochemistry, 1998
- A ten-minute DNA preparation from yeast efficiently releases autonomous plasmids for transformaion of Escherichia coliGene, 1987
- Positive control of a regulon for defenses against oxidative stress and some heat-shock proteins in Salmonella typhimuriumCell, 1985