scholarly journals Degradation of high affinity HuD targets releases Kv1.1 mRNA from miR-129 repression by mTORC1

2013 ◽  
Vol 202 (1) ◽  
pp. 53-69 ◽  
Author(s):  
Natasha M. Sosanya ◽  
Peggy P.C. Huang ◽  
Luisa P. Cacheaux ◽  
Chun Jung Chen ◽  
Kathleen Nguyen ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Messenger Rna ◽  
Translational Regulation ◽  
Rna Binding ◽  
Mrna Translation ◽  
Intrinsic Excitability ◽  
Site Specific ◽  
Voltage Gated ◽  
High Affinity ◽  
Mtorc1 Signaling

Little is known about how a neuron undergoes site-specific changes in intrinsic excitability during neuronal activity. We provide evidence for a novel mechanism for mTORC1 kinase–dependent translational regulation of the voltage-gated potassium channel Kv1.1 messenger RNA (mRNA). We identified a microRNA, miR-129, that repressed Kv1.1 mRNA translation when mTORC1 was active. When mTORC1 was inactive, we found that the RNA-binding protein, HuD, bound to Kv1.1 mRNA and promoted its translation. Unexpectedly, inhibition of mTORC1 activity did not alter levels of miR-129 and HuD to favor binding to Kv1.1 mRNA. However, reduced mTORC1 signaling caused the degradation of high affinity HuD target mRNAs, freeing HuD to bind Kv1.1 mRNA. Hence, mTORC1 activity regulation of mRNA stability and high affinity HuD-target mRNA degradation mediates the bidirectional expression of dendritic Kv1.1 ion channels.

scholarly journals Csde1 binds transcripts involved in protein homeostasis and controls their expression in erythropoiesis

2017 ◽  
Author(s):  
Kat S Moore ◽  
Nurcan Yagci ◽  
Floris van Alphen ◽  
Nahuel A Paolini ◽  
Rastislav Horos ◽  
...  
Keyword(s):  
Protein Expression ◽  
Mrna Expression ◽  
Mrna Stability ◽  
Cold Shock ◽  
Rna Binding ◽  
Mrna Translation ◽  
Mitochondrial Respiratory Chain ◽  
Protein Homeostasis ◽  
Diamond Blackfan Anemia ◽  
Cold Shock Domain

AbstractExpression of the RNA-binding protein Csde1 (Cold shock domain protein e1) is strongly upregulated during erythropoiesis compared to other hematopoietic lineages. In the severe congenital anemia Diamond Blackfan Anemia (DBA), however, Csde1 expression is impaired. Reduced expression of Csde1 in healthy erythroblasts impaired their proliferation and differentiation, which suggests an important role for Csde1 in erythropoiesis. To investigate the cellular pathways controlled by Csde1 in erythropoiesis, we identified the transcripts that physically associate with Csde1 in erythroid cells. These mainly encoded proteins involved in ribogenesis, mRNA translation and protein degradation, but also proteins associated with the mitochondrial respiratory chain and mitosis. Crispr/Cas9-mediated deletion of the first cold shock domain of Csde1 affected RNA expression and/or protein expression of Csde1-bound transcripts. For instance, protein expression of Pabpc1 was enhanced while Pabpc1 mRNA expression was reduced indicating more efficient translation of Pabpc1 followed by negative feedback on mRNA stability. Overall, the effect of reduced Csde1 function on mRNA stability and translation of Csde1-bound transcripts was modest. Clones with complete loss of Csde1, however, could not be generated. We suggest that Csde1 is involved in feed-back control in protein homeostasis and that it dampens stochastic changes in mRNA expression.

