Polysome-associated mRNA levels upon glucose repletion
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ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE31220 | GEO | 2011/09/05
SECONDARY ACCESSION(S): PRJNA154117
REPOSITORIES: GEO
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Project description:Cell survival in changing environments requires appropriate regulation of gene expression, including post-transcriptional gene regulatory mechanisms. Based on reporter gene studies in glucose-starved yeast, it was proposed that translationally silenced eukaryotic mRNAs accumulate in P-bodies and can return to active translation. We present evidence contradicting the notion that this model is a widespread and general phenomenon. First, genome-wide measurements of mRNA abundance, translation, and ribosome occupancy following glucose withdrawal show that most mRNAs are lost from the cell coincident with their loss from polysomes. Second, only a very limited sub-population of translationally repressed transcripts, comprising fewer than 400 genes, can be reactivated for translation upon glucose re-addition in the absence of new transcription. This highly selective post-transcriptional regulation could be a mechanism for cells to minimize the energetic costs of reversing gene-regulatory decisions in rapidly changing environments by transiently preserving a pool of transcripts whose translation is rate-limiting for growth. Sigma 1278b yeast were grown to OD600=1.0-1.1 in YPD in baffled flasks at 30C with vigorous shaking. Cells were treated with thiolutin to a final concentration of 3ug/mL, harvested by centrifugation, and resuspended in pre-warmed YPA medium lacking glucose. Cells were returned to 30C for shaking for 10 minutes. For the refed samples, glucose was added to a final concentration of 2% and samples were taken after 5 minutes. Polysome preparation and RNA isolation were as described in Experimental Procedues. A common RNA sample, polysomal RNA from cells grown in YPD, was used for one channel of each array.
2011-09-04 | E-GEOD-31220 | biostudies-arrayexpress
Project description:Cell survival in changing environments requires appropriate regulation of gene expression, including post-transcriptional gene regulatory mechanisms. Based on reporter gene studies in glucose-starved yeast, it was proposed that translationally silenced eukaryotic mRNAs accumulate in P-bodies and can return to active translation. We present evidence contradicting the notion that this model is a widespread and general phenomenon. First, genome-wide measurements of mRNA abundance, translation, and ribosome occupancy following glucose withdrawal show that most mRNAs are lost from the cell coincident with their loss from polysomes. Second, only a very limited sub-population of translationally repressed transcripts, comprising fewer than 400 genes, can be reactivated for translation upon glucose re-addition in the absence of new transcription. This highly selective post-transcriptional regulation could be a mechanism for cells to minimize the energetic costs of reversing gene-regulatory decisions in rapidly changing environments by transiently preserving a pool of transcripts whose translation is rate-limiting for growth.
2011-09-05 | GSE31392 | GEO
Project description:Cell survival in changing environments requires appropriate regulation of gene expression, including post-transcriptional gene regulatory mechanisms. Based on reporter gene studies in glucose-starved yeast, it was proposed that translationally silenced eukaryotic mRNAs accumulate in P-bodies and can return to active translation. We present evidence contradicting the notion that this model is a widespread and general phenomenon. First, genome-wide measurements of mRNA abundance, translation, and ribosome occupancy following glucose withdrawal show that most mRNAs are lost from the cell coincident with their loss from polysomes. Second, only a very limited sub-population of translationally repressed transcripts, comprising fewer than 400 genes, can be reactivated for translation upon glucose re-addition in the absence of new transcription. This highly selective post-transcriptional regulation could be a mechanism for cells to minimize the energetic costs of reversing gene-regulatory decisions in rapidly changing environments by transiently preserving a pool of transcripts whose translation is rate-limiting for growth. Sigma 1278b yeast were grown to OD600=1.0-1.1 in YPD in baffled flasks at 30C with vigorous shaking. Cells were harvested by centrifugation and resuspended in pre-warmed YPA medium lacking glucose. Cells were returned to 30C for shaking for 10,20,30,60, or 120 minutes.
2011-09-04 | E-GEOD-31392 | biostudies-arrayexpress
Project description:Gametes rely heavily on post-transcriptional control mechanisms to regulate their differentiation. In eggs, the storage and selective temporal activation of maternal mRNAs is essential for normal development. In the male, transcription ceases during spermiogenesis necessitating the post-transcriptional regulation of many paternal mRNAs required for spermatid differentiation and spermatozoan function. Messenger RNAs that are being actively translated form polysomes. whereas translationally inactive mRNAs are often sequestered in ribonucleoproteins (RNPs). Here we combine polysome display and microarray analyses of RNP and polysome fractions of testes from prepubertal and adult mice to characterize the translation state of individual mRNAs as spermatogenesis proceeds.. Consistent with published reports, many post-meiotic mRNAs known to be translationally delayed shift from the RNPs into the polysomes, confirming the validity of this approach. In addition, based upon the criterion of movement from RNPs to polysomes, we detect another 742 mouse testicular genes showing dramatic shifts between RNPs and polysomes. One sub-group of 35 genes including the known translationally delayed Pgk2, are initially transcribed and translationally repressed in meiotic spermatocytes, and translated post-meiotically. This high-through-put approach defines the changing translation patterns of a large number of genes as male germ cells differentiate and identifies a new group of post-transcriptionally regulated meiotic transcripts for future study. Mouse testes from animals of 3 different ages were fractionated on a sucrose gradient and transcripts were quantified in the RNP and Polysome fractions. Transcripts were identified that changed their RNP/Polysome representation at the different developmental time points.
