γ-H2AX formation in response to interstrand crosslinks requires XPF in human cells
| Autor: | Dennis H. Oh, Seiki Mogi |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Time Factors
DNA Repair Ultraviolet Rays DNA repair DNA damage Mitomycin macromolecular substances Biology Biochemistry Article Cell Line Histones chemistry.chemical_compound Angelicin Furocoumarins Humans Molecular Biology Psoralen Dose-Response Relationship Drug Furocoumarin Ficusin technology industry and agriculture Cell Biology Fibroblasts Molecular biology Chromatin DNA-Binding Proteins Cross-Linking Reagents DNA Repair Enzymes chemistry Cell culture DNA DNA Damage |
| Zdroj: | DNA Repair. 5:731-740 |
| ISSN: | 1568-7864 |
| DOI: | 10.1016/j.dnarep.2006.03.009 |
| Popis: | To further define the molecular mechanisms involved in processing interstrand crosslinks, we monitored the formation of phosphorylated histone H2AX (gamma-H2AX), which is generated in chromatin near double strand break sites, following DNA damage in normal and repair-deficient human cells. Following treatment with a psoralen derivative and ultraviolet A radiation doses that produce significant numbers of crosslinks, gamma-H2AX levels in nucleotide excision repair-deficient XP-A fibroblasts (XP12RO-SV) increased to levels that were twice those observed in normal control GM637 fibroblasts. A partial XPA revertant cell line (XP129) that is proficient in crosslink removal, exhibited reduced gamma-H2AX levels that were intermediate between those of GM637 and XP-A cells. XP-F fibroblasts (XP2YO-SV and XP3YO) that are also repair-deficient exhibited gamma-H2AX levels below even control fibroblasts following treatment with psoralen and ultraviolet A radiation. Similarly, another crosslinking agent, mitomycin C, did not induce gamma-H2AX in XP-F cells, although it did induce equivalent levels of gamma-H2AX in XPA and control GM637 cells. Ectopic expression of XPF in XP-F fibroblasts restored gamma-H2AX induction following treatment with crosslinking agents. Angelicin, a furocoumarin which forms only monoadducts and not crosslinks following ultraviolet A radiation, as well as ultraviolet C radiation, resulted only in weak induction of gamma-H2AX in all cells, suggesting that the double strand breaks observed with psoralen and ultraviolet A treatment result preferentially following crosslink formation. These results indicate that XPF is required to form gamma-H2AX and likely double strand breaks in response to interstrand crosslinks in human cells. Furthermore, XPA may be important to allow psoralen interstrand crosslinks to be processed without forming a double strand break intermediate. |
| Databáze: | OpenAIRE |
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