Epigenetic silencing of clustered tRNA genes in Arabidopsis.
Fiche publication
Date publication
octobre 2020
Journal
Nucleic acids research
Auteurs
Membres identifiés du Cancéropôle Est :
Dr MARÉCHAL-DROUARD Laurence, Mme COGNAT Valérie
Tous les auteurs :
Hummel G, Berr A, Graindorge S, Cognat V, Ubrig E, Pflieger D, Molinier J, Drouard L
Lien Pubmed
Résumé
Beyond their key role in translation, cytosolic transfer RNAs (tRNAs) are involved in a wide range of other biological processes. Nuclear tRNA genes (tDNAs) are transcribed by the RNA polymerase III (RNAP III) and cis-elements, trans-factors as well as genomic features are known to influence their expression. In Arabidopsis, besides a predominant population of dispersed tDNAs spread along the 5 chromosomes, some clustered tDNAs have been identified. Here, we demonstrate that these tDNA clusters are transcriptionally silent and that pathways involved in the maintenance of DNA methylation play a predominant role in their repression. Moreover, we show that clustered tDNAs exhibit repressive chromatin features whilst their dispersed counterparts contain permissive euchromatic marks. This work demonstrates that both genomic and epigenomic contexts are key players in the regulation of tDNAs transcription. The conservation of most of these regulatory processes suggests that this pioneering work in Arabidopsis can provide new insights into the regulation of RNA Pol III transcription in other organisms, including vertebrates.
Mots clés
Arabidopsis, genetics, Cell Nucleus, genetics, Chromatin, genetics, Epigenesis, Genetic, genetics, Gene Silencing, Multigene Family, genetics, RNA Polymerase III, genetics, RNA, Transfer, genetics, Transcription, Genetic
Référence
Nucleic Acids Res. 2020 10 9;48(18):10297-10312