1
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Román ÁC, Benítez DA, Díaz-Pizarro A, Del Valle-Del Pino N, Olivera-Gómez M, Cumplido-Laso G, Carvajal-González JM, Mulero-Navarro S. Next generation sequencing technologies to address aberrant mRNA translation in cancer. NAR Cancer 2024; 6:zcae024. [PMID: 38751936 PMCID: PMC11094761 DOI: 10.1093/narcan/zcae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 05/18/2024] Open
Abstract
In this review, we explore the transformative impact of next generation sequencing technologies in the realm of translatomics (the study of how translational machinery acts on a genome-wide scale). Despite the expectation of a direct correlation between mRNA and protein content, the complex regulatory mechanisms that affect this relationship remark the limitations of standard RNA-seq approaches. Then, the review characterizes crucial techniques such as polysome profiling, ribo-seq, trap-seq, proximity-specific ribosome profiling, rnc-seq, tcp-seq, qti-seq and scRibo-seq. All these methods are summarized within the context of cancer research, shedding light on their applications in deciphering aberrant translation in cancer cells. In addition, we encompass databases and bioinformatic tools essential for researchers that want to address translatome analysis in the context of cancer biology.
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Affiliation(s)
- Ángel-Carlos Román
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Dixan A Benítez
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Alba Díaz-Pizarro
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Nuria Del Valle-Del Pino
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Marcos Olivera-Gómez
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Guadalupe Cumplido-Laso
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Jose M Carvajal-González
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
| | - Sonia Mulero-Navarro
- Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura. Avda. de Elvas s/n, 06071 Badajoz, Spain
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2
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Zhou L, Li H, Sun T, Wen X, Niu C, Li M, Li W, Esteban MA, Hoffman AR, Hu JF, Cui J. Profiling mitochondria-polyribosome lncRNAs associated with pluripotency. Sci Data 2023; 10:755. [PMID: 37919270 PMCID: PMC10622415 DOI: 10.1038/s41597-023-02649-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 10/16/2023] [Indexed: 11/04/2023] Open
Abstract
Pluripotent stem cells (PSCs) provide unlimited resources for regenerative medicine because of their potential for self-renewal and differentiation into many different cell types. The pluripotency of these PSCs is dynamically regulated at multiple cellular organelle levels. To delineate the factors that coordinate this inter-organelle crosstalk, we profiled those long non-coding RNAs (lncRNAs) that may participate in the regulation of multiple cellular organelles in PSCs. We have developed a unique strand-specific RNA-seq dataset of lncRNAs that may interact with mitochondria (mtlncRNAs) and polyribosomes (prlncRNAs). Among the lncRNAs differentially expressed between induced pluripotent stem cells (iPSCs), fibroblasts, and positive control H9 human embryonic stem cells, we identified 11 prlncRNAs related to stem cell reprogramming and exit from pluripotency. In conjunction with the total RNA-seq data, this dataset provides a valuable resource to examine the role of lncRNAs in pluripotency, particularly for studies investigating the inter-organelle crosstalk network involved in germ cell development and human reproduction.
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Affiliation(s)
- Lei Zhou
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China.
| | - Hui Li
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China
| | - Tingge Sun
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China
| | - Xue Wen
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China
| | - Chao Niu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China
| | - Min Li
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China
| | - Wei Li
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China
| | - Miguel A Esteban
- Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Andrew R Hoffman
- Stanford University Medical School, VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA
| | - Ji-Fan Hu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China.
- Stanford University Medical School, VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA.
| | - Jiuwei Cui
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin, 130061, P.R. China.
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3
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Imai H, Utsumi D, Torihara H, Takahashi K, Kuroyanagi H, Yamashita A. Simultaneous measurement of nascent transcriptome and translatome using 4-thiouridine metabolic RNA labeling and translating ribosome affinity purification. Nucleic Acids Res 2023; 51:e76. [PMID: 37378452 PMCID: PMC10415123 DOI: 10.1093/nar/gkad545] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Regulation of gene expression in response to various biological processes, including extracellular stimulation and environmental adaptation requires nascent RNA synthesis and translation. Analysis of the coordinated regulation of dynamic RNA synthesis and translation is required to determine functional protein production. However, reliable methods for the simultaneous measurement of nascent RNA synthesis and translation at the gene level are limited. Here, we developed a novel method for the simultaneous assessment of nascent RNA synthesis and translation by combining 4-thiouridine (4sU) metabolic RNA labeling and translating ribosome affinity purification (TRAP) using a monoclonal antibody against evolutionarily conserved ribosomal P-stalk proteins. The P-stalk-mediated TRAP (P-TRAP) technique recovered endogenous translating ribosomes, allowing easy translatome analysis of various eukaryotes. We validated this method in mammalian cells by demonstrating that acute unfolded protein response (UPR) in the endoplasmic reticulum (ER) induces dynamic reprogramming of nascent RNA synthesis and translation. Our nascent P-TRAP (nP-TRAP) method may serve as a simple and powerful tool for analyzing the coordinated regulation of transcription and translation of individual genes in various eukaryotes.
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Affiliation(s)
- Hirotatsu Imai
- Department of Investigative Medicine, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa 903-0215, Japan
| | - Daisuke Utsumi
- Department of Dermatology, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa 903-0215, Japan
| | - Hidetsugu Torihara
- Department of Biochemistry, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa 903-0215, Japan
| | - Kenzo Takahashi
- Department of Dermatology, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa 903-0215, Japan
| | - Hidehito Kuroyanagi
- Department of Biochemistry, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa 903-0215, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa 903-0215, Japan
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4
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Shestakova ED, Smirnova VV, Shatsky IN, Terenin IM. Specific mechanisms of translation initiation in higher eukaryotes: the eIF4G2 story. RNA (NEW YORK, N.Y.) 2023; 29:282-299. [PMID: 36517212 PMCID: PMC9945437 DOI: 10.1261/rna.079462.122] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The eukaryotic initiation factor 4G2 (eIF4G2, DAP5, Nat1, p97) was discovered in 1997. Over the past two decades, dozens of papers have presented contradictory data on eIF4G2 function. Since its identification, eIF4G2 has been assumed to participate in noncanonical translation initiation mechanisms, but recent results indicate that it can be involved in scanning as well. In particular, eIF4G2 provides leaky scanning through some upstream open reading frames (uORFs), which are typical for long 5' UTRs of mRNAs from higher eukaryotes. It is likely the protein can also help the ribosome overcome other impediments during scanning of the 5' UTRs of animal mRNAs. This may explain the need for eIF4G2 in higher eukaryotes, as many mRNAs that encode regulatory proteins have rather long and highly structured 5' UTRs. Additionally, they often bind to various proteins, which also hamper the movement of scanning ribosomes. This review discusses the suggested mechanisms of eIF4G2 action, denotes obscure or inconsistent results, and proposes ways to uncover other fundamental mechanisms in which this important protein factor may be involved in higher eukaryotes.
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Affiliation(s)
- Ekaterina D Shestakova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Victoria V Smirnova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ilya M Terenin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
- Sirius University of Science and Technology, Sochi 354349, Russia
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5
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Grüttner S, Nguyen TT, Bruhs A, Mireau H, Kempken F. The P-type pentatricopeptide repeat protein DWEORG1 is a non-previously reported rPPR protein of Arabidopsis mitochondria. Sci Rep 2022; 12:12492. [PMID: 35864185 PMCID: PMC9304396 DOI: 10.1038/s41598-022-16812-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 07/15/2022] [Indexed: 11/17/2022] Open
Abstract
Gene expression in plant mitochondria is mainly regulated by nuclear-encoded proteins on a post-transcriptional level. Pentatricopeptide repeat (PPR) proteins play a major role by participating in mRNA stability, splicing, RNA editing, and translation initiation. PPR proteins were also shown to be part of the mitochondrial ribosome (rPPR proteins), which may act as regulators of gene expression in plants. In this study, we focus on a mitochondrial-located P-type PPR protein—DWEORG1—from Arabidopsis thaliana. Its abundance in mitochondria is high, and it has a similar expression pattern as rPPR proteins. Mutant dweorg1 plants exhibit a slow-growth phenotype. Using ribosome profiling, a decrease in translation efficiency for cox2, rps4, rpl5, and ccmFN2 was observed in dweorg1 mutants, correlating with a reduced accumulation of the Cox2 protein in these plants. In addition, the mitochondrial rRNA levels are significantly reduced in dweorg1 compared with the wild type. DWEORG1 co-migrates with the ribosomal proteins Rps4 and Rpl16 in sucrose gradients, suggesting an association of DWEORG1 with the mitoribosome. Collectively, this data suggests that DWEORG1 encodes a novel rPPR protein that is needed for the translation of cox2, rps4, rpl5, and ccmFN2 and provides a stabilizing function for mitochondrial ribosomes.
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Affiliation(s)
- Stefanie Grüttner
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098, Kiel, Germany
| | - Tan-Trung Nguyen
- Institut Jean-Pierre Bourgin INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Anika Bruhs
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098, Kiel, Germany
| | - Hakim Mireau
- Institut Jean-Pierre Bourgin INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France.
| | - Frank Kempken
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098, Kiel, Germany.
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6
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Reixachs‐Solé M, Eyras E. Uncovering the impacts of alternative splicing on the proteome with current omics techniques. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1707. [PMID: 34979593 PMCID: PMC9542554 DOI: 10.1002/wrna.1707] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022]
Abstract
The high-throughput sequencing of cellular RNAs has underscored a broad effect of isoform diversification through alternative splicing on the transcriptome. Moreover, the differential production of transcript isoforms from gene loci has been recognized as a critical mechanism in cell differentiation, organismal development, and disease. Yet, the extent of the impact of alternative splicing on protein production and cellular function remains a matter of debate. Multiple experimental and computational approaches have been developed in recent years to address this question. These studies have unveiled how molecular changes at different steps in the RNA processing pathway can lead to differences in protein production and have functional effects. New and emerging experimental technologies open exciting new opportunities to develop new methods to fully establish the connection between messenger RNA expression and protein production and to further investigate how RNA variation impacts the proteome and cell function. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing Translation > Regulation RNA Evolution and Genomics > Computational Analyses of RNA.
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Affiliation(s)
- Marina Reixachs‐Solé
- The John Curtin School of Medical ResearchAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
- EMBL Australia Partner Laboratory Network and the Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Eduardo Eyras
- The John Curtin School of Medical ResearchAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
- EMBL Australia Partner Laboratory Network and the Australian National UniversityCanberraAustralian Capital TerritoryAustralia
- Catalan Institution for Research and Advanced StudiesBarcelonaSpain
- Hospital del Mar Medical Research Institute (IMIM)BarcelonaSpain
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7
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Karmakar S, Ramirez O, Paul KV, Gupta AK, Kumari V, Botti V, de Los Mozos IR, Neuenkirchen N, Ross RJ, Karanicolas J, Neugebauer KM, Pillai MM. Integrative genome-wide analysis reveals EIF3A as a key downstream regulator of translational repressor protein Musashi 2 (MSI2). NAR Cancer 2022; 4:zcac015. [PMID: 35528200 PMCID: PMC9070473 DOI: 10.1093/narcan/zcac015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/04/2022] [Accepted: 04/19/2022] [Indexed: 01/29/2023] Open
Abstract
Musashi 2 (MSI2) is an RNA binding protein (RBP) that regulates asymmetric cell division and cell fate decisions in normal and cancer stem cells. MSI2 appears to repress translation by binding to 3′ untranslated regions (3′UTRs) of mRNA, but the identity of functional targets remains unknown. Here, we used individual nucleotide resolution cross-linking and immunoprecipitation (iCLIP) to identify direct RNA binding partners of MSI2 and integrated these data with polysome profiling to obtain insights into MSI2 function. iCLIP revealed specific MSI2 binding to thousands of mRNAs largely in 3′UTRs, but translational differences were restricted to a small fraction of these transcripts, indicating that MSI2 regulation is not triggered by simple binding. Instead, the functional targets identified here were bound at higher density and contain more ‘UAG’ motifs compared to targets bound nonproductively. To further distinguish direct and indirect targets, MSI2 was acutely depleted. Surprisingly, only 50 transcripts were found to undergo translational induction on acute loss. Using complementary approaches, we determined eukaryotic translation initiation factor 3A (EIF3A) to be an immediate, direct target. We propose that MSI2 downregulation of EIF3A amplifies these effects on translation. Our results also underscore the challenges in defining functional targets of RBPs since mere binding does not imply a discernible functional interaction.
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Affiliation(s)
| | - Oscar Ramirez
- Section of Hematology, Yale Cancer Center, New Haven, CT 06511, USA
| | - Kiran V Paul
- Section of Hematology, Yale Cancer Center, New Haven, CT 06511, USA
| | - Abhishek K Gupta
- Section of Hematology, Yale Cancer Center, New Haven, CT 06511, USA
| | - Vandana Kumari
- Section of Hematology, Yale Cancer Center, New Haven, CT 06511, USA
| | - Valentina Botti
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Igor Ruiz de Los Mozos
- Institute of Neurology, University College London and The Francis Crick Institute, London NW1 1AT, UK
| | - Nils Neuenkirchen
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Robert J Ross
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - John Karanicolas
- Program in Molecular Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Manoj M Pillai
- Section of Hematology, Yale Cancer Center, New Haven, CT 06511, USA
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8
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Tinti M, Kelner-Mirôn A, Marriott LJ, Ferguson MA. Polysomal mRNA Association and Gene Expression in Trypanosoma brucei. Wellcome Open Res 2022; 6:36. [PMID: 34250262 PMCID: PMC8240603 DOI: 10.12688/wellcomeopenres.16430.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2022] [Indexed: 11/20/2022] Open
Abstract
Background: The contrasting physiological environments of
Trypanosoma brucei procyclic (insect vector) and bloodstream (mammalian host) forms necessitates deployment of different molecular processes and, therefore, changes in protein expression. Transcriptional regulation is unusual in
T. brucei because the arrangement of genes is polycistronic; however, genes which are transcribed together are subsequently cleaved into separate mRNAs by
trans-splicing. Following pre-mRNA processing, the regulation of mature mRNA stability is a tightly controlled cellular process. While many stage-specific transcripts have been identified, previous studies using RNA-seq suggest that changes in overall transcript level do not necessarily reflect the abundance of the corresponding protein. Methods: To better understand the regulation of gene expression in
T. brucei, we performed a bioinformatic analysis of RNA-seq on total, sub-polysomal, and polysomal mRNA samples. We further cross-referenced our dataset with a previously published proteomics dataset to identify new protein coding sequences. Results: Our analyses showed that several long non-coding RNAs are more abundant in the sub-polysome samples, which possibly implicates them in regulating cellular differentiation in
T. brucei. We also improved the annotation of the
T.brucei genome by identifying new putative protein coding transcripts that were confirmed by mass spectrometry data. Conclusions: Several long non-coding RNAs are more abundant in the sub-polysome cellular fractions and might pay a role in the regulation of gene expression. We hope that these data will be of wide general interest, as well as being of specific value to researchers studying gene regulation expression and life stage transitions in
