title: Interactions between BRCA2 and RAD51 for promoting homologous recombination in Leishmania infantum.
abstract: In most organisms, the primary function of homologous recombination (HR) is to allow genome protection by the faithful repair of DNA double-strand breaks. The vital step of HR is the search for sequence homology, mediated by the RAD51 recombinase, which is stimulated further by proteins mediators such as the tumor suppressor BRCA2. The biochemical interplay between RAD51 and BRCA2 is unknown in Leishmania or Trypanosoma. Here we show that the Leishmania infantum BRCA2 protein possesses several critical features important for the regulation of DNA recombination at the genetic and biochemical level. A BRCA2 null mutant, generated by gene disruption, displayed genomic instability and gene-targeting defects. Furthermore, cytological studies show that LiRAD51 can no longer localize to the nucleus in this mutant. The Leishmania RAD51 and BRCA2 interact together and the purified proteins bind single-strand DNA. Remarkably, LiBRCA2 is a recombination mediator that stimulates the invasion of a resected DNA double-strand break in an undamaged template by LiRAD51 to form a D-loop structure. Collectively, our data show that LiBRCA2 and LiRAD51 promote HR at the genetic and biochemical level in L. infantum, the causative agent of visceral leishmaniasis.
authors.affiliation: Genome Stability Laboratory, Laval University Cancer Research Center, Hôtel-Dieu de Québec, 9 McMahon, Québec, G1R 2J6, Canada.
authors.forename: Marie-Michelle
authors.initials: MM
authors.lastname: Genois
authors.forename: Angana
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Ubeda
authors.forename: Rémi
authors.initials: R
authors.lastname: Buisson
authors.forename: Eric
authors.initials: E
authors.lastname: Paquet
authors.forename: Gaétan
authors.initials: G
authors.lastname: Roy
authors.forename: Marie
authors.initials: M
authors.lastname: Plourde
authors.forename: Yan
authors.initials: Y
authors.lastname: Coulombe
authors.forename: Marc
authors.initials: M
authors.lastname: Ouellette
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Masson
mesh_terms: D024682:BRCA2 Protein / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D020868:Gene Silencing; D024522:Genes, BRCA2; D059765:Homologous Recombination; D018314:Leishmania infantum / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011485:Protein Binding; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D051135:Rad51 Recombinase / Q000378:metabolism*
chemical_list: D024682:BRCA2 Protein; D015800:Protozoan Proteins; D004247:DNA; D051135:Rad51 Recombinase