scholarly journals Scavenger Decapping Activity Facilitates 5′ to 3′ mRNA Decay

2005 ◽  
Vol 25 (22) ◽  
pp. 9764-9772 ◽  
Author(s):  
Hudan Liu ◽  
Megerditch Kiledjian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mrna Stability ◽  
Mrna Decay ◽  
Hydrolytic Activity ◽  
Mrna Degradation ◽  
Mrna Turnover ◽  
Threefold Increase ◽  
Mechanistic Analysis ◽  
Decapping Enzyme ◽  
Mrna Half Life

ABSTRACT mRNA degradation occurs through distinct pathways, one primarily from the 5′ end of the mRNA and the second from the 3′ end. Decay from the 3′ end generates the m7GpppN cap dinucleotide, which is subsequently hydrolyzed to m7Gp and ppN in Saccharomyces cerevisiae by a scavenger decapping activity termed Dcs1p. Although Dcs1p functions in the last step of mRNA turnover, we demonstrate that its activity modulates earlier steps of mRNA decay. Disruption of the DCS1 gene manifests a threefold increase of the TIF51A mRNA half-life. Interestingly, the hydrolytic activity of Dcs1p was essential for the altered mRNA turnover, as Dcs1p, but not a catalytically inactive Dcs1p mutant, complemented the increased mRNA stability. Mechanistic analysis revealed that 5′ to 3′ exoribonucleolytic activity was impeded in the dcs1Δ strain, resulting in the accumulation of uncapped mRNA. These data define a new role for the Dcs1p scavenger decapping enzyme and demonstrate a novel mechanism whereby the final step in the 3′ mRNA decay pathway can influence 5′ to 3′ exoribonucleolytic activity.

scholarly journals Upf1p, Nmd2p, and Upf3p Regulate the Decapping and Exonucleolytic Degradation of both Nonsense-Containing mRNAs and Wild-Type mRNAs

2001 ◽  
Vol 21 (5) ◽  
pp. 1515-1530 ◽  
Author(s):  
Feng He ◽  
Allan Jacobson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mrna Decay ◽  
Translation Termination ◽  
Mrna Degradation ◽  
Wild Type ◽  
Rapid Degradation ◽  
Yeast Strains ◽  
Nonsense Mediated Mrna Decay ◽  
Exonucleolytic Degradation ◽  
Decapping Enzyme

ABSTRACT In Saccharomyces cerevisiae, rapid degradation of nonsense-containing mRNAs requires the decapping enzyme Dcp1p, the 5′-to-3′ exoribonuclease Xrn1p, and the three nonsense-mediated mRNA decay (NMD) factors, Upf1p, Nmd2p, and Upf3p. To identify specific functions for the NMD factors, we analyzed the mRNA decay phenotypes of yeast strains containing deletions of DCP1 orXRN1 and UPF1, NMD2, or UPF3. Our results indicate that Upf1p, Nmd2p, and Upf3p regulate decapping and exonucleolytic degradation of nonsense-containing mRNAs. In addition, we show that these factors also regulate the same processes in the degradation of wild-type mRNAs. The participation of the NMD factors in general mRNA degradation suggests that they may regulate an aspect of translation termination common to all transcripts.

Decapping the message: a beginning or an end

2006 ◽  
Vol 34 (1) ◽  
pp. 35-38 ◽  
Author(s):  
H. Liu ◽  
M. Kiledjian
Keyword(s):  
Mrna Stability ◽  
Mrna Turnover ◽  
Decapping Enzyme ◽  
Decapping Enzymes

Removal of the mRNA 5′ cap is an important step in the regulation of mRNA stability. mRNAs are degraded by at least two distinct exonucleolytic decay pathways, one from the 5′ end, and the second from the 3′ end. Two major cellular decapping enzymes have been identified, and each primarily functions in one of the two decay pathways. The Dcp2 decapping enzyme utilizes capped mRNA as substrate and hydrolyses the cap to release m7GDP (N7-methyl GDP), while a scavenger decapping enzyme, DcpS, utilizes cap dinucleotides or capped oligonucleotides as substrate and releases m7GMP (N7-methyl GMP). In this review, we will highlight the function of different decapping enzymes and their role in mRNA turnover.

