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Farajzadeh N, Shahbabian K, Bouaziz Y, Querido E, Chartrand P. Phosphorylation controls the oligomeric state of She2 and mRNA localization in yeast. RNA (NEW YORK, N.Y.) 2023; 29:745-755. [PMID: 36921931 PMCID: PMC10187671 DOI: 10.1261/rna.079555.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/24/2023] [Indexed: 05/18/2023]
Abstract
Messenger RNA (mRNA) localization is an important mechanism controlling local protein synthesis. In budding yeast, asymmetric localization of transcripts such as ASH1 mRNA to the bud tip depends on the She2 RNA-binding protein. She2 assembles as a tetramer to bind RNA, but the regulation of this process as part of the mRNA locasome is still unclear. Here, we performed a phosphoproteomic analysis of She2 in vivo and identified new phosphosites, several of which are located at the dimerization or tetramerization interfaces of She2. Remarkably, phosphomimetic mutations at these residues disrupt the capacity of She2 to promote Ash1 asymmetric accumulation. A detailed analysis of one of these residues, T109, shows that a T109D mutation inhibits She2 oligomerization and its interaction with She3 and the importin-α Srp1. She2 proteins harboring the T109D mutation also display reduced expression. More importantly, this phosphomimetic mutation strongly impairs the capacity of She2 to bind RNA and disrupts ASH1 mRNA localization. These results demonstrate that the control of She2 oligomerization by phosphorylation constitutes an important regulatory step in the mRNA localization pathway.
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Affiliation(s)
- Nastaran Farajzadeh
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - Karen Shahbabian
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - Yani Bouaziz
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - Emmanuelle Querido
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - Pascal Chartrand
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
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2
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Yueh LY, Tseng YT, Chu CY, Lo KY. The dedicated chaperones of eL43, Puf6 and Loc1, can also bind RPL43 mRNA and regulate the production of this ribosomal protein. J Biochem 2021; 171:85-96. [PMID: 34661244 DOI: 10.1093/jb/mvab110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 10/12/2021] [Indexed: 11/14/2022] Open
Abstract
The level of ribosome biogenesis is highly associated with cell growth rate. Because many ribosomal proteins have extraribosomal functions, overexpression or insufficient supply of these proteins may impair cellular growth. Therefore, the supply of ribosomal proteins is tightly controlled in response to rRNA syntheses and environmental stimuli. In our previous study, 2 RNA-binding proteins, Puf6 and Loc1, were identified as dedicated chaperones of the ribosomal protein eL43, with which they associate to maintain its protein level and proper loading. In this study, we demonstrate that Puf6 and Loc1 interact with RPL43 mRNA. Notably, Puf6 and Loc1 usually function as a dimeric complex to bind other mRNAs; however, in this instance, the individual proteins, but not the complex form, can bind RPL43 mRNA. Thus, Puf6 or Loc1 could bind RPL43 mRNA in loc1Δ or puf6Δ, respectively. The binding of Puf6 or Loc1 caused negative effects for eL43 production: decreased RNA stability and translation of RPL43A/B mRNA. The present results suggest that these dedicated chaperones control the protein levels of eL43 from the standpoint of stability and through regulating its production.
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Affiliation(s)
- Le-Yun Yueh
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Ting Tseng
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Yi Chu
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Kai-Yin Lo
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
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3
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Abouward R, Schiavo G. Walking the line: mechanisms underlying directional mRNA transport and localisation in neurons and beyond. Cell Mol Life Sci 2021; 78:2665-2681. [PMID: 33341920 PMCID: PMC8004493 DOI: 10.1007/s00018-020-03724-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/02/2020] [Accepted: 11/25/2020] [Indexed: 12/21/2022]
Abstract
Messenger RNA (mRNA) localisation enables a high degree of spatiotemporal control on protein synthesis, which contributes to establishing the asymmetric protein distribution required to set up and maintain cellular polarity. As such, a tight control of mRNA localisation is essential for many biological processes during development and in adulthood, such as body axes determination in Drosophila melanogaster and synaptic plasticity in neurons. The mechanisms controlling how mRNAs are localised, including diffusion and entrapment, local degradation and directed active transport, are largely conserved across evolution and have been under investigation for decades in different biological models. In this review, we will discuss the standing of the field regarding directional mRNA transport in light of the recent discovery that RNA can hitchhike on cytoplasmic organelles, such as endolysosomes, and the impact of these transport modalities on our understanding of neuronal function during development, adulthood and in neurodegeneration.
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Affiliation(s)
- Reem Abouward
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK
- The Francis Crick Institute, 1 Midland Rd, London, NW1 1AT, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK.
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4
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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: 5] [Impact Index Per Article: 1.3] [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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5
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Jung D, Seo JS, Nam J, Kim J. Functional association of Loc1 and Puf6 with RNA helicase Dhh1 in translational regulation of Saccharomyces cerevisiae Ste12. PLoS One 2019; 14:e0220137. [PMID: 31323064 PMCID: PMC6641207 DOI: 10.1371/journal.pone.0220137] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/09/2019] [Indexed: 12/14/2022] Open
Abstract
Loc1 and Puf6, which are localized predominantly to the nucleus, are required for the localization and translational repression of the ASH1 mRNA in the yeast, Saccharomyces cerevisiae. During its transport to the daughter cell, the ASH1 mRNA is translationally repressed via associations with She2, Loc1, and Puf6. Here, we investigated the roles of Loc1 and Puf6 in the translation of mRNAs other than that encoding ASH1. In loc1 or puf6 deletion strains, expression of the mating-specific transcription factor, Ste12, was significantly increased at the post-transcriptional level. These phenotypes required the 5’ untranslated region (UTR) of STE12, which carries the putative Puf6-binding sequences. The RNA helicase, Dhh1, which is a known positive regulator for the translation of STE12 mRNA, was found to be functionally connected with Loc1 and Puf6 in the context of Ste12 expression. Our results collectively show that the phosphorylation of the N-terminal Thr16 residue of Dhh1 affects the protein interactions of Dhh1 with Loc1 or Puf6, and consequently regulates Ste12 expression.
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Affiliation(s)
- Daehee Jung
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
| | - Jong Seok Seo
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
| | - Jayoung Nam
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
| | - Jinmi Kim
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
- * E-mail:
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6
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Qiu C, Bhat VD, Rajeev S, Zhang C, Lasley AE, Wine RN, Campbell ZT, Hall TMT. A crystal structure of a collaborative RNA regulatory complex reveals mechanisms to refine target specificity. eLife 2019; 8:48968. [PMID: 31397673 PMCID: PMC6697444 DOI: 10.7554/elife.48968] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/09/2019] [Indexed: 01/09/2023] Open
Abstract
In the Caenorhabditis elegans germline, fem-3 Binding Factor (FBF) partners with LST-1 to maintain stem cells. A crystal structure of an FBF-2/LST-1/RNA complex revealed that FBF-2 recognizes a short RNA motif different from the characteristic 9-nt FBF binding element, and compact motif recognition coincided with curvature changes in the FBF-2 scaffold. Previously, we engineered FBF-2 to favor recognition of shorter RNA motifs without curvature change (Bhat et al., 2019). In vitro selection of RNAs bound by FBF-2 suggested sequence specificity in the central region of the compact element. This bias, reflected in the crystal structure, was validated in RNA-binding assays. FBF-2 has the intrinsic ability to bind to this shorter motif. LST-1 weakens FBF-2 binding affinity for short and long motifs, which may increase target selectivity. Our findings highlight the role of FBF scaffold flexibility in RNA recognition and suggest a new mechanism by which protein partners refine target site selection.
