Analysis of plant mRNA upstream open reading frames

2005 ◽  
Vol 2 (1) ◽  
pp. 59-66
Author(s):  
Jin Yong-Feng ◽  
Jin Hui-Qing ◽  
Zhou Ping ◽  
Bian Teng-Fei

AbstractUpstream open reading frames (uORFs) in 5′-untranslated regions (5′-UTRs) of eukaryotic mRNAs play an important role in translation efficiency. Computational analysis of the upstream ATG (uATG) and uORFs of 5′-UTRs of plant mRNAs, adopted from the nucleotide sequence databank, was carried out. Statistical analysis revealed that up to 18% of 5′-UTRs contain uATG, which is much higher than the earlier estimate. Among them, about 50% of the genes have one uATG and nearly 20% of them have two uATGs. About 85% of uORFs are non-overlapping. Thirty per cent of uORF peptides comprise 1–5 aa, and about 80% of uORFs fall in the range of below 20 aa. Sequences flanking the uATG codon differ strikingly from the functional initiation codon and the uATG triplet is more frequently located in a non-optimal context. Consensus sequences of the ATG codon context of mRNA with and without uATG are similar, whereas the ATG codon context of mRNA without uATG is more frequently located in an optimal context than is mRNA with uATG. Most mRNAs with uATGs are possibly related to regulatory functions. In addition, most mRNA uORFs have no similarity between plant species whereas sequences of a few uORFs are highly conserved. For example, mRNA uORFs encoding S-adenosyl-l-methionine decarboxylase (AdoMetDC) share 75–100% homology between plant species, which is much more conserved than AdoMetDC protein.

2015 ◽  
Author(s):  
David E Weinberg ◽  
Premal Shah ◽  
Stephen W Eichhorn ◽  
Jeffrey A Hussmann ◽  
Joshua B Plotkin ◽  
...  

Ribosome-footprint profiling provides genome-wide snapshots of translation, but technical challenges can confound its analysis. Here, we use improved methods to obtain ribosome-footprint profiles and mRNA abundances that more faithfully reflect gene expression in Saccharomyces cerevisiae. Our results support proposals that both the beginning of coding regions and codons matching rare tRNAs are more slowly translated. They also indicate that emergent polypeptides with as few as three basic residues within a 10-residue window tend to slow translation. With the improved mRNA measurements, the variation attributable to translational control in exponentially growing yeast was less than previously reported, and most of this variation could be predicted with a simple model that considered mRNA abundance, upstream open reading frames, cap-proximal structure and nucleotide composition, and lengths of the coding and 5′- untranslated regions. Collectively, our results reveal key features of translational control in yeast and provide a framework for executing and interpreting ribosome- profiling studies.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Bohlen ◽  
Liza Harbrecht ◽  
Saioa Blanco ◽  
Katharina Clemm von Hohenberg ◽  
Kai Fenzl ◽  
...  

Abstract Translation efficiency varies considerably between different mRNAs, thereby impacting protein expression. Translation of the stress response master-regulator ATF4 increases upon stress, but the molecular mechanisms are not well understood. We discover here that translation factors DENR, MCTS1 and eIF2D are required to induce ATF4 translation upon stress by promoting translation reinitiation in the ATF4 5′UTR. We find DENR and MCTS1 are only needed for reinitiation after upstream Open Reading Frames (uORFs) containing certain penultimate codons, perhaps because DENR•MCTS1 are needed to evict only certain tRNAs from post-termination 40S ribosomes. This provides a model for how DENR and MCTS1 promote translation reinitiation. Cancer cells, which are exposed to many stresses, require ATF4 for survival and proliferation. We find a strong correlation between DENR•MCTS1 expression and ATF4 activity across cancers. Furthermore, additional oncogenes including a-Raf, c-Raf and Cdk4 have long uORFs and are translated in a DENR•MCTS1 dependent manner.


2017 ◽  
Author(s):  
Pierre Murat ◽  
Giovanni Marsico ◽  
Barbara Herdy ◽  
Avazeh Ghanbarian ◽  
Guillem Portella ◽  
...  

