title: Covalent crosslinks introduced via a triple helix-forming oligonucleotide coupled to psoralen are inefficiently repaired.
abstract: Triple helix-forming oligonucleotides (TFOs) represent potentially powerful tools to artificially modulate gene activity. In particular, they can be used to specifically introduce a lesion into a selected target sequence: interstrand crosslinks and monoadducts can be introduced via TFOs coupled to psoralen. The efficiency of these strategies depends on the cell ability to repair these lesions, an issue which is still controversial. Here we show, using psoralen-coupled TFOs and the yeast as a convenient cellular test system, that interstrand crosslinks are quantitatively poorly repaired, resulting in an efficient modification of target gene activity. In addition, these lesions result in the introduction of mutations in a high proportion of cells. We show that these mutations are generated by the Error-Prone Repair pathway, alone or in combination with Nucleotide Excision Repair. Taken together, these results suggest that TFOs coupled to psoralen could be used to inactivate a gene with significant efficiency.
authors.affiliation: CNRS UPR 9079, Institut de Recherche sur le Cancer, 7 rue Guy Moquet, 94801 Villejuif, France andLaboratoire de Biophysique, INSERM U 201, CNRS URA481, MHN, Paris, France.
authors.forename: F X
authors.initials: FX
authors.lastname: Barre
authors.forename: C
authors.initials: C
authors.lastname: Giovannangeli
authors.forename: C
authors.initials: C
authors.lastname: Hélène
authors.forename: A
authors.initials: A
authors.lastname: Harel-Bellan
mesh_terms: D000251:Adenosine Triphosphatases / Q000502:physiology; D000595:Amino Acid Sequence; D001483:Base Sequence; D004265:DNA Helicases / Q000502:physiology; D004260:DNA Repair; D004843:Epistasis, Genetic; D005363:Ficusin / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D005821:Genetic Techniques; D008025:Ligases / Q000502:physiology; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000502:physiology; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000378:metabolism*; D015183:Restriction Mapping; D029701:Saccharomyces cerevisiae Proteins; D044763:Ubiquitin-Conjugating Enzymes; D015003:Yeasts
chemical_list: D005656:Fungal Proteins; D009841:Oligonucleotides; D029701:Saccharomyces cerevisiae Proteins; D044763:Ubiquitin-Conjugating Enzymes; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases; D008025:Ligases; D005363:Ficusin