MS/MS spectra from representative differentially regulated proteins identified in this study. The inset shows the reporter ions used for quantitation. A. Vacuolar H + ATPase E1 isoform b (ATP6V1E1). B. Histone H2A type 3 (HIST3H2A). C. Proteolipid protein 1 (PLP1) D. Glutamate synthetase (GLUL). E. Calcium/calmodulin-dependent protein kinase IIA (CAMK2A). Immonium ions for leucine (Imm.L) and proline (Imm.P) are also labeled.