FIG. 6.

In vivo interaction of TR with the C-terminal domain of PSF-A (cPSF-A). HeLa cells were transfected with a CAT reporter (G5pBLCat2) with the Gal4 DBD or Gal4 DBD fusion of full-length PSF-A or the C-terminal region of PSF-A (amino acids 464 to 707) (cPSF-A) with or without TR-VP16 (amino acids 1 to 221 of TR fused to the VP16 activation domain). Gal4–cPSF-A exhibits a threefold increase in activity compared to Gal4 alone, and its interaction with TR is evident by further activation after expression of TR-VP16. In contrast, expression of Gal4–PSF-A (full length) leads to repression compared to Gal4 alone or when expressed with TR-VP16.