The binding of CLASP1 and TOG2 to microtubule ends is modulated by nucleotides. (A) Representative sum projection images of 1 nM Alexa488-CLASP1 on GMPCPP-stabilized microtubules in the absence or presence of the indicated nucleotide. Images are sum-projections of the 488-CLASP1 intensities from the first 5 s (100 frames) of 30-s videos imaged at 20 fps. The dotted lines indicate the positions of the corresponding linescans. (B) Fluorescence intensity linescans of the microtubules indicated by the dotted lines in A. (C) Representative kymographs of GMPCPP-stabilized microtubules incubated with 200 pM EGFP-L-TOG2-S with and without 1 mM GTP and imaged at 20 fps. (D) Quantification of the single-molecule EGFP-L-TOG2-S dwell times on GMPCPP-stabilized microtubules in the presence and absence of 1 mM GTP. The inset shows the cumulative distribution function of the data. N is the number of EGFP-L-TOG2-S binding events measured across three independent experimental repeats.