Figure 8. Microtubule depolymerization does not inhibit punctate EYFP-Stim1 localization.
A) Confocal images of HEK293 cells in the presence of 1.8 mM extracellular Ca2+ (left panel), following a 20 min incubation in 10 μM nocodazole (NZL; middle panel), and 15 min following store depletion with thapsigargin (Tg; 2 μM) in the continued presence of nocodazole (right panel). B) TIRFM images of EYFP-Stim1 expressing cells in 1.8 mM extracellular Ca2+ (left panel; i) following a 20 min treatment in 10 μM NZL (middle panel; ii), and 15 min following store depletion in the continued presence of NZL (right panel; iii). The same experiment is shown in C, except that cells were treated with 0.1 % DMSO instead of NZL. D) Fluorescence intensity profiles over time for the cells shown in B and C; each trace represents the average fluorescence intensity measured in a region of interest encompassing a single cell. Red traces: NZL-treated cells; black traces: DMSO-treated cells. The labeling of i, ii, and iii in the graph represent the times at which the still images in B and C were taken. E) Average maximal TIRFM fluorescence intensity measured in EYFP-Stim1 cells following the 20 min treatment in NZL (n = 6 cells over 3 coverslips) or DMSO (n = 5 cells over 3 coverslips), and in the same cells following store depletion with thapsigargin (Tg). Data are reported as mean ± SEM; p-values are based on t-test. Scalebars = 10 μm.