scholarly journals Dynamic profiling of mRNA turnover reveals gene-specific and system-wide regulation of mRNA decay

2011 ◽  
Vol 22 (15) ◽  
pp. 2787-2795 ◽  
Author(s):  
Sarah E. Munchel ◽  
Ryan K. Shultzaberger ◽  
Naoki Takizawa ◽  
Karsten Weis

RNA levels are determined by the rates of both transcription and decay, and a mechanistic understanding of the complex networks regulating gene expression requires methods that allow dynamic measurements of transcription and decay in living cells with minimal perturbation. Here, we describe a metabolic pulse-chase labeling protocol using 4-thiouracil combined with large-scale RNA sequencing to determine decay rates of all mRNAs in Saccharomyces cerevisiae. Profiling in various growth and stress conditions reveals that mRNA turnover is highly regulated both for specific groups of transcripts and at the system-wide level. For example, acute glucose starvation induces global mRNA stabilization but increases the degradation of all 132 detected ribosomal protein mRNAs. This effect is transient and can be mimicked by inhibiting the target-of-rapamycin kinase. Half-lives of mRNAs critical for galactose (GAL) metabolism are also highly sensitive to changes in carbon source. The fast reduction of GAL transcripts in glucose requires their dramatically enhanced turnover, highlighting the importance of mRNA decay in the control of gene expression. The approach described here provides a general platform for the global analysis of mRNA turnover and transcription and can be applied to dissect gene expression programs in a wide range of organisms and conditions.

2005 ◽  
Vol 25 (13) ◽  
pp. 5499-5513 ◽  
Author(s):  
Radharani Duttagupta ◽  
Bin Tian ◽  
Carol J. Wilusz ◽  
Danny T. Khounh ◽  
Patricia Soteropoulos ◽  
...  

ABSTRACT Regulation of mRNA turnover is an important cellular strategy for posttranscriptional control of gene expression, mediated by the interplay of cis-acting sequences and associated trans-acting factors. Pub1p, an ELAV-like yeast RNA-binding protein with homology to T-cell internal antigen 1 (TIA-1)/TIA-1-related protein (TIAR), is an important modulator of the decay of two known classes of mRNA. Our goal in this study was to determine the range of mRNAs whose stability is dependent on Pub1p, as well as to identify specific transcripts that directly bind to this protein. We have examined global mRNA turnover in isogenic PUB1 and pub1Δ strains through gene expression analysis and demonstrate that 573 genes exhibit a significant reduction in half-life in a pub1Δ strain. We also examine the binding specificity of Pub1p using affinity purification followed by microarray analysis to comprehensively distinguish between direct and indirect targets and find that Pub1p significantly binds to 368 cellular transcripts. Among the Pub1p-associated mRNAs, 53 transcripts encoding proteins involved in ribosomal biogenesis and cellular metabolism are selectively destabilized in the pub1Δ strain. In contrast, genes involved in transporter activity demonstrate association with Pub1p but display no measurable changes in transcript stability. Characterization of two candidate genes, SEC53 and RPS16B, demonstrate that both Pub1p-dependent regulation of stability and Pub1p binding require 3′ untranslated regions, which harbor distinct sequence motifs. These results suggest that Pub1p binds to discrete subsets of cellular transcripts and posttranscriptionally regulates their expression at multiple levels.


1998 ◽  
Vol 62 (4) ◽  
pp. 1492-1553 ◽  
Author(s):  
John E. G. McCarthy

SUMMARY Studies of the budding yeast Saccharomyces cerevisiae have greatly advanced our understanding of the posttranscriptional steps of eukaryotic gene expression. Given the wide range of experimental tools applicable to S. cerevisiae and the recent determination of its complete genomic sequence, many of the key challenges of the posttranscriptional control field can be tackled particularly effectively by using this organism. This article reviews the current knowledge of the cellular components and mechanisms related to translation and mRNA decay, with the emphasis on the molecular basis for rate control and gene regulation. Recent progress in characterizing translation factors and their protein-protein and RNA-protein interactions has been rapid. Against the background of a growing body of structural information, the review discusses the thermodynamic and kinetic principles that govern the translation process. As in prokaryotic systems, translational initiation is a key point of control. Modulation of the activities of translational initiation factors imposes global regulation in the cell, while structural features of particular 5′ untranslated regions, such as upstream open reading frames and effector binding sites, allow for gene-specific regulation. Recent data have revealed many new details of the molecular mechanisms involved while providing insight into the functional overlaps and molecular networking that are apparently a key feature of evolving cellular systems. An overall picture of the mechanisms governing mRNA decay has only very recently begun to develop. The latest work has revealed new information about the mRNA decay pathways, the components of the mRNA degradation machinery, and the way in which these might relate to the translation apparatus. Overall, major challenges still to be addressed include the task of relating principles of posttranscriptional control to cellular compartmentalization and polysome structure and the role of molecular channelling in these highly complex expression systems.


