Characterization of GATA1-containing protein complexes in L8057 cells. (A) Scheme of the sequential immunoprecipitation experiments. (B-D) L8057 cell crude nuclear extracts were first immuno-depleted with αSCL (B), αGFI1B (C), or αETO2 (D) antibodies (left panels). The lanes are named as in Figure 2. Coimmunoprecipitated proteins were analyzed by Western blot using antibodies indicated on the right of the panels. A second immunoprecipitation was performed on the depleted supernatant (right panels) using αGATA1 antibodies. Coimmunoprecipitated proteins were analyzed by Western blot using antibodies marked on the right of the panels. (E) Models of the possible composition of protein complexes from L8057 cells derived from experiments in this figure.