FIGURE 2.
LKB1S serine 399 is associated with AMPK activation by ONOO− and metformin. A, the lysates of HeLa-S3 transiently transfected with plasmid encoding LKB1S and various mutants were immunoprecipitated with anti-FLAG antibody following exposure of the transfected HeLa-S3 to 100 μm peroxynitrite. The activity of LKB1S in immunoprecipitates was analyzed by measuring incorporation of 32P into LKBtide. Con, control. B, as A, but lysates were immunoprecipitated with anti-AMPKα antibody to measure the activity of AMPK. C and E, as A, but lysates used for Western blot analysis of phospho-ACC (Ser-79) (P-ACC) and phospho-AMPK (Thr-172) (P-AMPK). D and F, as C and E, but prior to lysis, transfected HeLa-S3 were exposed to 5 mm metformin for 2 h. FL, full length. Error bars indicate S.D. *, p < 0.05.