scholarly journals A spatiotemporal translatome of mouse tissue development

2020 ◽  
Author(s):  
Hongwei Wang ◽  
Yan Wang ◽  
Jiaqi Yang ◽  
Nan Tang ◽  
Huihui Li ◽  
...  

AbstractThe precise regulation of gene expression in mammalian tissues during development results in their functional specification. Although previous transcriptomic and proteomic analyses have provided great biological insights into tissue-specific gene expression and the physiological relevance of these tissues in development, our understanding of translational regulation in developing tissues is lacking. In this study, we performed a spatiotemporally resolved translatome analysis of six mouse tissues at the embryonic and adult stages to quantify the effects of translational regulation and identify new translational components. We quantified the spatial and temporal divergences of gene expression and detected specific changes in gene expression and pathways underlying these divergences. We further showed that dynamic translational control can be achieved by modulating the translational efficiency, which resulted in the enhancement of tissue specificity during development. We also discovered thousands of actively translated upstream open reading frames (ORFs) that exhibited spatiotemporal patterns and demonstrated their regulatory roles in translational regulation. Furthermore, we identified known and novel micropeptides encoded by small ORFs from long noncoding RNAs that are functionally relevant to tissue development. Our data and analyses facilitate a better understanding of the complexity of translational regulation across tissue and developmental spectra and serve as a useful resource of the mouse translatome.

2020 ◽  
Vol 21 (17) ◽  
pp. 6238
Author(s):  
Ting Zhang ◽  
Anqi Wu ◽  
Yaping Yue ◽  
Yu Zhao

Gene expression is regulated at many levels, including mRNA transcription, translation, and post-translational modification. Compared with transcriptional regulation, mRNA translational control is a more critical step in gene expression and allows for more rapid changes of encoded protein concentrations in cells. Translation is highly regulated by complex interactions between cis-acting elements and trans-acting factors. Initiation is not only the first phase of translation, but also the core of translational regulation, because it limits the rate of protein synthesis. As potent cis-regulatory elements in eukaryotic mRNAs, upstream open reading frames (uORFs) generally inhibit the translation initiation of downstream major ORFs (mORFs) through ribosome stalling. During the past few years, with the development of RNA-seq and ribosome profiling, functional uORFs have been identified and characterized in many organisms. Here, we review uORF identification, uORF classification, and uORF-mediated translation initiation. More importantly, we summarize the translational regulation of uORFs in plant metabolic pathways, morphogenesis, disease resistance, and nutrient absorption, which open up an avenue for precisely modulating the plant growth and development, as well as environmental adaption. Additionally, we also discuss prospective applications of uORFs in plant breeding.


1998 ◽  
Vol 72 (5) ◽  
pp. 4364-4370 ◽  
Author(s):  
Michael W. Kimmick ◽  
Boris N. Afanasiev ◽  
Barry J. Beaty ◽  
Jonathan O. Carlson

ABSTRACT The nonstructural proteins NS1 and NS2 are thought to be expressed from the p7 promoter of Aedes densonucleosis virus (AeDNV). To study gene expression from the p7 promoter, eight different plasmids were constructed by fusing β-galactosidase or β-glucuronidase into the genome so that the reporter gene was in different open reading frames and under the transcriptional control of the p7 promoter. After transfection into C6/36 Aedes albopictus cells, constructs generated comparable amounts of RNA, but only the NS1 and NS2 fusion constructs produced appreciable levels of active enzyme. NS1 and NS2 fusion constructs contained wild-type AeDNV sequences from the p7 promoter downstream to nucleotide 458. The remaining constructs, with the exception of p7GUS.rf3, lacked some or all of these necessary sequences and inefficiently produced protein. These data suggest that sequences downstream of the p7 promoter play a role in translational regulation of gene expression from the p7 promoter of AeDNV.


