Translesion synthesis mechanisms depend on the nature of DNA damage in UV-irradiated human cells

Autor(es)

Quinet, Annabel ; Martins, Davi Jardim ; Vessoni, Alexandre Teixeira ; Biard, Denis ; Sarasin, Alain ; Stary, Anne ; Martins Menck, Carlos Frederico

• Tipo de documento: Artigo Científico
• Fonte: Nucleic Acids Research; v. 44, n. 12, p. 5717-5731, JUL 8 2016.
• Citações Web of Science: 10

Resumo

Ultraviolet-induced 6-4 photoproducts (6-4PP) and cyclobutane pyrimidine dimers (CPD) can be tolerated by translesion DNA polymerases (TLS Pols) at stalled replication forks or by gap-filling. Here, we investigated the involvement of Pol eta, Rev1 and Rev3L (Pol zeta catalytic subunit) in the specific bypass of 6-4PP and CPD in repair-deficient XP-C human cells. We combined DNA fiber assay and novel methodologies for detection and quantification of single-stranded DNA (ssDNA) gaps on ongoing replication forks and postreplication repair (PRR) tracts in the human genome. We demonstrated that Rev3L, but not Rev1, is required for postreplicative gap-filling, while Pol eta and Rev1 are responsible for TLS at stalled replication forks. Moreover, specific photolyases were employed to show that in XP-C cells, CPD arrest replication forks, while 6-4PP are responsible for the generation of ssDNA gaps and PRR tracts. On the other hand, in the absence of Pol eta or Rev1, both types of lesion block replication forks progression. Altogether, the data directly show that, in the human genome, Pol eta and Rev1 bypass CPD and 6-4PP at replication forks, while only 6-4PP are also tolerated by a Pol zeta-dependent gap-filling mechanism, independent of S phase. (AU)

• Processo FAPESP: 14/15982-6 - Consequências de deficiências de reparo de lesões no genoma
• Beneficiário: Carlos Frederico Martins Menck
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/08028-1 - CEGH-CEL - Centro de Estudos do Genoma Humano e de Células-Tronco
• Beneficiário: Mayana Zatz
• Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs