Developmental regulation of Canonical and small ORF translation from mRNAs
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE147619 | GEO | 2020/03/27
REPOSITORIES: GEO
Similar Datasets
Project description:We present a genome-wide assessment of small open reading frames (smORF) translation by ribosomal profiling of polysomal fractions in Drosophila S2 cell. In this way, mRNAs bound by multiple ribosomes and hence actively translated can be isolated and distinguished from mRNAs bound by sporadic, putatively non-productive single ribosomes or ribosomal subunits. Ribosomal profiling of large and small polysomal fractions in Drosophila S2 cells to assess translation of smORFs
2014-09-11 | E-GEOD-60384 | biostudies-arrayexpress
Project description:We present a genome-wide assessment of small open reading frames (smORF) translation by ribosomal profiling of polysomal fractions in Drosophila S2 cell. In this way, mRNAs bound by multiple ribosomes and hence actively translated can be isolated and distinguished from mRNAs bound by sporadic, putatively non-productive single ribosomes or ribosomal subunits.
2014-09-11 | GSE60384 | GEO
Project description:Background Protein synthesis is a highly energy demanding process and is regulated according to energy availability in plant cells. Light and sugar availability affect mRNA translation but the specific roles of these factors remain unclear. In this study, sucrose was applied to Arabidopsis seedlings kept in the light or in the dark, in order to distinguish sucrose and light effects on transcription and translation. These were studied using microarray analysis of steady state mRNA and mRNA bound to translating ribosomes. Results Steady state mRNA levels were affected differently by sucrose in the light and in the dark but general translation increased to a similar extend in both conditions. Alterations in polysomal mRNA association closely followed the changes induced on the transcript level. However, for 243 mRNAs, a change in ribosome occupancy was observed after sucrose treatment in the light, but not in the dark condition. Many of these mRNAs are annotated as encoding ribosomal proteins, supporting specific translational regulation of this group of transcripts. Unexpectedly, the numbers of ribosomes bound to each mRNA decreased for mRNAs with increased ribosome occupancy. Conclusions Our results suggest that sucrose regulate translation of these 243 mRNAs but specifically in the light, through a novel regulatory mechanism. Our data sows that increased polysomal association is not necessarily leading to more ribosomes per transcript, suggesting a mechanism of translational induction not solely dependent on increased translation initiation rates. Four different samples groups were used: Control, Darkness, Sucrose, Simultaneous Darkness and sucrose treatments. All sample groups was represented by both total mRNA hybridization and of mRNAs from polysomal enrichment. All sample groups were represented by three biological replicates.
2015-01-28 | E-GEOD-59306 | biostudies-arrayexpress
Project description:Background Protein synthesis is a highly energy demanding process and is regulated according to energy availability in plant cells. Light and sugar availability affect mRNA translation but the specific roles of these factors remain unclear. In this study, sucrose was applied to Arabidopsis seedlings kept in the light or in the dark, in order to distinguish sucrose and light effects on transcription and translation. These were studied using microarray analysis of steady state mRNA and mRNA bound to translating ribosomes. Results Steady state mRNA levels were affected differently by sucrose in the light and in the dark but general translation increased to a similar extend in both conditions. Alterations in polysomal mRNA association closely followed the changes induced on the transcript level. However, for 243 mRNAs, a change in ribosome occupancy was observed after sucrose treatment in the light, but not in the dark condition. Many of these mRNAs are annotated as encoding ribosomal proteins, supporting specific translational regulation of this group of transcripts. Unexpectedly, the numbers of ribosomes bound to each mRNA decreased for mRNAs with increased ribosome occupancy. Conclusions Our results suggest that sucrose regulate translation of these 243 mRNAs but specifically in the light, through a novel regulatory mechanism. Our data sows that increased polysomal association is not necessarily leading to more ribosomes per transcript, suggesting a mechanism of translational induction not solely dependent on increased translation initiation rates.
2015-01-28 | GSE59306 | GEO
Project description:Phosphorylation of Ribosomal Protein S6 (RPS6) was the first post-translational modification of the ribosome to be identified and is a commonly-used readout for mTORC1 activity. Although the cellular and organismal functions of RPS6 phosphorylation are known, its molecular consequences on translation are less well understood. Here we use selective ribosome footprinting to analyze the location of ribosomes containing phosphorylated RPS6 on endogenous mRNAs in cells. We find that RPS6 becomes progressively dephosphorylated on ribosomes as they translate an mRNA. As a consequence, average RPS6 phosphorylation is higher on mRNAs with short coding sequences (CDSs) compared to mRNAs with long CDSs. Loss of RPS6 phosphorylation causes a correspondingly larger drop in translation efficiency of mRNAs with short CDSs than long CDSs. Interestingly, mRNAs with 5’ TOP motifs are translated well also in the absence of RPS6 phosphorylation despite short CDS lengths, suggesting they are translated via a different mode. In sum this provides a dynamic view of RPS6 phosphorylation on ribosomes as they translate mRNAs and the functional consequence on translation.
