FIGURE 2.

ATM is autosphosphorylated on Ser³⁶⁷ in response to radiation exposure. A, effect of increasing radiation dose on ATM autophosphorylation on Ser³⁶⁷, Ser¹⁸⁹³, and Ser¹⁹⁸¹. Cells were irradiated (IR) with the indicated doses and incubated for 1 h prior to preparation of extracts, immunoprecipitation (IP) with anti-ATM antibodies, and immunoblotting with phosphospecific and anti-ATM antibodies. AT25ABR, which expresses no ATM protein, was used as a control. B, time course of ATM autophosphorylation on Ser³⁶⁷, Ser¹⁸⁹³, and Ser¹⁹⁸¹ in response to 10 Gy of radiation. Conditions were the same as described in A.