Figure 6

FRAP analysis of GFP-SUV420H2 shows that SUV420H2 is strongly associated to heterochromatin. (A) Schematic representation of various SUV420H2 truncations used. The catalytically active SET domain is indicated. (B) Cellular localization of SUV420H2 and the truncations expressed as GFP fusion proteins in L929 cells. Cells were fixed with paraformaldehyde and localization of fusion proteins was visualized with fluorescence microscopy. Dense foci seen by Hoechst staining represent pericentric heterochromatin regions (upper panels). GFP labelling is shown (lower panels). (C) Time-lapse series of confocal images of living cells expressing GFP-SUV420H2, GFP-SUV420H2 [1–280], GFP-SUV420H2 [281–462], and GFP-SUV420H2 [347–435] as indicated, during FRAP experiments. Images were recorded before (Prebleach) and at different time intervals after the bleach. Arrows indicate the photobleached areas. Relative fluorescence intensities are displayed in recovery curves (a-d). (D) Protein and truncations dynamics derived from FRAP curves. The percentage of fluorescence recovery after 30 s, and the number of FRAP curves used are indicated.