Stimulation of DNA repair by the spermatidal TP1 protein.
The chromatin remodeling process that takes place during spermiogenesis in mammals is characterized by a transient increase in DNA single-strand breaks (SSB). The mammalian transition proteins (TPs) are expressed at a high level at mid-spermiogenesis steps coincident with chromatin remodeling and could be involved in the repair of these lesions since SSB are no longer detected in terminally differentiated spermatids. We report that TP1 can stimulate the repair of SSB in vitro and demonstrate that in vivo repair of UV-induced DNA lesions is enhanced in mammalian cells stably expressing TP1. These results suggest that, aside from its role in DNA compaction, this major transition protein may contribute to the yet unidentified enzymatic activity responsible for the repair of SSB at mid-spermiogenesis steps. These results also suggest that the TP1 proteins have the potential to participate in the repair process following genotoxic insults and therefore may play an active role in the maintenance of the integrity of the male haploid genome during spermiogenesis.
Département de Biochimie, Faculté de Médicine, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4.
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Caron
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Veilleux
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Boissonneault
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D011088:DNA Ligases / Q000502:physiology; D004260:DNA Repair; D004270:DNA, Circular / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D004274:DNA, Recombinant / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D004277:DNA, Single-Stranded / Q000235:genetics* / Q000378:metabolism; D017930:Genes, Reporter; D007248:Infertility, Male / Q000235:genetics; D008156:Luciferases / Q000235:genetics; D008297:Male; D009707:Nucleosomes / Q000187:drug effects / Q000528:radiation effects; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013091:Spermatogenesis / Q000235:genetics / Q000502:physiology*; D014162:Transfection; D014466:Ultraviolet Rays
D002868:Chromosomal Proteins, Non-Histone; D004270:DNA, Circular; D004274:DNA, Recombinant; D004277:DNA, Single-Stranded; D009707:Nucleosomes; D011993:Recombinant Fusion Proteins; C053886:spermatid transition proteins; D004247:DNA; D008156:Luciferases; D011088:DNA Ligases