title: Impairment of methionine sulfoxide reductase during UV irradiation and photoaging.
abstract: During chronic UV irradiation, which is part of the skin aging process, proteins are damaged by reactive oxygen species resulting in the accumulation of oxidatively modified protein. UV irradiation generates irreversible oxidation of the side chains of certain amino acids resulting in the formation of carbonyl groups on proteins. Nevertheless, certain amino acid oxidation products such as methionine sulfoxide can be reversed back to their reduced form within proteins by specific repair enzymes, the methionine sulfoxide reductases A and B. Using quantitative confocal microscopy, the amount of methionine sulfoxide reductase A was found significantly lower in sun-exposed skin as compared to sun-protected skin. Due to the importance of the methionine sulfoxide reductase system in the maintenance of protein structure and function during aging and conditions of oxidative stress, the fate of this system was investigated after UVA irradiation of human normal keratinocytes. When keratinocytes are exposed to 15 J/cm(2) UVA, methionine sulfoxide reductase activity and content are decreased, indicating that the methionine sulfoxide reductase system is a sensitive target for UV-induced inactivation.
authors.affiliation: Laboratoire de Biologie et Biochimie Cellulaire du Vieillissement, EA 3106/IFR 117, Université Paris 7-Denis Diderot, 2 place Jussieu, Tour 33-23, 1er étage, CC 7128, 75251 Paris cedex 05, France.
authors.forename: Cédric R
authors.initials: CR
authors.lastname: Picot
authors.forename: Marielle
authors.initials: M
authors.lastname: Moreau
authors.forename: Mylène
authors.initials: M
authors.lastname: Juan
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Noblesse
authors.forename: Carine
authors.initials: C
authors.lastname: Nizard
authors.forename: Isabelle
authors.initials: I
authors.lastname: Petropoulos
authors.forename: Bertrand
authors.initials: B
authors.lastname: Friguet
mesh_terms: D004789:Enzyme Activation / Q000528:radiation effects; D006801:Humans; D051150:Methionine Sulfoxide Reductases; D018613:Microscopy, Confocal; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000032:analysis*; D050050:Protein Carbonylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D012867:Skin / Q000201:enzymology*; D015595:Skin Aging / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D017382:Reactive Oxygen Species; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase