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Maldonado RJK, Parent LJ. Dynamic interactions of retroviral Gag condensates with nascent viral RNA at transcriptional burst sites: implications for genomic RNA packaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.11.632546. [PMID: 39829876 PMCID: PMC11741468 DOI: 10.1101/2025.01.11.632546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/22/2025]
Abstract
Retroviruses are responsible for significant pathology in humans and animals, including the acquired immunodeficiency syndrome and a wide range of malignancies. A crucial yet poorly understood step in the replication cycle is the recognition and selection of unspliced viral RNA (USvRNA) by the retroviral Gag protein, which binds to the psi (Ψ) packaging sequence in the 5' leader, to package it as genomic RNA (gRNA) into nascent virions. It was previously thought that Gag initially bound gRNA in the cytoplasm. However, previous studies demonstrated that the Rous sarcoma virus (RSV) Gag protein traffics transiently through the nucleus, which is necessary for efficient gRNA packaging. These data formed a strong premise for the hypothesis that Gag selects nascent gRNA at transcription sites in the nucleus, the location of the highest concentration of USvRNA molecules in the cell. In support of this model, previous studies using fixed cells infected with RSV revealed that Gag co-localizes with large USvRNA nuclear foci representing viral transcriptional burst sites. To test this idea, we used single molecule labeling and imaging techniques to visualize fluorescently-tagged, actively transcribing viral genomes, and Gag proteins in living cells. Gag condensates were observed in the nucleus, transiently co-localized with USvRNA at transcriptional burst sites, forming co-localized viral ribonucleoprotein complexes (vRNPs). These results support a novel paradigm for retroviral assembly in which Gag traffics to transcriptional burst sites and interacts through a dynamic kissing interaction to capture nascent gRNA for incorporation into virions.
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Affiliation(s)
- Rebecca J. Kaddis Maldonado
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033
- Department of Microbiology & Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033
| | - Leslie J. Parent
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033
- Department of Microbiology & Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033
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2
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Asim MN, Ibrahim MA, Malik MI, Zehe C, Cloarec O, Trygg J, Dengel A, Ahmed S. EL-RMLocNet: An explainable LSTM network for RNA-associated multi-compartment localization prediction. Comput Struct Biotechnol J 2022; 20:3986-4002. [PMID: 35983235 PMCID: PMC9356161 DOI: 10.1016/j.csbj.2022.07.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 07/16/2022] [Accepted: 07/16/2022] [Indexed: 11/23/2022] Open
Abstract
Subcellular localization of Ribonucleic Acid (RNA) molecules provide significant insights into the functionality of RNAs and helps to explore their association with various diseases. Predominantly developed single-compartment localization predictors (SCLPs) lack to demystify RNA association with diverse biochemical and pathological processes mainly happen through RNA co-localization in multiple compartments. Limited multi-compartment localization predictors (MCLPs) manage to produce decent performance only for target RNA class of particular sub-type. Further, existing computational approaches have limited practical significance and potential to optimize therapeutics due to the poor degree of model explainability. The paper in hand presents an explainable Long Short-Term Memory (LSTM) network "EL-RMLocNet", predictive performance and interpretability of which are optimized using a novel GeneticSeq2Vec statistical representation learning scheme and attention mechanism for accurate multi-compartment localization prediction of different RNAs solely using raw RNA sequences. GeneticSeq2Vec generates optimized statistical vectors of raw RNA sequences by capturing short and long range relations of nucleotide k-mers. Using sequence vectors generated by GeneticSeq2Vec scheme, Long Short Term Memory layers extract most informative features, weighting of which on the basis of discriminative potential for accurate multi-compartment localization prediction is performed using attention layer. Through reverse engineering, weights of statistical feature space are mapped to nucleotide k-mers patterns to make multi-compartment localization prediction decision making transparent and explainable for different RNA classes and species. Empirical evaluation indicates that EL-RMLocNet outperforms state-of-the-art predictor for subcellular localization prediction of 4 different RNA classes by an average accuracy figure of 8% for Homo Sapiens species and 6% for Mus Musculus species. EL-RMLocNet is freely available as a web server at (https://sds_genetic_analysis.opendfki.de/subcellular_loc/).
