FIGURE 3.

Staurosporine mediates protection of yeast and mammalian AMPK activation loops from dephosphorylation. A and B, wild type Snf1 heterotrimer containing all three subunits (Snf1, Gal83, and Snf4) and Snf1-L183I enzyme without any β or γ subunits (A) or recombinant rat AMPK (B) were subjected to dephosphorylation in the presence or absence of 1 μm staurosporine. The reactions were conducted in triplicate, and the mean values ± S.E. are plotted. Representative Western blots are shown in the lower panels. C, phosphatase assay measuring hydrolysis of p-nitrophenylphosphate by PP2C in the presence or absence of 1 μm staurosporine. The mean values from duplicate reactions are plotted.