Figure 2. Binding of LA to HNF4α2 is exchangeable in mammalian cells.

The on- and off-rate of LA binding to rat HNF4α2 in mammalian cells was determined by incubating COS-7 cells transfected with HNF4α2 wt with [²H]LA (30 µM) for 1 to 5 hr after (on-rate) or before (off-rate) a 1.5-hr treatment with cycloheximide (50 µM, CHX). [¹H]LA (open) and [²H]LA (filled) bound to HNF4α2 was determined as in Figure 1 and graphed as a percent of the total bound LA normalized to the amount of HNF4α2 protein in the immunoprecipitate. Absolute amounts of LA and HNF4α2 protein are noted above each bar.