L-Ilf3 and L-NF90 Traffic to the Nucleolus Granular Component: Alternatively-Spliced Exon 3 Encodes a Nucleolar Localization Motif
Figure 8
Fluorescence recovery in HeLa cell nucleoli after photobleaching (FRAP) of GFP-tagged L-Ilf3, L-NF90 or B23.
Plasmids pEGFP-N1-L-Ilf3, pEGFP-N1-L-NF90 or pEGFP-N1-B23 were transfected into HeLa cells. After 24 hours, living cells were subjected to photobleaching. A. In HeLa cells expressing L-NF90-GFP, one nucleolus was targeted for laser bleaching (left panel, green circle in the upper cell) whereas another nucleolus from the same cell (blue circle in the upper cell) and a nucleolus from a distinct cell (yellow circle in the lower cell) were marked to serve as controls. Images were acquired every two seconds during 40 seconds before, immediately after or during 240 seconds after bleaching (prebleach, bleach, post-bleach 6 and 240 seconds, respectively). B. Fluorescence recordings emitted from the 3 delimited regions in A (green: bleached nucleolus; purple: control nucleolus from the same cell; yellow: control nucleolus from another unbleached cell). C. Kinetics of mean fluorescence recovery after photobleaching of GFP-tagged L-Ilf3 (n = 14), L-NF90 (n = 15) or B23 (n = 11) after a normalization of fluorescence intensity. The t1/2 of mean fluorescence recovery are indicated in the figure.