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Affiliation(s)
- Muhammad Nabeel Asim
- Department of Computer Science, Technical University of Kaiserslautern, Kaiserslautern 67663, Germany
- German Research Center for Artificial Intelligence GmbH, Kaiserslautern 67663, Germany
| | - Muhammad Ali Ibrahim
- Department of Computer Science, Technical University of Kaiserslautern, Kaiserslautern 67663, Germany
- German Research Center for Artificial Intelligence GmbH, Kaiserslautern 67663, Germany
| | - Muhammad Imran Malik
- School of Computer Science & Electrical Engineering, National University of Sciences and Technology, 44000, Islamabad, Pakistan
| | - Christoph Zehe
- Sartorius Corporate Research, Sartorius Stedim Cellca GmbH, 89081 Ulm, Germany
| | - Olivier Cloarec
- Sartorius Corporate Research, Sartorius Stedim Cellca GmbH, 89081 Ulm, Germany
| | - Johan Trygg
- Computational Life Science Cluster (CLiC), Umeå University, 90187 Umea, Sweden
- Sartorius Corporate Research, Sartorius Stedim Data Analytics, 90333 Umea, Sweden
| | - Andreas Dengel
- Department of Computer Science, Technical University of Kaiserslautern, Kaiserslautern 67663, Germany
- German Research Center for Artificial Intelligence GmbH, Kaiserslautern 67663, Germany
| | - Sheraz Ahmed
- German Research Center for Artificial Intelligence GmbH, Kaiserslautern 67663, Germany
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3
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Savulescu AF, Bouilhol E, Beaume N, Nikolski M. Prediction of RNA subcellular localization: Learning from heterogeneous data sources. iScience 2021; 24:103298. [PMID: 34765919 PMCID: PMC8571491 DOI: 10.1016/j.isci.2021.103298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
RNA subcellular localization has recently emerged as a widespread phenomenon, which may apply to the majority of RNAs. The two main sources of data for characterization of RNA localization are sequence features and microscopy images, such as obtained from single-molecule fluorescent in situ hybridization-based techniques. Although such imaging data are ideal for characterization of RNA distribution, these techniques remain costly, time-consuming, and technically challenging. Given these limitations, imaging data exist only for a limited number of RNAs. We argue that the field of RNA localization would greatly benefit from complementary techniques able to characterize location of RNA. Here we discuss the importance of RNA localization and the current methodology in the field, followed by an introduction on prediction of location of molecules. We then suggest a machine learning approach based on the integration between imaging localization data and sequence-based data to assist in characterization of RNA localization on a transcriptome level.
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Affiliation(s)
- Anca Flavia Savulescu
- Division of Chemical, Systems & Synthetic Biology, Institute for Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, 7925 Cape Town, South Africa
| | - Emmanuel Bouilhol
- Université de Bordeaux, Bordeaux Bioinformatics Center, Bordeaux, France
- Université de Bordeaux, CNRS, IBGC, UMR 5095, Bordeaux, France
| | - Nicolas Beaume
- Division of Medical Virology, Faculty of Health Sciences, University of Cape Town,7925 Cape Town, South Africa
| | - Macha Nikolski
- Université de Bordeaux, Bordeaux Bioinformatics Center, Bordeaux, France
- Université de Bordeaux, CNRS, IBGC, UMR 5095, Bordeaux, France
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4
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Abstract
It is increasingly recognized that local protein synthesis (LPS) contributes to fundamental aspects of axon biology, in both developing and mature neurons. Mutations in RNA-binding proteins (RBPs), as central players in LPS, and other proteins affecting RNA localization and translation are associated with a range of neurological disorders, suggesting disruption of LPS may be of pathological significance. In this review, we substantiate this hypothesis by examining the link between LPS and key axonal processes, and the implicated pathophysiological consequences of dysregulated LPS. First, we describe how the length and autonomy of axons result in an exceptional reliance on LPS. We next discuss the roles of LPS in maintaining axonal structural and functional polarity and axonal trafficking. We then consider how LPS facilitates the establishment of neuronal connectivity through regulation of axonal branching and pruning, how it mediates axonal survival into adulthood and its involvement in neuronal stress responses.
