Figure 3.

Diffusion coefficients for GFP-Drp1 obtained from FCS measurements. (A) Diffusion coefficients presented as a function of the hydrodynamic radius of the probe in LDVM for GFP-Drp1 in stable HeLa cell lines (full black circles 24c, full black triangles 22p, empty circles 25p, empty triangles 28p) and for GFP-Drp1 isoform 1 in transfected HeLa cells (full black squares for HeLa wt, empty squares for HeLa Drp1 KO). The average values of the diffusion coefficients measured in the cytoplasm in the stable cell lines were 6.2 ± 1.4, 7.7 ± 1.3, 7.8 ± 1.3 and 8.8 ± 1.7 μm² × s⁻¹ for the 22p, 24c, 28p and 25p cell lines, respectively. Error bars represent standard deviation. (B) Graph representing the correlation between the diffusion coefficients of GFP-Drp1 in stable HeLa cell lines and the concentration of GFP-Drp1 (expressed as monomeric GFP-Drp1 concentration, which is four-fold higher than the tetramer concentration). The average values of the GFP-Drp1 tetramer concentrations calculated based on the autocorrelation function (ACF) from FCS were 26 ± 9, 42 ± 17, 15 ± 7, and 28 ± 12 nM for the 24c, 22p, 25p, and 28p cell lines, respectively. Error bars represent standard deviation.