Artigo Produção Nacional Revisado por pares

Cloning and characterization of DNA polymerase η from Trypanosoma cruzi : Roles for translesion bypass of oxidative damage

2009; Wiley; Volume: 50; Issue: 5 Linguagem: Inglês

10.1002/em.20450

ISSN

1098-2280

Autores

Michelle Barbi de Moura, Bruno Luiz Fonseca Schamber‐Reis, Danielle Gomes Passos Silva, Matheus Andrade Rajão, Andréa Mara Macedo, Glória Regina Franco, Sérgio Danilo Junho Pena, Santuza Maria Ribeiro Teixeira, Carlos Renato Machado,

Tópico(s)

Biochemical and Molecular Research

Resumo

Abstract We report the cloning and characterization of the DNA polymerase η gene from Trypanosoma cruzi ( TcPolη ), the causative agent of Chagas disease. This protein, which can bypass cyclobutane pyrimidine dimers, contains motifs that are conserved between Y family polymerases. In vitro assays showed that the recombinant protein is capable of synthesizing DNA in undamaged primer‐templates. Intriguingly, T. cruzi overexpressing TcPolη does not increase its resistance to UV‐light (with or without caffeine) or cisplatin, despite the ability of the protein to enhance UV resistance in a RAD30 mutant of Saccharomyces cerevisiae . Parasites overexpressing TcPolη are also unable to restore growth after treatment with zeocin or gamma irradiation. T. cruzi overexpressing TcPolη are more resistant to treatment with hydrogen peroxide (H 2 O 2 ) compared to nontransfected cells. The observed H 2 O 2 resistance could be associated with its ability to bypass 8‐oxoguanine lesions in vitro. The results presented here suggest that TcPolη is able to bypass UV and oxidative lesions. However the overexpression of the gene only interferes in response to oxidative lesions, possibly due to the presence of these lesions during the S phase. Environ. Mol. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.

Referência(s)