and gene which are key homologous recombination elements in other microorganisms.

and gene which are key homologous recombination elements in other microorganisms. plasticité est probablement associée à l’existence d’évènements de recombinaison homologue qui. Il possède les gènes du groupe d’épistasie RAD52 con compris les gènes BIBX 1382 et et sont transcrits différemment chez les trophozo?tes lorsque des cassures double-brin de l’ADN sont induites par le rayonnement ultraviolet C. En outre il con a une surexpression de la recombinase EhRAD51 dans le noyau après thirty minutes. Dans cet content nous continuons notre analyse du mécanisme de recombinaison homologue chez en étudiant l’expression des protéines EhRAD51 EhRAD54 et EhBLM en réponse au dommage de l’ADN. Les analyses bioinformatiques montrent que EhRAD54 possède les caractéristiques moléculaires des protéines homologues ce qui indique qu’elle pourrait avoir les mêmes fonctions. Les essais de Traditional western blot montrent que les protéines EhRAD54 EhRAD51 et EhBLM BIBX 1382 s’expriment de fa?on différentielle à différents occasions après le dommage de l’ADN ce qui suggère leur r?le potentiel dans les différentes étapes de la recombinaison homologue chez ce protozoaire. Launch may be the protozoan causative of individual amoebiasis a neglected parasitic disease that impacts about 50 million people world-wide [29]. trophozoites present a dramatic virulence variability that is related to an excellent genome plasticity with ploidy adjustments unscheduled gene amplification and duplication occasions that will be associated with hereditary rearrangements mediated by homologous recombination (HR) occasions [1 17 32 HR may be the evolutionarily conserved pathway that promotes the restart of collapsed replication forks faithful chromosome segregation telomere maintenance and fix FGF-13 of DNA double-strand breaks (DSBs) [13 16 31 In eukaryotes HR is certainly completed by associates from the RAD52 epistasis group and extra BIBX 1382 proteins. Included in this RAD51 RAD54 and BLM proteins are fundamental elements for the realization of the various steps from the HR procedure. RAD51 may be BIBX 1382 the central recombinase which catalyzes strand transfer between a damaged DNA and its own undamaged homologous strand enabling the damaged region to be repaired [2 22 25 The RAD54 translocase is definitely a dsDNA-dependent ATPase of the Snf2/Swi2 family of SF2 helicases although it lacks classical helicase activity [9 10 RAD54 interacts with RAD51 and it has been implicated in nearly all mechanistic phases of HR including chromatin redesigning RAD51-ssDNA filament stability homology search and DNA strand invasion D-loop dissolution and branch migration dissociation of RAD51 from heteroduplex DNA to allow extension of the invading 3′-OH end by DNA polymerase and turnover of RAD51-dsDNA dead-end complexes [4 6 24 BLM is definitely a multifunctional RecQ DNA helicase of the SF2 family that has both DNA-stimulated ATPase and ATP-dependent DNA helicase activities having a 3′-5′ polarity [11]. Interacting with RAD51 and RAD54 proteins BLM can accurately control chromatin redesigning and RAD51 nucleofilament disruption in the synaptic phase [12 21 30 It also stimulates strand exchange carried out by RAD51 [3 23 In addition BLM can catalyze branch migration of Holliday junctions unwind D-loops and promote regression of model replication forks [18 20 We previously reported that has genes encoding putative EhRAD52 epistasis group users which participate in recombinational DNA restoration in other organisms including the EhRAD51 recombinase and the EhRAD54 translocase [14] as well as a putative EhBLM protein [5]. The transcriptional profile of the RAD52 epistasis group-related genes evidenced the absence of a coordinated transcriptional activation in response to DNA damage induced by UV-C irradiation suggesting that trophozoites have enough stationary levels of enzymes to perform the HR process that is essential for genome maintenance and survival. Interestingly the amount of mRNA was about 15-collapse higher at 30?min post-UV-C treatment and decreased 3 and 12?h later on. Congruently Western blot assays showed a dramatic increase in EhRAD51 protein in the nucleus at 30?min after DNA damage which helps the relevance of the recombinase EhRAD51 in DNA.