Translational control of ERK signaling through miRNA/4EHP-directed silencing

MicroRNAs (miRNAs) exert a broad influence over gene expression by directing effector activities that impinge on translation and stability of mRNAs. We recently discovered that the cap-binding protein 4EHP is a key component of the mammalian miRNA-Induced Silencing Complex (miRISC), which mediates gene silencing. However, little is known about the mRNA repertoire that is controlled by the 4EHP/miRNA mechanism or its biological importance. Here, using ribosome profiling, we identify a subset of mRNAs that are translationally controlled by 4EHP. We show that the Dusp6 mRNA, which encodes an ERK1/2 phosphatase, is translationally repressed by 4EHP and a specific miRNA, miR-145. This promotes ERK1/2 phosphorylation, resulting in augmented cell growth and reduced apoptosis. Our findings thus empirically define the integral role of translational repression in miRNA-induced gene silencing and reveal a critical function for this process in the control of the ERK signaling cascade in mammalian cells.

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Seeking a Role for Translational Control by Alternative Polyadenylation in Saccharomyces cerevisiae

Microorganisms ◽

10.3390/microorganisms9091885 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1885

Author(s):

Rachael E. Turner ◽

Traude H. Beilharz

Keyword(s):

Saccharomyces Cerevisiae ◽

Translational Control ◽

Model Organism ◽

Alternative Polyadenylation ◽

Ribosome Profiling ◽

Translation Efficiency ◽

Mrna Isoforms ◽

Cleavage And Polyadenylation ◽

Made In

Alternative polyadenylation (APA) represents an important mechanism for regulating isoform-specific translation efficiency, stability, and localisation. Though some progress has been made in understanding its consequences in metazoans, the role of APA in the model organism Saccharomyces cerevisiae remains a relative mystery because, despite abundant studies on the translational state of mRNA, none differentiate mRNA isoforms’ alternative 3′-end. This review discusses the implications of alternative polyadenylation in S. cerevisiae using other organisms to draw inferences. Given the foundational role that research in this yeast has played in the discovery of the mechanisms of cleavage and polyadenylation and in the drivers of APA, it is surprising that such an inference is required. However, because advances in ribosome profiling are insensitive to APA, how it impacts translation is still unclear. To bridge the gap between widespread observed APA and the discovery of any functional consequence, we also provide a review of the experimental techniques used to uncover the functional importance of 3′ UTR isoforms on translation.

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Ribosome profiling reveals a functional role for autophagy in mRNA translational control

Communications Biology ◽

10.1038/s42003-020-1090-2 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Juliet Goldsmith ◽

Timothy Marsh ◽

Saurabh Asthana ◽

Andrew M. Leidal ◽

Deepthisri Suresh ◽

...

Keyword(s):

Dna Damage ◽

Protein Synthesis ◽

Translational Control ◽

Mammalian Cells ◽

Dna Damage Repair ◽

Protein Translation ◽

Ribosome Profiling ◽

Parp Inhibition ◽

Genetic Ablation ◽

Damage Repair

AbstractAutophagy promotes protein degradation, and therefore has been proposed to maintain amino acid pools to sustain protein synthesis during metabolic stress. To date, how autophagy influences the protein synthesis landscape in mammalian cells remains unclear. Here, we utilize ribosome profiling to delineate the effects of genetic ablation of the autophagy regulator, ATG12, on translational control. In mammalian cells, genetic loss of autophagy does not impact global rates of cap dependent translation, even under starvation conditions. Instead, autophagy supports the translation of a subset of mRNAs enriched for cell cycle control and DNA damage repair. In particular, we demonstrate that autophagy enables the translation of the DNA damage repair protein BRCA2, which is functionally required to attenuate DNA damage and promote cell survival in response to PARP inhibition. Overall, our findings illuminate that autophagy impacts protein translation and shapes the protein landscape.

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Effect of piliation on Klebsiella pneumoniae infection in rat bladders

Infection and Immunity ◽

10.1128/iai.30.2.554-561.1980 ◽

1980 ◽

Vol 30 (2) ◽

pp. 554-561

Author(s):

R C Fader ◽

C P Davis

Keyword(s):

Electron Microscopy ◽

Urinary Tract ◽

Klebsiella Pneumoniae ◽

Mammalian Cells ◽

Parent Strain ◽

Single Parent ◽

Integral Role ◽

Tract Infections ◽

Scanning Electron

The possible role of pili in the pathogenesis of urinary tract infection caused by Klebsiella pneumoniae was investigated in a rat model of cystitis by utilizing piliated- and nonpiliated-phase organisms derived from a single parent strain. Bladder surfaces were examined for evidence of infection by scanning electron microscopy. In animals infected with piliated-phase organisms, foci of infection were evident in the majority of bladders examined. Rat bladders associated with nonpiliated-phase bacteria showed little evidence of infection. The ability of methyl-D-mannoside, a known inhibitor of pilus-mediated adherence to mammalian cells, to protect the bladder surface from colonization was also tested. The results showed a significant decrease in the ability of piliated-phase K. pneumoniae to establish infection in bladders. These observations suggest that pili may play an integral role in the ability of K. pneumoniae to cause urinary tract infections by mediating the attachment of the bacteria to the uroepithelial surface.

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Selective Translation Complex Profiling Reveals Staged Initiation and Co-translational Assembly of Initiation Factor Complexes

10.1101/806125 ◽

2019 ◽

Author(s):

Susan Wagner ◽

Anna Herrmannová ◽

Vladislava Hronová ◽

Neelam Sen ◽

Ross D. Hannan ◽

...

Keyword(s):

Gene Expression ◽

Translational Control ◽

Mammalian Cells ◽

Regulation Of Gene Expression ◽

Ribosome Profiling ◽

Initiation Factor ◽

Start Codon ◽

Codon Recognition ◽

Initiation Phase ◽

Gene Expression Studies

SUMMARYTranslational control targeting mainly the initiation phase is central to the regulation of gene expression. Understanding all of its aspects requires substantial technological advancements. Here we modified yeast Translational Complex Profile sequencing (TCP-seq), related to ribosome profiling, and adopted it for mammalian cells. Human TCP-seq, capable of capturing footprints of 40S subunits (40Ses) in addition to 80S ribosomes (80Ses), revealed that mammalian and yeast 40Ses distribute similarly across 5’UTRs indicating considerable evolutionary conservation. We further developed a variation called Selective TCP-seq (Sel-TCP-seq) enabling selection for 40Ses and 80Ses associated with an immuno-targeted factor in yeast and human. Sel-TCP-seq demonstrated that eIF2 and eIF3 travel along 5’UTRs with scanning 40Ses to successively dissociate upon start codon recognition. Manifesting the Sel-TCP-seq versatility for gene expression studies, we also identified four initiating 48S conformational intermediates, provided novel insights into ATF4 and GCN4 mRNA translational control, and demonstrated co-translational assembly of initiation factor complexes.

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The role of phosphatidic acid in the regulation of the Ras/MEK/Erk signaling cascade

FEBS Letters ◽

10.1016/s0014-5793(02)03483-x ◽

2002 ◽

Vol 531 (1) ◽

pp. 65-68 ◽

Cited By ~ 117

Author(s):

Bradley T Andresen ◽

Mark A Rizzo ◽

Kuntala Shome ◽

Guillermo Romero

Keyword(s):

Phosphatidic Acid ◽

Erk Signaling ◽

Signaling Cascade

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Distinct ribosome states trigger diverse mRNA quality control pathways

10.1101/2021.12.01.470814 ◽

2021 ◽

Author(s):

Anthony J. Veltri ◽

Karole N. D’Orazio ◽

Laura N. Lessen ◽

Raphael Loll-Krippleber ◽

Grant W. Brown ◽

...

Keyword(s):

Mrna Decay ◽

Ribosome Profiling ◽

Translational Repression ◽

Genetic Screens ◽

Mechanistic Insight ◽

Optimal Codons ◽

Key Factor ◽

Reporter Mrna ◽

Insight Into

AbstractKey protein adapters couple translation to mRNA decay on specific classes of problematic mRNAs in eukaryotes. Slow decoding on non-optimal codons leads to codon-optimality-mediated decay (COMD) and prolonged arrest at stall sites leads to no-go decay (NGD). The identities of the decay factors underlying these processes and the mechanisms by which they respond to translational distress remain open areas of investigation. We use carefully-designed reporter mRNAs to perform genetic screens and functional assays in S. cerevisiae. We characterize the roles of Hel2 and Syh1 in coordinating translational repression and mRNA decay on NGD reporter mRNAs, finding that Syh1 acts as the primary link to mRNA decay in NGD. Importantly, we observe that these NGD factors are not involved in the degradation of mRNAs enriched in non-optimal codons. Further, we establish that a key factor previously implicated in COMD, Not5, contributes modestly to the degradation of an NGD-targeted mRNA. Finally, we use ribosome profiling to reveal distinct ribosomal states associated with each reporter mRNA that readily rationalize the contributions of NGD and COMD factors to degradation of these reporters. Taken together, these results provide new mechanistic insight into the role of Syh1 in NGD and define the molecular triggers that determine how distinct pathways target mRNAs for degradation in yeast.

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The role of DUBs in the post-translational control of cell migration

Essays in Biochemistry ◽

10.1042/ebc20190022 ◽

2019 ◽

Vol 63 (5) ◽

pp. 579-594 ◽

Cited By ~ 2

Author(s):

Guillem Lambies ◽

Antonio García de Herreros ◽

Víctor M. Díaz

Keyword(s):

Cell Migration ◽

Translational Control ◽

Epithelial To Mesenchymal Transition ◽

Extracellular Matrix Remodeling ◽

Matrix Remodeling ◽

Mesenchymal Transition ◽

Tgfβ Receptors ◽

Fundamental Process ◽

Multistep Process

Abstract Cell migration is a multifactorial/multistep process that requires the concerted action of growth and transcriptional factors, motor proteins, extracellular matrix remodeling and proteases. In this review, we focus on the role of transcription factors modulating Epithelial-to-Mesenchymal Transition (EMT-TFs), a fundamental process supporting both physiological and pathological cell migration. These EMT-TFs (Snail1/2, Twist1/2 and Zeb1/2) are labile proteins which should be stabilized to initiate EMT and provide full migratory and invasive properties. We present here a family of enzymes, the deubiquitinases (DUBs) which have a crucial role in counteracting polyubiquitination and proteasomal degradation of EMT-TFs after their induction by TGFβ, inflammatory cytokines and hypoxia. We also describe the DUBs promoting the stabilization of Smads, TGFβ receptors and other key proteins involved in transduction pathways controlling EMT.

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