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Affiliation(s)
- Julie Qiaojin Lin
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Island Research Building, Cambridge Biomedical Campus, Cambridge, UK
| | | | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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5
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Chaudhuri A, Das S, Das B. Localization elements and zip codes in the intracellular transport and localization of messenger RNAs in Saccharomyces cerevisiae. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1591. [PMID: 32101377 DOI: 10.1002/wrna.1591] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022]
Abstract
Intracellular trafficking and localization of mRNAs provide a mechanism of regulation of expression of genes with excellent spatial control. mRNA localization followed by localized translation appears to be a mechanism of targeted protein sorting to a specific cell-compartment, which is linked to the establishment of cell polarity, cell asymmetry, embryonic axis determination, and neuronal plasticity in metazoans. However, the complexity of the mechanism and the components of mRNA localization in higher organisms prompted the use of the unicellular organism Saccharomyces cerevisiae as a simplified model organism to study this vital process. Current knowledge indicates that a variety of mRNAs are asymmetrically and selectively localized to the tip of the bud of the daughter cells, to the vicinity of endoplasmic reticulum, mitochondria, and nucleus in this organism, which are connected to diverse cellular processes. Interestingly, specific cis-acting RNA localization elements (LEs) or RNA zip codes play a crucial role in the localization and trafficking of these localized mRNAs by providing critical binding sites for the specific RNA-binding proteins (RBPs). In this review, we present a comprehensive account of mRNA localization in S. cerevisiae, various types of localization elements influencing the mRNA localization, and the RBPs, which bind to these LEs to implement a number of vital physiological processes. Finally, we emphasize the significance of this process by highlighting their connection to several neuropathological disorders and cancers. This article is categorized under: RNA Export and Localization > RNA Localization.
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Affiliation(s)
- Anusha Chaudhuri
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Subhadeep Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
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6
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Nedorezova DD, Fakhardo AF, Molden TA, Kolpashchikov DM. Deoxyribozyme‐Based DNA Machines for Cancer Therapy. Chembiochem 2019; 21:607-611. [DOI: 10.1002/cbic.201900525] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Daria D. Nedorezova
- Laboratory of Solution Chemistry of Advanced Materials and TechnologiesITMO University 9 Lomonosova Str. St. Petersburg 191002 Russian Federation
| | - Anna F. Fakhardo
- Laboratory of Solution Chemistry of Advanced Materials and TechnologiesITMO University 9 Lomonosova Str. St. Petersburg 191002 Russian Federation
| | - Tatiana A. Molden
- Chemistry DepartmentUniversity of Central Florida Orlando FL 32816-2366 USA
| | - Dmitry M. Kolpashchikov
- Chemistry DepartmentUniversity of Central Florida Orlando FL 32816-2366 USA
- Burnett School of Biomedical SciencesUniversity of Central Florida Orlando FL 32816 USA
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7
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Cohen-Zontag O, Baez C, Lim LQJ, Olender T, Schirman D, Dahary D, Pilpel Y, Gerst JE. A secretion-enhancing cis regulatory targeting element (SECReTE) involved in mRNA localization and protein synthesis. PLoS Genet 2019; 15:e1008248. [PMID: 31260446 PMCID: PMC6625729 DOI: 10.1371/journal.pgen.1008248] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/12/2019] [Accepted: 06/13/2019] [Indexed: 12/19/2022] Open
Abstract
The localization of mRNAs encoding secreted/membrane proteins (mSMPs) to the endoplasmic reticulum (ER) likely facilitates the co-translational translocation of secreted proteins. However, studies have shown that mSMP recruitment to the ER in eukaryotes can occur in a manner that is independent of the ribosome, translational control, and the signal recognition particle, although the mechanism remains largely unknown. Here, we identify a cis-acting RNA sequence motif that enhances mSMP localization to the ER and appears to increase mRNA stability, and both the synthesis and secretion of secretome proteins. Termed SECReTE, for secretion-enhancing cis regulatory targeting element, this motif is enriched in mRNAs encoding secretome proteins translated on the ER in eukaryotes and on the inner membrane of prokaryotes. SECReTE consists of ≥10 nucleotide triplet repeats enriched with pyrimidine (C/U) every third base (i.e. NNY, where N = any nucleotide, Y = pyrimidine) and can be present in the untranslated as well as the coding regions of the mRNA. Synonymous mutations that elevate the SECReTE count in a given mRNA (e.g. SUC2, HSP150, and CCW12) lead to an increase in protein secretion in yeast, while a reduction in count led to less secretion and physiological defects. Moreover, the addition of SECReTE to the 3'UTR of an mRNA for an exogenously expressed protein (e.g. GFP) led to its increased secretion from yeast cells. Thus, SECReTE constitutes a novel RNA motif that facilitates ER-localized mRNA translation and protein secretion.
