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SUMMARY:External Seminar "G-quadruplexes are nucleosome exclusion modules 
 supporting constitutive promoter and enhancer activities" by Jean-Christop
 he Andrau
DTSTART:20251205T100000Z
DTEND:20251205T113000Z
DTSTAMP:20260809T192700Z
UID:indico-event-116@indico.i2bc.paris-saclay.fr
CONTACT:benoit.moindrot@i2bc.paris-saclay.fr
DESCRIPTION:\nTitle: G-quadruplexes are nucleosome exclusion modules suppo
 rting constitutive promoter and enhancer activities\n \n\nSpeaker: Je
 an-Christophe ANDRAU\n\nTranscription and Epigenomics group\, Institut de 
 Génétique Moléculaire de Montpellier (IGMM)\, Montpellier\n \n\n\nAbst
 ract : G-quadruplexes (G4s) are stable single-stranded secondary DNA struc
 tures\, alternative to Watson-Crick pairing in vitro and in vivo. Increasi
 ng evidences indicate their importance in nuclear processes such as replic
 ation\, insulation and telomere structure and maintenance. Our group is in
 terested in G4’s relation to transcription at both promoters and enhance
 rs in which they are overrepresented. In mammals up to 80% of the promoter
 s and 20% of the enhancers carry experimentally validated G4s\, using vari
 ous detection methods including G4access\, a method we recently developed 
 (1). We propose that G4s and G4 clusters function as nucleosome exclusion 
 modules at both promoters and enhancers\, in which they tend to promote a 
 constitutive activity as opposed to more activable sequences. At promoters
 \, we have shown G4s contribute to promoter proximal pause release (2) whi
 le at enhancers\, they associate to the most active sequences. At model pr
 omoters and enhancers\, mutating G4 potential abolished or decreased trans
 cription\, indicating their importance in sustaining activity\, most likel
 y through chromatin opening. Intriguingly\, analysis of high-resolution lo
 ng-distance interactions revealed that G4 enhancers cluster with each othe
 r as well as with promoters and as opposed to other enhancers. Finally\, w
 e have observed that in the primate neural lineage\, G4s tend to appear at
  novel and active enhancers\, suggesting that are under a positive selecti
 ve pressure at least in this evolutionary branch. \n\n\nhttps://indico.i2
 bc.paris-saclay.fr/event/116/
LOCATION:B21-N0-00 - Auditorium (I2BC CNRS Gif)
URL:https://indico.i2bc.paris-saclay.fr/event/116/
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