Sentin interacts with EB1. (A) Coimmunoprecipitation of endogenous EB1 and Sentin. Sentin was immunoprecipitated with the anti-Sentin antibody followed by detection of EB1 and Sentin by each polyclonal antibody (PT, pellet). Extracts of control S2 cells (−) and those depleted of Sentin by RNAi (+) were used (WCE, whole cell extracts). (B and C) Sentin interacts with EB1. GST pull-down assay using several truncations of GST-EB1 and S2 cell extracts (B) or purified His-GFP-SentinC (841–982 aa). Sentin binds to the C-terminal region of EB1, as revealed by immunoblotting (B) or Coomassie blue staining (C). S, supernatant after the beads were incubated with S2 extracts or recombinant Sentin. P, beads after washing (2.5-fold or equal amount loaded compared with the supernatant in B or C, respectively). (D) Kymographs showing EB1-dependent tracking of His-GFP-SentinC (841–982 aa) at the growing plus ends of microtubules (red) in the in vitro plus end–tracking assay. Bar, 5 µm. Also see Video 4.