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Affiliation(s)
- Chen Qiu
- Epigenetics and Stem Cell Biology LaboratoryNational Institute of Environmental Health Sciences, National Institutes of HealthResearch Triangle ParkUnited States
| | - Vandita D Bhat
- Department of Biological SciencesUniversity of Texas at DallasRichardsonUnited States
| | - Sanjana Rajeev
- Department of Biological SciencesUniversity of Texas at DallasRichardsonUnited States
| | - Chi Zhang
- Department of Biological SciencesUniversity of Texas at DallasRichardsonUnited States
| | - Alexa E Lasley
- Department of Biological SciencesUniversity of Texas at DallasRichardsonUnited States
| | - Robert N Wine
- Epigenetics and Stem Cell Biology LaboratoryNational Institute of Environmental Health Sciences, National Institutes of HealthResearch Triangle ParkUnited States
| | - Zachary T Campbell
- Department of Biological SciencesUniversity of Texas at DallasRichardsonUnited States
| | - Traci M Tanaka Hall
- Epigenetics and Stem Cell Biology LaboratoryNational Institute of Environmental Health Sciences, National Institutes of HealthResearch Triangle ParkUnited States
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7
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Ribosome Biogenesis Modulates Ty1 Copy Number Control in Saccharomyces cerevisiae. Genetics 2017; 207:1441-1456. [PMID: 29046400 PMCID: PMC5714458 DOI: 10.1534/genetics.117.300388] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/12/2017] [Indexed: 11/26/2022] Open
Abstract
Transposons can impact the host genome by altering gene expression and participating in chromosome rearrangements. Therefore, organisms evolved different ways to minimize the level of transposition. In Saccharomyces cerevisiae and its close relative S. paradoxus, Ty1 copy number control (CNC) is mediated by the self-encoded restriction factor p22, which is derived from the GAG capsid gene and inhibits virus-like particle (VLP) assembly and function. Based on secondary screens of Ty1 cofactors, we identified LOC1, a RNA localization/ribosome biogenesis gene that affects Ty1 mobility predominantly in strains harboring Ty1 elements. Ribosomal protein mutants rps0bΔ and rpl7aΔ displayed similar CNC-specific phenotypes as loc1Δ, suggesting that ribosome biogenesis is critical for CNC. The level of Ty1 mRNA and Ty1 internal (Ty1i) transcripts encoding p22 was altered in these mutants, and displayed a trend where the level of Ty1i RNA increased relative to full-length Ty1 mRNA. The level of p22 increased in these mutants, and the half-life of p22 also increased in a loc1Δ mutant. Transcriptomic analyses revealed small changes in the level of Ty1 transcripts or efficiency of translation initiation in a loc1Δ mutant. Importantly, a loc1Δ mutant had defects in assembly of Gag complexes and packaging Ty1 RNA. Our results indicate that defective ribosome biogenesis enhances CNC by increasing the level of p22, and raise the possibility for versatile links between VLP assembly, its cytoplasmic environment, and a novel stress response.
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8
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Abstract
3'-untranslated regions (3'-UTRs) are the noncoding parts of mRNAs. Compared to yeast, in humans, median 3'-UTR length has expanded approximately tenfold alongside an increased generation of alternative 3'-UTR isoforms. In contrast, the number of coding genes, as well as coding region length, has remained similar. This suggests an important role for 3'-UTRs in the biology of higher organisms. 3'-UTRs are best known to regulate diverse fates of mRNAs, including degradation, translation, and localization, but they can also function like long noncoding or small RNAs, as has been shown for whole 3'-UTRs as well as for cleaved fragments. Furthermore, 3'-UTRs determine the fate of proteins through the regulation of protein-protein interactions. They facilitate cotranslational protein complex formation, which establishes a role for 3'-UTRs as evolved eukaryotic operons. Whereas bacterial operons promote the interaction of two subunits, 3'-UTRs enable the formation of protein complexes with diverse compositions. All of these 3'-UTR functions are accomplished by effector proteins that are recruited by RNA-binding proteins that bind to 3'-UTR cis-elements. In summary, 3'-UTRs seem to be major players in gene regulation that enable local functions, compartmentalization, and cooperativity, which makes them important tools for the regulation of phenotypic diversity of higher organisms.
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Affiliation(s)
- Christine Mayr
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
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9
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Zhang Q, Meng X, Li D, Chen S, Luo J, Zhu L, Singer RH, Gu W. Binding of DEAD-box helicase Dhh1 to the 5'-untranslated region of ASH1 mRNA represses localized translation of ASH1 in yeast cells. J Biol Chem 2017; 292:9787-9800. [PMID: 28450395 PMCID: PMC5465500 DOI: 10.1074/jbc.m117.776492] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/24/2017] [Indexed: 02/05/2023] Open
Abstract
Local translation of specific mRNAs is regulated by dynamic changes in their subcellular localization, and these changes are due to complex mechanisms controlling cytoplasmic mRNA transport. The budding yeast Saccharomyces cerevisiae is well suited to studying these mechanisms because many of its transcripts are transported from the mother cell to the budding daughter cell. Here, we investigated the translational control of ASH1 mRNA after transport and localization. We show that although ASH1 transcripts were translated after they reached the bud tip, some mRNAs were bound by the RNA-binding protein Puf6 and were non-polysomal. We also found that the DEAD-box helicase Dhh1 complexed with the untranslated ASH1 mRNA and Puf6. Loss of Dhh1 affected local translation of ASH1 mRNA and resulted in delocalization of ASH1 transcript in the bud. Forcibly shifting the non-polysomal ASH1 mRNA into polysomes was associated with Dhh1 dissociation. We further demonstrated that Dhh1 is not recruited to ASH1 mRNA co-transcriptionally, suggesting that it could bind to ASH1 mRNA within the cytoplasm. Of note, Dhh1 bound to the 5'-UTR of ASH1 mRNA and inhibited its translation in vitro These results suggest that after localization to the bud tip, a portion of the localized ASH1 mRNA becomes translationally inactive because of binding of Dhh1 and Puf6 to the 5'- and 3'-UTRs of ASH1 mRNA.
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Affiliation(s)
- Qianjun Zhang
- From the Department of Pathophysiology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong Province 515031, China and
| | - Xiuhua Meng
- the Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Delin Li
- From the Department of Pathophysiology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong Province 515031, China and
| | - Shaoyin Chen
- From the Department of Pathophysiology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong Province 515031, China and
| | - Jianmin Luo
- From the Department of Pathophysiology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong Province 515031, China and
| | - Linjie Zhu
- From the Department of Pathophysiology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong Province 515031, China and
| | - Robert H Singer
- the Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Wei Gu
- From the Department of Pathophysiology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong Province 515031, China and
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10
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Edelmann FT, Schlundt A, Heym RG, Jenner A, Niedner-Boblenz A, Syed MI, Paillart JC, Stehle R, Janowski R, Sattler M, Jansen RP, Niessing D. Molecular architecture and dynamics of ASH1 mRNA recognition by its mRNA-transport complex. Nat Struct Mol Biol 2017; 24:152-161. [PMID: 28092367 DOI: 10.1038/nsmb.3351] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 12/07/2016] [Indexed: 12/20/2022]
Abstract
mRNA localization is an essential mechanism of gene regulation and is required for processes such as stem-cell division, embryogenesis and neuronal plasticity. It is not known which features in the cis-acting mRNA localization elements (LEs) are specifically recognized by motor-containing transport complexes. To the best of our knowledge, no high-resolution structure is available for any LE in complex with its cognate protein complex. Using X-ray crystallography and complementary techniques, we carried out a detailed assessment of an LE of the ASH1 mRNA from yeast, its complex with its shuttling RNA-binding protein She2p, and its highly specific, cytoplasmic complex with She3p. Although the RNA alone formed a flexible stem loop, She2p binding induced marked conformational changes. However, only joining by the unstructured She3p resulted in specific RNA recognition. The notable RNA rearrangements and joint action of a globular and an unfolded RNA-binding protein offer unprecedented insights into the step-wise maturation of an mRNA-transport complex.
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Affiliation(s)
- Franziska Theresia Edelmann
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Andreas Schlundt
- Center for Integrated Protein Science Munich at Biomolecular NMR Spectroscopy, Department Chemie, Technische Universität München, Garching, Germany
| | - Roland Gerhard Heym
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Andreas Jenner
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Annika Niedner-Boblenz
- Biomedical Center of the Ludwig-Maximilians-Universität München, Department of Cell Biology, Planegg-Martinsried, Germany
| | | | - Jean-Christophe Paillart
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Ralf Stehle
- Center for Integrated Protein Science Munich at Biomolecular NMR Spectroscopy, Department Chemie, Technische Universität München, Garching, Germany
| | - Robert Janowski
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.,Center for Integrated Protein Science Munich at Biomolecular NMR Spectroscopy, Department Chemie, Technische Universität München, Garching, Germany
| | - Ralf-Peter Jansen
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.,Biomedical Center of the Ludwig-Maximilians-Universität München, Department of Cell Biology, Planegg-Martinsried, Germany
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11
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Yang YT, Ting YH, Liang KJ, Lo KY. The Roles of Puf6 and Loc1 in 60S Biogenesis Are Interdependent, and Both Are Required for Efficient Accommodation of Rpl43. J Biol Chem 2016; 291:19312-23. [PMID: 27458021 DOI: 10.1074/jbc.m116.732800] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Indexed: 12/22/2022] Open
Abstract
Puf6 and Loc1 have two important functional roles in the cells, asymmetric mRNA distribution and ribosome biogenesis. Puf6 and Loc1 are localized predominantly in the nucleolus. They bind ASH1 mRNA, repress its translation, and facilitate the transport to the daughter cells. Asymmetric mRNA distribution is important for cell differentiation. Besides their roles in mRNA localization, Puf6 and Loc1 have been shown to be involved in 60S biogenesis. In puf6Δ or loc1Δ cells, pre-rRNA processing and 60S export are impaired and 60S subunits are underaccumulated. The functional studies of Puf6 and Loc1 have been focused on ASH1 mRNA pathway, but their roles in 60S biogenesis are still not clear. In this study, we found that Puf6 and Loc1 interact directly with each other and both proteins interact with the ribosomal protein Rpl43 (L43e). Notably, the roles of Puf6 and Loc1 in 60S biogenesis are interdependent, and both are required for efficient accommodation of Rpl43. Loc1 is further required to maintain the protein level of Rpl43. Additionally, the recruitment of Rpl43 is required for the release of Puf6 and Loc1. We propose that Puf6 and Loc1 facilitate Rpl43 loading and are sequentially released from 60S after incorporation of Rpl43 into ribosomes in yeast.
