We previously established a genotoxicity detection system based on the transcriptional response of the yeast RNR3 gene to DNA damage. In order to further improve its sensitivity to genotoxicants, we have attempted to increase cell permeability by removing cell wall mannoproteins (CWPs). Here, we report that selected deletion of pleiotropic drug resistance (PDR) genes encoding membrane efflux tr...

The use of Saccharomyces cerevisiae mnn mutants has facilitated the study of the epitopes recognized by antisera against several antigenic factors of the genus Candida (Candida Check; Iatron Laboratories, Tokyo, Japan). We have taken advantage of the very well characterized structure of the mannans of the different mnn mutants to compare their reactivities with the factor antisera used in the i...

Yeast and hyphal walls of Candida albicans were extracted with sodium dodecyl sulfate (SDS). Some of the extracted proteins reacted with a specific beta-1,6-glucan antiserum but not with a beta-1,3-glucan antiserum. They lost their beta-1,6-glucan epitope after treatment with ice-cold aqueous hydrofluoric acid, suggesting that beta-1,6-glucan was linked to the protein through a phosphodiester b...

The characterization of proteins secreted by Cryptococcus neoformans is of relevance to the identification of vaccine candidates, because concentrated supernatants from the fungus have been shown to be immunoprotective in previous studies. After fractionation of supernatants by anion exchange chromatography and preparative electrophoresis, we obtained the N-terminal amino acid sequences of 13 m...

The fungal cell wall is a dynamic organelle required for cell shape, protection against the environment and, in pathogenic species, recognition by the innate immune system. The outer layer of the cell wall is comprised of glycosylated mannoproteins with the majority of these post-translational modifications being the addition of O- and N-linked mannosides. These polysaccharides are exposed on t...

Heat-shock and infection induce changes in protein expression in C. albicans. To investigate if these alterations induce changes in antigenicity, we have compared the reactivity mediated by IgA antibodies of protein extracts from a strain of C. albicans and the same strain recovered from an infected animal, both at 24 degrees C and 37 degrees C. The antigenic variability was detected mainly in ...

ybl006cDelta was selected using an Alcian-blue-based screen aimed to identify nonessential genes involved in the regulation of mannosylphosphorylation. When cells of this deletant were mixed with the cationic dye Alcian blue in a typical assay, they remained white, indicating a low number of mannosylphosphate groups on the cell surface. ybl006cDelta cells did not show any defect in growth rate ...

Grape variety has a significant impact on wine flavan-3-ol and polysaccharide profile. The main objective of this work was to study differences in diffusion from grape during the fermentative alcoholic maceration three Vitis sp. varieties: cold-hardy hybrid varieties Frontenac blanc, V. vinifera Cabernet-Sauvignon. Polysaccharides must were precipitated by ethanol quantified using phenol-sulfur...