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Affiliation(s)
- Osnat Cohen-Zontag
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Camila Baez
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Lisha Qiu Jin Lim
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Dvir Schirman
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Dvir Dahary
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Yitzhak Pilpel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Jeffrey E. Gerst
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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8
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Eagle WVI, Yeboah-Kordieh DK, Niepielko MG, Gavis ER. Distinct cis-acting elements mediate targeting and clustering of Drosophila polar granule mRNAs. Development 2018; 145:dev.164657. [PMID: 30333216 DOI: 10.1242/dev.164657] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 09/18/2018] [Indexed: 12/11/2022]
Abstract
Specification and development of Drosophila germ cells depend on molecular determinants within the germ plasm, a specialized cytoplasmic domain at the posterior of the embryo. Localization of numerous mRNAs to the germ plasm occurs by their incorporation, as single-transcript ribonucleoprotein (RNP) particles, into complex RNP granules called polar granules. Incorporation of mRNAs into polar granules is followed by recruitment of additional like transcripts to form discrete homotypic clusters. The cis-acting localization signals that target mRNAs to polar granules and promote homotypic clustering remain largely uncharacterized. Here, we show that the polar granule component (pgc) and germ cell-less (gcl) 3' untranslated regions contain complex localization signals comprising multiple, independently weak and partially functionally redundant localization elements (LEs). We demonstrate that targeting of pgc to polar granules and self-assembly into homotypic clusters are functionally separable processes mediated by distinct classes of LEs. We identify a sequence motif shared by other polar granule mRNAs that contributes to homotypic clustering. Our results suggest that mRNA localization signal complexity may be a feature required by the targeting and self-recruitment mechanism that drives germ plasm mRNA localization.
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Affiliation(s)
- Whitby V I Eagle
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | | - Matthew G Niepielko
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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9
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Abstract
A majority of messenger RNA precursors (pre-mRNAs) in the higher eukaryotes undergo alternative splicing to generate more than one mature product. By targeting the open reading frame region this process increases diversity of protein isoforms beyond the nominal coding capacity of the genome. However, alternative splicing also frequently controls output levels and spatiotemporal features of cellular and organismal gene expression programs. Here we discuss how these non-coding functions of alternative splicing contribute to development through regulation of mRNA stability, translational efficiency and cellular localization.
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10
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In the right place at the right time: visualizing and understanding mRNA localization. Nat Rev Mol Cell Biol 2014; 16:95-109. [PMID: 25549890 DOI: 10.1038/nrm3918] [Citation(s) in RCA: 413] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The spatial regulation of protein translation is an efficient way to create functional and structural asymmetries in cells. Recent research has furthered our understanding of how individual cells spatially organize protein synthesis, by applying innovative technology to characterize the relationship between mRNAs and their regulatory proteins, single-mRNA trafficking dynamics, physiological effects of abrogating mRNA localization in vivo and for endogenous mRNA labelling. The implementation of new imaging technologies has yielded valuable information on mRNA localization, for example, by observing single molecules in tissues. The emerging movements and localization patterns of mRNAs in morphologically distinct unicellular organisms and in neurons have illuminated shared and specialized mechanisms of mRNA localization, and this information is complemented by transgenic and biochemical techniques that reveal the biological consequences of mRNA mislocalization.
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11
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Lui J, Castelli LM, Pizzinga M, Simpson CE, Hoyle NP, Bailey KL, Campbell SG, Ashe MP. Granules harboring translationally active mRNAs provide a platform for P-body formation following stress. Cell Rep 2014; 9:944-54. [PMID: 25437551 PMCID: PMC4536303 DOI: 10.1016/j.celrep.2014.09.040] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 08/16/2014] [Accepted: 09/22/2014] [Indexed: 12/13/2022] Open
Abstract
The localization of mRNA to defined cytoplasmic sites in eukaryotic cells not only allows localized protein production but also determines the fate of mRNAs. For instance, translationally repressed mRNAs localize to P-bodies and stress granules where their decay and storage, respectively, are directed. Here, we find that several mRNAs are localized to granules in unstressed, actively growing cells. These granules play a key role in the stress-dependent formation of P-bodies. Specific glycolytic mRNAs are colocalized in multiple granules per cell, which aggregate during P-body formation. Such aggregation is still observed under conditions or in mutants where P-bodies do not form. In unstressed cells, the mRNA granules appear associated with active translation; this might enable a coregulation of protein expression from the same pathways or complexes. Parallels can be drawn between this coregulation and the advantage of operons in prokaryotic systems.
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Affiliation(s)
- Jennifer Lui
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Lydia M Castelli
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Mariavittoria Pizzinga
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Clare E Simpson
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Nathaniel P Hoyle
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Kathryn L Bailey
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Susan G Campbell
- Biosciences Department, Faculty of Health and Wellbeing, Sheffield Hallam University, Howards Street, Sheffield S1 1WB, UK
| | - Mark P Ashe
- Faculty of Life Sciences, Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK.
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12
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Caballero-Lima D, Hautbergue GM, Wilson SA, Sudbery PE. In Candida albicans hyphae, Sec2p is physically associated with SEC2 mRNA on secretory vesicles. Mol Microbiol 2014; 94:828-42. [PMID: 25231350 PMCID: PMC4278529 DOI: 10.1111/mmi.12799] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2014] [Indexed: 01/05/2023]
Abstract
Candida albicans hyphae grow in a highly polarized fashion from their tips. This polarized growth requires the continuous delivery of secretory vesicles to the tip region. Vesicle delivery depends on Sec2p, the Guanine Exchange Factor (GEF) for the Rab GTPase Sec4p. GTP bound Sec4p is required for the transit of secretory vesicles from the trans-Golgi to sites of polarized growth. We previously showed that phosphorylation of Sec2p at residue S584 was necessary for Sec2p to support hyphal, but not yeast growth. Here we show that on secretory vesicles SEC2 mRNA is physically associated with Sec2p. Moreover, we show that the phosphorylation of S584 allows SEC2 mRNA to dissociate from Sec2p and we speculate that this is necessary for Sec2p function and/or translation. During hyphal extension, the growing tip may be separated from the nucleus by up to 15 μm. Transport of SEC2 mRNA on secretory vesicles to the tip localizes SEC2 translation to tip allowing a sufficient accumulation of this key protein at the site of polarized growth.
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Affiliation(s)
- David Caballero-Lima
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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13
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Shahbabian K, Jeronimo C, Forget A, Robert F, Chartrand P. Co-transcriptional recruitment of Puf6 by She2 couples translational repression to mRNA localization. Nucleic Acids Res 2014; 42:8692-704. [PMID: 25013181 PMCID: PMC4117797 DOI: 10.1093/nar/gku597] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Messenger RNA (mRNA) localization is coupled to the translational repression of transcripts during their transport. It is still unknown if this coupling depends on physical interactions between translational control and mRNA localization machineries, and how these interactions are established at the molecular level. In yeast, localization of transcripts like ASH1 to the bud depends on the RNA-binding protein She2. During its transport, ASH1 mRNA translation is repressed by Puf6. Herein, we report that She2 recruits Puf6 on ASH1 co-transcriptionally. The recruitment of Puf6 depends on prior co-transcriptional loading of Loc1, an exclusively nuclear protein. These proteins form a ternary complex, in which Loc1 bridges Puf6 to She2, that binds the ASH1 3′UTR. Using a genome-wide ChIP-chip approach, we identified over 40 novel targets of Puf6, including several bud-localized mRNAs. Interestingly, the co-transcriptional recruitment of Puf6 on genes coding for these bud-localized mRNAs is also She2- and Loc1-dependent. Our results suggest a coordinated assembly of localization and translational control machineries on localized mRNAs during transcription, and underline the importance of co-transcriptional events in establishing the cytoplasmic fate of mRNAs.
