CKIδ promotes microtubule growth in Jurkat cells. (A) Analysis of EB3-GFP comets in control (EV), CKIδ-depleted (shdelta) Jurkat cell clones, and colcemid-treated EV cells. The box plot shows the distribution of mean growth speeds of tracked EB3-GFP comets per cell. On the right, an overlay of EB3 growth tracks collected over 1 min is shown in individual cells (dots mark centrosome position). Bar, 5 μm. (B) Maximum intensity projection of EB3-GFP signal in individual cells over 28 sequential frames (0.5 s per frame). Corresponding kymographs on the right show the growth of individual microtubules in control (EV) and CKIδ-depleted (shdelta) Jurkat cells. Bars, 5 µm. (C) Analysis of EB3-GFP comets in nonconjugated (Non-conj) or Raji-conjugated (Conj) Jurkat cells. The box plot shows the distribution of mean growth speeds of tracked EB3-GFP comets per cell. In box plots, whiskers are set at 5–95 percentiles; horizontal lines mark the median, and boxes indicate interquartile range (25–75%).