Tubulin tyrosination affects the interaction of MCAK with MTs. (A) Fluorescence images of MCAK binding to MTs. Equal amounts of taxol-stabilized (10 nM) tyrosinated (Tyr) or detyrosinated (Detyr) pure tubulin MTs (red) were incubated with 0.25 µM purified GFP-MCAK (green) in AMP-PNP– or ADP-vanadate (Va)–bound forms. (B and C) Quantitative analysis of full-length MCAK (B) or MCAK neck + motor domain (C) association with equal amounts (10 nM) of pure Tyr or Glu MTs at different motor concentrations and in the presence of various nucleotides. Motor binding was measured as the ratio of the motor signal versus MT signal (MCAK per MT %). Mean ± SEM. At least 100 MTs were analyzed for each condition. Bar, 5 µm.