Corrigendum to: Cytoplasmic polyadenylation element binding protein 2 (CPEB2) is required for tight-junction assembly for establishment of porcine trophectoderm epithelium

2019 ◽  
Vol 31 (3) ◽  
pp. 632
Author(s):  
Jeongwoo Kwon ◽  
Shuha Park ◽  
Min-Jung Seong ◽  
Inchul Choi ◽  
Nam-Hyung Kim
Keyword(s):  
Tight Junction ◽  
Mrna Stability ◽  
Rna Binding ◽  
Binding Protein ◽  
Mrna Translation ◽  
Coxsackie Virus ◽  
Cytoplasmic Polyadenylation ◽  
Apical Cell Membrane ◽  
Junction Protein ◽  
Element Binding Protein

Cytoplasmic polyadenylation element binding protein (CPEB) is an RNA-binding protein that promotes elongation of poly(A) tails and regulates mRNA translation. CPEB depletion in mammary epithelium is known to disrupt tight-junction (TJ) assembly via mislocalisation of tight junction protein 1 (TJP1), but the role of CPEB in the biological functions associated with TJs has not yet been studied. The objective of this study was to investigate the roles of CPEB2 during porcine parthenote development. CPEB2 was detected in both the nuclei and apical cytoplasm at the 4- and 8-cell stages and was localised to cell–cell contact after the initiation of the morula stage. Its depletion led to retarded blastocyst formation caused by impaired TJ assembly. Moreover, transcription of TJ-associated genes, including TJP1, Coxsackie virus and adenovirus receptor (CXADR) and occludin (OCLN), was not affected, but the corresponding proteins were not properly localised at the apical cell membrane in morulae, suggesting that CPEB2 confers mRNA stability or determines subcellular localisation for translation. Remarkably reduced relative levels of TJP1 transcripts bearing the 3′-untranslated region were noted, indicating that CPEB2 mediates TJP1 mRNA stability. In conclusion, our findings demonstrate that because of its regulation of TJP1, CPEB2 is required for TJ assembly during porcine blastocyst development.

scholarly journals Csde1 cooperates with Strap to control translation of erythroid transcripts

2017 ◽  
Author(s):  
Kat S. Moore ◽  
Nurcan Yagci ◽  
Floris van Alphen ◽  
Alexander B. Meijer ◽  
Peter A.C. ‘t Hoen ◽  
...  
Keyword(s):  
Growth Factors ◽  
Environmental Conditions ◽  
Rna Splicing ◽  
Translational Regulation ◽  
Rna Binding ◽  
Protein Complexes ◽  
Rna Binding Protein ◽  
Mrna Translation ◽  
Hematopoietic Progenitors ◽  
Control Translation

AbstractErythropoiesis is regulated at many levels, including control of mRNA translation. Changing environmental conditions, such as hypoxia, or the availability of nutrients and growth factors, require a rapid response enacted by the enhanced or repressed translation of existing transcripts. Csde1 is an RNA-binding protein required for erythropoiesis and strongly upregulated in erythroblasts relative to other hematopoietic progenitors. The aim of this study is to identify the Csde1-containing protein complexes, and investigate their role in regulating the translation of Csde1-bound transcripts. We show that Strap, also called Unrip, was the protein most strongly associated with Csde1 in erythroblasts. Strap is a WD40 protein involved in signaling and RNA splicing, but its role is unknown when associated with Csde1. Reduced expression of Strap did not alter the pool of transcripts bound by Csde1. Instead, it reduced the mRNA and/or protein expression of several Csde1-bound transcript, that encode for proteins essential for translational regulation during hypoxia, such as Hmbs, eIF4g3 and Pabpc4. Also affected by Strap knockdown were Vim, a Gata-1 target crucial for erythrocyte enucleation, and Elavl1, which stabilizes Gata-1 mRNA. Thus, we found that the Csde1/Strap complex is at the crossroad of multiple pathways governing translation in erythroblasts.

Cytoplasmic polyadenylation element binding protein 2 (CPEB2) is required for tight-junction assembly for establishment of porcine trophectoderm epithelium

2019 ◽  
Vol 31 (2) ◽  
pp. 412 ◽  
Author(s):  
Jeongwoo Kwon ◽  
Shuha Park ◽  
Min-Jung Seong ◽  
Inchul Choi ◽  
Nam-Hyung Kim
Keyword(s):  
Tight Junction ◽  
Mrna Stability ◽  
Rna Binding ◽  
Binding Protein ◽  
Mrna Translation ◽  
Coxsackie Virus ◽  
Cytoplasmic Polyadenylation ◽  
Apical Cell Membrane ◽  
Junction Protein ◽  
Element Binding Protein

