The Pseudouridine Synthase RPUSD4 Is an Essential Component of Mitochondrial RNA Granules.

TitleThe Pseudouridine Synthase RPUSD4 Is an Essential Component of Mitochondrial RNA Granules.
Publication TypeJournal Article
Year of Publication2017
AuthorsZaganelli, S, Rebelo-Guiomar, P, Maundrell, K, Rozanska, A, Pierredon, S, Powell, CA, Jourdain, AA, Hulo, N, Lightowlers, RN, Chrzanowska-Lightowlers, ZM, Minczuk, MA, Martinou, J-C
JournalJ Biol Chem
Date Published2017 Mar 17
KeywordsCell Line, Humans, Intramolecular Transferases, Mitochondria, Mitochondrial Proteins, Protein Transport, RNA, RNA Interference, RNA, Ribosomal, 16S, RNA, Small Interfering, RNA, Transfer, Met, RNA, Transfer, Phe

Mitochondrial gene expression is a fundamental process that is largely dependent on nuclear-encoded proteins. Several steps of mitochondrial RNA processing and maturation, including RNA post-transcriptional modification, appear to be spatially organized into distinct foci, which we have previously termed mitochondrial RNA granules (MRGs). Although an increasing number of proteins have been localized to MRGs, a comprehensive analysis of the proteome of these structures is still lacking. Here, we have applied a microscopy-based approach that has allowed us to identify novel components of the MRG proteome. Among these, we have focused our attention on RPUSD4, an uncharacterized mitochondrial putative pseudouridine synthase. We show that RPUSD4 depletion leads to a severe reduction of the steady-state level of the 16S mitochondrial (mt) rRNA with defects in the biogenesis of the mitoribosome large subunit and consequently in mitochondrial translation. We report that RPUSD4 binds 16S mt-rRNA, mt-tRNA(Met), and mt-tRNA(Phe), and we demonstrate that it is responsible for pseudouridylation of the latter. These data provide new insights into the relevance of RNA pseudouridylation in mitochondrial gene expression.

Alternate JournalJ. Biol. Chem.
Citation Key10.1074/jbc.M116.771105
PubMed ID28082677
PubMed Central IDPMC5377769