FIG. 5.
Modulation of PP1 activity by GADD34. (A) PP1 catalytic subunit isolated from rabbit skeletal muscle was assayed using 32P-labeled phosphorylase a and eIF-2α as substrates in the presence of increasing concentrations of recombinant His-tagged GADD34(230–674). A representative assay from three independent experiments that varied by less than 5% is shown. (B) Effects of increasing concentrations of recombinant human GADD34(230–674) and human GST-GM(1–240) on the in vitro dephosphorylation of eIF-2α by skeletal muscle PP1 catalytic subunit are shown, with standard error bars. The results represent the sum of three independent experiments carried out in duplicate.