2007-11-23 | E-GEOD-4711 | biostudies-arrayexpress
Project description:Gametes rely heavily on post-transcriptional control mechanisms to regulate their differentiation. In eggs, the storage and selective temporal activation of maternal mRNAs is essential for normal development. In the male, transcription ceases during spermiogenesis necessitating the post-transcriptional regulation of many paternal mRNAs required for spermatid differentiation and spermatozoan function. Messenger RNAs that are being actively translated form polysomes. whereas translationally inactive mRNAs are often sequestered in ribonucleoproteins (RNPs). Here we combine polysome display and microarray analyses of RNP and polysome fractions of testes from prepuberal and adult mice to characterize the translation state of individual mRNAs as spermatogenesis proceeds.. Consistent with published reports, many post-meiotic mRNAs known to be translationally delayed shift from the RNPs into the polysomes, confirming the validity of this approach. In addition, based upon the criterion of movement from RNPs to polysomes, we detect another 742 mouse testicular genes showing dramatic shifts between RNPs and polysomes. One sub-group of 35 genes including the known translationally delayed Pgk2, are initially transcribed and translationally repressed in meiotic spermatocytes, and translated post-meiotically. This high-through-put approach defines the changing translation patterns of a large number of genes as male germ cells differentiate and identifies a new group of post-transcriptionally regulated meiotic transcripts for future study. Keywords: time course
2006-05-15 | GSE4711 | GEO
Project description:Microarray comparisons of polysome loading in wild-type Arabidopsis and eif3h mutant Goal: To find the target mRNAs that are translationally regulated by eIF3h. BACKGROUND: The eukaryotic translation initiation factor eIF3 has multiple roles during the initiation of translation of cytoplasmic mRNAs. However, the contributions of individual subunits of eIF3 to the translation of specific mRNAs remain poorly understood. RESULTS: Working with stable reporter transgenes in Arabidopsis thaliana it was demonstrated that the h subunit of eIF3 contributes to the efficient translation initiation of mRNAs harboring upstream open reading frames (uORFs) in their 5’ leader sequence. uORFs, which can function as devices for translational regulation, are present in over 30% of Arabidopsis mRNAs, and are enriched among mRNAs for transcriptional regulators and protein modifying enzymes. Microarray comparisons of polysome loading in wild-type and eif3h mutant plants revealed that eIF3h generally helps to maintain efficient polysome loading of mRNAs harboring multiple uORFs. Independently, eIF3h also boosted polysome loading of mRNAs with long coding sequences. Moreover, the lesion in eIF3h revealed a concerted upregulation of translation for specific functional subgroups of mRNAs, including ribosomal proteins and proteins involved in photosynthesis. CONCLUSIONS: The intact eIF3h protein contributes to efficient translation initiation on 5’ leader sequences harboring multiple uORFs, although mRNA features independent of uORFs were also implicated. Moreover, our data suggest that regulons of translational control can be revealed by mutations in generic translation initiation factors. Keywords: mutant, polysome, non-polysome
2007-05-01 | GSE6024 | GEO
Project description:Trypanosoma brucei occupies distinct niches throughout its life cycle, both within the vertebrate host (fat tissue, bloodstream, central nervous system) and within the insect host, the tsetse fly (taken up with a bloodmeal and passing through the midgut, and migrating to the salivary glands). The immunological and biochemical complexity and variability of each of these environments require a reshaping of the protein landscape of the parasite both to evade surveillance and face changing metabolic demands. Whereas most well-studied organisms rely on transcriptional control as the main regulator of gene expression, post-transcriptional control mechanisms are particularly important in T. brucei, and these are often mediated by RNA-binding proteins. DRBD18 is a T. brucei RNA binding protein that interacts with ribosomal proteins and translation factors. Here, we tested a role for DRBD18 in translational control. We show that DRBD18 depletion by RNA interference leads to altered polysomal profiles with a specific depletion of heavy polysomes. RiboSeq analysis reveals that 101 transcripts change in translational efficiency (TE) upon DRBD18 depletion: 41 of them exhibit decreased TE and 60 increased TE. A further 66 transcripts are buffered, i.e. changes in transcript abundance are compensated by changes in TE such that the total translational output is expected not to change. Proteomic analysis validates much of these data. In DRBD18 depleted cells, a cohort of transcripts that code for procyclic form specific proteins are translationally repressed while, conversely, transcripts that code for bloodstream form specific proteins are translationally enhanced. These data suggest that DRBD18 contributes to the maintenance of the procyclic state through both positive and negative translational control of specific mRNAs.
2024-01-26 | PXD039064 | Pride
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth. Experiment using two-flactionated mRNA in 4 developmental stages, Polysomal mRNA vs. total mRNA. Biological replicates: 2. Compared 2DAG and 21DAG, or Young leaves and Mature leaves.
2015-09-01 | E-GEOD-69069 | biostudies-arrayexpress
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth.
2015-09-01 | GSE69069 | GEO
Project description:This is a polysome/monosome profiling study on yeast undergoing glucose depletion. Polysomes and monosomes are extracted and the transcripts bound to each fraction are measured by microarray. The study reveals that glucose depletion inhibits translation initiation in a mechanism involving eIF4A loss and 48S pre-initiation complex accumulation, while the pentose phosphate pathway is co-ordinately up-regulated
2011-11-11 | E-MEXP-3038 | biostudies-arrayexpress