Cytoplasmic polyadenylation element binding protein (CPEB) is an RNA-binding protein that promotes elongation of poly(A) tails and regulates mRNA translation. CPEB depletion in mammary epithelium is known to disrupt tight-junction (TJ) assembly via mislocalisation of tight junction protein 1 (TJP1), but the role of CPEB in the biological functions associated with TJs has not yet been studied. The objective of this study was to investigate the roles of CPEB2 during porcine parthenote development. CPEB2 was detected in both the nuclei and apical cytoplasm at the 4- and 8-cell stages and was localised to cell–cell contact after the initiation of the morula stage. Its depletion led to retarded blastocyst formation caused by impaired TJ assembly. Moreover, transcription of TJ-associated genes, including TJP1, Coxsackie virus and adenovirus receptor (CXADR) and occludin (OCLN), was not affected, but the corresponding proteins were not properly localised at the apical cell membrane in morulae, suggesting that CPEB2 confers mRNA stability or determines subcellular localisation for translation. Remarkably reduced relative levels of TJP1 transcripts bearing the 3′-untranslated region were noted, indicating that CPEB2 mediates TJP1 mRNA stability. In conclusion, our findings demonstrate that because of its regulation of TJP1, CPEB2 is required for TJ assembly during porcine blastocyst development.

scholarly journals mTORC1 promotes TOP mRNA translation through site-specific phosphorylation of LARP1

2021 ◽  
Author(s):  
Jian-Jun Jia ◽  
Roni M Lahr ◽  
Michael T Solgaard ◽  
Bruno J Moraes ◽  
Roberta Pointet ◽  
...  
Keyword(s):  
Rna Binding ◽  
Mrna Translation ◽  
Translation Control ◽  
Site Specific ◽  
Translation Repression ◽  
Eif4f Complex ◽  
Inhibitory Activities ◽  
Activation Status

Abstract LARP1 is a key repressor of TOP mRNA translation. It binds the m7Gppp cap moiety and the adjacent 5′TOP motif of TOP mRNAs, thus impeding the assembly of the eIF4F complex on these transcripts. mTORC1 controls TOP mRNA translation via LARP1, but the details of the mechanism are unclear. Herein we elucidate the mechanism by which mTORC1 controls LARP1’s translation repression activity. We demonstrate that mTORC1 phosphorylates LARP1 in vitro and in vivo, activities that are efficiently inhibited by rapamycin and torin1. We uncover 26 rapamycin-sensitive phospho-serine and -threonine residues on LARP1 that are distributed in 7 clusters. Our data show that phosphorylation of a cluster of residues located proximally to the m7Gppp cap-binding DM15 region is particularly sensitive to rapamycin and regulates both the RNA-binding and the translation inhibitory activities of LARP1. Our results unravel a new model of translation control in which the La module (LaMod) and DM15 region of LARP1, both of which can directly interact with TOP mRNA, are differentially regulated: the LaMod remains constitutively bound to PABP (irrespective of the activation status of mTORC1), while the C-terminal DM15 ‘pendular hook’ engages the TOP mRNA 5′-end to repress translation, but only in conditions of mTORC1 inhibition.

scholarly journals Translational regulation of Chk1 expression by eIF3a via interaction with the RNA-binding protein HuR

2020 ◽  
Vol 477 (10) ◽  
pp. 1939-1950 ◽  
Author(s):  
Zizheng Dong ◽  
Jianguo Liu ◽  
Jian-Ting Zhang
Keyword(s):  
Translational Regulation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Regulatory Function ◽  
Rna Recognition Motif ◽  
Eukaryotic Translation ◽  
Eukaryotic Translation Initiation