T. brucei.
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Affiliation(s)
- Michele Tinti
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Anna Kelner-Mirôn
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Lizzie J. Marriott
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Michael A.J. Ferguson
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
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9
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Tinti M, Kelner-Mirôn A, Marriott LJ, Ferguson MAJ. Polysomal mRNA Association and Gene Expression in Trypanosoma brucei. Wellcome Open Res 2021; 6:36. [PMID: 34250262 DOI: 10.12688/wellcomeopenres.16430.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2021] [Indexed: 11/20/2022] Open
Abstract
Background: The contrasting physiological environments of Trypanosoma brucei procyclic (insect vector) and bloodstream (mammalian host) forms necessitates deployment of different molecular processes and, therefore, changes in protein expression. Transcriptional regulation is unusual in T. brucei because the arrangement of genes is polycistronic; however, genes which are transcribed together are subsequently cleaved into separate mRNAs by trans-splicing. Following pre-mRNA processing, the regulation of mature mRNA stability is a tightly controlled cellular process. While many stage-specific transcripts have been identified, previous studies using RNA-seq suggest that changes in overall transcript level do not necessarily reflect the abundance of the corresponding protein. Methods: To better understand the regulation of gene expression in T. brucei, we performed a bioinformatic analysis of RNA-seq on total, sub-polysomal, and polysomal mRNA samples. We further cross-referenced our dataset with a previously published proteomics dataset to identify new protein coding sequences. Results: Our analyses showed that several long non-coding RNAs are more abundant in the sub-polysome samples, which possibly implicates them in regulating cellular differentiation in T. brucei. We also improved the annotation of the T.brucei genome by identifying new putative protein coding transcripts that were confirmed by mass spectrometry data. Conclusions: Several long non-coding RNAs are more abundant in the sub-polysome cellular fractions and might pay a role in the regulation of gene expression. We hope that these data will be of wide general interest, as well as being of specific value to researchers studying gene regulation expression and life stage transitions in T. brucei.
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Affiliation(s)
- Michele Tinti
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Anna Kelner-Mirôn
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Lizzie J Marriott
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Michael A J Ferguson
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
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10
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Tinti M, Kelner-Mirôn A, Marriott LJ, Ferguson MAJ. Polysomal mRNA Association and Gene Expression in Trypanosoma brucei. Wellcome Open Res 2021; 6:36. [PMID: 34250262 DOI: 10.12688/wellcomeopenres.16430.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2021] [Indexed: 11/20/2022] Open
Abstract
Background: The contrasting physiological environments of Trypanosoma brucei procyclic (insect vector) and bloodstream (mammalian host) forms necessitates deployment of different molecular processes and, therefore, changes in protein expression. Transcriptional regulation is unusual in T. brucei because the arrangement of genes is polycistronic; however, genes which are transcribed together are subsequently cleaved into separate mRNAs by trans-splicing. Following pre-mRNA processing, the regulation of mature mRNA stability is a tightly controlled cellular process. While many stage-specific transcripts have been identified, previous studies using RNA-seq suggest that changes in overall transcript level do not necessarily reflect the abundance of the corresponding protein. Methods: To better understand the regulation of gene expression in T. brucei, we performed a bioinformatic analysis of RNA-seq on total, sub-polysomal, and polysomal mRNA samples. We further cross-referenced our dataset with a previously published proteomics dataset to identify new protein coding sequences. Results: Our analyses showed that several long non-coding RNAs are more abundant in the sub-polysome samples, which possibly implicates them in regulating cellular differentiation in T. brucei. We also improved the annotation of the T.brucei genome by identifying new putative protein coding transcripts that were confirmed by mass spectrometry data. Conclusions: Several long non-coding RNAs are more abundant in the sub-polysome cellular fractions and might pay a role in the regulation of gene expression. We hope that these data will be of wide general interest, as well as being of specific value to researchers studying gene regulation expression and life stage transitions in T. brucei.
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Affiliation(s)
- Michele Tinti
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Anna Kelner-Mirôn
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Lizzie J Marriott
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
| | - Michael A J Ferguson
- Wellcome Centre for Anti-Infectives Research (WCAIR), School of Life Sciences, University of Dundee, Dundee, Dundee, UK
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11
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Liu K, Santos DA, Hussmann JA, Wang Y, Sutter BM, Weissman JS, Tu BP. Regulation of translation by methylation multiplicity of 18S rRNA. Cell Rep 2021; 34:108825. [PMID: 33691096 PMCID: PMC8063911 DOI: 10.1016/j.celrep.2021.108825] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 01/04/2021] [Accepted: 02/12/2021] [Indexed: 02/01/2023] Open
Abstract
N6-methyladenosine (m6A) is a conserved ribonucleoside modification that regulates many facets of RNA metabolism. Using quantitative mass spectrometry, we find that the universally conserved tandem adenosines at the 3' end of 18S rRNA, thought to be constitutively di-methylated (m62A), are also mono-methylated (m6A). Although present at substoichiometric amounts, m6A at these positions increases significantly in response to sulfur starvation in yeast cells and mammalian cell lines. Combining yeast genetics and ribosome profiling, we provide evidence to suggest that m6A-bearing ribosomes carry out translation distinctly from m62A-bearing ribosomes, featuring a striking specificity for sulfur metabolism genes. Our work thus reveals methylation multiplicity as a mechanism to regulate translation.
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Affiliation(s)
- Kuanqing Liu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Daniel A Santos
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Jeffrey A Hussmann
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Yun Wang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Benjamin M Sutter
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Benjamin P Tu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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12
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Llano E, Masek T, Gahurova L, Pospisek M, Koncicka M, Jindrova A, Jansova D, Iyyappan R, Roucova K, Bruce AW, Kubelka M, Susor A. Age-related differences in the translational landscape of mammalian oocytes. Aging Cell 2020; 19:e13231. [PMID: 32951297 PMCID: PMC7576272 DOI: 10.1111/acel.13231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/15/2020] [Accepted: 08/01/2020] [Indexed: 12/13/2022] Open
Abstract
Increasing maternal age in mammals is associated with poorer oocyte quality, involving higher aneuploidy rates and decreased developmental competence. Prior to resumption of meiosis, fully developed mammalian oocytes become transcriptionally silent until the onset of zygotic genome activation. Therefore, meiotic progression and early embryogenesis are driven largely by translational utilization of previously synthesized mRNAs. We report that genome‐wide translatome profiling reveals considerable numbers of transcripts that are differentially translated in oocytes obtained from aged compared to young females. Additionally, we show that a number of aberrantly translated mRNAs in oocytes from aged females are associated with cell cycle. Indeed, we demonstrate that four specific maternal age‐related transcripts (Sgk1, Castor1, Aire and Eg5) with differential translation rates encode factors that are associated with the newly forming meiotic spindle. Moreover, we report substantial defects in chromosome alignment and cytokinesis in the oocytes of young females, in which candidate CASTOR1 and SGK1 protein levels or activity are experimentally altered. Our findings indicate that improper translation of specific proteins at the onset of meiosis contributes to increased chromosome segregation problems associated with female ageing.