ABSTRACTRNA secondary structures in the 5’ untranslated regions (UTRs) of mRNAs have been characterised as key determinants of translation initiation. However the role of non-canonical secondary structures, such as RNA G-quadruplexes (rG4s), in modulating translation of human mRNAs and the associated mechanisms remain largely unappreciated. Here we use a ribosome profiling strategy to investigate the translational landscape of human mRNAs with structured 5’ untranslated regions (5’-UTR). We found that inefficiently translated mRNAs, containing rG4-forming sequences in their 5’-UTRs, have an accumulation of ribosome footprints in their 5’-UTRs. We show that rG4-forming sequences are determinants of 5’-UTR translation, suggesting that the folding of rG4 structures thwarts the translation of protein coding sequences (CDS) by stimulating the translation of repressive upstream open reading frames (uORFs). To support our model, we demonstrate that depletion of two rG4s-specialised DEAH-box helicases, DHX36 and DHX9, shifts translation towards rG4-containing uORFs reducing the translation of selected transcripts comprising proto-oncogenes, transcription factors and epigenetic regulators. Transcriptome-wide identification of DHX9 binding sites using individual-nucleotide resolution UV crosslinking and immunoprecipitation (iCLIP) demonstrate that translation regulation is mediated through direct physical interaction between the helicase and its rG4 substrate. Our findings unveil a previously unknown role for non-canonical structures in governing 5’-UTR translation and suggest that the interaction of helicases with rG4s could be considered as a target for future therapeutic intervention.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiro Takahashi ◽  
Shido Miyaki ◽  
Hitoshi Onouchi ◽  
Taichiro Motomura ◽  
Nobuo Idesako ◽  
...  

Abstract Upstream open reading frames (uORFs) are present in the 5′-untranslated regions of many eukaryotic mRNAs, and some peptides encoded by these regions play important regulatory roles in controlling main ORF (mORF) translation. We previously developed a novel pipeline, ESUCA, to comprehensively identify plant uORFs encoding functional peptides, based on genome-wide identification of uORFs with conserved peptide sequences (CPuORFs). Here, we applied ESUCA to diverse animal genomes, because animal CPuORFs have been identified only by comparing uORF sequences between a limited number of species, and how many previously identified CPuORFs encode regulatory peptides is unclear. By using ESUCA, 1517 (1373 novel and 144 known) CPuORFs were extracted from four evolutionarily divergent animal genomes. We examined the effects of 17 human CPuORFs on mORF translation using transient expression assays. Through these analyses, we identified seven novel regulatory CPuORFs that repressed mORF translation in a sequence-dependent manner, including one conserved only among Eutheria. We discovered a much higher number of animal CPuORFs than previously identified. Since most human CPuORFs identified in this study are conserved across a wide range of Eutheria or a wider taxonomic range, many CPuORFs encoding regulatory peptides are expected to be found in the identified CPuORFs.


Author(s):  
Xiaolei Zhang ◽  
Matthew Wakeling ◽  
James Ware ◽  
Nicola Whiffin

AbstractSummaryCurrent tools to annotate the predicted effect of genetic variants are heavily biased towards protein-coding sequence. Variants outside of these regions may have a large impact on protein expression and/or structure and can lead to disease, but this effect can be challenging to predict. Consequently, these variants are poorly annotated using standard tools. We have developed a plugin to the Ensembl Variant Effect Predictor, the UTRannotator, that annotates variants in 5’untranslated regions (5’UTR) that create or disrupt upstream open reading frames (uORFs). We investigate the utility of this tool using the ClinVar database, providing an annotation for 30.8% of all 5’UTR (likely) pathogenic variants, and highlighting 31 variants of uncertain significance as candidates for further follow-up. We will continue to update the UTR annotator as we gain new knowledge on the impact of variants in UTRs.Availability and implementationUTRannotator is freely available on Github: https://github.com/ImperialCardioGenetics/UTRannotatorSupplementary informationSupplementary data are available at bioRxiv.


2019 ◽  
Author(s):  
Hiro Takahashi ◽  
Shido Miyaki ◽  
Hitoshi Onouchi ◽  
Taichiro Motomura ◽  
Nobuo Idesako ◽  
...  

AbstractUpstream open reading frames (uORFs) are present in the 5’-untranslated regions of many eukaryotic mRNAs, and some peptides encoded by these regions play important regulatory roles in controlling main ORF (mORF) translation. We previously developed a novel pipeline, ESUCA, to comprehensively identify plant uORFs encoding functional peptides, based on genome-wide identification of uORFs with conserved peptide sequences (CPuORFs). Here, we applied ESUCA to diverse animal genomes, because animal CPuORFs have been identified only by comparing uORF sequences between a limited number of species, and how many previously identified CPuORFs encode regulatory peptides is unclear. By using ESUCA, 1,517 (1,373 novel and 144 known) CPuORFs were extracted from four evolutionarily divergent animal genomes. We examined the effects of 17 human CPuORFs on mORF translation using transient expression assays. Through these analyses, we identified seven novel regulatory CPuORFs that repressed mORF translation in a sequence-dependent manner, including one conserved only among Eutheria. We discovered a much higher number of animal CPuORFs than previously identified. Since most human CPuORFs identified in this study are conserved across a wide range of Eutheria or a wider taxonomic range, many CPuORFs encoding regulatory peptides are expected to be found in the identified CPuORFs.