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Affiliation(s)
- Yi-Ting Yang
- From the Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Ya-Han Ting
- From the Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Kei-Jen Liang
- From the Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Kai-Yin Lo
- From the Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan
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12
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Edelmann FT, Niedner A, Niessing D. ASH1 mRNP-core factors form stable complexes in absence of cargo RNA at physiological conditions. RNA Biol 2015; 12:233-7. [PMID: 25826656 PMCID: PMC4615642 DOI: 10.1080/15476286.2015.1017217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Asymmetric ASH1 mRNA transport during mitosis of budding yeast constitutes one of the best-studied examples of mRNA localization. Recently, 2 studies used in vitro motility assays to prove that motile ASH1 mRNA-transport complexes can be reconstituted entirely from recombinant factors. Both studies, however, differed in their conclusions on whether cargo RNA itself is required for particle assembly and thus activation of directional transport. Here we provide direct evidence that stable complexes do assemble in absence of RNA at physiologic conditions and even at ionic strengths above cellular levels. These results directly confirm the previous notion that the ASH1 transport machinery is not activated by the cargo RNA itself, but rather through protein-protein interactions.
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Affiliation(s)
- Franziska T Edelmann
- a Institute of Structural Biology ; Helmholtz Zentrum München - German Center for Environmental Health ; Neuherberg , Germany
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13
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Abstract
The segregation of approximately two dozen distinct mRNAs from yeast mother to daughter cell cytoplasm is a classical paradigm for eukaryotic mRNA transport. The information for transport resides in an mRNA element 40-100 nt in length, known as "zipcode." Targeted transport requires properly positioned actin filaments and cooperative loading of mRNA cargo to myosin. Cargo loading to myosin uses myosin 4 protein (Myo4p), swi5p-dependent HO expression 2 protein (She2p) and 3 protein (She3p), and zipcode. We previously determined a crystal structure of Myo4p and She3p, their 1:2 stoichiometry and interactome; we furthermore showed that the motor complex assembly requires two Myo4p⋅She3p heterotrimers, one She2p tetramer, and at least a single zipcode to yield a stable complex of [Myo4p⋅She3p⋅She2p⋅zipcode] in 2:4:4:1 stoichiometry in vitro. Here, we report a structure at 2.8-Å resolution of a cocrystal of a She2p tetramer bound to a segment of She3p. In this crystal structure, the She3p segment forms a striking hook that binds to a shallow hydrophobic pocket on the surface of each She2p subunit of the tetramer. Both She3p hook and cognate She2p binding pocket are composed of highly conserved residues. We also discovered a highly conserved region of She3p upstream of its hook region. Because this region consists of basic and aromatic residues, it likely represents part of She3p's binding activity for zipcode. Because She2p also exhibits zipcode-binding activity, we suggest that "hooking" She3p onto She2p aligns each of their zipcode-binding activities into a high-affinity site, thereby linking motor assembly to zipcode.
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14
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Singer-Krüger B, Jansen RP. Here, there, everywhere. mRNA localization in budding yeast. RNA Biol 2014; 11:1031-9. [PMID: 25482891 DOI: 10.4161/rna.29945] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
mRNA localization and localized translation is a common mechanism that contributes to cell polarity and cellular asymmetry. In metazoan, mRNA transport participates in embryonic axis determination and neuronal plasticity. Since the mRNA localization process and its molecular machinery are rather complex in higher eukaryotes, the unicellular yeast Saccharomyces cerevisiae has become an attractive model to study mRNA localization. Although the focus has so far been on the mechanism of ASH1 mRNA transport, it has become evident that mRNA localization also assists in protein sorting to organelles, as well as in polarity establishment and maintenance. A diversity of different pathways has been identified that targets mRNA to their destination site, ranging from motor protein-dependent trafficking of translationally silenced mRNAs to co-translational targeting, in which mRNAs hitch-hike to organelles on ribosomes during nascent polypeptide chain elongation. The presence of these diverse pathways in yeast allows a systemic analysis of the contribution of mRNA localization to the physiology of a cell.
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Affiliation(s)
- Birgit Singer-Krüger
- a Interfaculty Institute of Biochemistry ; University of Tübingen ; Tübingen , Germany
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15
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Niedner A, Edelmann FT, Niessing D. Of social molecules: The interactive assembly of ASH1 mRNA-transport complexes in yeast. RNA Biol 2014; 11:998-1009. [PMID: 25482892 PMCID: PMC4615550 DOI: 10.4161/rna.29946] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Asymmetric, motor-protein dependent transport of mRNAs and subsequent localized translation is an important mechanism of gene regulation. Due to the high complexity of such motile particles, our mechanistic understanding of mRNA localization is limited. Over the last two decades, ASH1 mRNA localization in budding yeast has served as comparably simple and accessible model system. Recent advances have helped to draw an increasingly clear picture on the molecular mechanisms governing ASH1 mRNA localization from its co-transcriptional birth to its delivery at the site of destination. These new insights help to better understand the requirement of initial nuclear mRNPs, the molecular basis of specific mRNA-cargo recognition via cis-acting RNA elements, the different stages of RNP biogenesis and reorganization, as well as activation of the motile activity upon cargo binding. We discuss these aspects in context of published findings from other model organisms.
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Affiliation(s)
- Annika Niedner
- a Institute of Structural Biology; Helmholtz Zentrum München - German Center for Environmental Health ; Neuherberg , Germany
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16
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Forget A, Chartrand P. Cotranscriptional assembly of mRNP complexes that determine the cytoplasmic fate of mRNA. Transcription 2014; 2:86-90. [PMID: 21468235 DOI: 10.4161/trns.2.2.14857] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Revised: 01/17/2011] [Accepted: 01/18/2011] [Indexed: 12/22/2022] Open
Abstract
Unlike prokaryotes, in which transcription and translation are coupled, eukaryotes physically separate transcription in the nucleus from mRNA translation and degradation in the cytoplasm. However, recent evidence has revealed that the full picture is more complex and that the nuclear transcription machinery plays specific roles in regulating the cytoplasmic fate of mRNA.
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Affiliation(s)
- Amélie Forget
- Département de Biochimie; Université de Montréal; Montréal QC Canada
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17
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Abstract
Nearly 20% of the budding yeast genome is transcribed periodically during the cell division cycle. The precise temporal execution of this large transcriptional program is controlled by a large interacting network of transcriptional regulators, kinases, and ubiquitin ligases. Historically, this network has been viewed as a collection of four coregulated gene clusters that are associated with each phase of the cell cycle. Although the broad outlines of these gene clusters were described nearly 20 years ago, new technologies have enabled major advances in our understanding of the genes comprising those clusters, their regulation, and the complex regulatory interplay between clusters. More recently, advances are being made in understanding the roles of chromatin in the control of the transcriptional program. We are also beginning to discover important regulatory interactions between the cell-cycle transcriptional program and other cell-cycle regulatory mechanisms such as checkpoints and metabolic networks. Here we review recent advances and contemporary models of the transcriptional network and consider these models in the context of eukaryotic cell-cycle controls.
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18
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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: 1.9] [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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Jung H, Gkogkas CG, Sonenberg N, Holt CE. Remote control of gene function by local translation. Cell 2014; 157:26-40. [PMID: 24679524 PMCID: PMC3988848 DOI: 10.1016/j.cell.2014.03.005] [Citation(s) in RCA: 235] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/04/2014] [Accepted: 03/04/2014] [Indexed: 12/12/2022]
Abstract
The subcellular position of a protein is a key determinant of its function. Mounting evidence indicates that RNA localization, where specific mRNAs are transported subcellularly and subsequently translated in response to localized signals, is an evolutionarily conserved mechanism to control protein localization. On-site synthesis confers novel signaling properties to a protein and helps to maintain local proteome homeostasis. Local translation plays particularly important roles in distal neuronal compartments, and dysregulated RNA localization and translation cause defects in neuronal wiring and survival. Here, we discuss key findings in this area and possible implications of this adaptable and swift mechanism for spatial control of gene function.
