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A novel role for a glycosylphosphatidylinositol‐anchored aspartyl protease, CgYps1, in the regulation of pH homeostasis in Candida glabrata
Author(s) -
Bairwa Gaurav,
Kaur Rupinder
Publication year - 2011
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2010.07496.x
Subject(s) - biology , proteases , candida glabrata , homeostasis , intracellular , mutant , protease , microbiology and biotechnology , biochemistry , virulence , saccharomyces cerevisiae , reactive oxygen species , enzyme , yeast , gene , candida albicans
Summary Proteases, key virulence factors of many bacterial and fungal pathogens, are pivotally important for nutrient acquisition, invasion and adherence to host cells and evasion/escape from host immune cells. In this study, we report a novel role for CgYps1, member of a family of 11 GPI‐linked aspartyl proteases, in a human opportunistic fungal pathogen, Candida glabrata , in the regulation of pH homeostasis under acidic environmental conditions. We show that CgYps1 is required to survive low‐external‐pH environment and the inability of Cgyps1 Δ mutant to maintain pH homeostasis results in intracellular acidification and increased reactive oxygen species (ROS) production. We also provide evidence that the reduced intracellular pH in Cgyps1 Δ mutant under acidic conditions is, partly, owing to the diminished activity of a plasma membrane proton pump, CgPma1, an orthologue of a key component of pH homeostasis machinery in Saccharomyces cerevisiae , Pma1. In addition, we have examined C. glabrata 's response to low environmental pH via genome‐wide expression analysis and several genes required for protein folding/modification and stress response pathways including seven of the CgYPS genes were found to be upregulated. Lastly, we show that C. glabrata responds to acidic environment by reducing total β‐glucan levels in the cell wall in a CgYps1‐dependent manner.