scholarly journals A Musashi-Related Protein is Essential for Gametogenesis in Arabidopsis

2019 ◽  
Author(s):  
Laura A. Moody ◽  
Ester Rabbinowitsch ◽  
Hugh G. Dickinson ◽  
Roxaana Clayton ◽  
David M. Emms ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Pollen Viability ◽  
Functional Characterization ◽  
Mrna Translation ◽  
High Rate ◽  
Loss Of Function ◽  
Gametophyte Development ◽  
Evolutionarily Conserved ◽  
Related Proteins

SUMMARYMusashi (Msi) proteins are an evolutionarily conserved group of RNA-binding proteins, required for targeted control of mRNA translation during many important developmental processes in animals. Most notably, Msi proteins play important roles during both spermatogenesis and oogenesis. Msi proteins also exist in plants but these are largely uncharacterized. Here we report the functional characterization of an Arabidopsis Msi orthologABORTED GAMETOPHYTE 2(AOG2), which encodes a protein containing two RNA recognition motifs and an ER-targeting signal. AOG2-GFP translational fusions were localized to the ER in transient assays, suggesting that AOG2 most likely binds to ER-targeted mRNAs. We show that disruptedAOG2function leads to a high rate of both ovule and seed abortion, and that homozygous loss of function mutants are embryo lethal. Furthermore, we demonstrate thatAOG2is required to establish asymmetry during pollen mitosis I, and that loss ofAOG2function leads to loss of pollen viability. Collectively the results reveal that AOG2 is required for the establishment of polarity and/or the progression of mitosis during gametophyte development in Arabidopsis, and thus Msi-related proteins have an evolutionarily conserved role in gametogenesis in both animals and plants.SIGNIFICANCE STATEMENTABORTED GAMETOPHYTE 2(AOG2) encodes a Musashi-related RNA-binding protein that is required for gametogenesis and embryogenesis in Arabidopsis.AOG2is required for the establishment of polarity and/or the progression of mitosis during gametophyte development in Arabidopsis, and thus Musashi-related proteins have an evolutionarily conserved role in gametogenesis in both animals and plants.

scholarly journals Two Yeast La Motif-containing Proteins Are RNA-binding Proteins that Associate with Polyribosomes

1999 ◽  
Vol 10 (11) ◽  
pp. 3849-3862 ◽  
Author(s):  
Suzanne G. Sobel ◽  
Sandra L. Wolin
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Rna Polymerase Iii ◽  
Mrna Translation ◽  
Protein Synthesis Inhibitors ◽  
La Protein ◽  
Evolutionarily Conserved ◽  
Synthetically Lethal ◽  
Type Strains

We have characterized two Saccharomyces cerevisiaeproteins, Sro9p and Slf1p, which contain a highly conserved motif found in all known La proteins. Originally described as an autoantigen in patients with rheumatic disease, the La protein binds to newly synthesized RNA polymerase III transcripts. In yeast, the La protein homologue Lhp1p is required for the normal pathway of tRNA maturation and also stabilizes newly synthesized U6 RNA. We show that deletions in both SRO9 and SLF1 are not synthetically lethal with a deletion in LHP1, indicating that the three proteins do not function in a single essential process. Indirect immunofluorescence microscopy reveals that although Lhp1p is primarily localized to the nucleus, Sro9p is cytoplasmic. We demonstrate that Sro9p and Slf1p are RNA-binding proteins that associate preferentially with translating ribosomes. Consistent with a role in translation, strains lacking either Sro9p or Slf1p are less sensitive than wild-type strains to certain protein synthesis inhibitors. Thus, Sro9p and Slf1p define a new and possibly evolutionarily conserved class of La motif-containing proteins that may function in the cytoplasm to modulate mRNA translation.

scholarly journals Core spliceosomal Sm proteins as constituents of cytoplasmic mRNPs in plants

2019 ◽  
Author(s):  
Malwina Hyjek-Składanowska ◽  
Mateusz Bajczyk ◽  
Marcin Gołębiewski ◽  
Przemysław Nuc ◽  
Agnieszka Kołowerzo-Lubnau ◽  
...  
Keyword(s):  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulation Of Gene Expression ◽  
Mrna Translation ◽  
Mrna Splicing ◽  
Sm Proteins ◽  
Cytoplasmic Bodies ◽  
Evolutionarily Conserved ◽  
Processing Steps

