γH2AX in the S Phase after UV Irradiation Corresponds to DNA Replication and Does Not Report on the Extent of DNA Damage
| Autor: | Aprotim Mazumder, Sitara Roy, Shivnarayan Dhuppar |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
DNA Replication
DNA Repair Ultraviolet Rays DNA repair DNA damage Population Pyrimidine dimer S Phase Histones 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Cell Line Tumor Humans DNA Breaks Double-Stranded Phosphorylation education Molecular Biology 030304 developmental biology 0303 health sciences education.field_of_study biology DNA replication DNA Cell Biology Cell cycle Histone chemistry A549 Cells Pyrimidine Dimers 030220 oncology & carcinogenesis biology.protein Biophysics Research Article |
| Zdroj: | Mol Cell Biol |
| ISSN: | 1098-5549 |
| DOI: | 10.1128/mcb.00328-20 |
| Popis: | Ultraviolet (UV) radiation is a major environmental mutagen. Exposure to UV leads to a sharp peak of γH2AX, the phosphorylated form of the histone variant H2AX, in the S phase within an asynchronous population of cells. γH2AX is often considered a definitive marker of DNA damage inside a cell. In this report, we show that γH2AX in the S-phase cells after UV irradiation reports neither on the extent of primary DNA damage in the form of cyclobutane pyrimidine dimers nor on the extent of its secondary manifestations in the form of DNA double-strand breaks or in the inhibition of global transcription. Instead, γH2AX in the S phase corresponds to the sites of active replication at the time of UV irradiation. This accumulation of γH2AX at replication sites slows down the replication. However, the cells do complete the replication of their genomes and arrest within the G(2) phase. Our study suggests that it is not DNA damage, but the response elicited, which peaks in the S phase upon UV irradiation. |
| Databáze: | OpenAIRE |
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