scholarly journals A non-canonical role for the EDC4 decapping factor in regulating MARF1-mediated mRNA decay

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
William R Brothers ◽  
Steven Hebert ◽  
Claudia L Kleinman ◽  
Marc R Fabian
Keyword(s):  
Essential Role ◽  
Mrna Decay ◽  
Rna Binding ◽  
Mrna Turnover ◽  
Core Component ◽  
P Bodies ◽  
Target Mrnas ◽  
Binding Domains ◽  
Bona Fide ◽  
Decapping Enzyme

EDC4 is a core component of processing (P)-bodies that binds the DCP2 decapping enzyme and stimulates mRNA decay. EDC4 also interacts with mammalian MARF1, a recently identified endoribonuclease that promotes oogenesis and contains a number of RNA binding domains, including two RRMs and multiple LOTUS domains. How EDC4 regulates MARF1 action and the identity of MARF1 target mRNAs is not known. Our transcriptome-wide analysis identifies bona fide MARF1 target mRNAs and indicates that MARF1 predominantly binds their 3’ UTRs via its LOTUS domains to promote their decay. We also show that a MARF1 RRM plays an essential role in enhancing its endonuclease activity. Importantly, we establish that EDC4 impairs MARF1 activity by preventing its LOTUS domains from binding target mRNAs. Thus, EDC4 not only serves as an enhancer of mRNA turnover that binds DCP2, but also as a repressor that binds MARF1 to prevent the decay of MARF1 target mRNAs.

mRNA degradation and maturation in prokaryotes: the global players

2011 ◽  
Vol 2 (6) ◽  
pp. 491-506 ◽  
Author(s):  
Soumaya Laalami ◽  
Harald Putzer
Keyword(s):  
Protein Synthesis ◽  
Messenger Rna ◽  
Mrna Decay ◽  
Mrna Degradation ◽  
Mrna Turnover ◽  
Model Organisms ◽  
Translation Regulation ◽  
Ecological Niches ◽  
Rnase E ◽  
General Role

AbstractThe degradation of messenger RNA is of universal importance for controlling gene expression. It directly affects protein synthesis by modulating the amount of mRNA available for translation. Regulation of mRNA decay provides an efficient means to produce just the proteins needed and to rapidly alter patterns of protein synthesis. In bacteria, the half-lives of individual mRNAs can differ by as much as two orders of magnitude, ranging from seconds to an hour. Most of what we know today about the diverse mechanisms of mRNA decay and maturation in prokaryotes comes from studies of the two model organisms Escherichia coli and Bacillus subtilis. Their evolutionary distance provided a large picture of potential pathways and enzymes involved in mRNA turnover. Among them are three ribonucleases, two of which have been discovered only recently, which have a truly general role in the initiating events of mRNA degradation: RNase E, RNase J and RNase Y. Their enzymatic characteristics probably determine the strategies of mRNA metabolism in the organism in which they are present. These ribonucleases are coded, alone or in various combinations, in all prokaryotic genomes, thus reflecting how mRNA turnover has been adapted to different ecological niches throughout evolution.

scholarly journals Interrogating the degradation pathways of unstable mRNAs with XRN1-resistant sequences

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Volker Boehm ◽  
Jennifer V. Gerbracht ◽  
Marie-Charlotte Marx ◽  
Niels H. Gehring
Keyword(s):  
Gene Expression ◽  
Mrna Decay ◽  
Mrna Degradation ◽  
Eukaryotic Cells ◽  
Mrna Turnover ◽  
Degradation Pathways ◽  
Messenger Rnas ◽  
Endonucleolytic Cleavage ◽  
Nonsense Mediated Mrna Decay ◽  
Cytokine Mrnas

