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Scientific Reports Apr 2022Protein synthesis is dysregulated in many diseases, but we lack a systems-level picture of how signaling molecules and RNA binding proteins interact with the...
Protein synthesis is dysregulated in many diseases, but we lack a systems-level picture of how signaling molecules and RNA binding proteins interact with the translational machinery, largely due to technological limitations. Here we present riboPLATE-seq, a scalable method for generating paired libraries of ribosome-associated and total mRNA. As an extension of the PLATE-seq protocol, riboPLATE-seq utilizes barcoded primers for pooled library preparation, but additionally leverages anti-rRNA ribosome immunoprecipitation on whole polysomes to measure ribosome association (RA). We compare RA to its analogue in ribosome profiling and RNA sequencing, translation efficiency, and demonstrate both the performance of riboPLATE-seq and its utility in detecting translational alterations induced by specific inhibitors of protein kinases.
Topics: High-Throughput Nucleotide Sequencing; Polyribosomes; Protein Biosynthesis; Ribosomes; Sequence Analysis, RNA
PubMed: 35383235
DOI: 10.1038/s41598-022-09638-3 -
Proceedings of the National Academy of... Apr 2023Ribosomes that stall while translating cytosolic proteins are incapacitated by incomplete nascent chains, termed "arrest peptides" (APs) that are destroyed by the...
Ribosomes that stall while translating cytosolic proteins are incapacitated by incomplete nascent chains, termed "arrest peptides" (APs) that are destroyed by the ubiquitin proteasome system (UPS) via a process known as the ribosome-associated quality control (RQC) pathway. By contrast, APs on ribosomes that stall while translocating secretory proteins into the endoplasmic reticulum (ER-APs) are shielded from cytosol by the ER membrane and the tightly sealed ribosome-translocon junction (RTJ). How this junction is breached to enable access of cytosolic UPS machinery and 26S proteasomes to translocon- and ribosome-obstructing ER-APs is not known. Here, we show that UPS and RQC-dependent degradation of ER-APs strictly requires conjugation of the ubiquitin-like (Ubl) protein UFM1 to 60S ribosomal subunits at the RTJ. Therefore, UFMylation of translocon-bound 60S subunits modulates the RTJ to promote access of proteasomes and RQC machinery to ER-APs.
Topics: Ribosomes; Endoplasmic Reticulum; Ribosomal Proteins; Quality Control; Ubiquitins
PubMed: 37036982
DOI: 10.1073/pnas.2220340120 -
Biomolecules May 2020Ribosomes are perhaps the most critical macromolecular machine as they are tasked with carrying out protein synthesis in cells. They are incredibly complex structures... (Review)
Review
Ribosomes are perhaps the most critical macromolecular machine as they are tasked with carrying out protein synthesis in cells. They are incredibly complex structures composed of protein components and heavily chemically modified RNAs. The task of assembling mature ribosomes from their component parts consumes a massive amount of energy and requires greater than 200 assembly factors. Among the most critical of these are small nucleolar ribonucleoproteins (snoRNPs). These are small RNAs complexed with diverse sets of proteins. As suggested by their name, they localize to the nucleolus, the site of ribosome biogenesis. There, they facilitate multiple roles in ribosomes biogenesis, such as pseudouridylation and 2'--methylation of ribosomal (r)RNA, guiding pre-rRNA processing, and acting as molecular chaperones. Here, we reviewed their activity in promoting the assembly of ribosomes in eukaryotes with regards to chemical modification and pre-rRNA processing.
Topics: Animals; Humans; Organelle Biogenesis; RNA, Ribosomal; Ribonucleoproteins, Small Nuclear; Ribosomes
PubMed: 32443616
DOI: 10.3390/biom10050783 -
Cell Reports Nov 2023Oncogene-induced senescence (OIS) is a persistent anti-proliferative response that acts as a barrier against malignant transformation. During OIS, cells undergo dynamic...
