TY - JOUR
T1 - DNA polymerase beta from Trypanosoma cruzi is involved in kinetoplast DNA replication and repair of oxidative lesions
AU - Schamber-Reis, Bruno Luiz Fonseca
AU - Nardelli, Sheila
AU - Régis-Silva, Carlos Gustavo
AU - Campos, Priscila Carneiro
AU - Cerqueira, Paula Gonalves
AU - Lima, Sabrina Almeida
AU - Franco, Glória Regina
AU - MacEdo, Andrea Mara
AU - Pena, Sergio Danilo Junho
AU - Cazaux, Christophe
AU - Hoffmann, Jean Sébastien
AU - Motta, Maria Cristina Mac Hado
AU - Schenkman, Sergio
AU - Teixeira, Santuza Maria Ribeiro
AU - MacHado, Carlos Renato
N1 - Funding Information:
This study was supported by CNPq-Brazil (MCT/CNPq/MS-SCTIE-DECIT 25/2006-Estudo de Doenças Negligenciadas), PRONEX and FAPEMIG . The research from S.M. Teixeira and C.R. Machado was supported, in part, by an International Research Scholars Grant from the Howard Hughes Medical Institute . We are grateful to Kátia Barroso Gonçalves and Neuza Antunes Rodrigues for technical support.
PY - 2012/6
Y1 - 2012/6
N2 - Specific DNA repair pathways from Trypanosoma cruzi are believed to protect genomic DNA and kinetoplast DNA (kDNA) from mutations. Particular pathways are supposed to operate in order to repair nucleotides oxidized by reactive oxygen species (ROS) during parasite infection, being 7,8-dihydro-8-oxoguanine (8oxoG) a frequent and highly mutagenic base alteration. If unrepaired, 8oxoG can lead to cytotoxic base transversions during DNA replication. In mammals, DNA polymerase beta (Polβ) is mainly involved in base excision repair (BER) of oxidative damage. However its biological role in T. cruzi is still unknown. We show, by immunofluorescence localization, that T. cruzi DNA polymerase beta (Tcpolβ) is restricted to the antipodal sites of kDNA in replicative epimastigote and amastigote developmental stages, being strictly localized to kDNA antipodal sites between G1/S and early G2 phase in replicative epimastigotes. Nevertheless, this polymerase was detected inside the mitochondrial matrix of trypomastigote forms, which are not able to replicate in culture. Parasites over expressing Tcpolβ showed reduced levels of 8oxoG in kDNA and an increased survival after treatment with hydrogen peroxide when compared to control cells. However, this resistance was lost after treating Tcpolβ overexpressors with methoxiamine, a potent BER inhibitor. Curiously, a presumed DNA repair focus containing Tcpolβ was identified in the vicinity of kDNA of cultured wild type epimastigotes after treatment with hydrogen peroxide. Taken together our data suggest participation of Tcpolβ during kDNA replication and repair of oxidative DNA damage induced by genotoxic stress in this organelle.
AB - Specific DNA repair pathways from Trypanosoma cruzi are believed to protect genomic DNA and kinetoplast DNA (kDNA) from mutations. Particular pathways are supposed to operate in order to repair nucleotides oxidized by reactive oxygen species (ROS) during parasite infection, being 7,8-dihydro-8-oxoguanine (8oxoG) a frequent and highly mutagenic base alteration. If unrepaired, 8oxoG can lead to cytotoxic base transversions during DNA replication. In mammals, DNA polymerase beta (Polβ) is mainly involved in base excision repair (BER) of oxidative damage. However its biological role in T. cruzi is still unknown. We show, by immunofluorescence localization, that T. cruzi DNA polymerase beta (Tcpolβ) is restricted to the antipodal sites of kDNA in replicative epimastigote and amastigote developmental stages, being strictly localized to kDNA antipodal sites between G1/S and early G2 phase in replicative epimastigotes. Nevertheless, this polymerase was detected inside the mitochondrial matrix of trypomastigote forms, which are not able to replicate in culture. Parasites over expressing Tcpolβ showed reduced levels of 8oxoG in kDNA and an increased survival after treatment with hydrogen peroxide when compared to control cells. However, this resistance was lost after treating Tcpolβ overexpressors with methoxiamine, a potent BER inhibitor. Curiously, a presumed DNA repair focus containing Tcpolβ was identified in the vicinity of kDNA of cultured wild type epimastigotes after treatment with hydrogen peroxide. Taken together our data suggest participation of Tcpolβ during kDNA replication and repair of oxidative DNA damage induced by genotoxic stress in this organelle.
KW - DNA repair
KW - Kinetoplast
KW - Oxidative stress
KW - Oxoguanine
KW - Trypanosoma cruzi
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U2 - 10.1016/j.molbiopara.2012.02.007
DO - 10.1016/j.molbiopara.2012.02.007
M3 - Article
C2 - 22369885
AN - SCOPUS:84859596155
SN - 0166-6851
VL - 183
SP - 122
EP - 131
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
IS - 2
ER -