title: FASTKD2 is an RNA-binding protein required for mitochondrial RNA processing and translation.
abstract: Mitochondrial RNA processing is an essential step for the synthesis of the components of the electron transport chain in all eukaryotic organisms, yet several aspects of mitochondrial RNA biogenesis and regulation are not sufficiently understood. RNA interactome capture identified several disease-relevant RNA-binding proteins (RBPs) with noncanonical RNA-binding architectures, including all six members of the FASTK (FAS-activated serine/threonine kinase) family of proteins. A mutation within one of these newly assigned FASTK RBPs, FASTKD2, causes a rare form of Mendelian mitochondrial encephalomyopathy. To investigate whether RNA binding of FASTKD2 contributes to the disease phenotype, we identified the RNA targets of FASTKD2 by iCLIP. FASTKD2 interacts with a defined set of mitochondrial transcripts including 16S ribosomal RNA (RNR2) and NADH dehydrogenase subunit 6 (ND6) messenger RNA. CRISPR-mediated deletion of FASTKD2 leads to aberrant processing and expression of RNR2 and ND6 mRNA that encodes a subunit of the respiratory complex I. Metabolic phenotyping of FASTKD2-deficient cells reveals impaired cellular respiration with reduced activities of all respiratory complexes. This work identifies key aspects of the molecular network of a previously uncharacterized, disease-relevant RNA-binding protein, FASTKD2, by a combination of genomic, molecular, and metabolic analyses.
authors.affiliation: European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Popow
authors.affiliation: European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Alleaume
authors.affiliation: Faculty of Computer and Information Science, University of Ljubljana, 1000 Ljubljana, Slovenia.
authors.forename: Tomaz
authors.initials: T
authors.lastname: Curk
authors.affiliation: European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schwarzl
authors.affiliation: Division of Inherited Metabolic Diseases, Department of General Pediatrics, University Children's Hospital Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Sauer
authors.affiliation: European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
authors.forename: Matthias W
authors.initials: MW
authors.lastname: Hentze
mesh_terms: D002460:Cell Line; D019069:Cell Respiration / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D008928:Mitochondria / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics*; D009245:NADH Dehydrogenase / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D012313:RNA / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D000077278:RNA, Mitochondrial; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics*
chemical_list: D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D012336:RNA, Ribosomal, 16S; D016601:RNA-Binding Proteins; D012313:RNA; C507225:MT-ND6 protein, human; D009245:NADH Dehydrogenase; C532222:FASTKD2 protein, human; D017346:Protein Serine-Threonine Kinases
keywords: Mendelian disease; RNA-binding proteins; iCLIP; mitochondria; oxidative phosphorylation; transcript processing