Figure 6. Htt redistributes to cytoplasmic stress granules (SG) under the ER-stress conditions, where it co-localizes with Caprin-1 and a SG marker G3BP1. (A) STHdh Q7/Q7 (left) and Q111/Q111 (right) cells were fixed 48 h after plating. Confocal immunofluorescent detection of Htt with 2166 monoclonal antibody is shown in green (Alexa Fluor 488); detection of Caprin-1 with polyclonal specific antibody is shown in red (Alexa Fluor 555); The nuclear staining (DAPI) is shown in blue; Merged images demonstrates little or no co-localization. (B) STHdh Q7/Q7 and Q111/Q111 cells were treated with 10 μM thapsigargin for 50 min before fixing, to induce ER stress. Htt and Caprin-1 were detected as described above. Yellow dots in merged images demonstrate Htt and Caprin-1 co-localization in stress granules. (C) STHdh Q7/Q7 and Q111/Q111 cells were treated with 10 μM thapsigargin for 50 min before fixing, to induce ER stress. Confocal immunofluorescent detection of Htt with rabbit polyclonal antibody to epitope 1–17 is shown in red (Alexa Fluor 555); detection of G3BP1 with mouse monoclonal antibody is shown in green (Alexa Fluor 488); The nuclear staining (DAPI) is shown in blue; Yellow dots in merged images demonstrates Htt and G3BP1 co-localization in stress granules.