H2AX phosphorylation within the G 1 phase after UV irradiation depends on nucleotide excision repair and not DNA double-strand breaks
2006; National Academy of Sciences; Volume: 103; Issue: 26 Linguagem: Inglês
10.1073/pnas.0603779103
ISSN1091-6490
AutoresThomas M. Marti, Eli Hefner, Luzviminda Feeney, Valerie Natale, James E. Cleaver,
Tópico(s)Epigenetics and DNA Methylation
ResumoThe variant histone H2AX is phosphorylated in response to UV irradiation of primary human fibroblasts in a complex fashion that is radically different from that commonly reported after DNA double-strand breaks. H2AX phosphorylation after exposure to ionizing radiation produces foci, which are detectable by immunofluorescence microscopy and have been adopted as clear and consistent quantitative markers for DNA double-strand breaks. Here we show that in contrast to ionizing radiation, UV irradiation mainly induces H2AX phosphorylation as a diffuse, even, pan-nuclear staining. UV induced pan-nuclear phosphorylation of H2AX is present in all phases of the cell cycle and is highest in S phase. H2AX phosphorylation in G(1) cells depends on nucleotide excision repair factors that may expose the S-139 site to kinase activity, is not due to DNA double-strand breaks, and plays a larger role in UV-induced signal transduction than previously realized.
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