Figure 3.
Effect of CBX2 Variants on Gene Target Promoters
(A) Transactivation of luciferase reporter driven by deletion construct of SF1 promoter in absence (0) or presence of overexpression of WT or both CBX2 mutants (P+L). Luciferase activity is expressed as relative to empty vector (luc). Construct +524/85 scr/inv contains the same sequence as in −85/+524 that was scrambled and inserted in the opposite direction. For reference to the ChIP experiments, construct −465/+524 contains ChIP fragments 1, 2, and 3; −85/+524 is fragment 2 and contains fragment 3; +239/+524 contains fragment 3.
(B) Real-time PCR of endogenous SF1 in H295R without (0) or with transfection of wild-type (WT) or mutant CBX2. The image represents the results of mean ± SD of three independent experiments.
The comparison between (A) and (B) suggests that the stimulatory effect of WT CBX2 on the −85/+524 sequence is dominant over the inhibitory effect of the bigger construct (−465/+524).