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Affiliation(s)
- Hosung Jung
- Department of Anatomy, Brain Research Institute, and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Christos G Gkogkas
- Patrick Wild Centre, Centre for Integrative Physiology, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada.
| | - Christine E Holt
- Department of Physiology Development and Neuroscience, Anatomy Building, Downing Street, University of Cambridge, Cambridge CB2 3DY, UK.
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20
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The functions and regulatory principles of mRNA intracellular trafficking. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:57-96. [PMID: 25201103 DOI: 10.1007/978-1-4939-1221-6_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The subcellular localization of RNA molecules is a key step in the control of gene expression that impacts a broad array of biological processes in different organisms and cell types. Like other aspects of posttranscriptional gene regulation discussed in this collection of reviews, the intracellular trafficking of mRNAs is modulated by a complex regulatory code implicating specific cis-regulatory elements, RNA-binding proteins, and cofactors that function combinatorially to dictate precise localization mechanisms. In this review, we first discuss the functional benefits of transcript localization, the regulatory principles involved, and specific molecular mechanisms that have been described for a few well-characterized mRNAs. We also overview some of the emerging genomic and imaging technologies that have provided significant insights into this layer of gene regulation. Finally, we highlight examples of human diseases where defective transcript localization has been documented.
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21
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Niedner A, Müller M, Moorthy BT, Jansen RP, Niessing D. Role of Loc1p in assembly and reorganization of nuclear ASH1 messenger ribonucleoprotein particles in yeast. Proc Natl Acad Sci U S A 2013; 110:E5049-58. [PMID: 24324176 PMCID: PMC3876240 DOI: 10.1073/pnas.1315289111] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Directional transport of mRNA is a universal feature in eukaryotes, requiring the assembly of motor-dependent RNA-transport particles. The cytoplasmic transport of mRNAs is preceded by the nuclear assembly of pre-messenger ribonucleoprotein particles (mRNPs). In budding yeast, the asymmetric synthesis of HO 1 (ASH1) pre-mRNP originates already cotranscriptionally and passes through the nucleolus before its nuclear export. The nucleolar localization of ASH1 mRNA protein 1 (Loc1p) is required for efficient ASH1 mRNA localization. Immunoprecipitation experiments have revealed that Loc1p forms cocomplexes with other components of the ASH1 transport complex. However, it remains unclear how Loc1p is recruited into this mRNP and why Loc1p is important for ASH1 mRNA localization. Here we demonstrate that Loc1p undergoes a direct and specific interaction with the ASH1 mRNA-binding Swi5p-dependent HO expression protein 2 (She2p). This cocomplex shows higher affinity and specificity for RNA bearing localization elements than the individual proteins. It also stabilizes the otherwise transient binding of She2p to ASH1 mRNA, suggesting that cooperative mRNA binding of Loc1p with She2p is the required nuclear function of Loc1p for ASH1 mRNA localization. After nuclear export, myosin-bound She3p joins the ASH1 mRNP to form a highly specific cocomplex with She2p and ASH1 mRNA. Because Loc1p is found only in the nucleus, it must be removed from the complex directly before or after export. In vitro and in vivo experiments indicate that the synergistic interaction of She2p and She3p displaces Loc1p from the ASH1 complex, allowing free Loc1p to rapidly reenter the nucle(ol)us. Together these findings suggest an ordered process of nuclear assembly and reorganization for the maturation of localizing ASH1 mRNPs.
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Affiliation(s)
- Annika Niedner
- Group Intracellular Transport and RNA Biology, Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, 85764 Neuherberg, Germany
- Department of Biochemistry, Gene Center of the Ludwig-Maximilians University, 81377 Munich, Germany; and
| | - Marisa Müller
- Group Intracellular Transport and RNA Biology, Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, 85764 Neuherberg, Germany
- Department of Biochemistry, Gene Center of the Ludwig-Maximilians University, 81377 Munich, Germany; and
| | - Balaji T. Moorthy
- Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany
| | - Ralf-Peter Jansen
- Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany
| | - Dierk Niessing
- Group Intracellular Transport and RNA Biology, Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, 85764 Neuherberg, Germany
- Department of Biochemistry, Gene Center of the Ludwig-Maximilians University, 81377 Munich, Germany; and
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22
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Etxebeste O, Villarino M, Markina-Iñarrairaegui A, Araújo-Bazán L, Espeso EA. Cytoplasmic dynamics of the general nuclear import machinery in apically growing syncytial cells. PLoS One 2013; 8:e85076. [PMID: 24376868 PMCID: PMC3869923 DOI: 10.1371/journal.pone.0085076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/21/2013] [Indexed: 12/20/2022] Open
Abstract
Karyopherins are transporters involved in the bidirectional, selective and active transport of macromolecules through nuclear pores. Importin-β1 is the paradigm of karyopherins and, together with its cargo-adapter importin-α, mediates the general nuclear import pathway. Here we show the existence of different cellular pools of both importin-α and -β1 homologues, KapA and KapB, in the coenocytic ascomycete Aspergillus nidulans. Fluorescence analysis of haploid and diploid strains expressing KapB::GFP and/or KapA::mRFP showed patches of both karyopherins concurrently translocating long distances in apically-growing cells. Anterograde and retrograde movements allowed those patches to reach cell tips and distal regions with an average speed in the range of μm/s. This bidirectional traffic required microtubules as well as kinesin and dynein motors, since it is blocked by benomyl and also by the inactivation of the dynein/dynactin complex through nudA1 or nudK317 mutations. Deletion of Kinesin-3 motor UncA, required for the transport through detyrosinated microtubules, strongly inhibited KapA and KapB movement along hyphae. Overall, this is the first report describing the bidirectional dynamics of the main nuclear import system in coenocytic fungi. A functional link is proposed between two key cellular machines of the filamentous fungal cell: nuclear transport and the tip-growth apparatus.
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Affiliation(s)
- Oier Etxebeste
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, San Sebastian, Spain
| | - María Villarino
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Ane Markina-Iñarrairaegui
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, San Sebastian, Spain
| | - Lidia Araújo-Bazán
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Department of Molecular Microbiology and Infection Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Eduardo A. Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- * E-mail:
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23
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Yasuda K, Kotani T, Yamashita M. A cis-acting element in the coding region of cyclin B1 mRNA couples subcellular localization to translational timing. Dev Biol 2013; 382:517-29. [DOI: 10.1016/j.ydbio.2013.05.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 05/09/2013] [Accepted: 05/13/2013] [Indexed: 12/20/2022]
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24
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Genz C, Fundakowski J, Hermesh O, Schmid M, Jansen RP. Association of the yeast RNA-binding protein She2p with the tubular endoplasmic reticulum depends on membrane curvature. J Biol Chem 2013; 288:32384-32393. [PMID: 24056370 DOI: 10.1074/jbc.m113.486431] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Localization of mRNAs contributes to the generation and maintenance of cellular asymmetry in a wide range of organisms. In Saccharomyces cerevisiae, the so-called locasome complex with its core components Myo4p, She2p, and She3p localizes more than 30 mRNAs to the yeast bud tip. A significant fraction of these mRNAs encodes membrane or secreted proteins. Their localization requires, besides the locasome, a functional segregation apparatus of the cortical endoplasmic reticulum (ER), including the machinery that is involved in the movement of ER tubules into the bud. Colocalization of RNA-containing particles with these tubules suggests a coordinated transport of localized mRNAs and the cortical ER to the bud. Association of localized mRNAs to the ER requires the presence of the locasome component She2p. Here we report that She2p is not only an RNA-binding protein but can specifically bind to ER-derived membranes in a membrane curvature-dependent manner in vitro. Although it does not contain any known curvature recognizing motifs, the protein shows a binding preference for liposomes with a diameter resembling that of yeast ER tubules. In addition, membrane binding depends on tetramerization of She2p. In an in vivo membrane-tethering assay, She2p can target a viral peptide GFP fusion protein to the cortical ER, indicating that a fraction of She2p associates with the ER in vivo. Combining RNA- and membrane-binding features makes She2p an ideal coordinator of ER tubule and mRNA cotransport.
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Affiliation(s)
- Christian Genz
- From the Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany
| | - Julia Fundakowski
- From the Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany
| | - Orit Hermesh
- From the Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany
| | - Maria Schmid
- the Gene Center, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Ralf-Peter Jansen
- From the Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany.