2020 ◽  
Author(s):  
Deniz Durmusoglu ◽  
Ibrahim Al’Abri ◽  
Scott P. Collins ◽  
Chase Beisel ◽  
Nathan Crook

AbstractSaccharomyces boulardii is a widely used yeast probiotic which can counteract various gastrointestinal disorders1. As a relative of Saccharomyces cerevisiae, S. boulardii exhibits rapid growth and is easy to transform2 and thus represents a promising chassis for the engineered secretion of biomolecules. To establish S. boulardii as a platform for delivery of biomolecules to the mammalian gut, we measured the amount and variance in protein expression enabled by promoters, terminators, selective markers, and copy number control elements in this organism. These genetic elements were characterized in plasmidic and genomic contexts, revealing strategies for tunable control of gene expression and CRISPR-mediated genome editing in this strain. We then leveraged this set of genetic parts to combinatorially assemble pathways enabling a wide range of drug and vitamin titers. Finally, we measured S. boulardii’s residence time in the gastrointestinal tracts of germ-free and antibiotic-treated mice, revealing the relationships between dosing strategy and colonization level. This work establishes S. boulardii as a genetically tractable commensal fungus and provides a set of strategies for engineering S. boulardii to synthesize and deliver biomolecules during gut colonization.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2043-2043
Author(s):  
Hiroyuki Mano ◽  
Yoshihiro Yamashita

Abstract AML is a clonal disorder of immature hematopoietic blasts and has a variable clinical outcome. Current classification of AML is based predominantly on the cytogenetic abnormalities and morphology of the malignant blasts and is not always helpful for optimization of treatment strategy. It is, for instance, very difficult to predict the prognosis of AML patients with a normal karyotype, who constitute ~50% of the AML population. DNA microarray analysis has the potential to provide a novel stratification scheme for AML patients, which is based on gene expression profile, and might help to predict the prognosis of, and optimize the treatment strategy for, each affected individual. However, leukemic blasts derived from bone marrow (BM) of AML-related disorders, are not homogeneous. The blasts may constitute from 20% to almost 100% of mononuclear cells (MNCs) in the marrow. Furthermore, given that many leukemic blasts possess the ability to differentiate to a certain extent, the marrow of AML patients contains not only the immature blasts (leukemic stem clone) but also differentiated blasts. A simple comparison of BM MNCs among heterogeneous AML patients is thus likely to reveal a large number of changes in gene expression that only reflect differences either in the percentage of blasts or in the differentiation ability of the blasts. To minimize such population-shift effects in microarray analyses, we established a large-scale cell depository “Blast Bank” for the storage of CD133 (AC133)-positive hematopoietic stem cell-like fractions from individuals with a wide range of hematopoietic disorders. In the present study, we have used Affymetrix HGU133 A&B microarrays to measure the expression profiles of ~33,000 genes in the Blast Bank specimens of 99 adults with AML-related disorders: 83 individuals with AML and 16 patients in the RAEB stage of MDS. In contrast to the previous microarray analyses of BM MNCs of AML, unsupervised hierarchical clustering of the subjects based on the expression profile did not separate the patients into FAB subtype-matched subgroups. Comparison of gene expression profile between the long-time and short-time survivors has identified a small number of outcome-related genes. Supervised class prediction, based on these genes, with k-nearest neighbor method or Cox proportional hazard model both succeeded to clearly separate individuals into subgroups with statistically distinct prognoses. Our analysis may pave a way toward the expression profile-based novel stratification scheme for AML.


Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Dorit Zuk ◽  
Jonathan P Belk ◽  
Allan Jacobson

Abstract In a screen for factors involved in mRNA turnover, four temperature-sensitive yeast strains (ts1189, ts942, ts817, and ts1100) exhibited defects in the decay of several mRNAs. Complementation of the growth and mRNA decay defects, and genetic experiments, revealed that ts1189 is mutated in the previously unknown MRT4 gene, ts942 is mutated in GRC5 (encoding the L9 ribosomal protein), ts817 contains a mutation in SLA2 (encoding a membrane protein), and ts1100 contains a mutation in THS1 (encoding the threonyl-tRNA synthetase). Three of the four mutants (mrt4, grc5, and sla2) were not defective in protein synthesis, suggesting that these strains contain mutations in factors that may play a specific role in mRNA decay. The mRNA stabilization observed in the ths1 strain, however, could be due to the significant drop in translation observed in this mutant at 37°. While the three interesting mutants appear to encode novel mRNA decay factors, at least one could be linked to a previously characterized mRNA decay pathway. The growth and mRNA decay defects of ts942 (grc5) cells were suppressed by overexpression of the NMD3 gene, encoding a protein shown to participate in a two-hybrid interaction with the nonsense-mediated decay protein Upf1p.


2021 ◽  
Vol 118 (18) ◽  
pp. e2020125118
Author(s):  
Yoshiaki Kita ◽  
Hirozumi Nishibe ◽  
Yan Wang ◽  
Tsutomu Hashikawa ◽  
Satomi S. Kikuchi ◽  
...  

Precise spatiotemporal control of gene expression in the developing brain is critical for neural circuit formation, and comprehensive expression mapping in the developing primate brain is crucial to understand brain function in health and disease. Here, we developed an unbiased, automated, large-scale, cellular-resolution in situ hybridization (ISH)–based gene expression profiling system (GePS) and companion analysis to reveal gene expression patterns in the neonatal New World marmoset cortex, thalamus, and striatum that are distinct from those in mice. Gene-ontology analysis of marmoset-specific genes revealed associations with catalytic activity in the visual cortex and neuropsychiatric disorders in the thalamus. Cortically expressed genes with clear area boundaries were used in a three-dimensional cortical surface mapping algorithm to delineate higher-order cortical areas not evident in two-dimensional ISH data. GePS provides a powerful platform to elucidate the molecular mechanisms underlying primate neurobiology and developmental psychiatric and neurological disorders.


2020 ◽  
Vol 49 (D1) ◽  
pp. D825-D830 ◽  
Author(s):  
◽  
Guang-Hui Liu ◽  
Yiming Bao ◽  
Jing Qu ◽  
Weiqi Zhang ◽  
...  

Abstract Organismal aging is driven by interconnected molecular changes encompassing internal and extracellular factors. Combinational analysis of high-throughput ‘multi-omics’ datasets (gathering information from genomics, epigenomics, transcriptomics, proteomics, metabolomics and pharmacogenomics), at either populational or single-cell levels, can provide a multi-dimensional, integrated profile of the heterogeneous aging process with unprecedented throughput and detail. These new strategies allow for the exploration of the molecular profile and regulatory status of gene expression during aging, and in turn, facilitate the development of new aging interventions. With a continually growing volume of valuable aging-related data, it is necessary to establish an open and integrated database to support a wide spectrum of aging research. The Aging Atlas database aims to provide a wide range of life science researchers with valuable resources that allow access to a large-scale of gene expression and regulation datasets created by various high-throughput omics technologies. The current implementation includes five modules: transcriptomics (RNA-seq), single-cell transcriptomics (scRNA-seq), epigenomics (ChIP-seq), proteomics (protein–protein interaction), and pharmacogenomics (geroprotective compounds). Aging Atlas provides user-friendly functionalities to explore age-related changes in gene expression, as well as raw data download services. Aging Atlas is freely available at https://bigd.big.ac.cn/aging/index.


2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Volker Boehm ◽  
Jennifer V. Gerbracht ◽  
Marie-Charlotte Marx ◽  
Niels H. Gehring

Abstract The turnover of messenger RNAs (mRNAs) is a key regulatory step of gene expression in eukaryotic cells. Due to the complexity of the mammalian degradation machinery, the contribution of decay factors to the directionality of mRNA decay is poorly understood. Here we characterize a molecular tool to interrogate mRNA turnover via the detection of XRN1-resistant decay fragments (xrFrag). Using nonsense-mediated mRNA decay (NMD) as a model pathway, we establish xrFrag analysis as a robust indicator of accelerated 5′–3′ mRNA decay. In tethering assays, monitoring xrFrag accumulation allows to distinguish decapping and endocleavage activities from deadenylation. Moreover, xrFrag analysis of mRNA degradation induced by miRNAs, AU-rich elements (AREs) as well as the 3′ UTRs of cytokine mRNAs reveals the contribution of 5′–3′ decay and endonucleolytic cleavage. Our work uncovers formerly unrecognized modes of mRNA turnover and establishes xrFrag as a powerful tool for RNA decay analyses.


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