Transcriptome and translatome of ribosomal protein-deficient human cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE168445 | GEO | 2022/01/27
REPOSITORIES: GEO
Similar Datasets
Project description:Ribosome assembly occurs mainly in the nucleolus yet recent studies have revealed robust enrichment and translation of mRNAs encoding many ribosomal proteins (RPs) in axons, far away from neuronal cell bodies. Here, we report a physical and functional interaction between locally synthesized RPs and ribosomes in the axon. We show that axonal RP translation is regulated through a novel sequence motif, CUIC, that forms an RNA-loop structure in the region immediately upstream of the initiation codon. Using imaging and subcellular proteomics techniques, we show that RPs synthesized in axons join axonal ribosomes in a nucleolus-independent fashion. Inhibition of axonal CUIC-regulated RP translation causes a significant decline in local translation activity and markedly reduces axon branching in the brain, revealing the physiological relevance of axonal RP synthesis in vivo. These results suggest that axonal translation supplies cytoplasmic RPs to maintain/modify local ribosomal function far from the nucleolus in neurons.
2019-12-11 | GSE135502 | GEO
Project description:Ribosome assembly occurs mainly in the nucleolus yet recent studies have revealed robust enrichment and translation of mRNAs encoding many ribosomal proteins (RPs) in axons, far away from neuronal cell bodies. Here, we report a physical and functional interaction between locally synthesized RPs and ribosomes in the axon. We show that axonal RP translation is regulated through a novel sequence motif, CUIC, that forms an RNA-loop structure in the region immediately upstream of the initiation codon. Using imaging and subcellular proteomics techniques, we show that RPs synthesized in axons join axonal ribosomes in a nucleolus-independent fashion. Inhibition of axonal CUIC-regulated RP translation causes a significant decline in local translation activity and markedly reduces axon branching in the brain, revealing the physiological relevance of axonal RP synthesis in vivo. These results suggest that axonal translation supplies cytoplasmic RPs to maintain/modify local ribosomal function far from the nucleolus in neurons.
2019-12-09 | PXD015574 | Pride
Project description:Ribosomes execute the transcriptional program in every cell. Critical to sustain nearly all cellular activities, ribosome biogenesis requires the translation of ~200 factors of which 80 are ribosomal proteins (RPs). As ribosome synthesis depends on RP mRNAs translation, a priority within the translatome architecture should exist to ensure the preservation of ribosome biogenesis capacity, particularly under adverse growth conditions. Here we show that under critical metabolic constraints characterized by mTOR inhibition, LARP1 complexed with the 40S subunit protects from ribophagy the mRNAs regulon for ribosome biogenesis and protein synthesis, acutely preparing the translatome to promptly resume ribosomes production after growth conditions return permissive. Characterizing the LARP1-protected translatome revealed a set of 5’TOP transcript isoforms other than RPs involved in energy production and in mitochondrial function, among other processes, indicating that the mTOR-LARP1-5’TOP axis acts at the translational level as a primary guardian of the cellular anabolic capacity
2021-10-30 | GSE186779 | GEO
Project description:Understanding the regulation and structure of ribosomes is essential to understanding protein synthesis and its dysregulation in disease. While ribosomes are believed to have a fixed stoichiometry among their core ribosomal proteins (RPs), some experiments suggest a more variable composition. Testing such variability requires direct and precise quantification of RPs. We used mass-spectrometry to directly quantify RPs across monosomes and polysomes of mouse embryonic stem cells (ESC) and budding yeast. Our data show that the stoichiometry among core RPs in wild-type yeast cells and ESC depends both on the growth conditions and on the number of ribosomes bound per mRNA. Furthermore, we find that the fitness of cells with a deleted RP-gene is inversely proportional to the enrichment of the corresponding RP in polysomes. Together, our findings support the existence of ribosomes with distinct protein composition and physiological function.
2015-08-28 | MSV000079280 | MassIVE
Project description:Owing to their morphological complexity and dense network connections, neurons modify their proteomes locally, using mRNAs and ribosomes present in the neuropil (tissue enriched for dendrites and axons). Although ribosome biogenesis largely takes place in the nucleus and perinuclear region, neuronal ribosomal protein (RP) mRNAs have been frequently detected remotely, in dendrites and axons. Here, using imaging and ribosome profiling, we directly detected the RP mRNAs and their translation in the neuropil. Combining brief metabolic labeling with mass spectrometry, we found that a group of RPs rapidly associated with translating ribosomes in the cytoplasm and that this incorporation is independent of canonical ribosome biogenesis. Moreover, the incorporation probability of some RPs was regulated by location (neurites vs. cell bodies) and changes in the cellular environment (following oxidative stress). Our results suggest new mechanisms for the local activation, repair and/or specialization of the translational machinery within neuronal processes, potentially allowing neuronal synapses a rapid means to regulate local protein synthesis.
2021-09-20 | PXD026973 | Pride
Project description:Ribosome biogenesis is a complex and energy-demanding process requiring tight coordination of ribosomal RNA (rRNA) and ribosomal protein (RP) production. Alteration of any step in this process may impact growth by leading to proteotoxic stress. Although the transcription factor Hsf1 has emerged as a central regulator of proteostasis, how its activity is coordinated with ribosome biogenesis is unknown. Here we show that arrest of ribosome biogenesis in the budding yeast S. cerevisiae triggers rapid activation of a highly specific stress pathway that coordinately up-regulates Hsf1 target genes and down-regulates RP genes. Activation of Hsf1 target genes requires neo-synthesis of RPs, which accumulate in an insoluble fraction, leading to sequestration of the RP transcriptional activator Ifh1. Our data suggest that levels of newly-synthetized RPs, imported into the nucleus but not yet assembled into ribosomes, work to continuously balance Hsf1 and Ifh1 activity, thus guarding against proteotoxic stress during ribosome assembly.
