title: Roles of Rad51 paralogs for promoting homologous recombination in Leishmania infantum.
abstract: To achieve drug resistance Leishmania parasite alters gene copy number by using its repeated sequences widely distributed through the genome. Even though homologous recombination (HR) is ascribed to maintain genome stability, this eukaryote exploits this potent mechanism driven by the Rad51 recombinase to form beneficial extrachromosomal circular amplicons. Here, we provide insights on the formation of these circular amplicons by analyzing the functions of the Rad51 paralogs. We purified three Leishmania infantum Rad51 paralogs homologs (LiRad51-3, LiRad51-4 and LiRad51-6) all of which directly interact with LiRad51. LiRad51-3, LiRad51-4 and LiRad51-6 show differences in DNA binding and annealing capacities. Moreover, it is also noteworthy that LiRad51-3 and LiRad51-4 are able to stimulate Rad51-mediated D-loop formation. In addition, we succeed to inactivate the LiRad51-4 gene and report a decrease of circular amplicons in this mutant. The LiRad51-3 gene was found to be essential for cell viability. Thus, we propose that the LiRad51 paralogs play crucial functions in extrachromosomal circular DNA amplification to circumvent drug actions and preserve survival.
authors.affiliation: Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada Centre de Recherche en Infectiologie, CHUL, 2705 boul. Laurier, Quebec, Quebec G1V 4G2, Canada.
authors.forename: Marie-Michelle
authors.initials: MM
authors.lastname: Genois
authors.affiliation: Centre de Recherche en Infectiologie, CHUL, 2705 boul. Laurier, Quebec, Quebec G1V 4G2, Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Plourde
authors.affiliation: Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada CHU de Québec Research Center, CHUL Pavilion, Oncology Axis, 2705 boul. Laurier, Quebec city, Quebec, G1V 4G2, Canada.
authors.forename: Chantal
authors.initials: C
authors.lastname: Éthier
authors.affiliation: Centre de Recherche en Infectiologie, CHUL, 2705 boul. Laurier, Quebec, Quebec G1V 4G2, Canada.
authors.forename: Gaétan
authors.initials: G
authors.lastname: Roy
authors.affiliation: Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada CHU de Québec Research Center, CHUL Pavilion, Oncology Axis, 2705 boul. Laurier, Quebec city, Quebec, G1V 4G2, Canada.
authors.forename: Guy G
authors.initials: GG
authors.lastname: Poirier
authors.affiliation: Centre de Recherche en Infectiologie, CHUL, 2705 boul. Laurier, Quebec, Quebec G1V 4G2, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Ouellette
authors.affiliation: Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada jean-yves.masson@fmed.ulaval.ca.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Masson
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D016054:DNA, Protozoan / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D059765:Homologous Recombination; D018314:Leishmania infantum / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D051135:Rad51 Recombinase / Q000235:genetics* / Q000378:metabolism; D061987:Sf9 Cells; D018411:Spodoptera
chemical_list: D016054:DNA, Protozoan; D020033:Protein Isoforms; D015800:Protozoan Proteins; D051135:Rad51 Recombinase