Widespread Co-translational RNA Decay Reveals Ribosome Dynamics
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ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae Schizosaccharomyces pombe
PROVIDER: GSE63120 | GEO | 2015/06/04
SECONDARY ACCESSION(S): PRJNA266705
REPOSITORIES: GEO
Similar Datasets
Project description:It is generally assumed that mRNAs undergoing translation are protected from decay. Here, we show that mRNAs are, in fact, co-translationally degraded. This is a widespread and conserved process affecting most genes, where 5′–3′ transcript degradation follows the last translating ribosome, producing an in vivo ribosomal footprint. By sequencing the ends of 5′ phosphorylated mRNA degradation intermediates, we obtain a genome-wide drug-free measurement of ribosome dynamics. We identify general translation termination pauses in both normal and stress conditions. In addition, we describe novel codon-specific ribosomal pausing sites in response to oxidative stress that are dependent on the RNase Rny1. Our approach is simple and straightforward and does not require the use of translational inhibitors or in vitro RNA footprinting that can alter ribosome protection patterns. RNA samples were quantified according to their 5’modification. Samples were quantified using 2 alternative methods. 5PSeq (measures 5’P RNAs) and 5PSeq-fragmented (measures the sequencing bias present in any sample by randomly fragmenting RNA, re-phosphorilating the 5’ends and subjecting the sample to 5PSeq; it is used as a negative control). Different strains of S. cerevisiae and S. pombe samples were analyzed. Cells were grown both in rich media (YPD or YES) and synthetic defined media (SD). Cells were subjected to different treatments such as inhibition of translation elongation with cyclohexamide (CHX), oxidative stress (0.2 mM H2O2) or inhibition of histidine biosyntesys (3-AT; 100mM 3-amino-1,2,4-triazole). S. cerevisiae samples grown in rich media were also analyzed after CHX treatment and sucrose fractionation into monosome and polyribosome fractionation. All samples were analyzed in biological duplicates.
2015-06-04 | E-GEOD-63120 | biostudies-arrayexpress
Project description:The polyglutamine expansion of huntingtin (mHtt) causes Huntington disease (HD) and neurodegeneration, but the mechanisms remain unclear. Here, we found that mHtt promotes ribosome stalling and suppresses protein synthesis. Depletion of mHtt enhances protein synthesis and increases the speed of ribosome translocation, while mHtt directly inhibits protein synthesis in vitro. We found interactions of ribosomal proteins and translating ribosomes with mHtt. High-resolution global ribosome footprint profiling (Ribo-Seq) and mRNA-Seq indicated a widespread shift in ribosome occupancy toward the 5’ and 3’ end and unique single-codon pauses on selected mRNA targets in HD cells, compared to controls. Thus, mHtt impedes ribosomal translocation during translation by promoting ribosome stalling, a novel mechanistic defect that can be exploited for HD therapeutics.
2020-07-22 | GSE146674 | GEO
Project description:The polyglutamine expansion of huntingtin (mHtt) causes Huntington disease (HD) and neurodegeneration, but the mechanisms remain unclear. Here, we found that mHtt promotes ribosome stalling and suppresses protein synthesis. Depletion of mHtt enhances protein synthesis and increases the speed of ribosome translocation, while mHtt directly inhibits protein synthesis in vitro. We found interactions of ribosomal proteins and translating ribosomes with mHtt. High-resolution global ribosome footprint profiling (Ribo-Seq) and mRNA-Seq indicated a widespread shift in ribosome occupancy toward the 5’ and 3’ end and unique single-codon pauses on selected mRNA targets in HD cells, compared to controls. Thus, mHtt impedes ribosomal translocation during translation by promoting ribosome stalling, a novel mechanistic defect that can be exploited for HD therapeutics.
2020-07-22 | GSE146673 | GEO
Project description:The polyglutamine expansion of huntingtin (mHtt) causes Huntington disease (HD) and neurodegeneration, but the mechanisms remain unclear. Here, we found that mHtt promotes ribosome stalling and suppresses protein synthesis. Depletion of mHtt enhances protein synthesis and increases the speed of ribosome translocation, while mHtt directly inhibits protein synthesis in vitro. We found interactions of ribosomal proteins and translating ribosomes with mHtt. High-resolution global ribosome footprint profiling (Ribo-Seq) and mRNA-Seq indicated a widespread shift in ribosome occupancy toward the 5’ and 3’ end and unique single-codon pauses on selected mRNA targets in HD cells, compared to controls. Thus, mHtt impedes ribosomal translocation during translation by promoting ribosome stalling, a novel mechanistic defect that can be exploited for HD therapeutics.
2021-02-13 | GSE166695 | GEO
Project description:We use mRNA-seq in combination with polysome profiling to determine translational status for all mRNAs in Drosophila mature oocytes and activated eggs. Puromycin-treated lysates are used as a negative control in polysome profiling experiments. Additionally, we use ribosome footprinting to globally measure translational efficiency of mRNAs in wild type mature oocytes as well as wild type and png mutant activated eggs. Lysates of hand-dissected Drosophila mature oocytes (containing ~540 M-NM-<g of total RNA) were subjected to separation by velocity sedimentation through sucrose gradients. In this way, free mRNAs (present in RNPs fraction) or those comigrating with ribosomal subunits (40S or 60S+80S fractions) or with varying numbers of bound ribosomes (low polysomes (2-4 ribosomes), medium polysomes (5-9 ribosomes), and heavy polysomes (more than 10 ribosomes) can be separated based on their size and collected as sucrose gradient fractions. To compare quantitatively the levels of every mRNA across the polysome gradient fractions, we added 5ng of S. cerevisiae mRNA as an exogenous spike-in to each of the six fractions of interest: RNPs, 40S, 60S+80S, low polysomes, medium polysomes and heavy polysomes. RNA was extraced from these fractions, follwing proteinase K treatment, by hot acid phenol method. In case of unfractionated lysates, RNA was extracted using TRIzol (Invitrogen) according to manufacturerM-bM-^@M-^Ys instructions. mRNA-seq samples were prepared from 1 M-NM-<g of total RNA (in case of sucrose gradient fractions and unfractionated lysates) and subject to Illumina based sequencing. Puromycin-treated lysates of mature oocytes or 0-2h Drosophila activated eggs (containing ~540 M-NM-<g of total RNA) were also subjected to separation by velocity sedimentation through sucrose gradients. Puromycin causes premature termination of elongating ribosomes and thus it can be used to determine whether the mRNAs co-sedimenting with the polysomal peaks (defined here as M-bM-^IM-%5 ribosomes) were actively engaged in translation. As an independent approach to assess translation and obtain information on the position of ribosomes on mRNAs, we employed ribosome footprinting. In addition to analyzing the same samples, as by polysome profiling, we also analyzed png mutant activated eggs by ribosome footprinting. Ribosome footprint profiling measures the number of ribosome-protected fragments (RPFs) derived from the mRNAs of each gene, resulting in a singular value of translational efficiency (TE) for each gene (TE=RPF/RNA).
2014-06-12 | E-GEOD-52799 | biostudies-arrayexpress
Project description:Recent studies highlight the importance of translational control in determining protein abundance, underscoring the value of measuring gene expression at the level of translation. We present a protocol for genome-wide, quantitative analysis of in vivo translation by deep sequencing. This ribosome profiling approach maps the exact positions of ribosomes on transcripts by nuclease footprinting. The nuclease-protected mRNA fragments are converted into a DNA library suitable for deep sequencing using a strategy that minimizes bias. The abundance of different footprint fragments in deep sequencing data reports on the amount of translation of a gene. Additionally, footprints reveal the exact regions of the transcriptome that are translated. To better define translated reading frames, we describe an adaptation that reveals the sites of translation initiation by pre-treating cells with harringtonine to immobilize initiating ribosomes. The protocol we describe requires 5 - 7 days to generate a completed ribosome profiling sequencing library. Ribosome profiling in cultured mammalian cells under three different footprinting conditions
2012-07-26 | E-GEOD-37744 | biostudies-arrayexpress
Project description:Ribosome profiling — RNase footprinting of ribosome-bound mRNA — has been a unique and powerful method, applied to widespread organisms to survey ribosome traversal along mRNAs. In contrast to eukaryotes, bacterial ribosome footprints show a broad range of sizes, reflecting the differential states of ribosomes. However, the origin remains unclear. Here, we show that rotated state of ribosomes and intramolecular RNA duplexes each extend bacterial ribosome footprints at the 5′ end. Combining elongation inhibitors, cryo-electron microscopy, and ribosome profiling, we demonstrated that the rotated state of ribosomes results in long footprints. Along the subunit rotation, ribosomal protein S1 — a 30S-subunit RNA-binding protein — sterically protects mRNA at the 5′ end of the ribosome from RNase digestion and facilitates elongation of the ribosome. Moreover, we found that ribosomes stalled on ycbZ mRNA generate prolonged footprints because of their unique RNA secondary structure proximal to ribosomes. Through the studies of footprint extension, our results revealed S1-mediated stabilization of translation elongation and provide ribosome profiling approach to probe the conformational diversity of ribosomes in bacteria.
