Carbonylation of ER chaperone proteins in aged mouse liver.
Progressive accumulation of oxidative damage to macromolecules in aged tissues is thought to contribute to the decline in tissue function characteristic of the aged phenotype. Mitochondria are a major intracellular source of reactive oxygen species (ROS); however, other organelles are also endogenous sources of oxyradicals and oxidants, which can damage macromolecules. We, therefore, sought to examine the relationship between aging and oxidative damage to ER resident proteins, which exist in a strongly oxidizing environment necessary for disulfide bond formation. In these studies, we have fractionated young and aged liver homogenates, resolved the proteins by 2D gel electrophoresis, assayed for oxidative damage as indicated by protein carbonylation, and identified BiP/Grp78, protein disulfide isomerase (PDI), and calreticulin as exhibiting an age-associated increase in oxidative damage. Increased carbonylation of these key proteins in aged liver suggests an age-associated impairment in protein folding, disulfide crosslinking, and glycosylation in the aged mouse liver.
Rabek
Jeffrey P
JP
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, TX 77550, USA.
Boylston
William H
WH
Papaconstantinou
John
J
D000375:Aging; D000447:Aldehydes / Q000032:analysis; D000595:Amino Acid Sequence; D000818:Animals; D037282:Calreticulin / Q000032:analysis / Q000737:chemistry; D002352:Carrier Proteins / Q000032:analysis / Q000737:chemistry; D002458:Cell Fractionation; D015180:Electrophoresis, Gel, Two-Dimensional; D004721:Endoplasmic Reticulum / Q000737:chemistry*; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D007659:Ketones / Q000032:analysis; D008099:Liver / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000737:chemistry; D018832:Molecular Chaperones / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D019704:Protein Disulfide-Isomerases / Q000032:analysis / Q000737:chemistry; D016415:Sequence Alignment
D000447:Aldehydes; D037282:Calreticulin; D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; C000717248:Hspa5 protein, mouse; D007659:Ketones; D018832:Molecular Chaperones; D019704:Protein Disulfide-Isomerases