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25
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Hannapel DJ. A perspective on photoperiodic phloem-mobile signals that control development. FRONTIERS IN PLANT SCIENCE 2013; 4:295. [PMID: 23935603 PMCID: PMC3731531 DOI: 10.3389/fpls.2013.00295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 07/16/2013] [Indexed: 05/23/2023]
Abstract
Phloem-mobile signals that are regulated by day length activate both flowering and tuber formation. Both signaling processes have numerous elements in common. In this review, FLOWERING LOCUS T and the three signals currently implicated in controlling tuberization, SP6A, miR172, and the StBEL5 complex, are discussed with a focus on their functional roles, their mechanisms of long-distance transport, and their possible interactions.
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Affiliation(s)
- David J. Hannapel
- *Correspondence: David J. Hannapel, Plant Biology Major, Iowa State University, 253 Horticulture Hall, Ames, IA 50011-1100, USA e-mail:
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26
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Single-molecule reconstitution of mRNA transport by a class V myosin. Nat Struct Mol Biol 2013; 20:952-7. [PMID: 23812374 PMCID: PMC3735863 DOI: 10.1038/nsmb.2614] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 05/14/2013] [Indexed: 12/27/2022]
Abstract
Molecular motors are instrumental in mRNA localization, which provides spatial and temporal control of protein expression and function. To obtain mechanistic insight into how a class V myosin transports mRNA, we performed single-molecule in vitro assays on messenger ribonucleoprotein (mRNP) complexes reconstituted from purified proteins and a localizing mRNA found in budding yeast. mRNA is required to form a stable, processive transport complex on actin--an elegant mechanism to ensure that only cargo-bound motors are motile. Increasing the number of localizing elements ('zip codes') on the mRNA, or configuring the track to resemble actin cables, enhanced run length and event frequency. In multi-zip-code mRNPs, motor separation distance varied during a run, thus showing the dynamic nature of the transport complex. Building the complexity of single-molecule in vitro assays is necessary to understand how these complexes function within cells.
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27
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Weis BL, Schleiff E, Zerges W. Protein targeting to subcellular organelles via MRNA localization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:260-73. [PMID: 23457718 DOI: 10.1016/j.bbamcr.2012.04.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cells have complex membranous organelles for the compartmentalization and the regulation of most intracellular processes. Organelle biogenesis and maintenance requires newly synthesized proteins, each of which needs to go from the ribosome translating its mRNA to the correct membrane for insertion or transclocation to an a organellar subcompartment. Decades of research have revealed how proteins are targeted to the correct organelle and translocated across one or more organelle membranes ro the compartment where they function. The paradigm examples involve interactions between a peptide sequence in the protein, localization factors, and various membrane embedded translocation machineries. Membrane translocation is either cotranslational or posttranslational depending on the protein and target organelle. Meanwhile research in embryos, neurons and yeast revealed an alternative targeting mechanism in which the mRNA is localized and only then translated to synthesize the protein in the correct location. In these cases, the targeting information is coded by the cis-acting sequences in the mRNA ("Zipcodes") that interact with localization factors and, in many cases, are transported by the molecular motors on the cytoskeletal filaments. Recently, evidence has been found for this "mRNA based" mechanism in organelle protein targeting to endoplasmic reticulum, mitochondria, and the photosynthetic membranes within chloroplasts. Here we review known and potential roles of mRNA localization in protein targeting to and within organelles. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Benjamin L Weis
- Goether University, Cluster of Excellence Macromolecular Complexes, Institute for Molecular Biosciences, Max-von-Laue Str. 9, D-60438 Frankfort, Germany
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28
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Müller-McNicoll M, Neugebauer KM. How cells get the message: dynamic assembly and function of mRNA-protein complexes. Nat Rev Genet 2013; 14:275-87. [PMID: 23478349 DOI: 10.1038/nrg3434] [Citation(s) in RCA: 299] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
mRNA is packaged into ribonucleoprotein particles called mRNPs. A multitude of RNA-binding proteins as well as a host of associated proteins participate in the fate of mRNA from transcription and processing in the nucleus to translation and decay in the cytoplasm. Methodological innovations in cell biology and genome-wide high-throughput approaches have revealed an unexpected diversity of mRNA-associated proteins and unforeseen interconnections between mRNA-processing steps. Recent insights into mRNP formation in vivo have also highlighted the importance of mRNP packaging, which can sort RNAs on the basis of their length and determine mRNA fate through alternative mRNP assembly, processing and export pathways.
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Affiliation(s)
- Michaela Müller-McNicoll
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
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29
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Hermesh O, Jansen RP. Take the (RN)A-train: localization of mRNA to the endoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2519-25. [PMID: 23353632 DOI: 10.1016/j.bbamcr.2013.01.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 01/08/2013] [Accepted: 01/11/2013] [Indexed: 11/25/2022]
Abstract
Protein translocation into the endoplasmic reticulum (ER) generally requires targeting of mRNAs encoding secreted or membrane proteins to the ER membrane. The prevalent view is that these mRNAs are delivered co-translationally, using the signal recognition particle (SRP) pathway. Here, SRP delivers signal sequence-containing proteins together with associated ribosomes and mRNA to the SRP receptor present on the ER surface. Recent studies demonstrate the presence of alternative pathways to recruit mRNAs to ER or to specific subdomains of the ER independent of SRP or translation. Such targeting of specific mRNAs to the ER subdomains allows the cell to sort proteins before translocation or to ensure co-localization of ER and mRNAs at specific locations. Translation-independent association of mRNAs involves ER-linked RNA-binding proteins and represents an alternative pathway of mRNA delivery to the ER. This article is part of a Special Issue entitled: Functional and structural diversity of endoplasmic reticulum.
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Affiliation(s)
- Orit Hermesh
- Interfaculty Institute for Biochemistry, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
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30
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Fundakowski J, Hermesh O, Jansen RP. Localization of a subset of yeast mRNAs depends on inheritance of endoplasmic reticulum. Traffic 2012; 13:1642-52. [PMID: 22994588 DOI: 10.1111/tra.12011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 09/17/2012] [Accepted: 09/20/2012] [Indexed: 12/23/2022]
Abstract
Localization of messenger RNA (mRNAs) contributes to generation and maintenance of cellular asymmetry, embryonic development and neuronal function. The She1-3 protein machinery in Saccharomyces cerevisiae localizes >30 mRNAs to the bud tip, including 13 mRNAs encoding membrane or secreted proteins. Ribonucleoprotein (RNP) particles can co-localize with tubular endoplasmic reticulum (ER) structures that form the initial elements for segregation of cortical ER (cER), suggesting a coordination of mRNA localization and cER distribution. By investigating localization of MS2-tagged mRNAs in yeast defective at various stages of cER segregation, we demonstrate that proper cER segregation is required for localization of only a subset of mRNAs. These mRNAs include WSC2, IST2, EAR1 and SRL1 that encode membrane or ER associated proteins and are expressed during S and G2 phases of the cell cycle when tubular ER movement into the bud occurs. Translation of WSC2 is not required for localization, ruling out co-translational targeting of this mRNA. Localization of ASH1 mRNA is independent of cER segregation, which is consistent with the expression pattern of ASH1 at late mitosis. Our findings indicate the presence of two different pathways to localize mRNAs to the yeast bud.
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Affiliation(s)
- Julia Fundakowski
- Interfaculty Institute of Biochemistry, Eberhard-Karls-Universität Tübingen, Tübingen, 72076, Germany
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31
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Inducible control of subcellular RNA localization using a synthetic protein-RNA aptamer interaction. PLoS One 2012; 7:e46868. [PMID: 23056498 PMCID: PMC3466194 DOI: 10.1371/journal.pone.0046868] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 09/05/2012] [Indexed: 12/18/2022] Open
Abstract
Evidence is accumulating in support of the functional importance of subcellular RNA localization in diverse biological contexts. In different cell types, distinct RNA localization patterns are frequently observed, and the available data indicate that this is achieved through a series of highly coordinated events. Classically, cis–elements within the RNA to be localized are recognized by RNA-binding proteins (RBPs), which then direct specific localization of a target RNA. Until now, the precise control of the spatiotemporal parameters inherent to regulating RNA localization has not been experimentally possible. Here, we demonstrate the development and use of a chemically–inducible RNA–protein interaction to regulate subcellular RNA localization. Our system is composed primarily of two parts: (i) the Tet Repressor protein (TetR) genetically fused to proteins natively involved in localizing endogenous transcripts; and (ii) a target transcript containing genetically encoded TetR–binding RNA aptamers. TetR–fusion protein binding to the target RNA and subsequent localization of the latter are directly regulated by doxycycline. Using this platform, we demonstrate that enhanced and controlled subcellular localization of engineered transcripts are achievable. We also analyze rules for forward engineering this RNA localization system in an effort to facilitate its straightforward application to studying RNA localization more generally.