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.

scholarly journals Degradation of Normal mRNA in the Nucleus of Saccharomyces cerevisiae

2003 ◽  
Vol 23 (16) ◽  
pp. 5502-5515 ◽  
Author(s):  
Biswadip Das ◽  
J. Scott Butler ◽  
Fred Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
In Situ Hybridization ◽  
Mrna Degradation ◽  
Northern Blotting ◽  
Mrna Turnover ◽  
Restrictive Temperature ◽  
Turnover Rates ◽  
Rapid Degradation ◽  
Cap Binding Complex

ABSTRACT A nuclear mRNA degradation (DRN) system was identified from analysis of mRNA turnover rates in nup116-Δ strains of Saccharomyces cerevisiae lacking the ability to export all RNAs, including poly(A) mRNAs, at the restrictive temperature. Northern blotting, in situ hybridization, and blocking transcription with thiolutin in nup116-Δ strains revealed a rapid degradation of mRNAs in the nucleus that was suppressed by the rrp6-Δ, rai1-Δ, and cbc1-Δ deletions, but not by the upf1-Δ deletion, suggesting that DRN requires Rrp6p, a 3′-to-5′ nuclear exonuclease, the Rat1p, a 5′-to-3′ nuclear exonuclease, and Cbc1p, a component of CBC, the nuclear cap binding complex, which may direct the mRNAs to the site of degradation. We propose that certain normal mRNAs retained in the nucleus are degraded by the DRN system, similar to degradation of transcripts with 3′ end formation defects in certain mutants.

Functions of microRNAs in Drosophila development

2010 ◽  
Vol 38 (4) ◽  
pp. 1137-1143 ◽  
Author(s):  
Christopher I. Jones ◽  
Sarah F. Newbury
Keyword(s):  
Mrna Stability ◽  
Molecular Mechanisms ◽  
Mrna Translation ◽  
Mrna Degradation ◽  
Mrna Turnover ◽  
Factors Affecting ◽  
Biologically Relevant ◽  
The Core ◽  
Cellular Factors

Control of mRNA translation and degradation has been shown to be key in the development of complex organisms. The core mRNA degradation machinery is highly conserved in eukaryotes and relies on processive degradation enzymes gaining access to the mRNA. Control of mRNA stability in eukaryotes is also intimately linked to the regulation of translation. A key question in the control of mRNA turnover concerns the mechanisms whereby particular mRNAs are specifically degraded in response to cellular factors. Recently, microRNAs have been shown to bind specifically to mRNAs and regulate their expression via repression of translation and/or degradation. To understand the molecular mechanisms during microRNA repression of mRNAs, it is necessary to identify their biologically relevant targets. However, computational methods have so far proved unreliable, therefore verification of biologically important targets at present requires experimental analysis. The present review aims to outline the mechanisms of mRNA degradation and then focus on the role of microRNAs as factors affecting particular Drosophila developmental processes via their post-transcriptional effects on mRNA degradation and translation. Examples of experimentally verified targets of microRNAs in Drosophila are summarized.

When mRNA translation meets decay

2017 ◽  
Vol 45 (2) ◽  
pp. 339-351 ◽  
Author(s):  
Alicia A. Bicknell ◽  
Emiliano P. Ricci
Keyword(s):  
Mrna Stability ◽  
Messenger Rna ◽  
Mrna Decay ◽  
Mrna Translation ◽  
Mrna Degradation ◽  
Mrna Surveillance ◽  
Protein Output

Messenger RNA (mRNA) translation and mRNA degradation are important determinants of protein output, and they are interconnected. Previously, it was thought that translation of an mRNA, as a rule, prevents its degradation. mRNA surveillance mechanisms, which degrade mRNAs as a consequence of their translation, were considered to be exceptions to this rule. Recently, however, it has become clear that many mRNAs are degraded co-translationally, and it has emerged that codon choice, by influencing the rate of ribosome elongation, affects the rate of mRNA decay. In this review, we discuss the links between translation and mRNA stability, with an emphasis on emerging data suggesting that codon optimality may regulate mRNA degradation.