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Affiliation(s)
- Edgar Llano
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
- Laboratory of RNA Biochemistry Department of Genetics and Microbiology Faculty of Science Charles University in Prague Prague Czech Republic
| | - Tomas Masek
- Laboratory of RNA Biochemistry Department of Genetics and Microbiology Faculty of Science Charles University in Prague Prague Czech Republic
| | - Lenka Gahurova
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
- Laboratory of Early Mammalian Developmental Biology (LEMDB) Department of Molecular Biology and Genetics Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - Martin Pospisek
- Laboratory of RNA Biochemistry Department of Genetics and Microbiology Faculty of Science Charles University in Prague Prague Czech Republic
| | - Marketa Koncicka
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
| | - Anna Jindrova
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
| | - Denisa Jansova
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
| | - Rajan Iyyappan
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
| | - Kristina Roucova
- Laboratory of RNA Biochemistry Department of Genetics and Microbiology Faculty of Science Charles University in Prague Prague Czech Republic
| | - Alexander W. Bruce
- Laboratory of Early Mammalian Developmental Biology (LEMDB) Department of Molecular Biology and Genetics Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - Michal Kubelka
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
| | - Andrej Susor
- Laboratory of Biochemistry and Molecular Biology of Germ Cells Institute of Animal Physiology and Genetics CAS Libechov Czech Republic
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13
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Skariah G, Todd PK. Translational control in aging and neurodegeneration. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1628. [PMID: 32954679 DOI: 10.1002/wrna.1628] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/19/2020] [Accepted: 09/07/2020] [Indexed: 12/13/2022]
Abstract
Protein metabolism plays central roles in age-related decline and neurodegeneration. While a large body of research has explored age-related changes in protein degradation, alterations in the efficiency and fidelity of protein synthesis with aging are less well understood. Age-associated changes occur in both the protein synthetic machinery (ribosomal proteins and rRNA) and within regulatory factors controlling translation. At the same time, many of the interventions that prolong lifespan do so in part by pre-emptively decreasing protein synthesis rates to allow better harmonization to age-related declines in protein catabolism. Here we review the roles of translation regulation in aging, with a specific focus on factors implicated in age-related neurodegeneration. We discuss how emerging technologies such as ribosome profiling and superior mass spectrometric approaches are illuminating age-dependent mRNA-specific changes in translation rates across tissues to reveal a critical interplay between catabolic and anabolic pathways that likely contribute to functional decline. These new findings point to nodes in posttranscriptional gene regulation that both contribute to aging and offer targets for therapy. This article is categorized under: Translation > Translation Regulation Translation > Ribosome Biogenesis Translation > Translation Mechanisms.
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Affiliation(s)
- Geena Skariah
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
- Ann Arbor VA Healthcare System, Department of Veterans Affairs, Ann Arbor, Michigan, USA
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14
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Nüske E, Marini G, Richter D, Leng W, Bogdanova A, Franzmann TM, Pigino G, Alberti S. Filament formation by the translation factor eIF2B regulates protein synthesis in starved cells. Biol Open 2020; 9:bio046391. [PMID: 32554487 PMCID: PMC7358136 DOI: 10.1242/bio.046391] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/26/2020] [Indexed: 12/11/2022] Open
Abstract
Cells exposed to starvation have to adjust their metabolism to conserve energy and protect themselves. Protein synthesis is one of the major energy-consuming processes and as such has to be tightly controlled. Many mechanistic details about how starved cells regulate the process of protein synthesis are still unknown. Here, we report that the essential translation initiation factor eIF2B forms filaments in starved budding yeast cells. We demonstrate that filamentation is triggered by starvation-induced acidification of the cytosol, which is caused by an influx of protons from the extracellular environment. We show that filament assembly by eIF2B is necessary for rapid and efficient downregulation of translation. Importantly, this mechanism does not require the kinase Gcn2. Furthermore, analysis of site-specific variants suggests that eIF2B assembly results in enzymatically inactive filaments that promote stress survival and fast recovery of cells from starvation. We propose that translation regulation through filament assembly is an efficient mechanism that allows yeast cells to adapt to fluctuating environments.
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Affiliation(s)
- Elisabeth Nüske
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Guendalina Marini
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Doris Richter
- Department of Cellular Biochemistry Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Weihua Leng
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Aliona Bogdanova
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Titus M Franzmann
- Department of Cellular Biochemistry Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
- Department of Cellular Biochemistry Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
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15
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Identifying the Translatome of Mouse NEBD-Stage Oocytes via SSP-Profiling; A Novel Polysome Fractionation Method. Int J Mol Sci 2020; 21:ijms21041254. [PMID: 32070012 PMCID: PMC7072993 DOI: 10.3390/ijms21041254] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 12/13/2022] Open
Abstract
Meiotic maturation of oocyte relies on pre-synthesised maternal mRNA, the translation of which is highly coordinated in space and time. Here, we provide a detailed polysome profiling protocol that demonstrates a combination of the sucrose gradient ultracentrifugation in small SW55Ti tubes with the qRT-PCR-based quantification of 18S and 28S rRNAs in fractionated polysome profile. This newly optimised method, named Scarce Sample Polysome Profiling (SSP-profiling), is suitable for both scarce and conventional sample sizes and is compatible with downstream RNA-seq to identify polysome associated transcripts. Utilising SSP-profiling we have assayed the translatome of mouse oocytes at the onset of nuclear envelope breakdown (NEBD)—a developmental point, the study of which is important for furthering our understanding of the molecular mechanisms leading to oocyte aneuploidy. Our analyses identified 1847 transcripts with moderate to strong polysome occupancy, including abundantly represented mRNAs encoding mitochondrial and ribosomal proteins, proteasomal components, glycolytic and amino acids synthetic enzymes, proteins involved in cytoskeleton organization plus RNA-binding and translation initiation factors. In addition to transcripts encoding known players of meiotic progression, we also identified several mRNAs encoding proteins of unknown function. Polysome profiles generated using SSP-profiling were more than comparable to those developed using existing conventional approaches, being demonstrably superior in their resolution, reproducibility, versatility, speed of derivation and downstream protocol applicability.
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16
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Wang D, Karamyshev AL. Next Generation Sequencing (NGS) Application in Multiparameter Gene Expression Analysis. Methods Mol Biol 2020; 2102:17-34. [PMID: 31989548 DOI: 10.1007/978-1-0716-0223-2_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Next generation sequencing (NGS) is routinely used in gene expression analyses. In particular, RNA-seq has been the method of choice for highly sensitive genome-wide quantification of RNA expression. The method can be used in a wide variety of model systems, including studies to gain insight into underlying mechanisms of toxicologic processes and disease development induced by environmental toxicants. RNA-seq has also been coupled to many other molecular biology protocols to monitor specific aspects of the gene expression process. Here, we describe two such coupling-(a) global run-on sequencing (GRO-seq) that coupled it to the nuclear run-on (NRO), and (b) polysome profiling that coupled it to sucrose-gradient-based polysome isolation. Simultaneous RNA-seq, GRO-seq, and polysome profiling analyses enabled genome-wide analysis of the mode of stability control of individual RNA molecules.
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Affiliation(s)
- Degeng Wang
- Department of Environmental Toxicology, Texas Tech University, Lubbock, TX, USA.
- The Institute of Environmental and Human Health (TIEHH), Texas Tech University, Lubbock, TX, USA.
| | - Andrey L Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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17
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El‐Naggar AM, Somasekharan SP, Wang Y, Cheng H, Negri GL, Pan M, Wang XQ, Delaidelli A, Rafn B, Cran J, Zhang F, Zhang H, Colborne S, Gleave M, Mandinova A, Kedersha N, Hughes CS, Surdez D, Delattre O, Wang Y, Huntsman DG, Morin GB, Sorensen PH. Class I HDAC inhibitors enhance YB-1 acetylation and oxidative stress to block sarcoma metastasis. EMBO Rep 2019; 20:e48375. [PMID: 31668005 PMCID: PMC6893361 DOI: 10.15252/embr.201948375] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/29/2019] [Accepted: 10/06/2019] [Indexed: 12/13/2022] Open
Abstract
Outcomes for metastatic Ewing sarcoma and osteosarcoma are dismal and have not changed for decades. Oxidative stress attenuates melanoma metastasis, and melanoma cells must reduce oxidative stress to metastasize. We explored this in sarcomas by screening for oxidative stress sensitizers, which identified the class I HDAC inhibitor MS-275 as enhancing vulnerability to reactive oxygen species (ROS) in sarcoma cells. Mechanistically, MS-275 inhibits YB-1 deacetylation, decreasing its binding to 5'-UTRs of NFE2L2 encoding the antioxidant factor NRF2, thereby reducing NFE2L2 translation and synthesis of NRF2 to increase cellular ROS. By global acetylomics, MS-275 promotes rapid acetylation of the YB-1 RNA-binding protein at lysine-81, blocking binding and translational activation of NFE2L2, as well as known YB-1 mRNA targets, HIF1A, and the stress granule nucleator, G3BP1. MS-275 dramatically reduces sarcoma metastasis in vivo, but an MS-275-resistant YB-1K81-to-alanine mutant restores metastatic capacity and NRF2, HIF1α, and G3BP1 synthesis in MS-275-treated mice. These studies describe a novel function for MS-275 through enhanced YB-1 acetylation, thus inhibiting YB-1 translational control of key cytoprotective factors and its pro-metastatic activity.
