Fig. 1. S100B and tau colocalize in living cells and interactions persist upon microtubule destabilization.

a Representation of N- and C-terminal halves of Venus constructs fused to tau and S100B termini and gain of fluorescence based on bimolecular fluorescence complementation. b HeLa cells were transfected with the BiFC constructs tau/tau and S100B/tau and incubated with 10 µM of nocodazole for 16 h. Nocodazole was then removed, and cells were visualized immediately after washing out nocodazole (t = 0) in time lapse for 30 min. Scale bar: 20 µm. c, d Wide-field microscopy and super-resolution radial fluctuations (SRRF) reconstruction of HeLa cells (c) after 24 h of transient transfection with the BiFC constructs tau/tau and S100B/tau; and (d) after 16 h of incubation with 10 µM of nocodazole, imaged ~15 min after washout. Scale bar: 20 µm. e Violin-plot representation of cells forming puncta (top panel) and number of puncta per cell (bottom panel) after 16 h of incubation with 10 µM of nocodazole. Plots are presented with floating boxes showing mean (white dot) and 1st and 3rd quartiles (floating black boxes). Minimum and maximum values of the distribution are shown as the bottom and top of the violin plot. The number of cells analyzed was 927 (tau/tau) and 873 (tau/S100B) in a total of 65 pictures/group from 4 independent experiments. Data were analyzed by means of a two-tailed t–student test. *, significant versus tau/tau, top p = 0.0097 and bottom p = 3.6673 × 10⁻³⁴.