2021-12-22 | GSE168977 | GEO
Project description:Sucrose gradient ultracentrifugation followed by microarray analysis was used to identify translationally-regulated mRNAs (mRNAs associated with ribosomes) from JFH1-infected and uninfected Huh-7.5.1 cells. Huh7 cells were infected with HCV JFH-1 strain. Controls consisted in non-infected cells and infected cells treated with an anti-protease. 3 days after infection, cell lysates were subjected to sucrose-gradient centrifugation in order to isolate polysome-free RNAs from polysome-bound (translated) RNAs. The non-polysomal, polysomal as well as cytosolic (non fractionned) RNAs, from infected, non-infected, and infected-treated cells were subject sur microarray analysis.
2013-02-12 | E-GEOD-44210 | biostudies-arrayexpress
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:Purpose: mRNA translation into protein is highly regulated, but the role of mRNA isoforms, noncoding RNAs (ncRNAs), and genetic variants has yet to be systematically studied. Using high-throughput sequencing (RNA-seq), we have measured cellular levels of mRNAs and ncRNAs, and their isoforms, in lymphoblast cell lines (LCL) and in polysomal fractions, the latter shown to yield strong correlations of mRNAs with expressed protein levels. Analysis of allelic RNA ratios at heterozygous SNPs served to reveal genetic factors in ribosomal loading. Methods: RNA-seq was performed on cytosolic extracts and polysomal fractions (3 ribosomes or more) from three lymphoblastoid cell lines. As each RNA fraction was amplified (NuGen kit), and relative contributions from various RNA classes differed between cytosol and polysomes, the fraction of any given RNA species loaded onto polysomes was difficult to quantitate. Therefore, we focused on relative recovery of the various RNA classes and rank order of single RNAs compared to total RNA. Results: RNA-seq of coding and non-coding RNAs (including microRNAs) in three LCLs revealed significant differences in polysomal loading of individual RNAs and isoforms, and between RNA classes. Moreover, correlated distribution between protein-coding and non-coding RNAs suggests possible interactions between them. Allele-selective RNA recruitment revealed strong genetic influence on polysomal loading for multiple RNAs. Allelic effects can be attributed to generation of different RNA isoforms before polysomal loading or to differential loading onto polysomes, the latter defining a direct genetic effect on translation. Several variants and genes identified by this approach are also associated with RNA expression and clinical phenotypes in various databases. Conclusions: These results provide a novel approach using complete transcriptome RNA-seq to study polysomal RNA recruitment and regulatory variants affecting protein translation. cells from 3 samples were grown to 5x105 cells/mL density in T75 tissue culture flask and harvested, total RNA and polysome bound RNA was sequenced by Ion Proton
2015-06-30 | E-GEOD-66135 | biostudies-arrayexpress
Project description:The yeast genome contains a substantial amount of duplicated ribosomal protein genes. Functional characterization of deletion strains of individual paralogs show that the phenotypes upon deletion are not the same for a given paralog pair, suggesting that ribosomal protein paralog genes have distinct functions and thus are not redundant. Here we aimed to explore the differential function of RPL22A and RPL22B in protein synthesis. For this aim, we compared the ribosome-bound mRNAs found in different polysomal fractions: monosome, polysomal low (2-3ribosomes/mRNA), and polysomal high (>3ribosomes/mRNA), relative to total mRNA, for 3 different yeast strains: ∆RPL22A, ∆RPL22B and wild-type. Our results show that the use of one or the other specific ribosomal paralog affects the protein synthesis rates of specific transcripts, suggesting that each ribosomal protein paralog is optimized for decoding a subset of transcripts. We also find that the ratio of these paralogs changes upon oxidative stress, and propose that ribosome heterogeneity might be employed as a strategy to tune protein translation upon oxidative stress.
2021-08-01 | GSE118296 | GEO
Project description:Terminal oligopyrimidine motif-containing (TOP) mRNAs encode all ribosomal proteins in mammals and are regulated to tune ribosome synthesis to cell state. Previous studies implicate LARP1 in 40S- or 80S-ribosome complexes that repress and stabilize TOP mRNAs. However, a mechanistic understanding of how LARP1 and TOP mRNAs interact with ribosomes to coordinate TOP mRNA outcomes is lacking. Here, we show that LARP1 senses the cellular supply of ribosomes by directly binding non-translating 80S ribosomes. Cryo-EM structures reveal a previously uncharacterized domain of LARP1 bound to and occluding the 40S mRNA channel and mutations at the LARP1-ribosome interface block formation of the 40S/80S-LARP1-TOP complexes. Free cytosolic ribosomes induce sequestration of TOP mRNAs in repressed 80S-LARP1-TOP complexes independent of alterations in mTOR signaling. Together, this work demonstrates a ribosome-sensing function of LARP1 that allows it to tune ribosome protein synthesis to the availability of free ribosomes.
2023-10-28 | GSE246077 | GEO