Figure 8.

 Quantitative association of Helios with a subset of the Ikaros within VL3-3M2 cells. Quantitative immunoprecipitation experiments were performed with purified IgG directed against the amino-terminal domains of either Ikaros (lanes 2–5,11–14) or Helios (lanes 6–9,15–18). Control immunoprecipitations contained no added antibody (lanes 1,10). The proteins present in the immunoprecipitation pellets (lanes 1–9) and supernatants (lanes 10–18) were analyzed by immunoblot, with the membranes probed with antibodies directed against either Helios (top) or Ikaros (bottom). The two isoforms predominantly expressed in VL3-3M2 cells are indicated to the left of the bottom panel. The amounts of anti-Ikaros or anti-Helios IgGs used in the immunoprecipitations were as follows: 1.5 μg (lanes 2,6,11,,15), 4.5 μg (lanes 3,7,12,16), 15 μg (lanes 4,8,13,,17), and 45 μg (lanes 5,9,14,,18).