GTPBP8 is required for mitoribosomal biogenesis and mitochondrial translation
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Exactive
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: 
Hongxia Zhao
PROVIDER: MSV000086865 | MassIVE | Mon Feb 15 05:32:00 GMT 2021
SECONDARY ACCESSION(S): PXD024185
REPOSITORIES: MassIVE
Similar Datasets
Project description:Pbp1 (polyA-binding protein - binding protein 1) is a stress granule marker and polyglutamine expansions in its mammalian ortholog ataxin-2 have been linked to neurodegenerative conditions. Pbp1 was recently shown to form intracellular assemblies that function in the negative regulation of TORC1 signaling under respiratory conditions. Furthermore, it was observed that loss of Pbp1 leads to mitochondrial dysfunction. Here, we show that loss of Pbp1 leads to a specific decrease in mitochondrial proteins whose encoding mRNAs are targets of the RNA-binding protein Puf3, suggesting a functional relationship between Pbp1 and Puf3. We found that Pbp1 stabilizes and promotes the translation of Puf3-target mRNAs in respiratory conditions, such as those involved in the assembly of cytochrome c oxidase. We further show that Pbp1 and Puf3 associate through their respective low complexity domains, which is required for target mRNA stabilization and translation. Our findings reveal a key role for Pbp1-containing assemblies in enabling the translation of mRNAs critical for mitochondrial biogenesis and respiration under metabolically challenging conditions. They may further explain prior associations of Pbp1/ataxin-2 with stress granule biology and RNA metabolism.
2023-05-08 | GSE227356 | GEO
Project description:Ribosome biogenesis relies on a number of specific factors. Some of them are remarkably conserved, suggesting that they play essential roles even in distant evolutionary contexts. This is namely the case for the UPF0054 protein YBEY found in all bacteria, but also in many Eukarya. Proposed to act as an endoribonuclease processing the 3’ end of 16S rRNA, YBEY is critically required for translation in model bacteria and plant chloroplasts. However, ribosomal RNA processing pathways are poorly conserved between distant phyla, suggesting that YBEY may have another important function in ribosome biogenesis. We studied the human YBEY homologue and found that it localises in mitochondria. The human mitochondrial rRNAs are flanked by tRNA genes and thereby processed by mitochondrial RNase P and RNase Z, making other ribonucleases superfluous. Yet, CRISPR-mediated knockout of the YBEY gene resulted in a decrease of the mitochondrial small ribosomal subunits (SSU), abolished translation in the organelles and, as a result, led to the inability of the knockout cells to respire. Mapping the ends of the mitochondrial rRNAs revealed no processing defects. Similarly, although human YBEY did show robust RNase activity in vitro and in vivo, mutations in key catalytic residues did not abolish its ability to complement the knockout phenotypes. The analysis of the mitoribosomes identified a distinct set of SSU proteins, mostly located in the head and the platform, to be significantly depleted in the absence of YBEY, including uS11m, required for translation initiation. Importantly, uS11m was the only SSU protein found to directly interact with YBEY in vitro, in vivo and in situ, and forming a stable stoichiometric complex with YBEY. The sum of our data supports the model where YBEY functions primarily as an essential ribosome biogenesis factor by recruiting uS11m in order to complete the assembly of translationally active SSUs.
2020-02-26 | GSE134960 | GEO
Project description:Caloric restriction (CR) without malnutrition appears to mitigate many detrimental effects of aging, in particular the age-related decline in skeletal muscle mitochondrial function. Although the mechanisms responsible for this protective effect remain unclear, CR is commonly believed to increase mitochondrial biogenesis; a concept that is now demanding closer scrutiny. Here we show that lifelong CR in mice prevents age-related loss of mitochondrial function, measured in isolated mitochondria and permeabilized muscle fibers. We find that these beneficial effects of CR occur without increasing mitochondrial abundance. Furthermore, whole-genome expression profiling and large-scale proteomic surveys revealed expression patterns inconsistent with increased mitochondrial biogenesis. These observations, combined with lower protein synthesis rates support an alternative hypothesis that CR preserves mitochondrial function not by increasing mitochondrial biogenesis, but rather by decreasing mitochondrial oxidant emission, increasing antioxidant scavenging, thereby minimizing oxidative damage to cellular components. Cross-sectional comparison of skeletal muscle from young (8mo), old (24mo) and old caloric restricted mice, obtained from the colony maintained on behalf of the National Institute on Aging.
