Figure 7.

Overexpressed HA-I does not disrupt the DNA-binding activity of large Ikaros isoforms. Gel shift experiments were performed with an Ikbs4 probe (Molnár and Georgopoulos 1994; Cobb et al. 2000) and extracts from untransfected VL3–3M2 cells (lanes 1–5) and clone 3 cells (lanes 6–10). Reactions contained no antibody (lanes 1,6) or antibodies directed against the common carboxy-terminal sequence of Ikaros (CTS, lanes 2,7), DNA-binding domain of Ikaros (DBD, lanes 3,8), HA epitope found on HA-I (lanes 4,9), or Toll-like receptor 4 as a negative control (lanes 5,10). The faster migrating complex (a) contains dimers of the endogenous Ikaros isoforms (V and VI). The slower migrating complex (b) is likely to contain multimers that include endogenous Ikaros dimers and one or more HA-I molecules.