Biochemical studies with DNA polymerase beta and DNA polymerase beta-PAK of Trypanosoma cruzi suggest the involvement of these proteins in mitochondrial DNA maintenance

Biochemical studies with DNA polymerase beta and DNA polymerase beta-PAK of Trypanosoma cruzi suggest the involvement of these proteins in mitochondrial DNA maintenance

Autor Lopes, Debora de Oliveira Google Scholar
Fonseca Schamber-Reis, Bruno Luiz Google Scholar
Regis-da-Silva, Carlos Gustavo Google Scholar
Rajao, Matheus Andrade Google Scholar
DaRocha, Wanderson Duarte Google Scholar
Macedo, Andrea Mara Google Scholar
Franco, Gloria Regina Google Scholar
Nardelli, Sheila Cristina Autor UNIFESP Google Scholar
Schenkman, Sergio Autor UNIFESP Google Scholar
Hoffmann, Jean-Sebastein Google Scholar
Cazaux, Christophe Google Scholar
Junho Pena, Sergio Danilo Google Scholar
Ribeiro Teixeira, Santuza Maria Google Scholar
Machado, Carlos Renato Google Scholar
Instituição Universidade Federal de Minas Gerais (UFMG)
Universidade Federal de São Paulo (UNIFESP)
CNRS
Resumo Mammalian DNA polymerase p is a nuclear enzyme involved in the base excision and single-stranded DNA break repair pathways. in trypanosomatids, this protein does not have a defined cellular localization, and its function is poorly understood. We characterized two Trypanosoma cruzi proteins homologous to mammalian DNA polymerase beta, TcPol beta and TcPol beta PAK, and showed that both enzymes localize to the parasite kinetoplast. in vitro assays with purified proteins showed that they have DNA polymerization and deoxyribose phosphate lyase activities. Optimal conditions for polymerization were different for each protein with respect to dNTP concentration and temperature, and TcPol beta PAK, in comparison to TcPol beta, conducted DNA synthesis over a much broader pH range. TcPol beta was unable to carry out mismatch extension or DNA synthesis across 8-oxodG lesions, and was able to discriminate between dNTP and ddNTP. These specific abilities of TcPol beta were not observed for TcPol beta PAK or other X family members, and are not due to a phenylalanine residue at position 395 in the C-terminal region of TcPol beta, as assessed by a site-directed mutagenesis experiment reversing this residue to a well conserved tyrosine. Our data suggest that both polymerases from T. cruzi could cooperate to maintain mitochondrial DNA integrity through their multiple roles in base excision repair, gap filling and translesion synthesis. (C) 2008 Elsevier B.V. All rights reserved.
Palavra-chave DNA repair
DNA polymerase beta
Primer extension assay
Trypanosoma cruzi
Mitochondria
Translesion synthesis
Idioma Inglês
Financiador PRONEX
Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Data de publicação 2008-11-01
Publicado em Dna Repair. Amsterdam: Elsevier B.V., v. 7, n. 11, p. 1882-1892, 2008.
ISSN 1568-7864 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 1882-1892
Fonte http://dx.doi.org/10.1016/j.dnarep.2008.07.018
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000260949000011
Endereço permanente http://repositorio.unifesp.br/handle/11600/31005

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