ABSTRACTIn light of recent studies, many of the cytoplasmic posttranscriptional mRNA processing steps take place in highly specialized microdomains referred to as cytoplasmic bodies. These evolutionarily conserved microdomains are sites of regulation for both mRNA translation and degradation. It has been shown that in the larch microsporocyte cytoplasm, there is a significant pool of Sm proteins not related to snRNP complexes. These Sm proteins accumulate within distinct cytoplasmic bodies (S-bodies) that also contain mRNA. Sm proteins constitute an evolutionarily ancient family of small RNA-binding proteins. In eukaryotic cells, these molecules are involved in pre-mRNA splicing. The latest research indicates that in addition to this well-known function, Sm proteins could also have an impact on mRNA at subsequent stages of its life cycle. The aim of this work was to verify the hypothesis that canonical Sm proteins are part of the cytoplasmic mRNP complex and thus function in the posttranscriptional regulation of gene expression in plants.

scholarly journals Pathogenic mechanisms of myotonic dystrophy

2009 ◽  
Vol 37 (6) ◽  
pp. 1281-1286 ◽  
Author(s):  
Johanna E. Lee ◽  
Thomas A. Cooper
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Genetic Disorder ◽  
Mrna Translation ◽  
Loss Of Function ◽  
Downstream Effects ◽  
Expanded Allele ◽  
Dystrophia Myotonica Protein Kinase ◽  
Dm Type 2

DM (myotonic dystrophy) is a dominantly inherited genetic disorder that is the most common cause of muscular dystrophy in adults affecting 1 in 8500 individuals worldwide. Different microsatellite expansions in two loci cause different forms of the disease that share similar features: DM1 (DM type 1) is caused by a tri- (CTG) nucleotide expansion within the DMPK (dystrophia myotonica protein kinase) 3′-untranslated region and DM2 (DM type 2) is caused by a tetra- (CCTG) nucleotide expansion within intron 1 of the ZNF9 (zinc finger 9) gene. The pathogenic mechanism of this disease involves the RNA transcribed from the expanded allele containing long tracts of (CUG)n or (CCUG)n. The RNA results in a toxic effect through two RNA-binding proteins: MBNL1 (muscleblind-like 1) and CUGBP1 (CUG-binding protein 1). In DM1, MBNL1 is sequestered on CUG repeat-containing RNA resulting in its loss-of-function, while CUGBP1 is up-regulated through a signalling pathway. The downstream effects include disrupted regulation of alternative splicing, mRNA translation and mRNA stability, which contribute to the multiple features of DM1. This review will focus on the RNA gain-of-function disease mechanism, the important roles of MBNL1 and CUGBP1 in DM1, and the relevance to other RNA dominant disorders.

scholarly journals The Bic-C Family of Developmental Translational Regulators

2012 ◽  
Vol 2012 ◽  
pp. 1-23 ◽  
Author(s):  
Chiara Gamberi ◽  
Paul Lasko
Keyword(s):  
Developmental Biology ◽  
Human Disease ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Protein Translation ◽  
Model Organisms ◽  
Founding Member ◽  
Evolutionarily Conserved ◽  
Translational Regulators

Regulation of mRNA translation is especially important during cellular and developmental processes. Many evolutionarily conserved proteins act in the context of multiprotein complexes and modulate protein translation both at the spatial and the temporal levels. Among these, Bicaudal C constitutes a family of RNA binding proteins whose founding member was first identified inDrosophilaand contains orthologs in vertebrates. We discuss recent advances towards understanding the functions of these proteins in the context of the cellular and developmental biology of many model organisms and their connection to human disease.

scholarly journals RNA-binding proteins La and HuR cooperatively modulate translation repression of PDCD4 mRNA