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Affiliation(s)
- Karen Shahbabian
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3C 3J7, Canada
| | - Célia Jeronimo
- Département de Médecine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3C 3J7, Canada
| | - Amélie Forget
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3C 3J7, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, Canada Département de Médecine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3C 3J7, Canada
| | - Pascal Chartrand
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3C 3J7, Canada
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14
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Polyansky AA, Hlevnjak M, Zagrovic B. Analogue encoding of physicochemical properties of proteins in their cognate messenger RNAs. Nat Commun 2014; 4:2784. [PMID: 24253588 PMCID: PMC3868254 DOI: 10.1038/ncomms3784] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 10/16/2013] [Indexed: 12/21/2022] Open
Abstract
Being related by the genetic code, mRNAs and their cognate proteins exhibit mutually interdependent compositions, which implies the possibility of a direct connection between their general physicochemical properties. Here we probe the general potential of the cell to encode information about proteins in the average characteristics of their cognate mRNAs and decode it in a ribosome-independent manner. We show that average protein hydrophobicity, calculated from either sequences or 3D structures, can be encoded in an analogue fashion by many different average mRNA sequence properties with the only constraint being that pyrimidine and purine bases be clearly distinguishable on average. Moreover, average characteristics of mRNA sequences enable discrimination between cytosolic and membrane proteins even in the absence of topogenic signal-based mechanisms. Our results suggest that protein and mRNA localization may be partly determined by basic physicochemical rationales and interdependencies between the two biomolecules. mRNA transport contributes to the proper localization of its cognate proteins. Here the authors report a correlation between the physicochemical properties of mRNAs and their cognate proteins, suggesting that these properties of mRNAs can predict the subcellular localization of their cognate proteins.
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Affiliation(s)
- Anton A Polyansky
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
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15
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Thomas MG, Pascual ML, Maschi D, Luchelli L, Boccaccio GL. Synaptic control of local translation: the plot thickens with new characters. Cell Mol Life Sci 2014; 71:2219-39. [PMID: 24212248 PMCID: PMC11113725 DOI: 10.1007/s00018-013-1506-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 10/11/2013] [Accepted: 10/21/2013] [Indexed: 12/18/2022]
Abstract
The production of proteins from mRNAs localized at the synapse ultimately controls the strength of synaptic transmission, thereby affecting behavior and cognitive functions. The regulated transcription, processing, and transport of mRNAs provide dynamic control of the dendritic transcriptome, which includes thousands of messengers encoding multiple cellular functions. Translation is locally modulated by synaptic activity through a complex network of RNA-binding proteins (RBPs) and various types of non-coding RNAs (ncRNAs) including BC-RNAs, microRNAs, piwi-interacting RNAs, and small interference RNAs. The RBPs FMRP and CPEB play a well-established role in synaptic translation, and additional regulatory factors are emerging. The mRNA repressors Smaug, Nanos, and Pumilio define a novel pathway for local translational control that affects dendritic branching and spines in both flies and mammals. Recent findings support a role for processing bodies and related synaptic mRNA-silencing foci (SyAS-foci) in the modulation of synaptic plasticity and memory formation. The SyAS-foci respond to different stimuli with changes in their integrity thus enabling regulated mRNA release followed by translation. CPEB, Pumilio, TDP-43, and FUS/TLS form multimers through low-complexity regions related to prion domains or polyQ expansions. The oligomerization of these repressor RBPs is mechanistically linked to the aggregation of abnormal proteins commonly associated with neurodegeneration. Here, we summarize the current knowledge on how specificity in mRNA translation is achieved through the concerted action of multiple pathways that involve regulatory ncRNAs and RBPs, the modification of translation factors, and mRNA-silencing foci dynamics.