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32
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Xing L, Bassell GJ. mRNA localization: an orchestration of assembly, traffic and synthesis. Traffic 2012; 14:2-14. [PMID: 22913533 DOI: 10.1111/tra.12004] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 08/20/2012] [Accepted: 08/22/2012] [Indexed: 12/14/2022]
Abstract
Asymmetrical mRNA localization and subsequent local translation provide efficient mechanisms for protein sorting in polarized cells. Defects in mRNA localization have been linked to developmental abnormalities and neurological diseases. Thus, it is critical to understand the machineries mediating and mechanisms underlying the asymmetrical distribution of mRNA and its regulation. The goal of this review is to summarize recent advances in the understanding of mRNA transport and localization, including the assembly and sorting of transport messenger ribonucleic protein (mRNP) granules, molecular mechanisms of active mRNP transport, cytoskeletal interactions and regulation of these events by extracellular signals.
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Affiliation(s)
- Lei Xing
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
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33
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Dahan N, Choder M. The eukaryotic transcriptional machinery regulates mRNA translation and decay in the cytoplasm. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:169-73. [PMID: 22982191 DOI: 10.1016/j.bbagrm.2012.08.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 07/28/2012] [Accepted: 08/29/2012] [Indexed: 11/29/2022]
Abstract
In eukaryotes, nuclear mRNA synthesis is physically separated from its cytoplasmic translation and degradation. Recent unexpected findings have revealed that, despite this separation, the transcriptional machinery can remotely control the cytoplasmic stages. Key to this coupling is the capacity of the transcriptional machinery to "imprint" the transcript with factors that escort it to the cytoplasm and regulate its localization, translation and decay. Some of these factors are known transcriptional regulators that also function in mRNA decay and are hence named "synthegradases". Imprinting can be carried out and/or regulated by RNA polymerase II or by promoter cis- and trans-acting elements. This article is part of a Special Issue entitled: RNA polymerase II Transcript Elongation.
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Affiliation(s)
- Nili Dahan
- Department of Molecular Microbiology, Technion-Israel Institute of Technology, Haifa, Israel
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34
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Risler JK, Kenny AE, Palumbo RJ, Gamache ER, Curcio MJ. Host co-factors of the retrovirus-like transposon Ty1. Mob DNA 2012; 3:12. [PMID: 22856544 PMCID: PMC3522557 DOI: 10.1186/1759-8753-3-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 06/18/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND Long-terminal repeat (LTR) retrotransposons have complex modes of mobility involving reverse transcription of their RNA genomes in cytoplasmic virus-like particles (VLPs) and integration of the cDNA copies into the host genome. The limited coding capacity of retrotransposons necessitates an extensive reliance on host co-factors; however, it has been challenging to identify co-factors that are required for endogenous retrotransposon mobility because retrotransposition is such a rare event. RESULTS To circumvent the low frequency of Ty1 LTR-retrotransposon mobility in Saccharomyces cerevisiae, we used iterative synthetic genetic array (SGA) analysis to isolate host mutations that reduce retrotransposition. Query strains that harbor a chromosomal Ty1his3AI reporter element and either the rtt101Δ or med1Δ mutation, both of which confer a hypertransposition phenotype, were mated to 4,847 haploid ORF deletion strains. Retrotransposition was measured in the double mutant progeny, and a set of 275 ORF deletions that suppress the hypertransposition phenotypes of both rtt101Δ and med1Δ were identified. The corresponding set of 275 retrotransposition host factors (RHFs) includes 45 previously identified Ty1 or Ty3 co-factors. More than half of the RHF genes have statistically robust human homologs (E < 1 x 10-10). The level of unintegrated Ty1 cDNA in 181 rhfΔ single mutants was altered <2-fold, suggesting that the corresponding co-factors stimulate retrotransposition at a step after cDNA synthesis. However, deletion of 43 RHF genes, including specific ribosomal protein and ribosome biogenesis genes and RNA degradation, modification and transport genes resulted in low Ty1 cDNA levels. The level of Ty1 Gag but not RNA was reduced in ribosome biogenesis mutants bud21Δ, hcr1Δ, loc1Δ, and puf6Δ. CONCLUSION Ty1 retrotransposition is dependent on multiple co-factors acting at different steps in the replication cycle. Human orthologs of these RHFs are potential, or in a few cases, presumptive HIV-1 co-factors in human cells. RHF genes whose absence results in decreased Ty1 cDNA include characterized RNA metabolism and modification genes, consistent with their having roles in early steps in retrotransposition such as expression, nuclear export, translation, localization, or packaging of Ty1 RNA. Our results suggest that Bud21, Hcr1, Loc1, and Puf6 promote efficient synthesis or stability of Ty1 Gag.
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Affiliation(s)
- Jenni K Risler
- Laboratory of Molecular Genetics, Wadsworth Center, Albany, NY, 12201, USA.
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35
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Gonsalvez GB, Long RM. Spatial regulation of translation through RNA localization. F1000 BIOLOGY REPORTS 2012; 4:16. [PMID: 22912650 PMCID: PMC3412389 DOI: 10.3410/b4-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
RNA localization is a mechanism to post-transcriptionally regulate gene
expression. Eukaryotic organisms ranging from fungi to mammals localize mRNAs to
spatially restrict synthesis of specific proteins to distinct regions of the
cytoplasm. In this review, we provide a general summary of RNA localization
pathways in Saccharomyces cerevisiae, Xenopus,
Drosophila and mammalian neurons.
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Affiliation(s)
- Graydon B. Gonsalvez
- Department of Cellular Biology and
Anatomy, Georgia Health Sciences UniversityC2915D,
1459 Laney Walker Blvd., Augusta, GA
30912USA
| | - Roy M. Long
- Department of Microbiology, Immunology
& Molecular Genetics, Medical College of
Wisconsin8701 Watertown Plank Rd., Milwaukee, WI
53226USA
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Jansen RP, Niessing D. Assembly of mRNA-protein complexes for directional mRNA transport in eukaryotes--an overview. Curr Protein Pept Sci 2012; 13:284-93. [PMID: 22708485 PMCID: PMC3474952 DOI: 10.2174/138920312801619493] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/10/2012] [Accepted: 01/20/2012] [Indexed: 12/11/2022]
Abstract
At all steps from transcription to translation, RNA-binding proteins play important roles in determining mRNA function. Initially it was believed that for the vast majority of transcripts the role of RNA-binding proteins is limited to general functions such as splicing and translation. However, work from recent years showed that members of this class of proteins also recognize several mRNAs via cis-acting elements for their incorporation into large motor-containing particles. These particles are transported to distant subcellular sites, where they become subsequently translated. This process, called mRNA localization, occurs along microtubules or actin filaments, and involves kinesins, dyneins, as well as myosins. Although mRNA localization has been detected in a large number of organisms from fungi to humans, the underlying molecular machineries are not well understood. In this review we will outline general principles of mRNA localization and highlight three examples, for which a comparably large body of information is available. The first example is She2p/She3p-dependent localization of ASH1 mRNA in budding yeast. It is particularly well suited to highlight the interdependence between different steps of mRNA localization. The second example is Staufen-dependent localization of oskar mRNA in the Drosophila embryo, for which the importance of nuclear events for cytoplasmic localization and translational control has been clearly demonstrated. The third example summarizes Egalitarian/Bicaudal D-dependent mRNA transport events in the oocyte and embryo of Drosophila. We will highlight general themes and differences, point to similarities in other model systems, and raise open questions that might be answered in the coming years.
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Affiliation(s)
- Ralf-Peter Jansen
- Interfaculty Institute for Biochemistry, University of Tübingen, Tübingen, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, München, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
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Shahbabian K, Chartrand P. Control of cytoplasmic mRNA localization. Cell Mol Life Sci 2012; 69:535-52. [PMID: 21984598 PMCID: PMC11115051 DOI: 10.1007/s00018-011-0814-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 08/09/2011] [Accepted: 09/01/2011] [Indexed: 12/17/2022]
Abstract
mRNA localization is a mechanism used by various organisms to control the spatial and temporal production of proteins. This process is a highly regulated event that requires multiple cis- and trans-acting elements that mediate the accurate localization of target mRNAs. The intrinsic nature of localization elements, together with their interaction with different RNA-binding proteins, establishes control mechanisms that can oversee the transcript from its birth in the nucleus to its specific final destination. In this review, we aim to summarize the different mechanisms of mRNA localization, with a particular focus on the various control mechanisms that affect the localization of mRNAs in the cytoplasm.
