TfR-pHuji colocalizes with CCPs and dynamin is recruited at the time of scission detected with TfR-pHuji. (A) Portion of a 3T3 cell cotransfected with TfR-pHuji and clc-GFP. The clusters of TfR-pHuji colocalize with CCPs (merged). (B) Fluorescence in the green and red channels of segmented clusters in a representative cell. Yellow dots, clusters detected in both channels (274 clusters); green dots, clusters detected in the GFP channel only (no matching structure in the red channel, 39 clusters); red dots, clusters detected in the pHuji channel only (no matching structure in the green channel, 34 clusters). Black dashed line shows linear regression of all clc-GFP clusters (R = 0.75). Green and red lines show the lower detection limits of GFP and pHuji clusters, respectively. (C, a) Proportion for n = 5 cells of clusters detected in both channels (yellow) or with either TfR-pHuji (red) or clc-GFP (green) as shown in B. (b) clc clusters enriched in TfR (yellow) or not (green) according to the top-right quadrant defined by the GFP and pHuji lower detection limits determined as in B and vice-versa (yellow and red). (D) Examples of nonterminal (a) and terminal (b) scission events in a cell coexpressing TfR-pHuji and clc-GFP. (c) Example of a scission event in a cell coexpressing TfR-pHuji and dyn1-GFP. Note the maximal recruitment of dyn1-GFP at −4 s. (E) Mean fluorescence of scission events aligned to their time of detection (left, 320 events in five cells cotransfected with TfR-pHuji and clc-GFP; right, 283 events in five cells cotransfected with TfR-pHuji and dyn1-GFP). Error bars represent SEM.