2013-01-01 | E-GEOD-36285 | biostudies-arrayexpress
Project description:Hyperaccurate mitochondrial translation increases cellular proteostatic capacity
| PRJEB17642 | ENA
Project description:Caloric restriction (CR) without malnutrition appears to mitigate many detrimental effects of aging, in particular the age-related decline in skeletal muscle mitochondrial function. Although the mechanisms responsible for this protective effect remain unclear, CR is commonly believed to increase mitochondrial biogenesis; a concept that is now demanding closer scrutiny. Here we show that lifelong CR in mice prevents age-related loss of mitochondrial function, measured in isolated mitochondria and permeabilized muscle fibers. We find that these beneficial effects of CR occur without increasing mitochondrial abundance. Furthermore, whole-genome expression profiling and large-scale proteomic surveys revealed expression patterns inconsistent with increased mitochondrial biogenesis. These observations, combined with lower protein synthesis rates support an alternative hypothesis that CR preserves mitochondrial function not by increasing mitochondrial biogenesis, but rather by decreasing mitochondrial oxidant emission, increasing antioxidant scavenging, thereby minimizing oxidative damage to cellular components.
2013-01-01 | GSE36285 | GEO
Project description:The synthesis of mitochondrial OXPHOS complexes is central to cellular metabolism, yet many molecular details of mitochondrial translation remain elusive. It is commonly held view that translation initiation in human mitochondria proceeded in a manner similar to bacterial systems, with the mitoribosomal small subunit bound to the initiation factors, mtIF2 and mtIF3, along with initiator tRNA and an mRNA. However, unlike in bacteria, most human mitochondrial mRNAs lack 5′ leader sequences that can mediate small subunit binding, raising the question of how leaderless mRNAs are recognized by mitoribosomes. By using novel in vitro mitochondrial translation initiation assays, alongside biochemical and genetic characterization of cellular knockouts of mitochondrial translation factors, we describe unique features of translation initiation in human mitochondria. We show that in vitro, leaderless mRNA transcripts can be loaded directly onto assembled 55S mitoribosomes, but not onto the mitoribosomal small subunit (28S). In addition, we demonstrate that while mtIF2 is indispensable for mitochondrial translation, mtIF3 activity is not required for translation of leaderless mitochondrial transcripts but is essential for translation of ATP6 in the case of the bicistronic ATP8/ATP6 transcript. Our results confirm important evolutionary divergences of the mitochondrial translation system, and further our understanding of a process central to eukaryotic metabolism.
2022-12-01 | GSE156937 | GEO
Project description:In animals the organization of the compact mitochondrial genome and lack of introns have necessitated a unique mechanism for RNA processing. To date the regulation of mitochondrial RNA processing and its importance for ribosome biogenesis and energy metabolism are not clear. To understand the in vivo role of the endoribonuclease component of the RNase P complex, MRPP3, we created conditional knockout mice. Here we show that MRPP3 is essential for life, and heart and skeletal muscle-specific knockout leads to a cardiomyopathy early in life, indicating that it is the only RNase P enzyme in mitochondria. We show that RNA processing is required for the biogenesis of the respiratory chain and mitochondrial function. Transcriptome-wide parallel analyses of RNA ends (PARE) and RNA-Seq enabled us to identify the in vivo cleavage sites of RNase P. Cleavage of the 5â² tRNA ends precedes 3â² end processing in vivo and is required for the correct biogenesis of the mitochondrial ribosomal subunits and mitoribosomal proteins that are differentially stabilized or degraded in the absence of mature rRNAs. Finally we identify that large mitoribosomal proteins can form a subcomplex on a precursor mt-RNA containing the 16S rRNA indicating that mitoribosomal biogenesis proceeds co-transcriptionally. Taken together our data show that RNA processing links transcription to translation via assembly of the mitoribosome. Total RNA was isolated from heart tissue from 11 week old control (Mrpp3loxP/loxP) and Mrpp3 knockout mice (Mrpp3loxP/loxP, +/Ckmm), TruSeq libraries produced in triplicate, sequenced and analysed for differential expression. Mitochondrial RNA was isolated from heart tissue from 11 week old control (Mrpp3loxP/loxP) and Mrpp3 knockout mice (Mrpp3loxP/loxP, +/Ckmm), PARE libraries produced in triplicate and sequenced for analysis of mitochondrial RNA processing.
2016-08-04 | E-GEOD-83471 | biostudies-arrayexpress
Project description:Ribosomal defects perturb stem cell differentiation, causing diseases called ribosomopathies. How ribosome levels control stem cell differentiation is not fully known. Here, we discovered three RNA helicases are required for ribosome biogenesis and for Drosophila oogenesis. Loss of these helicases, which we named Aramis, Athos and Porthos, lead to aberrant stabilization of p53, cell cycle arrest and stalled GSC differentiation. Unexpectedly, Aramis is required for efficient translation of a cohort of mRNAs containing a 5’-Terminal-Oligo-Pyrimidine (TOP)-motif, including mRNAs that encode ribosomal proteins and a conserved p53 inhibitor, Novel Nucleolar protein 1 (Non1). The TOP-motif co-regulates the translation of growth-related mRNAs in mammals. As in mammals, the La-related protein co-regulates the translation of TOP-motif containing RNAs during Drosophila oogenesis. Thus, a previously unappreciated TOP-motif in Drosophila responds to reduced ribosome biogenesis to co-regulate the translation of ribosomal proteins and a p53 repressor, thus coupling ribosome biogenesis to GSC differentiation.
2022-03-24 | GSE171347 | GEO
Project description:Ribosomal defects perturb stem cell differentiation, causing diseases called ribosomopathies. How ribosome levels control stem cell differentiation is not fully known. Here, we discovered three RNA helicases are required for ribosome biogenesis and for Drosophila oogenesis. Loss of these helicases, which we named Aramis, Athos and Porthos, lead to aberrant stabilization of p53, cell cycle arrest and stalled GSC differentiation. Unexpectedly, Aramis is required for efficient translation of a cohort of mRNAs containing a 5’-Terminal-Oligo-Pyrimidine (TOP)-motif, including mRNAs that encode ribosomal proteins and a conserved p53 inhibitor, Novel Nucleolar protein 1 (Non1). The TOP-motif co-regulates the translation of growth-related mRNAs in mammals. As in mammals, the La-related protein co-regulates the translation of TOP-motif containing RNAs during Drosophila oogenesis. Thus, a previously unappreciated TOP-motif in Drosophila responds to reduced ribosome biogenesis to co-regulate the translation of ribosomal proteins and a p53 repressor, thus coupling ribosome biogenesis to GSC differentiation.
2022-03-24 | GSE171349 | GEO
Project description:Ribosomal defects perturb stem cell differentiation, causing diseases called ribosomopathies. How ribosome levels control stem cell differentiation is not fully known. Here, we discovered three RNA helicases are required for ribosome biogenesis and for Drosophila oogenesis. Loss of these helicases, which we named Aramis, Athos and Porthos, lead to aberrant stabilization of p53, cell cycle arrest and stalled GSC differentiation. Unexpectedly, Aramis is required for efficient translation of a cohort of mRNAs containing a 5’-Terminal-Oligo-Pyrimidine (TOP)-motif, including mRNAs that encode ribosomal proteins and a conserved p53 inhibitor, Novel Nucleolar protein 1 (Non1). The TOP-motif co-regulates the translation of growth-related mRNAs in mammals. As in mammals, the La-related protein co-regulates the translation of TOP-motif containing RNAs during Drosophila oogenesis. Thus, a previously unappreciated TOP-motif in Drosophila responds to reduced ribosome biogenesis to co-regulate the translation of ribosomal proteins and a p53 repressor, thus coupling ribosome biogenesis to GSC differentiation.
2022-03-24 | GSE171348 | GEO