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Affiliation(s)
- Karen Shahbabian
- Department of Biochemistry, Université de Montréal, 2900 Edouard-Montpetit, Montréal, Qc Canada
| | - Pascal Chartrand
- Department of Biochemistry, Université de Montréal, 2900 Edouard-Montpetit, Montréal, Qc Canada
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38
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Krementsova EB, Hodges AR, Bookwalter CS, Sladewski TE, Travaglia M, Sweeney HL, Trybus KM. Two single-headed myosin V motors bound to a tetrameric adapter protein form a processive complex. ACTA ACUST UNITED AC 2012; 195:631-41. [PMID: 22084309 PMCID: PMC3257522 DOI: 10.1083/jcb.201106146] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myo4p, one of two class V myosins in budding yeast, continuously transports messenger RNA (mRNA) cargo in the cell but is nonprocessive when characterized in vitro. The adapter protein She3p tightly binds to the Myo4p rod, forming a single-headed motor complex. In this paper, we show that two Myo4p-She3p motors are recruited by the tetrameric mRNA-binding protein She2p to form a processive double-headed complex. The binding site for She3p was mapped to a single α helix that protrudes at right angles from She2p. Processive runs of several micrometers on yeast actin-tropomyosin filaments were observed only in the presence of She2p, and, thus, motor activity is regulated by cargo binding. While moving processively, each head steps ~72 nm in a hand-over-hand motion. Coupling two high-duty cycle monomeric motors via a common cargo-binding adapter protein creates a complex with transport properties comparable with a single dimeric processive motor such as vertebrate myosin Va.
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Affiliation(s)
- Elena B Krementsova
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA
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39
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An intracellular transmission control protocol: assembly and transport of ribonucleoprotein complexes. Curr Opin Cell Biol 2012; 24:202-10. [PMID: 22278045 DOI: 10.1016/j.ceb.2011.12.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 12/21/2011] [Accepted: 12/27/2011] [Indexed: 12/31/2022]
Abstract
Initially assumed to be a special feature of highly polarized eukaryotic cells, recent evidence suggests that mRNA localization coupled with local translation is a widespread strategy for spatial restriction of protein synthesis within cells. Genome-wide analyses and live imaging approaches have shed new light on the prevalence and the mechanistic details of this phenomenon. Here we review some of the recent findings that have emerged from research from the RNA localization field, from the birth of mRNAs in the nucleus, to their delivery at specific sites within the cytoplasm.
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40
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Heym RG, Niessing D. Principles of mRNA transport in yeast. Cell Mol Life Sci 2011; 69:1843-53. [PMID: 22159587 PMCID: PMC3350770 DOI: 10.1007/s00018-011-0902-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/20/2011] [Accepted: 11/28/2011] [Indexed: 12/20/2022]
Abstract
mRNA localization and localized translation is a common mechanism by which cellular asymmetry is achieved. In higher eukaryotes the mRNA transport machinery is required for such diverse processes as stem cell division and neuronal plasticity. Because mRNA localization in metazoans is highly complex, studies at the molecular level have proven to be cumbersome. However, active mRNA transport has also been reported in fungi including Saccharomyces cerevisiae, Ustilago maydis and Candida albicans, in which these events are less difficult to study. Amongst them, budding yeast S. cerevisiae has yielded mechanistic insights that exceed our understanding of other mRNA localization events to date. In contrast to most reviews, we refrain here from summarizing mRNA localization events from different organisms. Instead we give an in-depth account of ASH1 mRNA localization in budding yeast. This approach is particularly suited to providing a more holistic view of the interconnection between the individual steps of mRNA localization, from transcriptional events to cytoplasmic mRNA transport and localized translation. Because of our advanced mechanistic understanding of mRNA localization in yeast, the present review may also be informative for scientists working, for example, on mRNA localization in embryogenesis or in neurons.
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Affiliation(s)
- Roland Gerhard Heym
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, 81377 Munich, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, 81377 Munich, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
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Kurischko C, Kuravi VK, Herbert CJ, Luca FC. Nucleocytoplasmic shuttling of Ssd1 defines the destiny of its bound mRNAs. Mol Microbiol 2011; 81:831-49. [PMID: 21762218 DOI: 10.1111/j.1365-2958.2011.07731.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mechanisms that control mRNA metabolism are critical for cell function, development and stress response. The Saccharomyces cerevisiae mRNA-binding protein Ssd1 has been implicated in mRNA processing, ageing, stress response and maintenance of cell integrity. Ssd1 is a substrate of the LATS/NDR tumour suppressor orthologue Cbk1 kinase. Previous data indicate that Ssd1 localizes to the cytoplasm; however, biochemical interactions suggest that Ssd1 at least transiently localizes to the nucleus. We therefore explored whether nuclear localization is important for Ssd1 cytoplasmic functions. We identified a functional NLS in the N-terminal domain of Ssd1. An Ssd1-derived NLS-GFP fusion protein and several C-terminally truncated Ssd1 proteins, which presumably lack nuclear export sequences, accumulate in the nucleus. Alanine substitution of the Ssd1 NLS prevents Ssd1 nuclear entry, mRNA binding and disrupts Srl1 mRNA localization. Moreover, Ssd1-NLS mutations abolish Ssd1 toxicity in the absence of Cbk1 phosphorylation and cause Ssd1 to localize prominently to cytoplasmic puncta. These data indicate that nuclear shuttling is critical for Ssd1 mRNA binding and Ssd1-mRNA localization in the cytoplasm. Collectively these data support the model that Ssd1 functions analogously to hnRNPs, which bind mRNA co-transcriptionally, are exported to the cytoplasm and target mRNAs to sites of localized translation and P-bodies.
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Affiliation(s)
- Cornelia Kurischko
- Department of Animal Biology and Mari Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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42
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Müller M, Heym RG, Mayer A, Kramer K, Schmid M, Cramer P, Urlaub H, Jansen RP, Niessing D. A cytoplasmic complex mediates specific mRNA recognition and localization in yeast. PLoS Biol 2011; 9:e1000611. [PMID: 21526221 PMCID: PMC3079584 DOI: 10.1371/journal.pbio.1000611] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 03/10/2011] [Indexed: 11/18/2022] Open
Abstract
The localization of ash mRNA in yeast requires the binding of She2p and the myosin adaptor protein She3p to its localization element, which is highly specific and leads to the assembly of stable transport complexes. In eukaryotes, hundreds of mRNAs are localized by specialized transport complexes. For localization, transcripts are recognized by RNA-binding proteins and incorporated into motor-containing messenger ribonucleoprotein particles (mRNPs). To date, the molecular assembly of such mRNPs is not well understood and most details on cargo specificity remain unresolved. We used ASH1-mRNA transport in yeast to provide a first assessment of where and how localizing mRNAs are specifically recognized and incorporated into mRNPs. By using in vitro–interaction and reconstitution assays, we found that none of the implicated mRNA-binding proteins showed highly specific cargo binding. Instead, we identified the cytoplasmic myosin adapter She3p as additional RNA-binding protein. We further found that only the complex of the RNA-binding proteins She2p and She3p achieves synergistic cargo binding, with an at least 60-fold higher affinity for localizing mRNAs when compared to control RNA. Mutational studies identified a C-terminal RNA-binding fragment of She3p to be important for synergistic RNA binding with She2p. The observed cargo specificity of the ternary complex is considerably higher than previously reported for localizing mRNAs. It suggests that RNA binding for mRNP localization generally exhibits higher selectivity than inferred from previous in vitro data. This conclusion is fully consistent with a large body of in vivo evidence from different organisms. Since the ternary yeast complex only assembles in the cytoplasm, specific mRNA recognition might be limited to the very last steps of mRNP assembly. Remarkably, the mRNA itself triggers the assembly of mature, motor-containing complexes. Our reconstitution of a major portion of the mRNA-transport complex offers new and unexpected insights into the molecular assembly of specific, localization-competent mRNPs and provides an important step forward in our mechanistic understanding of mRNA localization in general. In eukaryotes, the majority of cells are asymmetric and a way to establish such polarity is directional transport of macromolecules along cytoskeletal filaments. Among the cargoes transported, mRNAs play an essential role, as their localized translation contributes significantly to the generation of asymmetry. To date, hundreds of asymmetrically localized mRNAs in various organisms have been identified. These mRNAs are recognized by RNA-binding proteins and incorporated into large motor-containing messenger ribonucleoprotein particles (mRNPs) whose molecular assembly is poorly understood. In this study, we used the well-characterized process of ASH1-mRNA transport in Saccharomyces cerevisiae to address the question of how localizing mRNAs are recognized and specifically incorporated into mRNPs. Surprisingly, we found that the previously implicated mRNA-binding proteins She2p and Puf6p do not bind to cargo mRNAs with high specificity. Instead, the cytoplasmic motor-adapter protein She3p is responsible for synergistic cargo binding with She2p and for the stable incorporation of specific localizing mRNA into the transport complex. We propose that the specific recognition of localizing mRNAs happens at the very last step of cytoplasmic mRNP maturation. Other organisms might employ similar mechanisms to establish cellular polarity.
