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UVA irradiation induces L-isoaspartyl formation in melanoma cell proteins
- Source :
- Free radical biologymedicine. 31(1)
- Publication Year :
- 2001
-
Abstract
- It has been reported that UVA effects are partly mediated by production of reactive oxygen species. Moreover, oxidative stress increases protein damage, involving the occurrence of isoaspartyl residues, a product of protein deamidation/isomerization reactions. This work was undertaken in order to study the effects of UVA irradiation, mediated by oxidation, on sensitive protein targets. Melanoma cells exposed to UVA rays have been chosen as a model for monitoring the occurrence of L-isoaspartyl sites. A dramatic increase of these abnormal residues, specifically recognized and methylated by the enzyme L-isoaspartate(D-aspartate) O-methyltransferase (PCMT; EC 2.1.1.77), can be detected after exposure of M14 cells to raising doses of UVA. The effect of UVA on NO and TBARS accumulation, as well as on DNA fragmentation, has also been investigated. NO formation parallels the increase in isoaspartyl formation, while lipid peroxidation occurs only at the highest UVA doses. No DNA fragmentation has been detected under the employed experimental conditions. These results, as a whole, indicate that protein damages are one of the early events on UVA-induced cell injury. The endogenous activity of PCMT remains remarkably stable under UVA treatment, suggesting that this enzyme might play a crucial role in the repair and/or disposal of damaged proteins in UVA-irradiated cells.
- Subjects :
- Ultraviolet Rays
Free radicals
DNA Fragmentation
medicine.disease_cause
Nitric Oxide
Biochemistry
Lipid peroxidation
chemistry.chemical_compound
Physiology (medical)
Oxidative damage
Protein D-Aspartate-L-Isoaspartate Methyltransferase
medicine
TBARS
Tumor Cells, Cultured
Animals
Humans
UVA radiation
Protein Methyltransferases
Melanoma cells
Protein deamidation
Deamidation
Melanoma
chemistry.chemical_classification
Reactive oxygen species
Aspartic Acid
Isoaspartyl methylation
DNA, Neoplasm
Neoplasm Proteins
Rats
Isoaspartyl methylation, Melanoma cells, Oxidative damage, Protein deamidation, Protein repair, UVA radiation, Free radicals
Protein repair
Enzyme
chemistry
DNA fragmentation
sense organs
Reactive Oxygen Species
Oxidative stress
DNA Damage
Subjects
Details
- ISSN :
- 08915849
- Volume :
- 31
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Free radical biologymedicine
- Accession number :
- edsair.doi.dedup.....98169eb57e8280bdee5926dcd7dbec9d