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Affiliation(s)
- Amal M El‐Naggar
- Department of Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
- Department of PathologyFaculty of MedicineMenoufia UniversityShibin El KomEgypt
| | | | - Yemin Wang
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | | | | | - Melvin Pan
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | - Xue Qi Wang
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | - Alberto Delaidelli
- Department of Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | - Bo Rafn
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | - Jordan Cran
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | - Fan Zhang
- Vancouver Prostate CentreVancouverBCCanada
| | - Haifeng Zhang
- Department of Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | | | | | - Anna Mandinova
- Brigham and Women's HospitalHarvard UniversityBostonMAUSA
| | - Nancy Kedersha
- Massachusetts General HospitalHarvard UniversityBostonMAUSA
| | - Christopher S Hughes
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | | | | | | | - David G Huntsman
- Department of Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
| | - Gregg B Morin
- Michael Smith Genome Sciences CentreVancouverBCCanada
| | - Poul H Sorensen
- Department of Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Molecular Oncology, BC Cancerpart of the Provincial Health Services AuthorityVancouverBCCanada
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18
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Vopálenský V, Sýkora M, Mašek T, Pospíšek M. Messenger RNAs of Yeast Virus-Like Elements Contain Non-templated 5' Poly(A) Leaders, and Their Expression Is Independent of eIF4E and Pab1. Front Microbiol 2019; 10:2366. [PMID: 31736885 PMCID: PMC6831550 DOI: 10.3389/fmicb.2019.02366] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 09/30/2019] [Indexed: 02/01/2023] Open
Abstract
We employed virus-like elements (VLEs) pGKL1,2 from Kluyveromyces lactis as a model to investigate the previously neglected transcriptome of the broader group of yeast cytoplasmic linear dsDNA VLEs. We performed 5′ and 3′ RACE analyses of all pGKL1,2 mRNAs and found them not 3′ polyadenylated and containing frequently uncapped 5′ poly(A) leaders that are not complementary to VLE genomic DNA. The degree of 5′ capping and/or 5′ mRNA polyadenylation is specific to each gene and is controlled by the corresponding promoter region. The expression of pGKL1,2 transcripts is independent of eIF4E and Pab1 and is enhanced in lsm1Δ and pab1Δ strains. We suggest a model of primitive pGKL1,2 gene expression regulation in which the degree of 5′ mRNA capping and 5′ non-template polyadenylation, together with the presence of negative regulators such as Pab1 and Lsm1, play important roles. Our data also support a hypothesis of a close relationship between yeast linear VLEs and poxviruses.
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Affiliation(s)
- Václav Vopálenský
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Michal Sýkora
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Tomáš Mašek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Martin Pospíšek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
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19
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Pillon MC, Sobhany M, Stanley RE. Characterization of the molecular crosstalk within the essential Grc3/Las1 pre-rRNA processing complex. RNA (NEW YORK, N.Y.) 2018; 24:721-738. [PMID: 29440475 PMCID: PMC5900568 DOI: 10.1261/rna.065037.117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Grc3 is an essential well-conserved eukaryotic polynucleotide kinase (PNK) that cooperates with the endoribonuclease Las1 to process the preribosomal RNA (rRNA). Aside from being dependent upon Las1 for coordinated kinase and nuclease function, little is known about Grc3 substrate specificity and the molecular mechanisms governing kinase activity. Here we characterize the kinase activity of Grc3 and identify key similarities and differences between Grc3 and other polynucleotide kinase family members. In contrast to other PNK family members, Grc3 has distinct substrate preference for RNA substrates in vitro. By disrupting conserved residues found at the Grc3 kinase active site, we identified specific residues required to support Grc3-directed Las1-mediated pre-rRNA cleavage in vitro and in vivo. The crosstalk between Grc3 and Las1 ensures the direct coupling of cleavage and phosphorylation during pre-rRNA processing. Taken together, our studies provide key insight into the polynucleotide kinase activity of the essential enzyme Grc3 and its molecular crosstalk with the endoribonuclease Las1.
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Affiliation(s)
- Monica C Pillon
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA
| | - Mack Sobhany
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA
| | - Robin E Stanley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA
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20
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Karamysheva ZN, Tikhonova EB, Grozdanov PN, Huffman JC, Baca KR, Karamyshev A, Denison RB, MacDonald CC, Zhang K, Karamyshev AL. Polysome Profiling in Leishmania, Human Cells and Mouse Testis. J Vis Exp 2018. [PMID: 29683462 DOI: 10.3791/57600] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Proper protein expression at the right time and in the right amounts is the basis of normal cell function and survival in a fast-changing environment. For a long time, the gene expression studies were dominated by research on the transcriptional level. However, the steady-state levels of mRNAs do not correlate well with protein production, and the translatability of mRNAs varies greatly depending on the conditions. In some organisms, like the parasite Leishmania, the protein expression is regulated mostly at the translational level. Recent studies demonstrated that protein translation dysregulation is associated with cancer, metabolic, neurodegenerative and other human diseases. Polysome profiling is a powerful method to study protein translation regulation. It allows to measure the translational status of individual mRNAs or examine translation on a genome-wide scale. The basis of this technique is the separation of polysomes, ribosomes, their subunits and free mRNAs during centrifugation of a cytoplasmic lysate through a sucrose gradient. Here, we present a universal polysome profiling protocol used on three different models - parasite Leishmania major, cultured human cells and animal tissues. Leishmania cells freely grow in suspension and cultured human cells grow in adherent monolayer, while mouse testis represents an animal tissue sample. Thus, the technique is adapted to all of these sources. The protocol for the analysis of polysomal fractions includes detection of individual mRNA levels by RT-qPCR, proteins by Western blot and analysis of ribosomal RNAs by electrophoresis. The method can be further extended by examination of mRNAs association with the ribosome on a transcriptome level by deep RNA-seq and analysis of ribosome-associated proteins by mass spectroscopy of the fractions. The method can be easily adjusted to other biological models.
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Affiliation(s)
| | - Elena B Tikhonova
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - Petar N Grozdanov
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - James C Huffman
- Department of Biological Sciences, Texas Tech University; CISER (Center for the Integration of STEM Education & Research), Texas Tech University
| | - Kristen R Baca
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center; CISER (Center for the Integration of STEM Education & Research), Texas Tech University
| | - Alexander Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - R Brian Denison
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - Clinton C MacDonald
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University
| | - Andrey L Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center;
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21
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Franzmann TM, Jahnel M, Pozniakovsky A, Mahamid J, Holehouse AS, Nüske E, Richter D, Baumeister W, Grill SW, Pappu RV, Hyman AA, Alberti S. Phase separation of a yeast prion protein promotes cellular fitness. Science 2018. [DOI: 10.1126/science.aao5654 eaao5654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Biophysical responses of proteins to stress
Much recent work has focused on liquid-liquid phase separation as a cellular response to changing physicochemical conditions. Because phase separation responds critically to small changes in conditions such as pH, temperature, or salt, it is in principle an ideal way for a cell to measure and respond to changes in the environment. Small pH changes could, for instance, induce phase separation of compartments that store, protect, or inactivate proteins. Franzmann
et al.
used the yeast translation termination factor Sup35 as a model for a phase separation–induced stress response. Lowering the pH induced liquid-liquid phase separation of Sup35. The resulting liquid compartments subsequently hardened into gels, which sequestered the termination factor. Raising the pH triggered dissolution of the gels, concomitant with translation restart. Protecting Sup35 in gels could provide a fitness advantage to recovering yeast cells that must restart the translation machinery after stress.