scholarly journals Suppressors of mRNA Decapping Defects Restore Growth Without Major Effects on mRNA Decay Rates or Abundance

Genetics ◽  
2020 ◽  
Vol 216 (4) ◽  
pp. 1051-1069
Author(s):  
Minseon Kim ◽  
Ambro van Hoof
Keyword(s):  
Mrna Decay ◽  
Slow Growth ◽  
Mrna Degradation ◽  
Decay Rates ◽  
Major Pathway ◽  
Mrna Decapping ◽  
Link Type ◽  
Suppression Mechanism ◽  
Decapping Enzyme ◽  
Insight Into

Faithful degradation of mRNAs is a critical step in gene expression, and eukaryotes share a major conserved mRNA decay pathway. In this major pathway, the two rate-determining steps in mRNA degradation are the initial gradual removal of the poly(A) tail, followed by removal of the cap structure. Removal of the cap structure is carried out by the decapping enzyme, containing the Dcp2 catalytic subunit. Although the mechanism and regulation of mRNA decay is well understood, the consequences of defects in mRNA degradation are less clear. Dcp2 has been reported as either essential or nonessential. Here, we clarify that Dcp2 is not absolutely required for spore germination and extremely slow growth, but in practical terms it is impossible to continuously culture dcp2∆ under laboratory conditions without suppressors arising. We show that null mutations in at least three different genes are each sufficient to restore growth to a dcp2∆, of which kap123∆ and tl(gag)g∆ appear the most specific. We show that kap123∆ and tl(gag)g∆ suppress dcp2 by mechanisms that are different from each other and from previously isolated dcp2 suppressors. The suppression mechanism for tL(GAG)G is determined by the unique GAG anticodon of this tRNA, and thus likely by translation of some CUC or CUU codons. Unlike previously reported suppressors of decapping defects, these suppressors do not detectably restore decapping or mRNA decay to normal rates, but instead allow survival while only modestly affecting RNA homeostasis. These results provide important new insight into the importance of decapping, resolve previously conflicting publications about the essentiality of DCP2, provide the first phenotype for a tl(gag)g mutant, and show that multiple distinct mechanisms can bypass Dcp2 requirement.

scholarly journals Transient ribosome slowdown at the decoding step triggers mRNA degradation independent of Znf598 in zebrafish

2021 ◽  
Author(s):  
Yuichiro Mishima ◽  
Peixun Han ◽  
Seisuke Kimura ◽  
Shintaro Iwasaki
Keyword(s):  
Mrna Stability ◽  
Mrna Decay ◽  
Expression Patterns ◽  
Mrna Degradation ◽  
Zebrafish Embryos ◽  
Reading Frame ◽  
Genome Wide ◽  
Codon Composition ◽  
Kinetics Of

The control of mRNA stability plays a central role in regulating gene expression patterns. Recent studies have revealed that codon composition in the open reading frame (ORF) determines mRNA stability in multiple organisms. Based on genome-wide correlation approaches, this previously unrecognized role of the genetic code is attributable to the kinetics of the codon-decoding process by the ribosome. However, complementary experimental analysis is required to define the codon effects on mRNA stability apart from the related cotranslational mRNA decay pathways such as those triggered by aberrant ribosome stalls. In the current study, we performed a set of reporter-based analyses to define codon-mediated mRNA decay and ribosome stall-dependent mRNA decay in zebrafish embryos. Our analysis showed that the effect of codons on mRNA stability stems from the decoding process, independent of Znf598 and stall-dependent mRNA decay. We propose that codon-mediated mRNA decay is triggered by transiently slowed ribosomes engaging in a productive translation cycle in zebrafish embryos.

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