KIF17 attenuates MT polymerization. (A) Maximum projection of EB1-FL-GFP in 10 sequential frames (2-s intervals) of a time-lapse recording of Caco2 cells. EB1-GFP was expressed by cDNA microinjection. The first frame is shown in blue, the last frame in red, and intermediary frames in green. (B) Analysis of EB1-GFP–labeled MT dynamics (persistent growth) and mean polymerization rates (net displacement/time) in Caco2 cells expressing control (shNC) or KIF17 (shKIF17#1) shRNAs and in cells expressing RFP or RFP-KIF17^G754E. Data compiled from at least five cells/experiment in three experiments. n = the number of EB1-labeled MTs analyzed. (C–E) Histograms show polymerization rates of EB1-GFP–labeled MTs in Caco2 cells infected with shNC or shKIF17#1 (C), coexpressing RFP or RFP-KIF17^G754E (D), or expressing EB1-FL-GFP or EB1-FL^EE-GFP (E). Data were compiled from at least six cells per experiment in three experiments. n = the number of EB1-labeled MT ends analyzed.