Comparison of the repression activities of two domains in ET to that of the full-length ET on activated transcription. (A) Effect of ET(558–647) and full-length ET on transcription activated by PU.1, Sp1, CTF, and Oct2. ET(558–647) is as effective as ET in repressing these activators except Sp1. Relative luciferase activities are shown with the activity in cells transfected with the reporter plasmid alone defined as Fig. 1. (B) Effect of ET(1–85) and full-length ET on transcription activated by PU.1, Sp1, CTF, and Oct2. ET(1–85) can only repress PU.1, but not other activators.