Author(s):  
Xiaolei Zhang ◽  
Matthew Wakeling ◽  
James Ware ◽  
Nicola Whiffin

Abstract Summary Current tools to annotate the predicted effect of genetic variants are heavily biased towards protein-coding sequence. Variants outside of these regions may have a large impact on protein expression and/or structure and can lead to disease, but this effect can be challenging to predict. Consequently, these variants are poorly annotated using standard tools. We have developed a plugin to the Ensembl Variant Effect Predictor, the UTRannotator, that annotates variants in 5′untranslated regions (5′UTR) that create or disrupt upstream open reading frames. We investigate the utility of this tool using the ClinVar database, providing an annotation for 31.9% of all 5′UTR (likely) pathogenic variants, and highlighting 31 variants of uncertain significance as candidates for further follow-up. We will continue to update the UTRannotator as we gain new knowledge on the impact of variants in UTRs. Availability and implementation UTRannotator is freely available on Github: https://github.com/ImperialCardioGenetics/UTRannotator. Supplementary information Supplementary data are available at Bioinformatics online.


2021 ◽  
Author(s):  
Justin Rendleman ◽  
Mahabub Pasha Mohammad ◽  
Matthew Pressler ◽  
Shuvadeep Maity ◽  
Vladislava Hronova ◽  
...  

Translation includes initiation, elongation, and termination, followed by ribosome recycling. We characterize a new sequence element in 5' untranslated regions that consists of an adjacent start and stop codon and thereby excludes elongation. In these start-stop elements, an initiating ribosome is simultaneously positioned for termination without having translocated. At the example of activating transcription factor 4 (ATF4), we demonstrate that start-stops modify downstream re-initiation, thereby repressing translation of upstream open reading frames and enhancing ATF4 inducibility under stress. Start-stop elements are abundant in both mammals and yeast and affect key regulators such as DROSHA and the oncogenic transcription factor NFIA. They provide a unique regulatory layer that impedes ribosome scanning without the energy-expensive peptide production that accompanies upstream open reading frames.


Endocrinology ◽  
2008 ◽  
Vol 150 (3) ◽  
pp. 1361-1368 ◽  
Author(s):  
Adhanet H. Kidane ◽  
Gerhard Heinrich ◽  
Ron P. H. Dirks ◽  
Brechje A. de Ruyck ◽  
Nicolette H. Lubsen ◽  
...  

Brain-derived neurotrophic factor (BDNF) is a neurotrophin with important growth-promoting properties. We report here the first characterization of a BDNF gene in an amphibian, Xenopus laevis, and demonstrate that environmental factors can activate this gene in a promoter-specific fashion. The Xenopus BDNF gene contains six promoter-specific 5′-exons and one 3′-protein-encoding exon. We examined the expression of promoter-specific transcripts in Xenopus neuroendocrine melanotrope cells. These cells make a good model to study how environmental factors control gene expression. In animals placed on a black background melanotrope cells more actively produce and release αMSH than in animals on a white background. BDNF is cosequestered and coreleased with αMSH and stimulates biosynthesis of proopiomelanocortin (POMC), the precursor protein for αMSH. Our analysis of the expression of the BDNF transcripts revealed that there is differential use of some BDNF promoters in melanotrope cells, depending on the adaptation state of the frog. During black-background adaptation, stimulation of expression of BDNF transcript IV preceded that of the POMC transcript, suggesting the BDNF gene is an effector gene for POMC expression. The possible mechanisms regulating expression of the various transcripts are discussed on the basis of the potential calcium- and cAMP-responsive elements in the promoter region of exon IV. Finally, we show that the upstream open reading frames of BDNF transcripts I and IV markedly decrease BDNF translation efficiency, giving the first indication for a functional role of untranslated BDNF exons. We show promoter-specific expression of BDNF transcripts in neuroendocrine melanotrope cells and provide evidence that upstream open reading frames of BDNF transcripts decrease translation efficiency.


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