Candida glabrata is an important cause of human mucosal and bloodstream infections. In contrast to the polymorphic yeast C. albicans, C. glabrata does not form true hyphae in vivo but shows a high intrinsic resistance to antifungal agents, such as fluconazole. In fungi, the cell wall provides physical strength, limits permeability and protects the cell from hostile degrading enzymes. For pathogenic fungi, the cell wall is the first point of interaction with host cells. In these processes cell wall proteins (CWPs) mediate adhesion, foster biofilm formation and modulate the immune response. The cell wall of fungi therefore has become recognised as an attractive target for antifungal drug development. However, the cell wall is not static but a highly dynamic structure that facilitates morphological plasticity and adaptation to environmental conditions. In order to explore the cell wall of C. glabrata, its composition, architecture, proteome and dynamics will be analysed using biochemical, immunological and molecular methods. In the bakers yeast, Saccharomyces cerevisiae, the cell wall backbone consists of carbohydrate polymers such as beta-1,3-glucan, beta-1,6-glucan and chitin to which proteins are covalently attached.
The cell wall proteom will be studied by a systematic in silico analysis of all putative glycosylphosphatidylinositol-modified (GPI) proteins and proteins that have a mild alkali-sensitive link to the cell wall backbone. These predictions will be confirmed by extracting cell wall-protein fractions from purified cell walls using chemical and enzymatic methods, protein separation and identification using electrospray ionisation tandem mass spectrometry (ESI-MS). Molecular and functional analysis of identified proteins will give information on important fungal attributes such as the capacity of C. glabrata for adhesion, fungus-host interactions, immunomodulation, biofilm formation, cell wall expansion or remodelling.