Science
, this issue p.
eaao5654
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Affiliation(s)
- Titus M. Franzmann
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Marcus Jahnel
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
- Biotec, Technische Universität Dresden, Tatzberg 47/48, 01307 Dresden, Germany
| | - Andrei Pozniakovsky
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Julia Mahamid
- European Molecular Biology Laboratory, Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Alex S. Holehouse
- Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Elisabeth Nüske
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Doris Richter
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Wolfgang Baumeister
- Max Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Stephan W. Grill
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
- Biotec, Technische Universität Dresden, Tatzberg 47/48, 01307 Dresden, Germany
| | - Rohit V. Pappu
- Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Anthony A. Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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22
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Franzmann TM, Jahnel M, Pozniakovsky A, Mahamid J, Holehouse AS, Nüske E, Richter D, Baumeister W, Grill SW, Pappu RV, Hyman AA, Alberti S. Phase separation of a yeast prion protein promotes cellular fitness. Science 2018; 359:359/6371/eaao5654. [DOI: 10.1126/science.aao5654] [Citation(s) in RCA: 395] [Impact Index Per Article: 65.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/27/2017] [Indexed: 12/13/2022]
Abstract
Despite the important role of prion domains in neurodegenerative disease, their physiological function has remained enigmatic. Previous work with yeast prions has defined prion domains as sequences that form self-propagating aggregates. Here, we uncovered an unexpected function of the canonical yeast prion protein Sup35. In stressed conditions, Sup35 formed protective gels via pH-regulated liquid-like phase separation followed by gelation. Phase separation was mediated by the N-terminal prion domain and regulated by the adjacent pH sensor domain. Phase separation promoted yeast cell survival by rescuing the essential Sup35 translation factor from stress-induced damage. Thus, prion-like domains represent conserved environmental stress sensors that facilitate rapid adaptation in unstable environments by modifying protein phase behavior.
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23
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Liu CL, Place AR, Jagus R. Use of Antibiotics for Maintenance of Axenic Cultures of Amphidinium carterae for the Analysis of Translation. Mar Drugs 2017; 15:E242. [PMID: 28763019 PMCID: PMC5577597 DOI: 10.3390/md15080242] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 07/17/2017] [Accepted: 07/27/2017] [Indexed: 11/16/2022] Open
Abstract
Most dinoflagellates in culture are bacterized, complicating the quantification of protein synthesis, as well as the analysis of its regulation. In bacterized cultures of Amphidinium carterae Hulbert, up to 80% of protein synthetic activity appears to be predominantly bacterial based on responses to inhibitors of protein synthesis. To circumvent this, axenic cultures of A. carterae were obtained and shown to respond to inhibitors of protein synthesis in a manner characteristic of eukaryotes. However, these responses changed with time in culture correlating with the reappearance of bacteria. Here we show that culture with kanamycin (50 μg/mL), carbenicillin (100 μg/mL), and streptomycin sulfate (50 μg/mL) (KCS), but not 100 units/mL of penicillin and streptomycin (PS), prevents the reappearance of bacteria and allows A. carterae protein synthesis to be quantified without the contribution of an associated bacterial community. We demonstrate that A. carterae can grow in the absence of a bacterial community. Furthermore, maintenance in KCS does not inhibit the growth of A. carterae cultures but slightly extends the growth phase and allows accumulation to somewhat higher saturation densities. We also show that cultures of A. carterae maintained in KCS respond to the eukaryotic protein synthesis inhibitors cycloheximide, emetine, and harringtonine. Establishment of these culture conditions will facilitate our ability to use polysome fractionation and ribosome profiling to study mRNA recruitment. Furthermore, this study shows that a simple and fast appraisal of the presence of a bacterial community in A. carterae cultures can be made by comparing responses to cycloheximide and chloramphenicol rather than depending on lengthier culture-based assessments.
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Affiliation(s)
- Chieh-Lun Liu
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.
| | - Allen R Place
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.
| | - Rosemary Jagus
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.
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Polysome profiling of mAb producing CHO cell lines links translational control of cell proliferation and recombinant mRNA loading onto ribosomes with global and recombinant protein synthesis. Biotechnol J 2017; 12. [DOI: 10.1002/biot.201700177] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 05/07/2017] [Accepted: 05/15/2017] [Indexed: 12/13/2022]
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25
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Grc3 programs the essential endoribonuclease Las1 for specific RNA cleavage. Proc Natl Acad Sci U S A 2017; 114:E5530-E5538. [PMID: 28652339 DOI: 10.1073/pnas.1703133114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Las1 is a recently discovered endoribonuclease that collaborates with Grc3-Rat1-Rai1 to process precursor ribosomal RNA (rRNA), yet its mechanism of action remains unknown. Disruption of the mammalian Las1 gene has been linked to congenital lethal motor neuron disease and X-linked intellectual disability disorders, thus highlighting the necessity to understand Las1 regulation and function. Here, we report that the essential Las1 endoribonuclease requires its binding partner, the polynucleotide kinase Grc3, for specific C2 cleavage. Our results establish that Grc3 drives Las1 endoribonuclease cleavage to its targeted C2 site both in vitro and in Saccharomyces cerevisiae. Moreover, we observed Las1-dependent activation of the Grc3 kinase activity exclusively toward single-stranded RNA. Together, Las1 and Grc3 assemble into a tetrameric complex that is required for competent rRNA processing. The tetrameric Grc3/Las1 cross talk draws unexpected parallels to endoribonucleases RNaseL and Ire1, and establishes Grc3/Las1 as a unique member of the RNaseL/Ire1 RNA splicing family. Together, our work provides mechanistic insight for the regulation of the Las1 endoribonuclease and identifies the tetrameric Grc3/Las1 complex as a unique example of a protein-guided programmable endoribonuclease.
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Stastna M, Gottlieb RA, Van Eyk JE. Exploring ribosome composition and newly synthesized proteins through proteomics and potential biomedical applications. Expert Rev Proteomics 2017; 14:529-543. [PMID: 28532181 DOI: 10.1080/14789450.2017.1333424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
INTRODUCTION Protein synthesis is the outcome of tightly regulated gene expression which is responsive to a variety of conditions. Efforts are ongoing to monitor individual stages of protein synthesis to ensure maximum efficiency and accuracy. Due to post-transcriptional regulation mechanisms, the correlation between translatome and proteome is higher than between transcriptome and proteome. However, the most accurate approach to assess the key modulators and final protein expression is directly by using proteomics. Areas covered: This review covers various proteomic strategies that were used to better understand post-transcriptional regulation, specifically during and early after translation. The methods that identify both regulatory proteins associated with translational components and newly synthesized proteins are discussed. Expert commentary: Emerging proteomic approaches make it possible to monitor protein dynamics in cells, tissues and whole animals. The ability to detect alteration in protein abundance soon after their synthesis enables earlier recognition of disease causing factors and candidates to prevent/rectify disease phenotype.
