Genetic instability triggered by G-quadruplex interacting Phen-DC compounds in Saccharomyces cerevisiae.
G-quadruplexes are nucleic acid secondary structures for which many biological roles have been proposed but whose existence in vivo has remained elusive. To assess their formation, highly specific G-quadruplex ligands are needed. Here, we tested Phen-DC(3) and Phen-DC(6), two recently released ligands of the bisquinolinium class. In vitro, both compounds exhibit high affinity for the G4 formed by the human minisatellite CEB1 and inhibit efficiently their unwinding by the yeast Pif1 helicase. In vivo, both compounds rapidly induced recombination-dependent rearrangements of CEB1 inserted in the Saccharomyces cerevisiae genome, but did not affect the stability of other tandem repeats lacking G-quadruplex forming sequences. The rearrangements yielded simple-deletion, double-deletion or complex reshuffling of the polymorphic motif units, mimicking the phenotype of the Pif1 inactivation. Treatment of Pif1-deficient cells with the Phen-DC compounds further increased CEB1 instability, revealing additional G4 formation per cell. In sharp contrast, the commonly used N-methyl-mesoporphyrin IX G-quadruplex ligand did not affect CEB1 stability. Altogether, these results demonstrate that the Phen-DC bisquinolinium compounds are potent molecular tools for probing the formation of G-quadruplexes in vivo, interfere with their processing and elucidate their biological roles.
Recombinaison et Instabilité Génétique, Institut Curie Centre de Recherche, CNRS UMR3244, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
Aurèle
A
Piazza
Jean-Baptiste
JB
Boulé
Judith
J
Lopes
Katie
K
Mingo
Eric
E
Largy
Marie-Paule
MP
Teulade-Fichou
Alain
A
Nicolas
D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D054856:G-Quadruplexes / Q000187:drug effects*; D014644:Genetic Variation; D006801:Humans; D008024:Ligands; D018598:Minisatellite Repeats / Q000187:drug effects*; D009154:Mutation; D010618:Phenanthrolines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011806:Quinolinium Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
D008024:Ligands; D010618:Phenanthrolines; D011806:Quinolinium Compounds; D029701:Saccharomyces cerevisiae Proteins; C085463:PIF1 protein, S cerevisiae; D004265:DNA Helicases