Figure 6
FA distance from and/or orientation relative to the closest edge of the ventral membrane influence its dynamics. (a) Cartoon illustrating classification of FAs based on distance from or orientation relative to the closest edge of the ventral (adherent) portion of the plasma membrane. ‘Outer’ FAs (black outline) are close to the edge of the ventral membrane, ‘inner’ FAs (white outline) are located away from the edge with outer FAs located in between. In ‘pointing’ FAs (purple) the longest axis is oriented more or less perpendicular to the closest membrane edge, and in ‘parallel’ FAs (blue) the longest axis is more or less parallel to the edge. (b) Quantification of U2OS cell FRAP data based on FA distance from the closest edge of the ventral membrane. VASP[34]: outer n = 100, inner n = 114, Zyxin[70]: outer n = 185, inner n = 260, Paxillin[40]: outer n = 120, inner n = 200, Vinculin[37]: outer n = 91 inner n = 158 FAs from [cells]. Error bars indicate 2xSEM. Asterisks indicate significant p-values generated by two sided Mann Whitney test: *p < 0.01, **p < 0.001. (c) Quantification of U2OS cell FRAP data based on FA orientation relative to the closest edge of the ventral membrane. VASP[34]: pointing n = 109, parallel n = 93, Zyxin[70]: pointing n = 199, parallel n = 209, Paxillin[40]: pointing n = 136, parallel n = 134, Vinculin[37]: pointing n = 119, parallel n = 95 FAs from [cells]. Error bars and asterisks as above. (d) Parameters obtained by fitting the FRAP data after categorising the FAs based on the combination of their distance from and their orientation relative to the closest edge of the ventral membrane. This is especially revealing for VASP and zyxin, as it shows that it are specifically the outer and pointing FAs that have strongly altered VASP and zyxin dynamics compared to all other FA types. N-numbers per protein for consecutively: outer and pointing, outer and parallel, inner and pointing and inner and parallel FAs: VASP: 64, 34, 45, 58, Zyxin: 90, 90, 104, 118, Paxillin: 65, 51, 67, 82, Vinculin: 56, 35, 63, 60. Error bars and asterisks as above.