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Affiliation(s)
- Miroslava Stastna
- a Heart Institute , Cedars-Sinai Medical Center , Los Angeles , CA , USA.,b Advanced Clinical BioSystems Research Institute , Cedars-Sinai Medical Center , Los Angeles , CA , USA.,c Institute of Analytical Chemistry of the Czech Academy of Sciences, v. v. i ., Brno , Czech Republic
| | - Roberta A Gottlieb
- a Heart Institute , Cedars-Sinai Medical Center , Los Angeles , CA , USA
| | - Jennifer E Van Eyk
- a Heart Institute , Cedars-Sinai Medical Center , Los Angeles , CA , USA.,b Advanced Clinical BioSystems Research Institute , Cedars-Sinai Medical Center , Los Angeles , CA , USA
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27
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Translation complex profile sequencing to study the in vivo dynamics of mRNA–ribosome interactions during translation initiation, elongation and termination. Nat Protoc 2017; 12:697-731. [DOI: 10.1038/nprot.2016.189] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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28
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Namjoshi SV, Raab-Graham KF. Screening the Molecular Framework Underlying Local Dendritic mRNA Translation. Front Mol Neurosci 2017; 10:45. [PMID: 28286470 PMCID: PMC5323403 DOI: 10.3389/fnmol.2017.00045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/10/2017] [Indexed: 12/13/2022] Open
Abstract
In the last decade, bioinformatic analyses of high-throughput proteomics and transcriptomics data have enabled researchers to gain insight into the molecular networks that may underlie lasting changes in synaptic efficacy. Development and utilization of these techniques have advanced the field of learning and memory significantly. It is now possible to move from the study of activity-dependent changes of a single protein to modeling entire network changes that require local protein synthesis. This data revolution has necessitated the development of alternative computational and statistical techniques to analyze and understand the patterns contained within. Thus, the focus of this review is to provide a synopsis of the journey and evolution toward big data techniques to address still unanswered questions regarding how synapses are modified to strengthen neuronal circuits. We first review the seminal studies that demonstrated the pivotal role played by local mRNA translation as the mechanism underlying the enhancement of enduring synaptic activity. In the interest of those who are new to the field, we provide a brief overview of molecular biology and biochemical techniques utilized for sample preparation to identify locally translated proteins using RNA sequencing and proteomics, as well as the computational approaches used to analyze these data. While many mRNAs have been identified, few have been shown to be locally synthesized. To this end, we review techniques currently being utilized to visualize new protein synthesis, a task that has proven to be the most difficult aspect of the field. Finally, we provide examples of future applications to test the physiological relevance of locally synthesized proteins identified by big data approaches.
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Affiliation(s)
- Sanjeev V Namjoshi
- Center for Learning and Memory, The University of Texas at Austin, AustinTX, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, AustinTX, USA
| | - Kimberly F Raab-Graham
- Center for Learning and Memory, The University of Texas at Austin, AustinTX, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, AustinTX, USA; Department of Physiology and Pharmacology, Wake Forest Health Sciences, Medical Center Boulevard, Winston-SalemNC, USA
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29
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van Attekum MHA, Terpstra S, Slinger E, von Lindern M, Moerland PD, Jongejan A, Kater AP, Eldering E. Macrophages confer survival signals via CCR1-dependent translational MCL-1 induction in chronic lymphocytic leukemia. Oncogene 2017; 36:3651-3660. [PMID: 28192408 PMCID: PMC5584520 DOI: 10.1038/onc.2016.515] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 12/22/2022]
Abstract
Protective interactions with bystander cells in micro-environmental niches, such as lymph nodes (LNs), contribute to survival and therapy resistance of chronic lymphocytic leukemia (CLL) cells. This is caused by a shift in expression of B-cell lymphoma 2 (BCL-2) family members. Pro-survival proteins B-cell lymphoma-extra large (BCL-XL), BCL-2-related protein A1 (BFL-1) and myeloid leukemia cell differentiation protein 1 (MCL-1) are upregulated by LN-residing T cells through CD40L interaction, presumably via nuclear factor (NF)-κB signaling. Macrophages (Mφs) also reside in the LN, and are assumed to provide important supportive functions for CLL cells. However, if and how Mφs are able to induce survival is incompletely known. We first established that Mφs induced survival because of an exclusive upregulation of MCL-1. Next, we investigated the mechanism underlying MCL-1 induction by Mφs in comparison with CD40L. Genome-wide expression profiling of in vitro Mφ- and CD40L-stimulated CLL cells indicated activation of the phosphoinositide 3-kinase (PI3K)-V-Akt murine thymoma viral oncogene homolog (AKT)-mammalian target of rapamycin (mTOR) pathway, which was confirmed in ex vivo CLL LN material. Inhibition of PI3K-AKT-mTOR signaling abrogated MCL-1 upregulation and survival by Mφs, as well as CD40 stimulation. MCL-1 can be regulated at multiple levels, and we established that AKT leads to increased MCL-1 translation, but does not affect MCL-1 transcription or protein stabilization. Furthermore, among Mφ-secreted factors that could activate AKT, we found that induction of MCL-1 and survival critically depended on C-C motif chemokine receptor-1 (CCR1). In conclusion, this study indicates that two distinct micro-environmental factors, CD40L and Mφs, signal via CCR1 to induce AKT activation resulting in translational stabilization of MCL-1, and hence can contribute to CLL cell survival.
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Affiliation(s)
- M H A van Attekum
- Department of Hematology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - S Terpstra
- Department of Hematology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - E Slinger
- Department of Hematology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - M von Lindern
- Department of Hematopoiesis, Sanquin Research, Amsterdam, The Netherlands
| | - P D Moerland
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A Jongejan
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A P Kater
- Department of Hematology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Lymphoma and Myeloma Center Amsterdam (LYMMCARE), Amsterdam, The Netherlands
| | - E Eldering
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Lymphoma and Myeloma Center Amsterdam (LYMMCARE), Amsterdam, The Netherlands
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Aboulhouda S, Di Santo R, Therizols G, Weinberg D. Accurate, Streamlined Analysis of mRNA Translation by Sucrose Gradient Fractionation. Bio Protoc 2017; 7:e2573. [PMID: 29170751 DOI: 10.21769/bioprotoc.2573] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The efficiency with which proteins are produced from mRNA molecules can vary widely across transcripts, cell types, and cellular states. Methods that accurately assay the translational efficiency of mRNAs are critical to gaining a mechanistic understanding of post-transcriptional gene regulation. One way to measure translational efficiency is to determine the number of ribosomes associated with an mRNA molecule, normalized to the length of the coding sequence. The primary method for this analysis of individual mRNAs is sucrose gradient fractionation, which physically separates mRNAs based on the number of bound ribosomes. Here, we describe a streamlined protocol for accurate analysis of mRNA association with ribosomes. Compared to previous protocols, our method incorporates internal controls and improved buffer conditions that together reduce artifacts caused by non-specific mRNA-ribosome interactions. Moreover, our direct-from-fraction qRT-PCR protocol eliminates the need for RNA purification from gradient fractions, which greatly reduces the amount of hands-on time required and facilitates parallel analysis of multiple conditions or gene targets. Additionally, no phenol waste is generated during the procedure. We initially developed the protocol to investigate the translationally repressed state of the HAC1 mRNA in S. cerevisiae, but we also detail adapted procedures for mammalian cell lines and tissues.
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Affiliation(s)
- Soufiane Aboulhouda
- Department of Molecular and Cellular Pharmacology, University of California, San Francisco, CA, USA
| | - Rachael Di Santo
- Department of Molecular and Cellular Pharmacology, University of California, San Francisco, CA, USA
| | - Gabriel Therizols
- Department of Molecular and Cellular Pharmacology, University of California, San Francisco, CA, USA
| | - David Weinberg
- Department of Molecular and Cellular Pharmacology, University of California, San Francisco, CA, USA.,Sandler Faculty Fellows Program, University of California, San Francisco, CA, USA
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31
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Chen CYA, Shyu AB. Emerging Themes in Regulation of Global mRNA Turnover in cis. Trends Biochem Sci 2016; 42:16-27. [PMID: 27647213 DOI: 10.1016/j.tibs.2016.08.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 11/25/2022]
Abstract
mRNA is the molecule that conveys genetic information from DNA to the translation apparatus. mRNAs in all organisms display a wide range of stability, and mechanisms have evolved to selectively and differentially regulate individual mRNA stability in response to intracellular and extracellular cues. In recent years, three seemingly distinct aspects of RNA biology-mRNA N6-methyladenosine (m6A) modification, alternative 3' end processing and polyadenylation (APA), and mRNA codon usage-have been linked to mRNA turnover, and all three aspects function to regulate global mRNA stability in cis. Here, we discuss the discovery and molecular dissection of these mechanisms in relation to how they impact the intrinsic decay rate of mRNA in eukaryotes, leading to transcriptome reprogramming.