2023-07-28 | GSE155243 | GEO
Project description:Recent studies have revealed that the mRNA translation is punctuated by ribosomal pauses through the body of transcripts. However, little is known about its physiological significance and regulatory aspects. Here we present a multi-dimensional ribosome profiling approach to quantify the dynamics of initiation and elongation of 80S ribosomes across the entire transcriptome in mammalian cells. We show that a subset of transcripts have a significant pausing of 80S ribosome around the start codon, creating a major barrier to the commitment of translation elongation. Intriguingly, genes encoding ribosome proteins themselves exhibit an exceptionally high initiation pausing on their transcripts. Our studies also reveal that the initiation pausing is dependent on the 5M-bM-^@M-^Y untranslated region (5M-bM-^@M-^Y UTR) of mRNAs and subject to the regulation of mammalian target of rapamycin complex 1 (mTORC1). Thus, the initiation pausing of 80S ribosome represents a novel regulatory step in translational control mediated by nutrient signaling pathway. Monitor the translational status of transcriptome in mammalian cells under different conditions
2011-11-12 | E-GEOD-25626 | biostudies-arrayexpress
Project description:Synthesis and degradation of cellular constituents must be balanced to maintain cellular homeostasis, especially during adaptation to environmental stress. The role of autophagy in the degradation of proteins and organelles is well-characterized. However, autophagy-mediated RNA degradation in response to stress and the potential preference of specific RNAs to undergo autophagy-mediated degradation have not been examined. In this study, we demonstrate selective mRNA degradation by rapamycin-induced autophagy in yeast. Profiling of mRNAs from the vacuole reveals that subsets of mRNAs, such as those encoding amino acid biosynthesis and ribosomal proteins, are preferentially delivered to the vacuole by autophagy for degradation. We also reveal that autophagy-mediated mRNA degradation is tightly coupled with translation by ribosomes. Genome-wide ribosome profiling suggested a high correspondence between ribosome association and targeting to the vacuole. We propose that autophagy-mediated mRNA degradation is a unique and previously-unappreciated function of autophagy that affords post-transcriptional gene regulation.
2021-03-08 | GSE149016 | GEO
Project description:The ribosome-associated protein quality control (RQC) system that resolves stalled translation events is activated when ribosomes collide and form disome, trisome or higher order complexes. However, it is unclear whether this system distinguishes collision complexes formed on defective mRNAs from those with functional roles on endogenous transcripts. Here, we performed disome and trisome footprint profiling in yeast and found collisions were enriched on diverse sequence motifs known to slow translation. When 60S recycling was inhibited, disomes accumulated at stop codons and could move into the 3’UTR to reinitiate translation. The ubiquitin ligase and RQC factor Hel2/ZNF598 generally recognized collisions but did not trigger degradation of endogenous transcripts. However, loss of Hel2 triggered the integrated stress response, via phosphorylation of eIF2alpha, thus linking these pathways. Our results suggest that Hel2 has a role in sensing ribosome collisions on endogenous mRNAs and such events may be important for cellular homeostasis.
2020-05-26 | GSE139036 | GEO