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Affiliation(s)
- María Gabriela Thomas
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
| | - Malena Lucía Pascual
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Buenos Aires, Argentina
| | - Darío Maschi
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- Present Address: Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO USA
| | - Luciana Luchelli
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
| | - Graciela Lidia Boccaccio
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Buenos Aires, Argentina
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16
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Müller C, Bauer NM, Schäfer I, White R. Making myelin basic protein -from mRNA transport to localized translation. Front Cell Neurosci 2013; 7:169. [PMID: 24098271 PMCID: PMC3784684 DOI: 10.3389/fncel.2013.00169] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/10/2013] [Indexed: 01/19/2023] Open
Abstract
In the central nervous system (CNS) of most vertebrates, oligodendrocytes enwrap neuronal axons with extensions of their plasma membrane to form the myelin sheath. Several proteins are characteristically found in myelin of which myelin basic protein (MBP) is the second most abundant one after proteolipid protein. The lack of functional MBP in rodents results in a severe hypomyelinated phenotype in the CNS demonstrating its importance for myelin synthesis. Mbp mRNA is transported from the nucleus to the plasma membrane and is translated locally at the axon-glial contact site. Axonal properties such as diameter or electrical activity influence the degree of myelination. As oligodendrocytes can myelinate many axonal segments with varying properties, localized MBP translation represents an important part of a rapid and axon-tailored synthesis machinery. MBP's ability to compact cellular membranes may be problematic for the integrity of intracellular membranous organelles and can also explain why MBP is transported in oligodendrocytes in the form of an mRNA rather than as a protein. Here we review the recent findings regarding intracellular transport and signaling mechanisms leading to localized translation of Mbp mRNA in oligodendrocytes. More detailed insights into the MBP synthesis pathway are important for a better understanding of the myelination process and may foster the development of remyelination therapies for demyelinating diseases.
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Affiliation(s)
- Christina Müller
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Germany
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17
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Abstract
mRNA has become an important alternative to DNA as a tool for cell reprogramming. To be expressed, exogenous DNA must be transmitted through the cell cytoplasm and placed into the nucleus. In contrast, exogenous mRNA simply has to be delivered into the cytoplasm. This can result in a highly uniform transfection of the whole population of cells, an advantage that has not been observed with DNA transfer. The use of mRNA, instead of DNA, in medical applications increases protocol safety by abolishing the risk of transgene insertion into host genomes. In this chapter, we review the aspects of mRNA structure and function that are important for its "transgenic" behavior, such as the composition of mRNA molecules and complexes with RNA binding proteins, localization of mRNA in cytoplasmic compartments, translation, and the duration of mRNA expression. In immunotherapy, mRNA is employed in reprogramming of antigen presenting cells (vaccination) and cytolytic lymphocytes. Other applications include generation of induced pluripotent stem (iPS) cells, and genome engineering with modularly assembled nucleases. The most investigated applications of mRNA technology are also reviewed here.
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18
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Nevalainen M, Kaakinen M, Metsikkö K. Distribution of mRNA transcripts and translation activity in skeletal myofibers. Cell Tissue Res 2013; 353:539-48. [PMID: 23736382 DOI: 10.1007/s00441-013-1659-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/06/2013] [Indexed: 01/26/2023]
Abstract
We examine the distribution of gene products in skeletal myofibers, which are highly differentiated multinucleated cells exhibiting a specific cellular architecture. In situ hybridization studies of adult rat myofibers with a single nucleus infected with influenza virus suggested that the viral mRNA products were distributed beneath the sarcolemma around the nucleus of origin. In situ hybridization studies with a poly-T oligonucleotide probe to detect endogenous mRNAs indicated their concentration around the nuclei and distribution beneath the sarcolemma in a cross-striated fashion at the A-I junctions (costamers). Labeling with bromouridine resulted in a similar distribution pattern. The ribosomal distribution pattern indicated concentration around the myonuclei but an intracellular component was also seen. Localization of the translating ribosomes by puromycylation revealed prominent spots perinuclearly and in the core regions of the myofibers. These spots flanked Golgi elements. Our results thus suggest that the total mRNA pool is heavily concentrated within the perinuclear and subsarcolemmal regions. However, the ribosomes and the translational activity did not follow this distribution pattern, so the mRNA transcripts were not restricted to a region beneath the sarcolemma. Furthermore, experiments utilizing green fluorescent protein showed the rapid movement of proteins within the endomembrane system, which thus facilitated proteins to reach their site of function irrespective of the site of synthesis.
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Affiliation(s)
- Mika Nevalainen
- Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, P.O. Box 5000, Aapistie 7, FI-90014, Oulu, Finland.
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19
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Abstract
mRNA localization is a crucial mechanism for post-transcriptional control of gene expression used in numerous cellular contexts to generate asymmetric enrichment of an encoded protein. This process has emerged as a fundamental regulatory mechanism that operates in a wide range of organisms to control an array of cellular processes. Recently, significant advances have been made in our understanding of the mechanisms that regulate several steps in the mRNA localization pathway. Here we discuss the progress made in understanding localization element recognition, paying particular attention to the role of RNA structure. We also consider the function of mRNP granules in mRNA transport, as well as new results pointing to roles for the endocytic pathway in mRNA localization.
