Video 11. Detection of single XBP1 wild-type (WT) transcripts in inositol-requiring enzyme 1 alpha (IRE1α)-GFP foci is possible but extremely rare.

Download video file ^{(2.4MB, mp4)}

HeLa cell line stably expressing XBP1 WT reporter transcripts, NLS-stdMCP-stdHalo, and IRE1α-GFP. Cells were treated with 5 µg/ml tunicamycin and 50 µM 4µ8C for 2–3 hours prior to image acquisition. Simultaneous image acquisition for both channels (XBP1 WT, red, and IRE1α-GFP, gray) using 50 ms exposure times (100 frames total). The movie is played at 20 fps. The scale bar is 5 μm. White arrow indicates a single XBP1 mRNA particle that colocalizes with an IRE1α cluster.