Force-induced formation and propagation of adhesion nanodomains in living fungal cells.
Understanding how cell adhesion proteins form adhesion domains is a key challenge in cell biology. Here, we use single-molecule atomic force microscopy (AFM) to demonstrate the force-induced formation and propagation of adhesion nanodomains in living fungal cells, focusing on the covalently anchored cell-wall protein Als5p from Candida albicans. We show that pulling on single adhesins with AFM tips terminated with specific antibodies triggers the formation of adhesion domains of 100-500 nm and that the force-induced nanodomains propagate over the entire cell surface. Control experiments (with cells lacking Als5p, single-site mutation in the protein, bare tips, and tips modified with irrelevant antibodies) demonstrate that Als5p nanodomains result from protein redistribution triggered by force-induced conformational changes in the initially probed proteins, rather than from nonspecific cell-wall perturbations. Als5p remodeling is independent of cellular metabolic activity because heat-killed cells show the same behavior as live cells. Using AFM and fluorescence microscopy, we also find that nanodomains are formed within ∼30 min and migrate at a speed of ∼20 nm·min(-1), indicating that domain formation and propagation are slow, time-dependent processes. These results demonstrate that mechanical stimuli can trigger adhesion nanodomains in fungal cells and suggest that the force-induced clustering of adhesins may be a mechanism for activating cell adhesion.
Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
David
D
Alsteens
Melissa C
MC
Garcia
Peter N
PN
Lipke
Yves F
YF
Dufrêne
D001696:Biomechanical Phenomena; D002176:Candida albicans / Q000378:metabolism*; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism*; D006358:Hot Temperature; D050296:Microbial Viability; D018625:Microscopy, Atomic Force / Q000379:methods*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D049329:Nanostructures / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D058767:Protein Unfolding; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism; D013997:Time Factors
C109455:ALA1 protein, Candida albicans; D015815:Cell Adhesion Molecules; D005656:Fungal Proteins