FIGURE 3.

CaMKII-PP2A interactions are regulated by G6P. A, CaM-Sepharose was dipped into Xenopus egg extracts that had been treated with or without G6P for 0.5 h at room temperature and incubated for 1 h at 4 °C. Beads were retrieved by centrifugation and analyzed for the presence of candidate phosphatases by immunoblotting. B, CaM-Sepharose was incubated with Xenopus egg extracts for 1 h at 4 °C and then removed by centrifugation. This process was repeated three times. Depleted and undepleted extracts were analyzed by CaMKII or PP2A immunoblotting. C, CaM-Sepharose was incubated with either CaMKII-depleted or undepleted extracts described in B treated with or without G6P. Beads were retrieved by centrifugation and analyzed by PP2A C subunit immunoblotting. D, CaMKII antibody or control IgG coupled to protein G beads was dipped into Xenopus egg extracts treated with or without G6P, incubated for 1 h at 4 °C, and retrieved for CaMKII or PP2A C immunoblotting.