Disruption of a gene encoding glycerol 3-phosphatase from Candida albicans impairs intracellular glycerol accumulation-mediated salt-tolerance.
Intracellular glycerol accumulation is critical for Candida albicans to maintain osmolarity, and therefore defects in glycerol homeostasis can have severe effects on the morphogenetic plasticity and pathogenicity of this fungus. The final step of glycerol synthesis involves the dephosphorylation of glycerol 3-phosphate by glycerol 3-phosphatase (GPP1). We have identified a single copy of the GPP orthologous gene (GPP1) in the C. albicans haploid genome, as well as the paralogous gene 2-deoxyglucose-6-phosphate phosphatase (DOG1); both belong to a family of low molecular weight phosphatases. A knockout of the GPP1 gene in C. albicans caused increased susceptibility to high salt concentrations, indicating a deficiency in osmoregulation. Reintroduction of the GPP1 gene complemented the impairment of salt-tolerance in the gpp1/gpp1 mutant. Northern blot analysis showed that the GPP1 gene was strongly responsive to osmotic stress, and its transcriptional expression was positively correlated with intracellular glycerol accumulation. These results demonstrate that the GPP1 gene plays an important role in the osmoregulation in C. albicans.
Fan
Jinjiang
J
Mammalian Cell Genetics, Health Sector, Biotechnology Research Institute, National Research Council of Canada, Montreal, Que., Canada H4P 2R2.
Whiteway
Malcolm
M
Shen
Shi-Hsiang
SH
D000595:Amino Acid Sequence; D000818:Animals; D002176:Candida albicans / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005990:Glycerol / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology*
D029701:Saccharomyces cerevisiae Proteins; D012965:Sodium Chloride; D010744:Phosphoric Monoester Hydrolases; C040842:glycerol-1-phosphatase; D005990:Glycerol