FIGURE 2.

Modification of CaMKII by metabolism. A, Xenopus egg extracts were treated with or without G6P for 4 h at room temperature and centrifuged at 200,000 × g. Cytosolic extracts were fractionated by gel filtration chromatography, and fractions were immunoblotted for CaMKII. B, Xenopus egg extracts treated with or without G6P and okadaic acid (OA) were fractionated and analyzed as in A. C–E, post-translational modifications of CaMKII were identified by MS analysis. Upper panels, change of phosphorylation with or without G6P. Lower panels, tandem mass spectra used for identification and localization of phosphorylation modifications on phosphopeptide containing corresponding site. C, Thr²⁸⁷ phosphorylation levels with or without G6P. D, Ser³⁹⁵ phosphorylation levels with or without G6P. E, Thr³⁹³ phosphorylation levels with or without G6P. WB, Western blot.