KIF17 colocalizes with EB1 at MT plus ends. (A) Immunostaining of tyrosinated α-tubulin and KIF17 in Caco2 cells. Color overlay: enlargement of boxed regions showing KIF17 (green) at the plus ends of MTs (red, see arrows). (B) Immunostaining of KIF17 and EB1 in Caco2 and MDCK cells. Overlay panels show magnifications of EB1 (red) and KIF17 (green) from the boxed regions. In the bottom overlay panels, the KIF17 image was shifted 3 pixels to highlight the coincident staining pattern. (C) High-magnification images of EB1 and KIF17 in Caco2 cells. Arrows, KIF17 puncta at the head of EB1 comets; arrowheads, KIF17 puncta along the EB1 tail. (D) Quantification of KIF17 colocalization with EB1-labeled MTs in Caco2 (n = 4,575) and MDCK (n = 2,622) cells (n = the number of EB1-labeled MT ends analyzed in at least three experiments). Random colocalization was determined and subtracted from each dataset as described in Material and methods. +BP, analysis after preincubation of KIF17 IgG with immunogenic peptide (n = 1,203); Tot., total EB1-labeled MTs throughout entire cell (n = 2,622); Pro., EB1-labeled MTs in cell protrusions (n = 231). Error bars indicate SEM.