Figure 3.

Interactions between native Ikaros and the TdT D‘ element. (A) Gel shift experiments were performed with nuclear extracts from RLm11 cells, using the wild-type and mutant D‘ probes, as indicated (top). Reactions contained no antibody, preimmune (p.i.), or anti-Ikaros serum (α-Ik). The Ikaros-containing complex is indicated (a). (B) A methylation interference experiment was performed with complex “a” obtained with the wild-type D‘ probe. Pools of bound and free probe molecules were analyzed. Probes were labeled on the top or bottom strand as indicated. Guanines that inhibit complex formation when methylated are indicated on the sequence (circles). (C) Gel shift experiments were performed with nuclear extracts from RLm11 cells, using wild-type and mutant D‘ elements, as indicated at the top and in the diagram at the bottom (mutant sequences underlined; Ikaros recognition sites in bold). The presence of p.i. or α-Ik antibodies is indicated at the top.