FIGURE 7.

Characterization of the HeLa cell line that enables inducible expression of the split-GFP probes in the presence of doxycycline. (A) Schematics of the split-GFP probes used in the HeLa cell line. (B) Western blotting of whole cell extracts prepared from the HeLa cells cultivated with different concentration (0, 30, 100, and 300 ng/ml) of doxycycline for the indicated time. Scale bars represent 100 μm. (C) The HeLa cells were imaged by fluorescence confocal microscopy 0, 12, 24, and 48 h after the addition of doxycycline. Mitochondria were stained with mitotracker. Scale bars, 10 μm. (D,E) Representative images of the HeLa cells after 6 h-induction of ERj1N-V5-GFP11 with 200 ng/ml doxycycline, or (F) transiently expressing the same probes were fixed and then imaged by a confocal fluorescence microscope. Mitochondria were stained by anti-Tom20 antibodies. Maximum projection images were shown. Scale bars represent 10 μm. (G) We performed 3 independent experiments and counted more than 60 cells showing GFP signals in total. Error bars represent standard errors (n = 3).