The Perfect Adhesive

Candida albicans is a eukaryotic commensal of man that survives on mucous membranes. The fungus attaches to the host surface and other microorganisms through Als and other proteins on the cell surface. Following adhesion the Als proteins initiate a process leading to cellular aggregation, thus forming small microcolonies of fungi. Mature Als proteins possess four regions, an Immunoglobulin-like region, a Threonine-rich region that forms amyloids, a Tandem Repeat region with hydrophobic interacting surfaces and a Stalk region. Als adhesion begins as a receptor-ligand interaction with a target peptide. Cellular aggregation occurs later, the modular hydrophobic Tandem Repeat domains associating with one another while amyloid is forming in the Threonine-rich region. Formation of amyloid leads to high-strength, stable associations between cells in the fungal aggregate. Als proteins contribute to make C. albicans a highly successful commensal microorganism and a worrisome opportunistic pathogen.