Figure 3

Diffusional dynamics of Caveolin3 and TinyDysf within C2C12 cell membranes before and after laser damage

(A) Conventional epifluorescence image of a C2C12 cell transfected with Caveolin3-mEosFPthermo (upper left). Individual dots correspond to caveolar structures (scale bar, 10 μm). Close-up of the region marked by the white square, obtained by SMLM analysis (upper right, scale bar, 2 μm). Representative examples of mature caveolae (bottom, scale bar, 100 nm).

(B) Example trajectories showing the movement of individual Caveolin3-mEosFPthermo proteins. Color bar, time in the image sequence (0–9 s); scale bar, 500 nm.

(C and D) Average diffusion coefficients, D, of Caveolin3-mEosFPthermo and CAAX-mEosFPthermo before (blue) and within 2 min after (red) lesioning as a function of the distance to the lesion site. Each data point corresponds to D log-averaged over all trajectories recorded on at least five cells on a single day (in total six and four days for Caveolin3 and CAAX, respectively). Boxes indicate mean ± SD, the median is given by the line, and whiskers mark the 95% confidence level. Solid lines indicate the average over the data points shown in corresponding colors, except for the data after lesioning in panel C, which were fitted with an exponential, D(r)=D0exp[−r/r0]+D∞, yielding D0 = 0.029 μm² s⁻¹, r0 = 3.7 μm and D∞ = 0.014 μm² s⁻¹ with a coefficient of determination, R² = 0.98. A line fit, D(r)=mr+D0, is also included as a dashed line, yielding slope m = −2.3 × 10⁻³ μm s⁻¹ and offset D0 = 0.035 μm² s⁻¹, with R² = 0.91.