Role of the amyloid region in the formation and propagation of Als adhesive nanodomains on Candida albicans

摘要

The most prevalent fungal pathogen in humans Candida albicans expresses on its surface Als (Agglutinin-like sequence) proteins which mediate both yeast-to-host tissue adherence and yeast aggregation. Although adhesins often show weak binding to specific ligands, Als mediate remarkably strong adherence. By combining single-molecule atomic force microscopy (AFM) with the tools of genetics and cell biology, we unraveled the various Als protein domains to understand how they synergize to strengthen the cell adhesion and aggregation. The complementary role of the ligand-binding domains, amyloid-forming regions and the less specific hydrophobic tandem repeat domains give raise to a fascinating new mechanism of cell-activation resulting in force-activated clustering of hundreds of adhesion molecules. The amyloid heptapeptide sequence plays a crucial role in this mechanism providing a cohesive strength to the Als protein by forming molecular zipper that mediates protein interactions between cells.