Oncogene-induced senescence (OIS) is a persistent anti-proliferative response that acts as a barrier against malignant transformation. During OIS, cells undergo dynamic remodeling, which involves alterations in protein and organelle homeostasis through autophagy. Here, we show that ribosomes are selectively targeted for degradation by autophagy during OIS. By characterizing senescence-dependent alterations in the ribosomal interactome, we find that the deubiquitinase USP10 dissociates from the ribosome during the transition to OIS. This release of USP10 leads to an enhanced ribosome ubiquitination, particularly of small subunit proteins, including lysine 275 on RPS2. Both reinforcement of the USP10-ribosome interaction and mutation of RPS2 K275 abrogate ribosomal delivery to lysosomes without affecting bulk autophagy. We show that the selective recruitment of ubiquitinated ribosomes to autophagosomes is mediated by the p62 receptor. While ribophagy is not required for the establishment of senescence per se, it contributes to senescence-related metabolome alterations and facilitates the senescence-associated secretory phenotype.
Topics: Ribosomes; Ubiquitination; Ubiquitin; Autophagy; Oncogenes; Cellular Senescence
PubMed: 37930887
DOI: 10.1016/j.celrep.2023.113381 -
Cells Sep 2020Ribosomopathies are a group of rare diseases in which genetic mutations cause defects in either ribosome biogenesis or function, given specific phenotypes. Ribosomal... (Review)
Review
Ribosomopathies are a group of rare diseases in which genetic mutations cause defects in either ribosome biogenesis or function, given specific phenotypes. Ribosomal proteins, and multiple other factors that are necessary for ribosome biogenesis (rRNA processing, assembly of subunits, export to cytoplasm), can be affected in ribosomopathies. Despite the need for ribosomes in all cell types, these diseases result mainly in tissue-specific impairments. Depending on the type of ribosomopathy and its pathogenicity, there are many potential therapeutic targets. The present manuscript will review our knowledge of ribosomopathies, discuss current treatments, and introduce the new therapeutic perspectives based on recent research. Diamond-Blackfan anemia, currently treated with blood transfusion prior to steroids, could be managed with a range of new compounds, acting mainly on anemia, such as L-leucine. Treacher Collins syndrome could be managed by various treatments, but it has recently been shown that proteasomal inhibition by MG132 or Bortezomib may improve cranial skeleton malformations. Developmental defects resulting from ribosomopathies could be also treated pharmacologically after birth. It might thus be possible to treat certain ribosomopathies without using multiple treatments such as surgery and transplants. Ribosomopathies remain an open field in the search for new therapeutic approaches based on our recent understanding of the role of ribosomes and progress in gene therapy for curing genetic disorders.
Topics: Anemia, Diamond-Blackfan; Humans; Ribosomal Proteins; Ribosomes
PubMed: 32932838
DOI: 10.3390/cells9092080 -
Trends in Biochemical Sciences Sep 2021Ribosomes that stall inappropriately during protein synthesis harbor proteotoxic components linked to cellular stress and neurodegenerative diseases. Molecular... (Review)
Review
Ribosomes that stall inappropriately during protein synthesis harbor proteotoxic components linked to cellular stress and neurodegenerative diseases. Molecular mechanisms that rescue stalled ribosomes must selectively detect rare aberrant translational complexes and process the heterogeneous components. Ribosome-associated quality control pathways eliminate problematic messenger RNAs and nascent proteins on stalled translational complexes. In addition, recent studies have uncovered general principles of stall recognition upstream of quality control pathways and fail-safe mechanisms that ensure nascent proteome integrity. Here, we discuss developments in our mechanistic understanding of the detection and rescue of stalled ribosomal complexes in eukaryotes.
Topics: Protein Biosynthesis; Protein Processing, Post-Translational; Proteins; RNA, Messenger; Ribosomes
PubMed: 33966939
DOI: 10.1016/j.tibs.2021.03.008 -
Molecular Cell Feb 2023mRNA translation is a highly conserved and tightly controlled mechanism for protein synthesis and is well known to be altered by oncogenes to promote cancer development.... (Review)
Review
mRNA translation is a highly conserved and tightly controlled mechanism for protein synthesis and is well known to be altered by oncogenes to promote cancer development. This distorted mRNA translation is accompanied by the vulnerability of cancer to inhibitors of key mRNA translation components. Novel studies also suggest that these alternations could be utilized for immunotherapy. Ribosome heterogeneity and alternative responses to nutrient shortages, which aid cancer growth and spread, are proposed to elicit aberrant protein production but may also result in previously unidentified therapeutic targets, such as the presentation of cancer-specific peptides at the surface of cancer cells (neoepitopes). This review will assess the driving forces in tRNA and ribosome function that underlie proteome diversification due to alterations in mRNA translation in cancer cells.
