Correlation of cellular traction forces and dissociation kinetics of adhesive protein zyxin by means of multidimensional microscopy

SIGAUT, LORENA; BIANCHI, MICAELA; VON BILDERLING, CATALINA; PIETRASANTA, LÍA I

San Luis

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Biofísica; 2019

Cells exert traction forces on the extracellular matrix to which they are adhered through theformation of focal adhesion. Spatial-temporal regulation of traction forces is crucial in celladhesion, migration, cellular division and remodeling of the extracellular matrix. By cultivatingcells on polyacrylamide hydrogels of different stiffness we were able to investigate the effects ofsubstrate stiffness on the generation of cellular traction forces by Traction Force Microscopy(TFM), and characterize the molecular dynamic of focal adhesion protein zyxin by FluorescenceCorrelation Spectroscopy (FCS) and Fluorescence Recovery After Photobleaching (FRAP). Asthe rigidity of the substrate increases, we observed an increment of both, cellular tractiongeneration and zyxin residence time at the focal adhesion, while its diffusion would not bealtered. Moreover, we found a linear correlation between the traction forces exerted by cells andthe residence time of zyxin at the substrate elasticity studied. We found that this correlationpersists at the focal adhesion level, even if there is no variation in substrate stiffness, byperforming combined TFM and FRAP experiments, revealing that focal adhesions that exertgreater traction, present longer residence time for zyxin, i.e. zyxin protein has less probability todissociate from the focal adhesion.