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Affiliation(s)
- Catherine A Pratt
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI, USA
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20
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Imbrie GA, Wu H, Seldin DC, Dominguez I. Asymmetric Localization of CK2α During Xenopus Oogenesis. ACTA ACUST UNITED AC 2012; Suppl 4:11328. [PMID: 25346867 PMCID: PMC4207361 DOI: 10.4172/2161-0436.s4-001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The establishment of the dorso-ventral axis is a fundamental process that occurs after fertilization. Dorsal axis specification in frogs starts immediately after fertilization, and depends upon activation of Wnt/β-catenin signaling. The protein kinase CK2α can modulate Wnt/β-catenin signaling and is necessary for dorsal axis specification in Xenopus laevis. Our previous experiments show that CK2α transcripts and protein are animally localized in embryos, overlapping the region where Wnt/β-catenin signaling is activated. Here we determined whether the animal localization of CK2α in the embryo is preceded by its localization in the oocyte. We found that CK2α transcripts were detected from stage I, their levels increased during oogenesis, and were animally localized as early as stage III. CK2α transcripts were translated during oogenesis and CK2α protein was localized to the animal hemisphere of stage VI oocytes. We cloned the CK2α 3’UTR and showed that the 2.8 kb CK2α transcript containing the 3’UTR was enriched during oogenesis. By injecting ectopic mRNAs, we demonstrated that both the coding and 3’UTR regions were necessary for proper CK2α transcript localization. This is the first report showing the involvement of coding and 3’UTR regions in animal transcript localization. Our findings demonstrate the pre-localization of CK2α transcript and thus, CK2α protein, in the oocyte. This may help restrict CK2α expression in preparation for dorsal axis specification.
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Affiliation(s)
- Gregory A Imbrie
- Hematology-Oncology Section, Department of Medicine, Boston University Medical School, 650 Albany Street, Boston, MA, USA
| | - Hao Wu
- Hematology-Oncology Section, Department of Medicine, Boston University Medical School, 650 Albany Street, Boston, MA, USA
| | - David C Seldin
- Hematology-Oncology Section, Department of Medicine, Boston University Medical School, 650 Albany Street, Boston, MA, USA
| | - Isabel Dominguez
- Hematology-Oncology Section, Department of Medicine, Boston University Medical School, 650 Albany Street, Boston, MA, USA
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Peña EJ, Heinlein M. RNA transport during TMV cell-to-cell movement. FRONTIERS IN PLANT SCIENCE 2012; 3:193. [PMID: 22973280 PMCID: PMC3428586 DOI: 10.3389/fpls.2012.00193] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/06/2012] [Indexed: 05/08/2023]
Abstract
Studies during the last 25 years have provided increasing evidence for the ability of plants to support the cell-to-cell and systemic transport of RNA molecules and that this process plays a role in plant development and in the systemic orchestration of cellular responses against pathogens and other environmental challenges. Since RNA viruses exploit the cellular RNA transport machineries for spreading their genomes between cells they represent convenient models to investigate the underlying mechanisms. In this regard, the intercellular spread of Tobacco mosaic virus (TMV) has been studied for many years. The RNA of TMV moves cell-to-cell in a non-encapsidated form in a process depending on virus-encoded movement protein (MP). Here, we discuss the current state of the art in studies using TMV and its MP as a model for RNA transport. While the ability of plants to transport viral and cellular RNA molecules is consistent with RNA transport phenomena in other systems, further studies are needed to increase our ability to visualize viral RNA (vRNA) in vivo and to distinguish RNA-transport related processes from those involved in antiviral defense.
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Affiliation(s)
- Eduardo J. Peña
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de StrasbourgStrasbourg, France
| | - Manfred Heinlein
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de StrasbourgStrasbourg, France
- Department of Plant Physiology, University of BaselBasel, Switzerland
- *Correspondence: Manfred Heinlein, Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, UPR 2357, Université de Strasbourg, 12, Rue du Général Zimmer, 67084 Strasbourg cedex, France. e-mail:
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