A tRNA modifying enzyme facilitates RNase P activity in Arabidopsis nuclei
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ABSTRACT: RNase P is the essential activity that performs the 5’ maturation of 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 understand their integration with gene expression pathways. 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 B in vivo. Beyond RNase P, these enzymes can also interact with RNase Z. We show that TRM1A/B localize in the nucleus and find that their double knock out mutation results in a severe macroscopic phenotype. Using a combination of immuno-detections, mass spectrometry and a transcriptome wide tRNAseq approach, we observe that TRM1A/B are responsible for the m2,2G26 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/B mutants for specific tRNAs, in particular, tRNAs containing a m2,2G modification at position 26 that are strongly down-regulated in TRM1A/B mutants. Altogether, results indicate that the m2,2G adding enzymes TRM1A/B functionally cooperate with nuclear RNase P in vivo for the early steps of cytosolic tRNAs biogenesis.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE223876 | GEO | 2023/09/04
REPOSITORIES: GEO
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