Figure 7.

Ectopic lamin B1 does not impair c-Fos/c-Jun heterodimerization in vivo. (A) FRET was determined using the acceptor photobleaching method in transiently transfected COS-7 cells (see details in Materials and Methods). The graph shows the quantification of protein–protein interactions calculated as the percentage of pixels in the donor channel that increase their intensity value after photobleaching in 20–30 cells from two to four independent experiments. Cells were cotransfected with CFP-Jun + YFP-Fos (open bars) or CFP-Jun + YFP-Fos and either HA-LMN A or HA-LMN B1 (black bars). For negative controls, cells were cotransfected with YFP + CFP-Jun (striped bar). Results were analyzed using one-way ANOVA and Bonferroni's post hoc test. For simplicity, only comparisons with appropriate controls are shown. (NS) No significant difference (p > 0.05). (B) Lysates of COS-7 cells were subjected to immunoprecipitation with either anti-c-Fos or anti-lamin A/C antibodies as indicated, and the precipitated material was subjected to Western blot analysis (WB) to examine lamin A/C and lamin B1 expression.