eIF3a is a putative subunit of the eukaryotic translation initiation factor 3 complex. Accumulating evidence suggests that eIF3a may have a translational regulatory function by suppressing translation of a subset of mRNAs while accelerating that of other mRNAs. Albeit the suppression of mRNA translation may derive from eIF3a binding to the 5′-UTRs of target mRNAs, how eIF3a may accelerate mRNA translation remains unknown. In this study, we show that eIF3a up-regulates translation of Chk1 but not Chk2 mRNA by interacting with HuR, which binds directly to the 3′-UTR of Chk1 mRNA. The interaction between eIF3a and HuR occurs at the 10-amino-acid repeat domain of eIF3a and the RNA recognition motif domain of HuR. This interaction may effectively circularize Chk1 mRNA to form an end-to-end complex that has recently been suggested to accelerate mRNA translation. Together with previous findings, we conclude that eIF3a may regulate mRNA translation by directly binding to the 5′-UTR to suppress or by interacting with RNA-binding proteins at 3′-UTRs to accelerate mRNA translation.

scholarly journals Translation of the Chloroplast psbA mRNA Requires the Nuclear-encoded Poly(A)-binding Protein, RB47

1998 ◽  
Vol 142 (2) ◽  
pp. 435-442 ◽  
Author(s):  
Christopher B. Yohn ◽  
Amybeth Cohen ◽  
Cristen Rosch ◽  
Michael R. Kuchka ◽  
Stephen P. Mayfield
Keyword(s):  
Photosystem Ii ◽  
Reaction Center ◽  
Untranslated Region ◽  
Translational Regulation ◽  
Rna Binding ◽  
Binding Protein ◽  
Biochemical Data ◽  
Cohesive Model ◽  
High Affinity ◽  
Translational Activator

A set of nuclear mutants of C. reinhardtii were identified that specifically lack translation of the chloroplast-encoded psbA mRNA, which encodes the photosystem II reaction center polypeptide D1. Two of these mutants are deficient in the 47-kD member (RB47) of the psbA RNA-binding complex, which has previously been identified both genetically and biochemically as a putative translational activator of the chloroplast psbA mRNA. RB47 is a member of the poly(A)-binding protein family, and binds with high affinity and specificity to the 5′ untranslated region of the psbA mRNA. The results presented here confirm RB47's role as a message-specific translational activator in the chloroplast, and bring together genetic and biochemical data to form a cohesive model for light- activated translational regulation in the chloroplast.

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 Application of the 3'-Untranslated Region of Messenger RNA from Measles Virus Matrix Protein as an RNA Stabilizer: Implications in Pharmaceutical Biotechnology

2019 ◽  
Vol 9 (1) ◽  
pp. 53
Author(s):  
Marzieh Marzbany ◽  
Fatemeh Ghassemi ◽  
Mahsa Rasekhian
Keyword(s):  
Mrna Stability ◽  
Messenger Rna ◽  
Untranslated Region ◽  
Measles Virus ◽  
Matrix Protein ◽  
Rna Binding ◽  
Rna Stability ◽  
Minimum Free Energy ◽  
Expression Vectors ◽  
Dependent Manner

BACKGROUND: The market for the use of recombinant proteins for medical applications has been increasing in recent years. In many cases including fast production of significant amounts of protein for research purposes, transient transfection is the method of choice. In this regard expression vectors are one of the decisive factors in the cost-effectiveness of the production process. The genetic elements found in the 3’untranslated region (UTR) of mRNA expressed by such vectors, play an essential role in determining its stability and thus in the efficiency of the process. METHODS: In this study, the 3'UTR of matrix protein from the Measles Virus (MV) was used to construct a reporter plasmid containing Enhanced Green Fleurocent Protein (EGFP). The reporter construct was transfected into three cell lines. The effect of 3'UTR on mRNA stability was evaluated by real-time PCR. Secondary structure of the mrna was predicted based on minimum free energy. 3'UTR was analyzed in silico for the presence of binding motifs for trans-acting elements with known effects on RNA stability. RESULTS: Addition of 3’UTR of MV matrix protein sequence to the 3’ end of the mRNA, increased the EGFP- mRNA stability in time and cell-dependent manner. Analysis for the presence of known cis-acting motifs in 3’UTR indicated the presence of two PABPC1 binding sites, an RNA-binding protein, known for its stability and translation enhancing effects. CONCLUSION: Our results verified the potential of the 3'UTR region of matrix protein mRNA for improvement of transient recombinant protein production and vector design for mammalian cell hosts.

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