Fig. 4.
RRM1 mutations and NEM treatment of cells. (A) HEK293 cells with the indicated RRM1 mutations were treated with 1 μM of gemcitabine and lysates were prepared with NEM. Transfected RRM1 was visualized in Western blots using anti-Flag antibody. (B) C444A-mutant RRM1, transfected into HEK293 cells, was immunoprecipitated with mouse-anti Flag antibody. Western blot was carried out using rabbit-anti Flag antibody. (C) H23 cells were treated with 1 μM of gemcitabine for 2 h followed by 0.2 mM NEM for 0.5 h. Cell lysates were prepared without NEM. (D) H23 cells were treated with NEM for 0.5 h followed by 2 h with gemcitabine. (E) HEK293 cells were treated with or without 1 μM of gemcitabine for 3 h. Endogenous RRM1 was immunoprecipitated with anti-RRM1 with NEM in the lysis buffer. RRM2 was detected in immunoprecipitates and lysates.