High-Resolution Quantification of Focal Adhesion Spatiotemporal Dynamics in Living Cells
(A) Each of the adhesions in the cells is tracked, allowing the position and properties of single adhesions and populations to be assessed. Here a single adhesion (in green), the surrounding adhesions (in blue) and the cell edge (in red) are followed for 49 minutes. The cell edge is only outlined in the first frame. The scale bar is 10 µm. (B) The intensity of EGFP- Paxillin in the tracked adhesion in (A) through time. The green, yellow and red lines are smoothed using the Lowess algorithm and correspond to the assembly, stable and disassembly phases, respectively. (C) The normalized log-linear fit of the Paxillin intensity through time during the assembly phase of the adhesion in part (B). The inset depicts several of the images from which the Paxillin intensity was gathered. (D) The normalized log-linear fit of the Paxillin intensity through time during the disassembly phase of the adhesion in part (B). The inset depicts several of the images from which the Paxillin intensity was gathered. (E) The assembly and disassembly rates for adhesions whose Paxillin intensity curve fits have R2 values of 0.9 or greater. The top and bottom lines of the boxes indicate the 3rd and 1st quartiles respectively, while the bold central lines indicate the median values. The whiskers extend up to 1.5 times the interquartile range.