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Affiliation(s)
- Marisa Müller
- Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, München, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
| | - Roland Gerhard Heym
- Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, München, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
| | - Andreas Mayer
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
| | - Katharina Kramer
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Maria Schmid
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
| | - Patrick Cramer
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
- Center for Integrated Protein Science CIPSM, München, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ralf-Peter Jansen
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
- Interfaculty Institute for Biochemistry, University of Tübingen, Tübingen, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München–German Research Center for Environmental Health, München, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-University, München, Germany
- * E-mail:
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43
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Quenault T, Lithgow T, Traven A. PUF proteins: repression, activation and mRNA localization. Trends Cell Biol 2011; 21:104-12. [DOI: 10.1016/j.tcb.2010.09.013] [Citation(s) in RCA: 199] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 09/20/2010] [Accepted: 09/28/2010] [Indexed: 12/15/2022]
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Chang HY, Fan CC, Chu PC, Hong BE, Lee HJ, Chang MS. hPuf-A/KIAA0020 modulates PARP-1 cleavage upon genotoxic stress. Cancer Res 2011; 71:1126-34. [PMID: 21266351 DOI: 10.1158/0008-5472.can-10-1831] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human hPuf-A/KIAA0020 was first identified as a new minor histocompatibility antigen in 2001. Its zebrafish orthologue contains six Pumilio-homology RNA-binding domains and has been shown to participate in the development of eyes and primordial germ cells, but the cellular function of hPuf-A remains unclear. In this report, we showed that hPuf-A predominantly localized in the nucleoli with minor punctate signals in the nucleoplasm. The nucleolar localization of hPuf-A would redistribute to the nucleoplasm after the treatment of RNA polymerase inhibitors (actinomycin D and 5,6-dichlorobenzimidazole riboside) and topoisomerase inhibitors [camptothecin (CPT) and etoposide]. Interestingly, knockdown of hPuf-A sensitized cells to CPT and UV treatment and cells constitutively overexpressing hPuf-A became more resistant to genotoxic exposure. Affinity gel pull-down coupled with mass spectrometric analysis identified PARP-1 as one of the hPuf-A interacting proteins. hPuf-A specifically interacts with the catalytic domain of PARP-1 and inhibits poly(ADP-ribosyl)ation of PARP-1 in vitro. Depletion of hPuf-A increased the cleaved PARP-1 and overexpression of hPuf-A lessened PARP-1 cleavage when cells were exposed to CPT and UV light. Collectively, hPuf-A may regulate cellular response to genotoxic stress by inhibiting PARP-1 activity and thus preventing PARP-1 degradation by caspase-3.
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Affiliation(s)
- Hao-Yen Chang
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
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45
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Slobodin B, Gerst JE. RaPID: an aptamer-based mRNA affinity purification technique for the identification of RNA and protein factors present in ribonucleoprotein complexes. Methods Mol Biol 2011; 714:387-406. [PMID: 21431754 DOI: 10.1007/978-1-61779-005-8_24] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
RNA metabolism involves regulatory processes, such as transcription, splicing, nuclear export, transport and localization, association with sites of RNA modification, silencing and decay, and necessitates a wide variety of diverse RNA-interacting proteins. These interactions can be direct via RNA-binding proteins (RBPs) or indirect via other proteins and RNAs that form ribonucleoprotein complexes that together control RNA fate. While pull-down methods for the isolation of known RBPs are commonly used, strategies have also been described for the direct isolation of messenger RNAs (mRNAs) and their associated factors. The latter techniques allow for the identification of interacting proteins and RNAs, but most suffer from problems of low sensitivity and high background. Here we describe a simple and highly effective method for RNA purification and identification (RaPID) that allows for the isolation of specific mRNAs of interest from yeast and mammalian cells, and subsequent analysis of the associated proteins and RNAs using mass spectrometry and reverse transcription-PCR, respectively. This method employs the MS2 coat RBP fused to both GFP and streptavidin-binding protein to precipitate MS2 aptamer-tagged RNAs using immobilized streptavidin.
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Affiliation(s)
- Boris Slobodin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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46
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47
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Powrie EA, Zenklusen D, Singer RH. A nucleoporin, Nup60p, affects the nuclear and cytoplasmic localization of ASH1 mRNA in S. cerevisiae. RNA (NEW YORK, N.Y.) 2011; 17:134-144. [PMID: 21036941 PMCID: PMC3004054 DOI: 10.1261/rna.1210411] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 09/27/2010] [Indexed: 05/30/2023]
Abstract
The biogenesis of a localization-competent mRNP begins in the nucleus. It is thought that the coordinated action of nuclear and cytoplasmic components of the localization machinery is required for the efficient export and subsequent subcellular localization of these mRNAs in the cytoplasm. Using quantitative poly(A)(+) and transcript-specific fluorescent in situ hybridization, we analyzed different nonessential nucleoporins and nuclear pore-associated proteins for their potential role in mRNA export and localization. We found that Nup60p, a nuclear pore protein located on the nucleoplasmic side of the nuclear pore complex, was required for the mRNA localization pathway. In a Δnup60 background, localized mRNAs were preferentially retained within the nucleus compared to nonlocalized transcripts. However, the export block was only partial and some transcripts could still reach the cytoplasm. Importantly, downstream processes were also affected. Localization of ASH1 and IST2 mRNAs to the bud was impaired in the Δnup60 background, suggesting that the assembly of a localization competent mRNP ("locasome") was inhibited when NUP60 was deleted. These results demonstrate transcript specificity of a nuclear mRNA retention defect and identify a specific nucleoporin as a functional component of the localization pathway in budding yeast.
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Affiliation(s)
- Erin A Powrie
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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48
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Yasuda K, Kotani T, Ota R, Yamashita M. Transgenic zebrafish reveals novel mechanisms of translational control of cyclin B1 mRNA in oocytes. Dev Biol 2010; 348:76-86. [DOI: 10.1016/j.ydbio.2010.09.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/16/2010] [Accepted: 09/17/2010] [Indexed: 12/21/2022]
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49
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Slobodin B, Gerst JE. A novel mRNA affinity purification technique for the identification of interacting proteins and transcripts in ribonucleoprotein complexes. RNA (NEW YORK, N.Y.) 2010; 16:2277-90. [PMID: 20876833 PMCID: PMC2957065 DOI: 10.1261/rna.2091710] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Intracellular mRNA targeting and localized translation are potential determinants for protein localization. To facilitate targeting, mRNAs possess specific cis-acting sequence motifs that are recognized by trans-acting RNA-binding proteins (RBPs). While many mRNAs are trafficked, our knowledge of the RBPs involved and presence of additional transcripts within these ribonucleoprotein (RNP) complexes is limited. To facilitate the identification of RBPs and transcripts that bind to specific mRNAs, we developed RNA-binding protein purification and identification (RaPID), a novel technique that allows for the affinity purification of MS2 aptamer-tagged mRNAs and subsequent detection of bound RBPs and transcripts using mass-spectometry and RT-PCR, respectively. RaPID effectively isolated specific mRNAs from both yeast and mammalian cells, and identified known mRNA-RBP interactions (e.g., ASH1-She2; β-Actin-IMP1). By isolating tagged OXA1 mRNA using RaPID, we could identify a yeast COPI subunit (i.e., Sec27) as a candidate interacting protein. This finding was strengthened by the observation that a portion of OXA1 mRNA was delocalized in a sec27-1 temperature-sensitive mutant at restrictive temperatures. Finally, RaPID could also be used to show biochemically the coexistence of different RNA species within the same RNP complex (e.g., coprecipitation of the yeast SRO7, WSC2, SEC3, and IST2 mRNAs with ASH1 mRNA) for the first time.
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Affiliation(s)
- Boris Slobodin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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The cytoplasmic fate of an mRNP is determined cotranscriptionally: exception or rule? Genes Dev 2010; 24:1827-31. [PMID: 20810644 DOI: 10.1101/gad.1972810] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
She2p is an RNA-binding protein that recognizes a zipcode on specific mRNAs necessary for the assembly of a protein complex that localizes them to the yeast bud tip. In this issue of Genes & Development, Shen and colleagues (pp. 1914-1926) demonstrate that She2p associates with RNAPII globally, but then recognizes the nascent chain only if it contains a zipcode. This demonstrates yet another case where the mRNA's cytoplasmic fate is determined by the RNAPII complex.
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