Null mutants ofCandida albicansfor cell-wall-related genes form fragile biofilms that display an almost identical extracellular matrix proteome

Abstract

By two-dimensional gel electrophoresis (2-DE) and mass spectrometry, we have characterized the polypeptide species present in extracts obtained by 60% ethanol treatment of whole mature (48 h) biofilms formed by a reference strain (CAI4-URA3) and four Candida albicans null mutants for cell-wall-related genes (ALG5, CSA1, MNN9 and PGA10) Null mutants form fragile biofilms that appeared partially split and weakly attached to the substratum contrary to those produced by the reference strain. An almost identical, electrophoretic profile consisting of about 276 spots was visualized in all extracts examined. Proteomic analysis led to the identification of 131 polypeptides, corresponding to 86 different protein species, being the rest isoforms-83 displayed negative hydropathic indexes and 82 lack signal peptide. The majority of proteins appeared at pI between 4 and 6, and molecular mass between 10 and 94 kDa. The proteins identified belonged to the following Gene Ontology categories: 21.9% unknown molecular function, 16.2% oxidoreductase activity, 13.3% hydrolase activity and 41.8% distributed between other different GO categories. Strong defects in biofilm formation appreciated in the cell-wall mutant strains could be attributed to defects in aggregation due to abnormal cell wall formation rather than to differences in the biofilm extracellular matrix composition.

Transcriptome Assembly and Profiling of Candida auris Reveals Novel Insights into Biofilm-Mediated Resistance

“…A number of GPI-linked cell wall proteins were upregulated at the early biofilm time point, highlighting their role in the initial adherence stage. In C. albicans , IFF4 and CSA1 have been shown to be involved in adherence to both mucosal and abiotic substrates, as well as cell-cell cohesion ( 23 – 25 ). Transcriptional studies from Fox et al identified IFF4 as a member of a group of 10 adhesion genes that are induced at the later stages of biofilm formation and hypothesized its role in mediating cell-cell contact ( 26 ).…”

Thioredoxin Reductase 1 Is a Highly Immunogenic Cell Surface Antigen in Paracoccidioides spp., Candida albicans, and Cryptococcus neoformans

“…This pattern has been associated before with increased antifungal activity for an antibody to the C. albicans cell wall (Casanova et al, 1990), which is promising for antifungal therapy. Consistent with this extracellular presence of TRR1, it was found in C. neoformans extracellular vesicles (Rodrigues et al, 2008) and on the extracellular matrix of mature C. albicans biofilms (Martínez et al, 2016). This suggests that cell wall TRR1 would indeed be a good target for therapeutic antibodies, which cannot penetrate intact fungal cells.…”

Blue Light Induced Edible Mushroom (Lentinula edodes) Proteomic Analysis

“…The expression of phosphopyruvate hydratase, which is involved in energy metabolism, in the BL condition is increased to Moscot score 730, suggesting that LE metabolism is active. In particular, 5-methyltetrahydropteroyltriglutamate-homocysteine s-methyltransferase, which is the second highest expression level, is known to be involved in methionine regeneration through methionine biosynthesis and methyltransfer [17], and is found in the fungi cell wall [18,19]. In order to confirm the expression level of up-regulated proteins in this BL condition, the result of qRT-PCR was also the same as the result of 2D electrophoresis.…”