The siRNA suppressor RTL1 is redox-regulated through glutathionylation of a conserved cysteine in the double-stranded-RNA-binding domain.
Fiche publication
Date publication
novembre 2017
Journal
Nucleic acids research
Auteurs
Membres identifiés du Cancéropôle Est :
Dr CARAPITO Christine
Tous les auteurs :
Charbonnel C, Niazi AK, Elvira-Matelot E, Nowak E, Zytnicki M, de Bures A, Jobet E, Opsomer A, Shamandi N, Nowotny M, Carapito C, Reichheld JP, Vaucheret H, Sáez-Vásquez J
Lien Pubmed
Résumé
RNase III enzymes cleave double stranded (ds)RNA. This is an essential step for regulating the processing of mRNA, rRNA, snoRNA and other small RNAs, including siRNA and miRNA. Arabidopsis thaliana encodes nine RNase III: four DICER-LIKE (DCL) and five RNASE THREE LIKE (RTL). To better understand the molecular functions of RNase III in plants we developed a biochemical assay using RTL1 as a model. We show that RTL1 does not degrade dsRNA randomly, but recognizes specific duplex sequences to direct accurate cleavage. Furthermore, we demonstrate that RNase III and dsRNA binding domains (dsRBD) are both required for dsRNA cleavage. Interestingly, the four DCL and the three RTL that carry dsRBD share a conserved cysteine (C230 in Arabidopsis RTL1) in their dsRBD. C230 is essential for RTL1 and DCL1 activities and is subjected to post-transcriptional modification. Indeed, under oxidizing conditions, glutathionylation of C230 inhibits RTL1 cleavage activity in a reversible manner involving glutaredoxins. We conclude that the redox state of the dsRBD ensures a fine-tune regulation of dsRNA processing by plant RNase III.
Mots clés
3' Untranslated Regions, genetics, Amino Acid Sequence, Arabidopsis, genetics, Arabidopsis Proteins, chemistry, Base Sequence, Cysteine, genetics, Glutathione, metabolism, Models, Molecular, Nucleic Acid Conformation, Oxidation-Reduction, Protein Domains, RNA Cleavage, RNA, Double-Stranded, chemistry, RNA, Plant, chemistry, RNA, Small Interfering, genetics, RNA-Binding Motifs, genetics, Repressor Proteins, chemistry, Ribonuclease III, genetics, Sequence Homology, Nucleic Acid
Référence
Nucleic Acids Res.. 2017 Nov 16;45(20):11891-11907