2020 ◽  
pp. jbc.RA120.014894
Author(s):  
Ravi Kumar ◽  
Dipak Kumar Poria ◽  
Partho Sarothi Ray
Keyword(s):  
Inflammatory Response ◽  
Chronic Inflammation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Critical Role ◽  
Regulation Of Gene Expression ◽  
Mrna Translation ◽  
Suppressor Gene ◽  
Cooperative Action ◽  
Translation Repression

Post-transcriptional regulation of gene expression plays a critical role in controlling the inflammatory response. An uncontrolled inflammatory response results in chronic inflammation, often leading to tumorigenesis. Programmed cell death 4 (PDCD4) is a pro-inflammatory tumor-suppressor gene which helps to prevent the transition from chronic inflammation to cancer. PDCD4 mRNA translation is regulated by an interplay between the oncogenic microRNA miR-21 and the RNA-binding protein (RBP) HuR in response to LPS stimulation, but the role of other regulatory factors remain unknown. Here we report that the RBP Lupus antigen (La) interacts with the 3’UTR of PDCD4 mRNA and prevents miR-21-mediated translation repression. While LPS causes nuclear-cytoplasmic translocation of HuR, it enhances cellular La expression. Remarkably, La and HuR were found to bind cooperatively to the PDCD4 mRNA and mitigate miR-21-mediated translation repression. The cooperative action of La and HuR reduced cell proliferation and enhanced apoptosis, reversing the pro-oncogenic function of miR-21. Together, these observations demonstrate a cooperative interplay between two RBPs, triggered differentially by the same stimulus, which exerts a synergistic effect on PDCD4 expression and thereby helps maintain a balance between inflammation and tumorigenesis.

scholarly journals Multiple roles of heterogeneous nuclear ribonucleoprotein K during skeletal muscle cell differentiation

2021 ◽  
Author(s):  
Keisuke Hitachi ◽  
Yuri Kiyofuji ◽  
Masashi Nakatani ◽  
Kunihiro Tsuchida
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Protein Complexes ◽  
Myogenic Differentiation ◽  
Cell Physiology ◽  
Transcriptional Level ◽  
Loss Of Function ◽  
Independent Manner ◽  
Multiple Functions

RNA-binding proteins (RBPs) regulate cell physiology via the formation of ribonucleic-protein complexes with coding and non-coding RNAs. RBPs have multiple functions in the same cells; however, the precise mechanism through which their pleiotropic functions are determined remains unknown. In this study, we revealed the multiple inhibitory functions of hnRNPK for myogenic differentiation. We first identified hnRNPK as a lncRNA Myoparr binding protein. Gain- and loss-of-function experiments showed that hnRNPK repressed the expression of myogenin at the transcriptional level via binding to Myoparr. Moreover, hnRNPK repressed the expression of a set of genes coding for aminoacyl-tRNA synthetases in a Myoparr-independent manner. Mechanistically, hnRNPK regulated the eIF2α/Atf4 pathway, one branch of the intrinsic pathways of the endoplasmic reticulum sensors, in differentiating myoblasts. Thus, our findings demonstrate that hnRNPK plays multiple lncRNA-dependent and -independent roles in the inhibition of myogenic differentiation, indicating that the analysis of lncRNA-binding proteins will be useful for elucidating both the physiological functions of lncRNAs and the multiple functions of RBPs.

scholarly journals Functional characterization of splicing regulatory elements

2021 ◽  
Author(s):  
Scott I Adamson ◽  
Lijun Zhan ◽  
Brenton R Graveley
Keyword(s):  
High Throughput ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Functional Characterization ◽  
Regulatory Elements ◽  
Small Subset ◽  
General Sequence ◽  
Splicing Regulators ◽  
Splicing Regulatory Elements

Background: RNA binding protein-RNA interactions mediate a variety of processes including pre-mRNA splicing, translation, decay, polyadenylation and many others. Previous high-throughput studies have characterized general sequence features associated with increased and decreased splicing of certain exons, but these studies are limited by not knowing the mechanisms, and in particular, the mediating RNA binding proteins, underlying these associations. Results: Here we utilize ENCODE data from diverse data modalities to identify functional splicing regulatory elements and their associated RNA binding proteins. We identify features which make splicing events more sensitive to depletion of RNA binding proteins, as well as which RNA binding proteins act as splicing regulators sensitive to depletion. To analyze the sequence determinants underlying RBP-RNA interactions impacting splicing, we assay tens of thousands of sequence variants in a high-throughput splicing reporter called Vex-seq and confirm a small subset in their endogenous loci using CRISPR base editors. Finally, we leverage other large transcriptomic datasets to confirm the importance of RNA binding proteins which we designed experiments around and identify additional RBPs which may act as additional splicing regulators of the exons studied. Conclusions: This study identifies sequence and other features underlying splicing regulation mediated specific RNA binding proteins, as well as validates and identifies other potentially important regulators of splicing in other large transcriptomic datasets.

scholarly journals Quantitative Proteomics Reveals the Defense Response of Wheat against Puccinia striiformis f. sp. tritici

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yuheng Yang ◽  
Yang Yu ◽  
Chaowei Bi ◽  
Zhensheng Kang
Keyword(s):  
Quantitative Proteomics ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Puccinia Striiformis ◽  
Post Inoculation ◽  
Control Groups ◽  
Stimulus Response ◽  
Wheat Gene ◽  
Related Proteins ◽  
And Control

Abstract Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is considered one of the most aggressive diseases to wheat production. In this study, we used an iTRAQ-based approach for the quantitative proteomic comparison of the incompatible Pst race CYR23 in infected and non-infected leaves of the wheat cultivar Suwon11. A total of 3,475 unique proteins were identified from three key stages of interaction (12, 24, and 48 h post-inoculation) and control groups. Quantitative analysis showed that 530 proteins were differentially accumulated by Pst infection (fold changes >1.5, p < 0.05). Among these proteins, 10.54% was classified as involved in the immune system process and stimulus response. Intriguingly, bioinformatics analysis revealed that a set of reactive oxygen species metabolism-related proteins, peptidyl–prolyl cis–trans isomerases (PPIases), RNA-binding proteins (RBPs), and chaperonins was involved in the response to Pst infection. Our results were the first to show that PPIases, RBPs, and chaperonins participated in the regulation of the immune response in wheat and even in plants. This study aimed to provide novel routes to reveal wheat gene functionality and better understand the early events in wheat–Pst incompatible interactions.

scholarly journals G3BP1-linked mRNA partitioning supports selective protein synthesis in response to oxidative stress

2020 ◽  
Vol 48 (12) ◽  
pp. 6855-6873 ◽  
Author(s):  
Syam Prakash Somasekharan ◽  
Fan Zhang ◽  
Neetu Saxena ◽  
Jia Ni Huang ◽  
I-Chih Kuo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Stress Adaptation ◽  
Rna Granules ◽  
Before And After ◽  
Selective Translation ◽  
Energy Consuming ◽  
Limit Energy

Abstract Cells limit energy-consuming mRNA translation during stress to maintain metabolic homeostasis. Sequestration of mRNAs by RNA binding proteins (RBPs) into RNA granules reduces their translation, but it remains unclear whether RBPs also function in partitioning of specific transcripts to polysomes (PSs) to guide selective translation and stress adaptation in cancer. To study transcript partitioning under cell stress, we catalogued mRNAs enriched in prostate carcinoma PC-3 cell PSs, as defined by polysome fractionation and RNA sequencing (RNAseq), and compared them to mRNAs complexed with the known SG-nucleator protein, G3BP1, as defined by spatially-restricted enzymatic tagging and RNAseq. By comparing these compartments before and after short-term arsenite-induced oxidative stress, we identified three major categories of transcripts, namely those that were G3BP1-associated and PS-depleted, G3BP1-dissociated and PS-enriched, and G3BP1-associated but also PS-enriched. Oxidative stress profoundly altered the partitioning of transcripts between these compartments. Under arsenite stress, G3BP1-associated and PS-depleted transcripts correlated with reduced expression of encoded mitochondrial proteins, PS-enriched transcripts that disassociated from G3BP1 encoded cell cycle and cytoprotective proteins whose expression increased, while transcripts that were both G3BP1-associated and PS-enriched encoded proteins involved in diverse stress response pathways. Therefore, G3BP1 guides transcript partitioning to reprogram mRNA translation and support stress adaptation.

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