FIG. 7.

Transactivation ability of mutant proteins. (A) Oct-3/4-dependent activation of reporter constructs. Luciferase reporter plasmids carrying various regulatory elements were transfected into ZHBTc4 ES cells in the presence or absence of Tc. The data were calibrated by both pRL-CMV and PGK-luc, and the ratio for PGK was set at 1.0. Fgf4-5", Fgf4-3", 6W, 052, and Rex1 showed severalfold-higher ratios, confirming their Oct-3/4-dependent activation in ES cells. (B) Expression of luciferase reporters in rescued ES cells. Reporter plasmids tested in A were transfected into ES cells rescued by wild-type, ΔN, or ΔC, and their activities were estimated. The data were calibrated by both pRL-CMV and PGK-luc, and the ratio for PGK was set at 1.0 as above. Note the lower magnitude of activation of 6W in ΔN than in the others.