TanGIBLE can visualize the cytoplasmic foci composed of defective proteins. (A and B) In relation to Fig. 7, TanGIBLE can detect cytoplasmic foci composed of defective proteins. HeLa cells expressing C-terminally Flag-tagged TanGIBLE (A, TanGIBLE-Flag) or N-terminally Flag-tagged TanGIBLE (B, Flag-TanGIBLE) were treated with 10 μg/ml puromycin for 2 h, followed by 1% Triton X-100 extraction and 4% paraformaldehyde fixation. Fixed cells were stained with anti-Flag polyclonal (shown in green to detect TanGIBLE) and anti-polyubiquitin FK2 (shown in red to detect ubiquitin-positive cytoplasmic foci) antibodies. Note that signal intensities of TanGIBLE on respective foci do not correlate with those of polyubiquitin. For example, foci indicated with green arrowheads show far more intense TanGIBLE signals compared to polyubiquitin, while those with red arrowheads do not (B). TanGIBLE image was taken at 1/60 s exposure time, while polyubiquitin image was taken at 1/8 s, respectively. Scale bar: 20 μm.