Fig. 4.

Intracellular localization of CRP2 regulates gene transactivation. (A) A summary showing schematic view of wild-type CRP2 and four fusion protein expression constructs and their cellular localization and transfection efficiency. Indirect immunofluorescent staining of CV1 cells overexpressing V5-tagged proteins (green). NLS, SV40 nuclear localization signal; NES, PKI nuclear export signal; SR, Mxi1 strong repression domain; SRpm, Mxi1 strong repressor domain point mutant. (B) Effects of regulated cellular redistribution of CRP2 on SMA gene activation. CV1 cells were cotransfected with SMA-luciferase reporter and expression vectors encoding SRF, GATA6, and various CRP2 constructs, as indicated. Values are expressed as fold-activation increases in luciferase activity ± SEM compared with the level of activity with empty expression vector alone (lane 1).