A tRNA-modifying enzyme facilitates RNase P activity in Arabidopsis nuclei.
Fiche publication
Date publication
novembre 2023
Journal
Nature plants
Auteurs
Membres identifiés du Cancéropôle Est :
Mr HAMMANN Philippe, Mme COGNAT Valérie
Tous les auteurs :
Arrivé M, Bruggeman M, Skaltsogiannis V, Coudray L, Quan YF, Schelcher C, Cognat V, Hammann P, Chicher J, Wolff P, Gobert A, Giegé P
Lien Pubmed
Résumé
RNase P is the essential activity that performs the 5' maturation of transfer RNA (tRNA) precursors. Beyond the ancestral form of RNase P containing a ribozyme, protein-only RNase P enzymes termed PRORP were identified in eukaryotes. In human mitochondria, PRORP forms a complex with two protein partners to become functional. In plants, although PRORP enzymes are active alone, we investigate their interaction network to identify potential tRNA maturation complexes. Here we investigate functional interactions involving the Arabidopsis nuclear RNase P PRORP2. We show, using an immuno-affinity strategy, that PRORP2 occurs in a complex with the tRNA methyl transferases TRM1A and TRM1B in vivo. Beyond RNase P, these enzymes can also interact with RNase Z. We show that TRM1A/TRM1B localize in the nucleus and find that their double knockout mutation results in a severe macroscopic phenotype. Using a combination of immuno-detections, mass spectrometry and a transcriptome-wide tRNA sequencing approach, we observe that TRM1A/TRM1B are responsible for the mG26 modification of 70% of cytosolic tRNAs in vivo. We use the transcriptome wide tRNAseq approach as well as RNA blot hybridizations to show that RNase P activity is impaired in TRM1A/TRM1B mutants for specific tRNAs, in particular, tRNAs containing a mG modification at position 26 that are strongly downregulated in TRM1A/TRM1B mutants. Altogether, results indicate that the mG-adding enzymes TRM1A/TRM1B functionally cooperate with nuclear RNase P in vivo for the early steps of cytosolic tRNA biogenesis.
Référence
Nat Plants. 2023 11 9;: