Fig. 6.
Depletion/reconstitution experiments. Nuclear extracts were prepared from hemin-treated U937 cells, then depleted of KuAg by affinity absorption to KuAg-derivatized beads followed by serial incubations with HRE-derivatized beads to remove non-KuAg HREBPs. Fraction A (primarily KuAg) was the eluate from KuAg-derivatized beads. KuAg-depleted extract was incubated with HRE-derivatized beads to obtain Fraction B, the eluate from these beads comprising predominantly non-KuAg HREBPs. Gel mobility assays were then performed with radiolabeled HRE probes and these various extracts alone, or reconstituted with fraction A, B, or A+B. Lane 1, free probe; lane 2, unmanipulated extract; lane 3, depleted extract; lane 4, depleted extract + Fraction A; lane 5, depleted extract + Fraction B; lane 6, depleted extract + Fractions A + B. The arrow indicates the position of the major gel shift band.