scholarly journals Vectorial Channeling as a Mechanism for Translational Control by Functional Prions and Condensates

2021 ◽  
Author(s):  
Xinyu Gu ◽  
Nicholas P Schafer ◽  
Peter G Wolynes
Keyword(s):  
Experimental Data ◽  
Dendritic Spines ◽  
Translational Control ◽  
Messenger Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Potential Of Mean Force ◽  
Translation Control ◽  
Through Diffusion

Translation of messenger RNA is regulated through a diverse set of RNA-binding proteins. A significant fraction of RNA-binding proteins contain prion-like domains which form functional prions. This raises the question of how prions can play a role in translational control. Local control of translation in dendritic spines by prions has been invoked in the mechanism of synaptic plasticity and memory. We show how channeling through diffusion and processive translation cooperate in highly ordered mRNA/prion aggregates as well as in less ordered mRNA/protein condensates depending on their substructure. We show the direction of translational control, whether it is repressive or activating, depends on the polarity of the mRNA distribution in mRNA/prion assemblies which determines whether vectorial channeling can enhance recycling of ribosomes. Our model also addresses the effect of changes of substrate concentration in assemblies that have been suggested previously to explain translation control by assemblies through the introduction of a potential of mean force biasing diffusion of ribosomes inside the assemblies. The results from the model are compared with the experimental data on translational control by two functional RNA-binding prions, CPEB involved in memory and Rim4 involved in gametogenesis.

scholarly journals Vectorial channeling as a mechanism for translational control by functional prions and condensates

2021 ◽  
Vol 118 (47) ◽  
pp. e2115904118
Author(s):  
Xinyu Gu ◽  
Nicholas P. Schafer ◽  
Peter G. Wolynes
Keyword(s):  
Experimental Data ◽  
Synaptic Plasticity ◽  
Dendritic Spines ◽  
Translational Control ◽  
Messenger Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Potential Of Mean Force ◽  
Through Diffusion

Translation of messenger RNA (mRNA) is regulated through a diverse set of RNA-binding proteins. A significant fraction of RNA-binding proteins contains prion-like domains which form functional prions. This raises the question of how prions can play a role in translational control. Local control of translation in dendritic spines by prions has been invoked in the mechanism of synaptic plasticity and memory. We show how channeling through diffusion and processive translation cooperate in highly ordered mRNA/prion aggregates as well as in less ordered mRNA/protein condensates depending on their substructure. We show that the direction of translational control, whether it is repressive or activating, depends on the polarity of the mRNA distribution in mRNA/prion assemblies which determines whether vectorial channeling can enhance recycling of ribosomes. Our model also addresses the effect of changes of substrate concentration in assemblies that have been suggested previously to explain translational control by assemblies through the introduction of a potential of mean force biasing diffusion of ribosomes inside the assemblies. The results from the model are compared with the experimental data on translational control by two functional RNA-binding prions, CPEB involved in memory and Rim4 involved in gametogenesis.

Messenger-RNA-binding proteins and the messages they carry

2002 ◽  
Vol 3 (3) ◽  
pp. 195-205 ◽  
Author(s):  
Gideon Dreyfuss ◽  
V. Narry Kim ◽  
Naoyuki Kataoka
Keyword(s):  
Messenger Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins

scholarly journals Identification of mRNAs Associated with αCP2-Containing RNP Complexes

2003 ◽  
Vol 23 (19) ◽  
pp. 7055-7067 ◽  
Author(s):  
Shelly A. Waggoner ◽  
Stephen A. Liebhaber
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Cell Function ◽  
Rna Binding Proteins ◽  
Translation Control ◽  
Viral Mrnas ◽  
Posttranscriptional Gene Regulation ◽  
Direct Binding

ABSTRACT Posttranscriptional controls in higher eukaryotes are central to cell differentiation and developmental programs. These controls reflect sequence-specific interactions of mRNAs with one or more RNA binding proteins. The α-globin poly(C) binding proteins (αCPs) comprise a highly abundant subset of K homology (KH) domain RNA binding proteins and have a characteristic preference for binding single-stranded C-rich motifs. αCPs have been implicated in translation control and stabilization of multiple cellular and viral mRNAs. To explore the full contribution of αCPs to cell function, we have identified a set of mRNAs that associate in vivo with the major αCP2 isoforms. One hundred sixty mRNA species were consistently identified in three independent analyses of αCP2-RNP complexes immunopurified from a human hematopoietic cell line (K562). These mRNAs could be grouped into subsets encoding cytoskeletal components, transcription factors, proto-oncogenes, and cell signaling factors. Two mRNAs were linked to ceroid lipofuscinosis, indicating a potential role for αCP2 in this infantile neurodegenerative disease. Surprisingly, αCP2 mRNA itself was represented in αCP2-RNP complexes, suggesting autoregulatory control of αCP2 expression. In vitro analyses of representative target mRNAs confirmed direct binding of αCP2 within their 3′ untranslated regions. These data expand the list of mRNAs that associate with αCP2 in vivo and establish a foundation for modeling its role in coordinating pathways of posttranscriptional gene regulation.

scholarly journals Roles of Organellar RNA-Binding Proteins in Plant Growth, Development, and Abiotic Stress Responses

2020 ◽  
Vol 21 (12) ◽  
pp. 4548 ◽  
Author(s):  
Kwanuk Lee ◽  
Hunseung Kang
Keyword(s):  
Abiotic Stress ◽  
Plant Growth ◽  
Stress Responses ◽  
Translational Control ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Rna Metabolism ◽  
Functional Roles ◽  
Growth Development

Organellar gene expression (OGE) in chloroplasts and mitochondria is primarily modulated at post-transcriptional levels, including RNA processing, intron splicing, RNA stability, editing, and translational control. Nucleus-encoded Chloroplast or Mitochondrial RNA-Binding Proteins (nCMRBPs) are key regulatory factors that are crucial for the fine-tuned regulation of post-transcriptional RNA metabolism in organelles. Although the functional roles of nCMRBPs have been studied in plants, their cellular and physiological functions remain largely unknown. Nevertheless, existing studies that have characterized the functions of nCMRBP families, such as chloroplast ribosome maturation and splicing domain (CRM) proteins, pentatricopeptide repeat (PPR) proteins, DEAD-Box RNA helicase (DBRH) proteins, and S1-domain containing proteins (SDPs), have begun to shed light on the role of nCMRBPs in plant growth, development, and stress responses. Here, we review the latest research developments regarding the functional roles of organellar RBPs in RNA metabolism during growth, development, and abiotic stress responses in plants.

scholarly journals Translational Control of Cytochrome c by RNA-Binding Proteins TIA-1 and HuR

2006 ◽  
Vol 26 (8) ◽  
pp. 3295-3307 ◽  
Author(s):  
Tomoko Kawai ◽  
Ashish Lal ◽  
Xiaoling Yang ◽  
Stefanie Galban ◽  
Krystyna Mazan-Mamczarz ◽  
...  
Keyword(s):  
Er Stress ◽  
Translational Control ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Expression Patterns ◽  
Mrna Levels ◽  
Coding Region ◽  
Translation Rate ◽  
Translational Repressor

ABSTRACT Stresses affecting the endoplasmic reticulum (ER) globally modulate gene expression patterns by altering posttranscriptional processes such as translation. Here, we use tunicamycin (Tn) to investigate ER stress-triggered changes in the translation of cytochrome c, a pivotal regulator of apoptosis. We identified two RNA-binding proteins that associate with its ∼900-bp-long, adenine- and uridine-rich 3′ untranslated region (UTR): HuR, which displayed affinity for several regions of the cytochrome c 3′UTR, and T-cell-restricted intracellular antigen 1 (TIA-1), which preferentially bound the segment proximal to the coding region. HuR did not appear to influence the cytochrome c mRNA levels but instead promoted cytochrome c translation, as HuR silencing greatly diminished the levels of nascent cytochrome c protein. By contrast, TIA-1 functioned as a translational repressor of cytochrome c, with interventions to silence TIA-1 dramatically increasing cytochrome c translation. Following treatment with Tn, HuR binding to cytochrome c mRNA decreased, and both the presence of cytochrome c mRNA within actively translating polysomes and the rate of cytochrome c translation declined. Taken together, our data suggest that the translation rate of cytochrome c is determined by the opposing influences of HuR and TIA-1 upon the cytochrome c mRNA. Under unstressed conditions, cytochrome c mRNA is actively translated, but in response to ER stress agents, both HuR and TIA-1 contribute to lowering its biosynthesis rate. We propose that HuR and TIA-1 function coordinately to maintain precise levels of cytochrome c production under unstimulated conditions and to modify cytochrome c translation when damaged cells are faced with molecular decisions to follow a prosurvival or a prodeath path.

scholarly journals Abstract P-22: Enhanced Crosslinking and Immunoprecipitation (Eclip) Data Reveal Interactions of RNA Binding Proteins with the Human Ribosome

2021 ◽  
Vol 11 (Suppl_1) ◽  
pp. S21-S21
Author(s):  
Andrey Buyan ◽  
Ivan Kulakovskiy ◽  
Sergey Dmitriev
Keyword(s):  
Translational Control ◽  
Nuclear Export ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Repetitive Sequences ◽  
Structural Data

Background: The ribosome is a protein-synthesizing molecular machine composed of four ribosomal RNAs (rRNAs) and dozens of ribosomal proteins. In mammals, the ribosome has a complicated structure with an additional outer layer of rRNA, including large tentacle-like extensions. A number of RNA binding proteins (RBPs) interact with this layer to assist ribosome biogenesis, nuclear export and decay, or to modulate translation. Plenty of methods have been developed in the last decade in order to study such protein-RNA interactions, including RNA pulldown and crosslinking-immunoprecipitation (CLIP) assays. Methods: In the current study, using publicly available data of the enhanced CLIP (eCLIP) experiments for 223 proteins studied in the ENCODE project, we found a number of RBPs that bind rRNAs in human cells. To locate their binding sites in rRNAs, we used a newly developed computational protocol for mapping and evaluation of the eCLIP data with the respect to the repetitive sequences. Results: For two proteins with known ribosomal localization, uS3/RPS3 and uS17/RPS11, the identified sites were in good agreement with structural data, thus validating our approach. Then, we identified rRNA contacts of overall 22 RBPs involved in rRNA processing and ribosome maturation (DDX21, DDX51, DDX52, NIP7, SBDS, UTP18, UTP3, WDR3, and WDR43), translational control during stress (SERBP1, G3BP1, SND1), IRES activity (PCBP1/hnRNPE1), and other translation-related functions. In many cases, the identified proteins interact with the rRNA expansion segments (ES) of the human ribosome pointing to their important role in protein synthesis. Conclusion: Our study identifies a number of RBPs as interacting partners of the human ribosome and sheds light on the role of rRNA expansion segments in translation.

scholarly journals RNA binding protein RBM3 augments kissing loop formation with lncRNAs to enhance translational control

2021 ◽  
Author(s):  
Afreen Asif Ali Sayed ◽  
Sonali Choudhury ◽  
Dharmalingam Subramaniam ◽  
Sumedha Gunewardena ◽  
Sivapriya Ponnurangam ◽  
...  
Keyword(s):  
Translational Control ◽  
Binding Proteins ◽  
Rna Binding ◽  
Epithelial Mesenchymal Transition ◽  
Rna Binding Proteins ◽  
Tumor Xenograft ◽  
Rna Seq ◽  
Loop Formation ◽  
Mesenchymal Transition ◽  
Kissing Loop

Background and Aims: Translational regulation involve the coordinated actions of RNA binding proteins (RBPs) and non-coding RNAs. For efficient translation, the mRNA needs to be circularized. While RNA binding proteins and translation factors have been shown to regulate the circularization, the role of lncRNAs in the process is not yet defined. Methods: We first performed RNA-seq and RNA-immunoprecipitation coupled-Seq (RIP-Seq) to identify differentially expressed lncRNA and mRNA in RBM3 overexpressing cell lines. We manipulated lncRNA expression in the cells and determined effects on gene expression and cell viability and motility. The studies were confirmed in vivo in intestine specific RBM3 transgenic and RBM3 knockout mouse models. Results: In comparing the RNA-Seq and RIP-Seq datasets, we identified increased expression of lncRNA LSAMP-3 and Flii-1 that bind to RBM3. In addition, there was an increase in expression of epithelial mesenchymal transition and angiogenesis markers following RBM3 overexpression. Moreover, modeling studies suggest that these lncRNAs formed kissing-loop interactions on target mRNAs including transcripts that encode epithelial mesenchymal transition and angiogenesis. While RBM3 transgenic mice showed increased LSAMP-3 and Flii-1, this was reduced in the RBM3 knockout mice. Also, RBM3 overexpression increased tumor xenograft growth, which was suppressed by knockdown of the lncRNAs. Also, knockdown of endogenous RBM3 specifically in the intestine suppressed azoxymethane-dextran sodium sulfate driven colitis-associated cancers, with a corresponding reduction in the expression of lncRNAs and transcripts that encode epithelial mesenchymal transition and angiogenesis. Conclusion: We propose that RBPs such as RBM3 mediate their function through regulatory lncRNAs that enable circularization to control translation.

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