Generation of Remosomes by the SWI/SNF Chromatin Remodeler Family.
Fiche publication
Date publication
octobre 2019
Journal
Scientific reports
Auteurs
Membres identifiés du Cancéropôle Est :
Dr HAMICHE Ali
Tous les auteurs :
Shukla MS, Syed SH, Boopathi R, Simon EB, Nahata S, Ramos L, Dalkara D, Moskalenko C, Travers A, Angelov D, Dimitrov S, Hamiche A, Bednar J
Lien Pubmed
Résumé
Chromatin remodelers are complexes able to both alter histone-DNA interactions and to mobilize nucleosomes. The mechanism of their action and the conformation of remodeled nucleosomes remain a matter of debates. In this work we compared the type and structure of the products of nucleosome remodeling by SWI/SNF and ACF complexes using high-resolution microscopy combined with novel biochemical approaches. We find that SWI/SNF generates a multitude of nucleosome-like metastable particles termed "remosomes". Restriction enzyme accessibility assay, DNase I footprinting and AFM experiments reveal perturbed histone-DNA interactions within these particles. Electron cryo-microscopy shows that remosomes adopt a variety of different structures with variable irregular DNA path, similar to those described upon RSC remodeling. Remosome DNA accessibility to restriction enzymes is also markedly increased. We suggest that the generation of remosomes is a common feature of the SWI/SNF family remodelers. In contrast, the ACF remodeler, belonging to ISWI family, only produces repositioned nucleosomes and no evidence for particles associated with extra DNA, or perturbed DNA paths was found. The remosome generation by the SWI/SNF type of remodelers may represent a novel mechanism involved in processes where nucleosomal DNA accessibility is required, such as DNA repair or transcription regulation.
Référence
Sci Rep. 2019 Oct 2;9(1):14212