FIG. 7.
Sp1 is phosphorylated by ATM in vitro. The lysates of 293T cells transfected with plasmid expressing Flag-tagged wild-type ATM (Flag-wt ATM) or kinase-dead ATM (Flag-kd ATM) were immunoprecipitated with anti-Flag antibody. Each of immunocomplexes containing Flag-wt ATM or Flag-kd ATM protein were incubated with purified Sp1 or p53 as substrates in the presence of [γ-32P]ATP. Sp1 and p53 were resolved by SDS-10% PAGE, followed by autoradiography. The amounts of immunoprecipitated Flag-wt ATM and Flag-kd ATM were confirmed by immunoblot analysis with anti-ATM antibody.