2020 ◽  
Vol 21 (5) ◽  
pp. 1592
Author(s):  
Han Kyoung Choe ◽  
Jun Cho

Activity-dependent regulation of gene expression is critical in experience-mediated changes in the brain. Although less appreciated than transcriptional control, translational control is a crucial regulatory step of activity-mediated gene expression in physiological and pathological conditions. In the first part of this review, we overview evidence demonstrating the importance of translational controls under the context of synaptic plasticity as well as learning and memory. Then, molecular mechanisms underlying the translational control, including post-translational modifications of translation factors, mTOR signaling pathway, and local translation, are explored. We also summarize how activity-dependent translational regulation is associated with neurodevelopmental and psychiatric disorders, such as autism spectrum disorder and depression. In the second part, we highlight how recent application of high-throughput sequencing techniques has added insight into genome-wide studies on translational regulation of neuronal genes. Sequencing-based strategies to identify molecular signatures of the active neuronal population responding to a specific stimulus are discussed. Overall, this review aims to highlight the implication of translational control for neuronal gene regulation and functions of the brain and to suggest prospects provided by the leading-edge techniques to study yet-unappreciated translational regulation in the nervous system.


2021 ◽  
Author(s):  
UDAYKUMAR KAGE ◽  
Donald Gardiner ◽  
Jiri S Stiller ◽  
Kemal Kazan

To date, translational regulation of key genes controlling infection-related processes in fungal pathogens during their interactions with plants has not been studied. Here, we employed ribosome profiling (ribo-seq) to study translational responses and how such responses are coordinated with transcriptional changes in the fungal pathogen Fusarium graminearum (Fg), which causes Fusarium head blight (FHB), a destructive disease of cereal crops worldwide. Transcription and translation were not always coordinated with approximately 22% of Fg genes showing a discordant relationship during wheat infection. Nitrite reductase, which we show here as an important component of fungal virulence, is only regulated at the translational level in Fg. In addition, more than 1000 new open reading frames (ORFs), many of which are short and highly conserved, were identified in the Fg genome. Like in higher eukaryotes, translation is controlled by upstream ORFs (uORFs) in Fg during infection. Similarly, miRNAs control both transcription and translation in Fg during wheat infection. However, Fgdicer2-dependent miRNAs do not have a significant effect on transcriptional gene expression at the global outset. The ribo-seq study undertaken here for the first time in any fungal pathogen discovered novel insights about the biology of an important plant pathogen.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 156-156
Author(s):  
Craig M Forester ◽  
Gun Woo-Byeon ◽  
Juan Oses-Prieto ◽  
Al Burlingame ◽  
Maria Barna ◽  
...  

Erythropoiesis is an intricately orchestrated process responsible for rapidly responding to an array of signaling cues to direct cell fates. While gene expression during erythropoiesis has mainly been studied at the transcription level, regulation of gene expression at the level of translation is still poorly understood. As translational control is one of the fastest steps to regulate protein abundance in the cell, we hypothesize that this mechanism plays an important role to rapidly control protein levels in response to extracellular cues during erythroid differentiation. However, outstanding questions remain on how translational control regulates specific gene programs in early erythroid states including 1.) how mRNA are selected for translation in normal erythropoiesis and 2.) how components of the translational machinery are regulated by upstream signaling pathways to orchestrate the translational landscape. In addressing these questions, we have nuncovered a dynamic interplay between Eukaryotic Initiation Factor 4E (eIF4E), the major mRNA cap binding protein that controls translation initiation and its repressor protein, 4EBP1 in erythropoiesis. Specifically, using in vivo phospho-flow cytometry analysis of the eIF4E-4EBP1 axis, eIF4E activity is high in early erythroid phases and is repressed by 4EBP1 in order to allow erythroid maturation. Surprisingly, high eIF4E activity in early erythroid precursors occurs without an increase in global protein synthesis. Utilizing a model of CD34+ human cord blood cells (HUDEP-2), we show that constitutive overexpression of eIF4E impaired erythropoietic maturation. To capture the specific proteins potentially regulated by eIF4E activity during erythropoiesis, we performed quantitative TMT mass spectrometry during HUDEP-2 erythroid differentiation. Our results revealed that eIF4E controls a specific key network of genes necessary for maintenance of early erythroid precursors. By analyzing the 5' untranslated region (5'UTR) of the eIF4E-dependent mRNA network, we identify a highly conserved, CT-rich motif which is required for these mRNAs to be more efficiently translated with increasing eIF4E levels. These results demonstrate wide-spread translational control of CT-rich mRNAs by eIF4E during early erythropoiesis. We are currently employing DMS-MaPseq to understand whether these motifs are also part of structured RNA elements that confer sensitivity to eIF4E levels. We have further extended these findings to a novel transgenic mouse model we have developed that allows in vivo assessment of increased eIF4E temporally at concise phases of erythroid maturation. Understanding this balance of eIF4E activity provides a novel insight into how of translational control dictates gene expression to determine phases of maturation in a crucial differentiation process. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Author(s):  
Guillermo Eastman ◽  
Elizabeth R. Sharlow ◽  
John S. Lazo ◽  
George S. Bloom ◽  
José R. Sotelo-Silveira

ABSTRACTBackgroundDefining the cellular mechanisms that drive Alzheimer’s disease (AD) pathogenesis and progression will be aided by studies defining how gene expression patterns change during pre-symptomatic AD and the ensuing periods of steadily declining cognition. Previous studies have emphasized changes in transcriptional regulation, but not translational regulation, leaving the ultimate results of gene expression alterations relatively unexplored in the context of AD.ObjectiveTo identify genes whose expression might be regulated at the transcriptional, and especially at the translational levels in AD, we analyzed gene expression in cerebral cortex of two AD model mouse strains, CVN (APPSwDI;NOS2-/-) and Tg2576 (APPSw), and their companion wild type (WT) strains at 6 months of age by tandem RNA-Seq and Ribo-Seq (ribosome profiling).MethodsIdentical starting pools of bulk RNA were used for RNA-Seq and Ribo-Seq. Differential gene expression analysis was performed at the transcriptional and translational levels separately, and also at the translational efficiency level. Regulated genes were functionally evaluated by gene ontology tools.ResultsCompared to WT mice, AD model mice had similar levels of transcriptional regulation, but displayed differences in translational regulation. A specific microglial signature associated with early stages of Aβ accumulation was up-regulated at both transcriptome and translatome levels in CVN mice. Although the two mice strains did not share many regulated genes, they showed common regulated pathways related to APP metabolism associated with neurotoxicity and neuroprotection.ConclusionThis work represents the first genome-wide study of brain translational regulation in animal models of AD, and provides evidence of a tight and early translational regulation of gene expression controlling the balance between neuroprotective and neurodegenerative processes in brain.


Reproduction ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 595-617 ◽  
Author(s):  
Matthew Brook ◽  
Joel W S Smith ◽  
Nicola K Gray

Gametogenesis is a highly complex process that requires the exquisite temporal, spatial and amplitudinal regulation of gene expression at multiple levels. Translational regulation is important in a wide variety of cell types but may be even more prevalent in germ cells, where periods of transcriptional quiescence necessitate the use of post-transcriptional mechanisms to effect changes in gene expression. Consistent with this, studies in multiple animal models have revealed an essential role for mRNA translation in the establishment and maintenance of reproductive competence. While studies in humans are less advanced, emerging evidence suggests that translational regulation plays a similarly important role in human germ cells and fertility. This review highlights specific mechanisms of translational regulation that play critical roles in oogenesis by activating subsets of mRNAs. These mRNAs are activated in a strictly determined temporal manner via elements located within their 3′UTR, which serve as binding sites fortrans-acting factors. While we concentrate on oogenesis, these regulatory events also play important roles during spermatogenesis. In particular, we focus on the deleted in azoospermia-like (DAZL) family of proteins, recently implicated in the translational control of specific mRNAs in germ cells; their relationship with the general translation initiation factor poly(A)-binding protein (PABP) and the process of cytoplasmic mRNA polyadenylation.


2015 ◽  
Vol 71 (a1) ◽  
pp. s29-s30
Author(s):  
Udo Heinemann ◽  
Yasuhiro Murakawa ◽  
Markus Landthaler ◽  
Florian Mayr ◽  
Anja Schütz

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