Figure 3
From: Intrabody-based FRET probe to visualize endogenous histone acetylation
Time-lapse FRET visualization of H3K9ac in HeLa cells using YPet-scFv-SeCFPdC5H3 probe. Cells were treated with DMSO (vehicle) or 1 μM TSA were imaged every 30 min for 8 h, and the YFP/CFP ratio (a,b) or nucleus/cytoplasm ratio (c,d), relative to the value at time 0, was plotted (averages of 15 cells with the standard deviations). (a,b) Changes of FRET index (YFP/CFP), ratio of 520 nm fluorescence intensity (YFP) to 477 nm intensity (CFP) with 458 nm excitation, in the nucleus (a) and cytoplasm (b) in cells treated with DMSO (blue) and TSA (red). The FRET index increased drastically in the nucleus, but not in the cytoplasm, in TSA-treated cells. (c and d) Changes of nucleus to cytoplasmic (N/C) ratio. N/C ratio of YFP (d) is more increased than CFP (c) in TSA-treated cells. (e) Example images and the summary of fold change. CFP, YFP, and merged images at 0 and 6 h after the addition of TSA are shown (left). The numbers of fold increase in nucleus/cytoplasm ratio and YFP/CFP ratio at 6 h (relative to those at 0 h) are shown with the standard deviations (N = 15).