Topics: Proteome; Protein Biosynthesis; Ribosomes; Peptides; RNA, Transfer; Neoplasms
PubMed: 36521491
DOI: 10.1016/j.molcel.2022.11.014 -
BMB Reports Nov 2022Ribosomes, acting as the cellular factories for protein production, are essential for all living organisms. Ribosomes are composed of both proteins and RNAs and are... (Review)
Review
Ribosomes, acting as the cellular factories for protein production, are essential for all living organisms. Ribosomes are composed of both proteins and RNAs and are established through the coordination of several steps, including transcription, maturation of ribosomal RNA (rRNA), and assembly of ribosomal proteins. In particular, diverse factors required for ribosome biogenesis, such as transcription factors, small nucleolar RNA (snoRNA)-associated proteins, and assembly factors, are tightly regulated by various post-translational modifications. Among these modifications, small ubiquitin-related modifier (SUMO) targets lots of proteins required for gene expression of ribosomal proteins, rRNA, and snoRNAs, rRNA processing, and ribosome assembly. The tight control of SUMOylation affects functions and locations of substrates. This review summarizes current studies and recent progress of SUMOylation-mediated regulation of ribosome biogenesis. [BMB Reports 2022; 55(11): 535-540].
Topics: Ubiquitin; Ribosomes; RNA Processing, Post-Transcriptional; RNA, Small Nucleolar; Ribosomal Proteins
PubMed: 36195568
DOI: 10.5483/BMBRep.2022.55.11.130 -
Biochemistry and Cell Biology =... Oct 2023Telomeres are nucleoprotein structures that play a pivotal role in the protection and maintenance of eukaryotic chromosomes. Telomeres and the enzyme telomerase, which... (Review)
Review
Telomeres are nucleoprotein structures that play a pivotal role in the protection and maintenance of eukaryotic chromosomes. Telomeres and the enzyme telomerase, which replenishes telomeric DNA lost during replication, are important factors necessary to ensure continued cell proliferation. Cell proliferation is also dependent on proper and efficient protein synthesis, which is carried out by ribosomes. Mutations in genes involved in either ribosome biogenesis or telomere biology result in cellular abnormalities and can cause human genetic diseases, defined as ribosomopathies and telomeropathies, respectively. Interestingly, recent discoveries indicate that many of the ribosome assembly and rRNA maturation factors have additional noncanonical functions in telomere biology. Similarly, several key proteins and enzymes involved in telomere biology, including telomerase, have unexpected roles in rRNA transcription and maturation. These observations point to an intriguing cross-talk mechanism potentially explaining the multiple pleiotropic symptoms of mutations in many causal genes identified in various telomeropathy and ribosomopathy diseases. In this review, we provide a brief summary of eukaryotic telomere and rDNA loci structures, highlight several universal features of rRNA and telomerase biogenesis, evaluate intriguing interconnections between telomere biology and ribosome assembly, and conclude with an assessment of overlapping features of human diseases of telomeropathies and ribosomopathies.
Topics: Humans; Telomerase; Telomere; Mutation; Ribosomes; Eukaryota; Biology
PubMed: 36989538
DOI: 10.1139/bcb-2022-0383 -
Genes Mar 2021Ribosome biogenesis is a complex process that is responsible for the formation of ribosomes and ultimately global protein synthesis. The first step in this process is... (Review)
Review
Ribosome biogenesis is a complex process that is responsible for the formation of ribosomes and ultimately global protein synthesis. The first step in this process is the synthesis of the ribosomal RNA in the nucleolus, transcribed by RNA Polymerase I. Historically, abnormal nucleolar structure is indicative of poor cancer prognoses. In recent years, it has been shown that ribosome biogenesis, and rDNA transcription in particular, is dysregulated in cancer cells. Coupled with advancements in screening technology that allowed for the discovery of novel drugs targeting RNA Polymerase I, this transcriptional machinery is an increasingly viable target for cancer therapies. In this review, we discuss ribosome biogenesis in breast cancer and the different cellular pathways involved. Moreover, we discuss current therapeutics that have been found to affect rDNA transcription and more novel drugs that target rDNA transcription machinery as a promising avenue for breast cancer treatment.
Topics: Breast Neoplasms; DNA, Ribosomal; Female; Gene Expression Regulation; Humans; RNA, Ribosomal; Ribosomes; Transcription, Genetic
PubMed: 33805424
DOI: 10.3390/genes12040502