The anti-E2F7 antibody is able to supershift DNA-protein complexes that contain either E2F7-A or E2F7-B. Complex formation employing a radiolabeled E2F element from the human DHFR promoter and nuclear extracts from Saos-2 cells transfected with either pcDNA3-HA-E2F7-A (A) or pcDNA3-HA-E2F7-B (B) were analyzed by EMSA. Extracts were preincubated in the presence of an antibody to the HA tag, the anti-E2F7-B antibody, the anti-E2F7 antibody, or the corresponding pre-immune serum (PI). The arrow indicates the position of the HA-E2F7-A- or HA-E2F7-B-containing complexes, whereas arrowheads indicate the position of super-shifted complexes.
The antibody immunoprecipitates endogenous E2F7-A and E2F7-B. 500 ug of whole cell extracts from K562 cells were immunoprecipitated with 2 ul of the crude rabbit serum or the corresponding pre-immune serum (PI). Immunoprecipitated proteins were fractionated on 8% SDS-PAGE and transferred to nitrocellulose membranes. The membranes were then probed with a previously described anti-E2F7 antibody (1). Peroxidase-conjugated anti-rabbit antibodies followed by ECL were then used. The arrows point to immunoprecipitated E2F7-A and E2F7-B.