Cells maintain contact and dynamically interact with each other and with the surrounding acellular matrix (ECM) via transmembrane adhesion receptors, such as integrins, which provide a physical link between the ECM and the cell cytoskeleton and promote the assembly of large signaling platforms.
The adhesion structures (AS) between cell and ECM take different specialized forms, ranging from classical focal adhesions (FA) to podosomes and invadopodia.
AS have highly complex multiprotein architectures, composed of hundreds of molecules dynamically interacting at scales that are well below the light diffraction limit. Thus, unravelling the nanoscale organization of AS poses a daunting challenge to researchers, which classical light microscopy is unable to overcome.
Super-resolution imaging methods overcome the diffraction limit and allow optical microscopes to achieve unprecedented resolutions. It is now possible to localize single AS proteins in three dimensions, determine their diffusive behaviors, orientations, and how much mechanical force is transmitted across individual components
