Protein oxidation in aging and the removal of oxidized proteins

Abstract

Reactive oxygen species (ROS) are generated constantly within cells at low concentrations even under physiological conditions. During aging the levels of ROS can increase due to a limited capacity of antioxidant systems and repair mechanisms. Proteins are among the main targets for oxidants due to their high rate constants for several reactions with ROS and their abundance in biological systems. Protein damage has an important influence on cellular viability since most protein damage is non-repairable, and has deleterious consequences on protein structure and function. In addition, damaged and modified proteins can form cross-links and provide a basis for many senescence-associated alterations and may contribute to a range of human pathologies. Two proteolytic systems are responsible to ensure the maintenance of cellular functions: the proteasomal (UPS) and the lysosomal system. Those degrading systems provide a last line of antioxidative protection, removing irreversible damaged proteins and recycling amino acids for the continuous protein synthesis. But during aging, both systems are affected and their proteolytic activity declines significantly. Here we highlight the recent advantages in the understanding of protein oxidation and the fate of these damaged proteins during aging. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine.

Keywords: 3,4-Dihydroxyphenylalanine; 4-hydroxy-2-nonenal; AGE; AGEs; AMBRA; ATG; Activating molecule in Beclin 1-regulated autophagy; Advanced glycation end products; Aging; Alfy; Autophagy; Autophagy-linked FYVE protein; Autophagy-related gene; CMA; Chaperone-mediated-autophagy; DOPA; HDAC6; HNE; Histone deacetylase 6; JNK1; Jun N-terminal kinase 1; LC3; LC3 interaction region; LIR; Lipofuscin; Lmp2; Lmp7; Low molecular weight of protein 2; Low molecular weight protein 7; MDA; MECL1; MTOC; Malondialdehyde; Methionine sulfoxide reductases; Microtubule organizing center; Microtubule-associated-protein-light-chain-3; Msrs; Multicatalytic endopeptidase complex like 1; NBR1; NDP52; Neighbor of BRCA1 gene 1; Nuclear domain 10 protein; PE; Phosphatidylethanolamine; Proteasome; Protein oxidation; RNS; ROS; RUBICON; RUN domain and cysteine-rich domain containing Beclin1-interacting protein; Reactive nitrogen species; Reactive oxygen species; SOD; Superoxide dismutase; UBA; UPS; UVRAG; Ubiquitin-associated domain; Ubiquitin-proteasome system; Ultraviolet irradiation resistance-associated gene.