TY - JOUR
T1 - Characterization of the Trypanosoma cruzi Rad51 gene and its role in recombination events associated with the parasite resistance to ionizing radiation
AU - Regis-da-Silva, Carlos Gustavo
AU - Freitas, Jorge Marcelo
AU - Passos-Silva, Danielle Gomes
AU - Furtado, Carolina
AU - Augusto-Pinto, Luiz
AU - Pereira, Márcio Tadeu
AU - DaRocha, Wanderson Duarte
AU - Franco, Glória Regina
AU - Macedo, Andréa Mara
AU - Hoffmann, Jean Sebastien
AU - Cazaux, Christophe
AU - Pena, Sérgio Danilo Junho
AU - Teixeira, Santuza Maria Ribeiro
AU - Machado, Carlos Renato
N1 - Funding Information:
Supported by CNPq-Brazil, PRONEX and CAPES-COFECUB. The research from S.M.R. 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 - 2006/10
Y1 - 2006/10
N2 - The Rad51 gene encodes a highly conserved enzyme involved in DNA double-strand break (DSB) repair and recombination processes. We cloned and characterized the Rad51 gene from Trypanosoma cruzi, the protozoan parasite that causes Chagas disease. This gene is expressed in all three forms of the parasite life cycle, with mRNA levels that are two-fold more abundant in the intracellular amastigote form. The recombinase activity of the TcRad51 gene product was verified by an increase in recombination events observed in transfected mammalian cells expressing TcRad51 and containing two inactive copies of the neomycin-resistant gene. As a component of the DSB repair machinery, we investigated the role of TcRad51 in the resistance to ionizing radiation and zeocin treatment presented by T. cruzi. When exposed to gamma irradiation, different strains of the parasite survive to dosages as high as 1 kGy. A role for TcRad51 in this process was evidenced by the increased expression of its mRNA after irradiation. Furthermore, transfected parasites over-expressing TcRad51 have a faster kinetics of recovery of the normal pattern of chromosomal bands after irradiation as well as a higher resistance to zeocin treatment than do wild-type cultures.
AB - The Rad51 gene encodes a highly conserved enzyme involved in DNA double-strand break (DSB) repair and recombination processes. We cloned and characterized the Rad51 gene from Trypanosoma cruzi, the protozoan parasite that causes Chagas disease. This gene is expressed in all three forms of the parasite life cycle, with mRNA levels that are two-fold more abundant in the intracellular amastigote form. The recombinase activity of the TcRad51 gene product was verified by an increase in recombination events observed in transfected mammalian cells expressing TcRad51 and containing two inactive copies of the neomycin-resistant gene. As a component of the DSB repair machinery, we investigated the role of TcRad51 in the resistance to ionizing radiation and zeocin treatment presented by T. cruzi. When exposed to gamma irradiation, different strains of the parasite survive to dosages as high as 1 kGy. A role for TcRad51 in this process was evidenced by the increased expression of its mRNA after irradiation. Furthermore, transfected parasites over-expressing TcRad51 have a faster kinetics of recovery of the normal pattern of chromosomal bands after irradiation as well as a higher resistance to zeocin treatment than do wild-type cultures.
KW - Ionizing radiation
KW - RAD51
KW - Recombination
KW - Trypanosoma cruzi
UR - http://www.scopus.com/inward/record.url?scp=33748792822&partnerID=8YFLogxK
U2 - 10.1016/j.molbiopara.2006.05.012
DO - 10.1016/j.molbiopara.2006.05.012
M3 - Artículo Científico
C2 - 16828179
AN - SCOPUS:33748792822
SN - 0166-6851
VL - 149
SP - 191
EP - 200
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
IS - 2
ER -