2019-06-24 | GSE125226 | GEO
Project description:Ribosomal protein haploinsufficiency (RPH) underlies diverse human diseases with distinct and specific phenotypes, including Diamond-Blackfan anemia (DBA). Although multiple mechanisms have been proposed for the erythroid-specific hematopoietic defects observed in DBA, only recently has the role of selectively impaired translation been highlighted in these phenotypes. Exactly how and to what extent this impairment of translation occurs is currently unknown. Here, by identifying a novel DBA gene affecting ribosome biogenesis, we show that both RPH and impaired ribosome biogenesis (IRB) limit the availability of actively translating ribosomes, resulting in the hematopoietic and translational defects observed in DBA. Our results show that the selective impairment of translation is due to a quantitative defect, where ribosomes of invariant protein composition have a reduced abundance, rather than a qualitative defect, where a subset of ribosomes lack specific ribosomal proteins (RPs) and thus may have altered translational capacity. In RPH, we find that cellular RP homeostasis is largely maintained through translational co-regulation, and we identify a selective subset of transcripts that have impaired association with the ribosome. Surprisingly, these transcripts have short and unstructured 5’ UTRs and are highly abundant and efficiently translated in healthy human erythroid progenitors, suggesting that the impaired translation of a number of key transcripts, including GATA1, may underlie DBA. Overall, our study identifies mechanisms by which RPH and IRB affect mRNA translation, illuminating how these alterations can result in cell-type specific defects and cause human disease.
2018-02-25 | GSE89183 | GEO
Project description:Emerging studies have linked the ribosome to more selective control of gene regulation. However, an outstanding question is whether ribosome heterogeneity at the level of core ribosomal proteins (RPs) enables ribosomes to preferentially translate specific mRNAs genome-wide. Here, we measured the absolute abundance of RPs in translating ribosomes and profiled transcripts that are enriched or depleted from select subsets of ribosomes within embryonic stem cells. We find that heterogeneity in RP composition endows ribosomes with different selectivity for translating subpools of transcripts including those controlling metabolism, the cell cycle, and development. As a paradigm example, we show that mRNAs enriched in binding to RPL10A/uL1-containing ribosomes require RPL10A/uL1 for their efficient translation. Within several of these transcripts, we find this level of regulation is mediated, at least in part, by internal ribosome entry sites. Together, these results reveal a critical functional link between ribosome heterogeneity and the post-transcriptional circuitry of gene expression.
2017-06-15 | GSE73357 | GEO
Project description:The rapid transport of ribosomal proteins (RPs) into the nucleus and their efficient assembly into rRNA are prerequisites for ribosome biogenesis. Proteins that act as dedicated chaperones for RPs to maintain their stability and facilitate their assembly have not been identified in filamentous fungi. PlCYP5 is a nuclear cyclophilin in the nematophagous fungus Purpureocillium lilacinum, and up-regulated expression in response to abiotic stress and nematode egg-parasitism. Here, we found that PlCYP5 interacted with the unassembled small ribosomal subunit protein, PlRPS15, of the uS19 family. PlRPS15 contained a eukaryote-specific N-terminal extension that mediated the interaction. The phenotypes of the PlCYP5 loss-of-function mutant were similar to those of the PlRPS15 knockdown mutant (e.g., growth and ribosome biogenesis defects). PlCYP5 maintained the solubility of PlRPS15 independent of its catalytic peptide-prolyl isomerase function and supported the integration of PlRPS15 into pre-ribosomes. PlCYP5 homologs in Arabidopsis thaliana, Homo sapiens, Schizosaccharomyces pombe, Sclerotinia sclerotiorum, Botytis cinerea, and Metarhizium anisopliae were identified. Notably, the interaction of their homologs corresponding to the PlCYP5-PlRPS15 pattern existed in three filamentous fungi, while lacked in other species. In summary, our data disclosed a special RP dedicated chaperone system in filamentous fungi, in which cyclophilin was enlisted to perform the chaperone funtion.
2021-07-10 | GSE179712 | GEO
Project description:Plant ribosomes are heterogeneous due to genome duplications that resulted in several paralog genes encoding each ribosomal protein (RP). The mainstream view suggests that heterogeneity provides sufficient ribosomes throughout the Arabidopsis lifespan without any functional implications. Nevertheless, genome duplications are known to produce sub- and neofunctionalization of initially redundant genes. Functional divergence of RP paralogs can be considered ribosome specialization if the diversified functions of these paralogs remain within the context of protein translation, especially if RP divergence should contribute to a preferential or ultimately even rigorous selection of transcripts to be translated by a RP-defined ribosome subpopulation. Here we provide evidence that cold acclimation triggers a reprogramming in structural RPs at the transcriptome and proteome level. The reprogramming alters the abundance of RPs or RP paralogs in non-translational 60S large subunits (LSUs) and translational polysome fractions, a phenomenon known as substoichiometry. Cold triggered substoichiometry of ribosomal complexes differ once Arabidopsis REIL-like mediated late maturation step for the LSU is impaired. Interestingly, remodeling of ribosomes after a cold stimulus appears to be significantly constrained to specific spatial regions of the ribosome. The regions that are significantly changed during cold acclimation as judged by transcriptome or proteome data include the polypeptide exit tunnel and the P-Stalk. Both substructures of the ribosome represent plausible targets of mechanisms that may constrain translation by controlled ribosome heterogeneity. This work represents a step forward towards understanding heterogeneity and potential specialization of plant ribosomal complexes.
2021-06-28 | PXD016292 | Pride