FIG 1 .

CME is heavily affected without Arp2/3. Dynamics of GFP-tagged components at every stage of CME were recorded in live cells by spinning-disk confocal microscopy and quantitatively analyzed. Recorded displacement data of individual patches (n > 20) were aligned at the start of their lifetime and then averaged. MSD plots for WT cells were truncated at the time when 50% of spots have disappeared, corresponding to the median lifetime. For mutant cells, MSD plots represent the first 70 s of recording. Components of the early (A), coat (B), Myo/WASP (C), actin (D), and scission (E) module show dynamic behavior in WT cells. In arp2 cells, early, coat, and Myo/WASP components lost dynamics and remained static at the plasma membrane, while some actin module as well as scission module components retained partial dynamics in arp2 mutants. Prk1 and Sjl2 did not localize to any clear patch structures, and the dynamics could not be quantitatively analyzed in arp2 cells. The results for WT cells are in blue, and those for arp2 cells are in red. MSD plots correspond to means ± SEM. See Movies S1 and S2 in the supplemental material.