Prenatal alcohol exposure alters phosphorylation and glycosylation of proteins in rat offspring liver

To gain more insights into the translational and PTM that occur in rat offspring exposed to alcohol in utero, 2-D PAGE with total, phospho- and glycoprotein staining and MALDI-MS/MS and database searching were conducted. The results, based on fold-change expression, revealed a down-regulation of total protein expression by prenatal alcohol exposure in 7-day-old and 3-month-old rats. There was an up-regulation of protein phosphorylation but a down-regulation of glycosylation by prenatal alcohol exposure in both age groups. Of 31. protein spots examined per group, differentially expressed proteins were identified as ferritin light chain, aldo-keto reductase, tumor rejection antigen gp96, fructose-1, 6-bisphosphatase, glycerol-3-phosphate dehydrogenase, malate dehydrogenase, and gamma-actin. Increased phosphorylation was observed in proteins such as calmodulin, gluthatione S-transferase, glucose regulated protein 58, alpha-enolase, eukaryotic translation elongation factor 1 beta-2, riboprotein large P2, agmatinase, ornithine carbamoyltransferase, quinolinate phosphoribosyltransferase, formimidoyltransferase cyclodeaminase, and actin. In addition, glycosylation of adenosine kinase, adenosylhomocysteine hydrolase, and 3-hydroxyanthranilate dioxygenase was reduced. Pathways affected by these protein alterations include cell signaling, cellular stress, protein synthesis, cytoskeleton, as well as glucose, aminoacid, adenosine and energy metabolism. The activity of the gluconeogenic enzyme fructose-1, 6-bisphosphatase was elevated by prenatal alcohol. The observations may have important physiological implications.