Fig. 5: DAG potentiates the mechanochemical activity of Drp1 to accelerate membrane fission.

a Representative images from a time series showing membrane tubes of the indicated lipid composition after flowing in Drp1 and GTP. The complete time series associated with these images are provided as Supplementary Movie 5. b Plots showing the kinetics of fission on tubes of the indicated lipid compositions upon flowing in Drp1 with GTP. c Membrane tube size distributions for templates formed of the indicated lipid compositions. Histograms were fitted to a Gaussian distribution to calculate the mean and SD. d Top horizontal panel shows a representative fluorescence micrograph of a membrane tube imaged for membrane fluorescence after Drp1 binding and before GTP addition. A time-lapse movie was then acquired upon flow through of GTP. The bottom vertical panel shows a kymograph generated across the central region of the membrane tube, which is boxed in red, from such a movie showing the stepwise constriction and fission of the membrane tube. e Plot showing the membrane fluorescence profile (gray) along the white dotted line shown in the kymograph in (d) after the conversion of this signal to the membrane tube radius using the previously described in situ calibration procedure⁸⁷. The profile was fitted to a plateau with a one-phase exponential decay function (red) to estimate the scaffolded tube radius and the pre-fission tube radius. Fission time is measured as the interval between the onset of GTPase-induced constriction and membrane fission. f Quantification of the scaffolded tube radius on membrane templates of the indicated lipid composition. Data represents the mean\(\,\pm \,\)SD of at least 40 scaffolds. g Quantification of the pre-fission tube radius on membrane templates of the indicated lipid composition. Data represents the mean\(\,\pm \,\)SD of at least 9 fission events. h Quantification of the fission time on membrane templates of the indicated lipid composition. Data represents the mean \(\pm \,\)SD of 10 fission events. Statistical significance was estimated using unpaired Mann-Whitney’s test. **** denotes p < 0.0001 and *** denotes p = 0.0007.