Figure 4.

The hormone-binding domain is sufficient for T3-induced degradation. The expression plasmids for the wild-type TRβ1 (lanes 1–2), truncation mutant ΔA/B (lanes 3–4), or ΔA/B/C (lanes 5–6) were transfected into CV1 cells. Cells were treated with (lanes 2, 4, and 6) or without (lanes 1, 3, and 5) 100 nM T3. Fifty micrograms of total cell lysates was analyzed by Western blotting similarly as described for Fig. 2A.