Force-induced formation and propagation of adhesion nanodomains in living fungal cells

Proc Natl Acad Sci U S A. 2010 Nov 30;107(48):20744-9. doi: 10.1073/pnas.1013893107. Epub 2010 Nov 8.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomechanical Phenomena
  • Candida albicans / metabolism*
  • Cell Adhesion
  • Cell Adhesion Molecules / chemistry*
  • Cell Adhesion Molecules / metabolism*
  • Fungal Proteins / chemistry*
  • Fungal Proteins / metabolism*
  • Hot Temperature
  • Microbial Viability*
  • Microscopy, Atomic Force / methods*
  • Microscopy, Fluorescence
  • Models, Biological
  • Nanostructures / chemistry*
  • Protein Structure, Tertiary
  • Protein Unfolding
  • Saccharomyces cerevisiae / cytology*
  • Saccharomyces cerevisiae / metabolism
  • Time Factors

Substances

  • ALA1 protein, Candida albicans
  • Cell Adhesion Molecules
  • Fungal Proteins