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Affiliation(s)
- Chyi-Ying A Chen
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ann-Bin Shyu
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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32
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Frydryskova K, Masek T, Borcin K, Mrvova S, Venturi V, Pospisek M. Distinct recruitment of human eIF4E isoforms to processing bodies and stress granules. BMC Mol Biol 2016; 17:21. [PMID: 27578149 PMCID: PMC5006505 DOI: 10.1186/s12867-016-0072-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/16/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eukaryotic translation initiation factor 4E (eIF4E) plays a pivotal role in the control of cap-dependent translation initiation, modulates the fate of specific mRNAs, occurs in processing bodies (PBs) and is required for formation of stress granules (SGs). In this study, we focused on the subcellular localization of a representative compendium of eIF4E protein isoforms, particularly on the less studied members of the human eIF4E protein family, eIF4E2 and eIF4E3. RESULTS We showed that unlike eIF4E1, its less studied isoform eIF4E3_A, encoded by human chromosome 3, localized to stress granules but not PBs upon both heat shock and arsenite stress. Furthermore, we found that eIF4E3_A interacts with human translation initiation factors eIF4G1, eIF4G3 and PABP1 in vivo and sediments into the same fractions as canonical eIF4E1 during polysome analysis in sucrose gradients. Contrary to this finding, the truncated human eIF4E3 isoform, eIF4E3_B, showed no localization to SGs and no binding to eIF4G. We also highlighted that eIF4E2 may exhibit distinct functions under different stresses as it readily localizes to P-bodies during arsenite and heat stresses, whereas it is redirected to stress granules only upon heat shock. We extended our study to a number of protein variants, arising from alternative mRNA splicing, of each of the three eIF4E isoforms. Our results surprisingly uncovered differences in the ability of eIF4E1_1 and eIF4E1_3 to form stress granules in response to cellular stresses. CONCLUSION Our comparison of all three human eIF4E isoforms and their protein variants enriches the intriguing spectrum of roles attributed to the eukaryotic initiation translation factors of the 4E family, which exhibit a distinctive localization within different RNA granules under different stresses. The localization of eIF4E3_A to stress granules, but not to processing bodies, along with its binding to eIF4G and PABP1 suggests a role of human eIF4E3_A in translation initiation rather than its involvement in a translational repression and mRNA decay and turnover. The localization of eIF4E2 to stress granules under heat shock but not arsenite stress indicates its distinct function in cellular response to these stresses and points to the variable protein content of SGs as a consequence of different stress insults.
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Affiliation(s)
- Klara Frydryskova
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic
| | - Tomas Masek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic.
| | - Katerina Borcin
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic
| | - Silvia Mrvova
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic
| | - Veronica Venturi
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Martin Pospisek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic.
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Sharma H, Anand B. Fluorescence bimolecular complementation enables facile detection of ribosome assembly defects in Escherichia coli. RNA Biol 2016; 13:872-82. [PMID: 27388791 DOI: 10.1080/15476286.2016.1207037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Assembly factors promote the otherwise non-spontaneous maturation of ribosome under physiological conditions inside the cell. Systematic identification and characterization of candidate assembly factors are fraught with bottlenecks due to lack of facile assay system to capture assembly defects. Here, we show that bimolecular fluorescence complementation (BiFC) allows detection of assembly defects that are induced by the loss of assembly factors. The fusion of N and C-terminal fragments of Venus fluorescent protein to the ribosomal proteins uS13 and uL5, respectively, in Escherichia coli facilitated the incorporation of the tagged uS13 and uL5 onto the respective ribosomal subunits. When the ribosomal subunits associated to form the 70S particle, the complementary fragments of Venus were brought into proximity and rendered the Venus fluorescent. Assembly defects that inhibit the subunits association were provoked by either the loss of the known assembly factors such as RsgA and SrmB or the presence of small molecule inhibitors of ribosome maturation such as Lamotrigine and several ribosome-targeting antibiotics and these showed abrogation of the fluorescence complementation. This suggests that BiFC can be employed as a surrogate measure to detect ribosome assembly defects proficiently by circumventing the otherwise cumbersome procedures. BiFC thus offers a facile platform not only for systematic screening to validate potential assembly factors but also to discover novel small molecule inhibitors of ribosome assembly toward mapping the complex assembly landscape of ribosome.
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Affiliation(s)
- Himanshu Sharma
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Assam , India
| | - Baskaran Anand
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Assam , India
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Tsai PW, Chien CY, Yeh YC, Tung L, Chen HF, Chang TH, Lan CY. Candida albicans Hom6 is a homoserine dehydrogenase involved in protein synthesis and cell adhesion. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2016; 50:863-871. [PMID: 27089825 DOI: 10.1016/j.jmii.2016.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/22/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND/PURPOSE Candida albicans is a common fungal pathogen in humans. In healthy individuals, C. albicans represents a harmless commensal organism, but infections can be life threatening in immunocompromised patients. The complete genome sequence of C. albicans is extremely useful for identifying genes that may be potential drug targets and important for pathogenic virulence. However, there are still many uncharacterized genes in the Candida genome database. In this study, we investigated C. albicans Hom6, the functions of which remain undetermined experimentally. METHODS HOM6-deleted and HOM6-reintegrated mutant strains were constructed. The mutant strains were compared with wild-type in their growth in various media and enzyme activity. Effects of HOM6 deletion on translation were further investigated by cell susceptibility to hygromycin B or cycloheximide, as well as by polysome profiling, and cell adhesion to polystyrene was also determined. RESULTS C. albicans Hom6 exhibits homoserine dehydrogenase activity and is involved in the biosynthesis of methionine and threonine. HOM6 deletion caused translational arrest in cells grown under amino acid starvation conditions. Additionally, Hom6 protein was found in both cytosolic and cell-wall fractions of cultured cells. Furthermore, HOM6 deletion reduced C. albicans cell adhesion to polystyrene, which is a common plastic used in many medical devices. CONCLUSION Given that there is no Hom6 homologue in mammalian cells, our results provided an important foundation for future development of new antifungal drugs.
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Affiliation(s)
- Pei-Wen Tsai
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Chu-Yang Chien
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ying-Chieh Yeh
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Luh Tung
- Genomics Research Center, Academia Sinica, Nankang, Taipei, Taiwan
| | - Hsueh-Fen Chen
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, Nankang, Taipei, Taiwan
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan; Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
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Dynamic secretion during meiotic reentry integrates the function of the oocyte and cumulus cells. Proc Natl Acad Sci U S A 2016; 113:2424-9. [PMID: 26864200 DOI: 10.1073/pnas.1519990113] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The differentiation of the female gamete into a developmentally competent oocyte relies on the protected environment of the ovarian follicle. The oocyte plays a key role in establishing this microenvironment by releasing paracrine factors that control the functions of surrounding somatic cells. Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are secreted during follicle growth and play pivotal roles in this local regulation. The current view is that the function of these secreted factors declines in the periovulatory period when the oocyte reenters the meiotic cell cycle. Here, we provide evidence that oocyte reentry into meiosis is instead associated with a shift in the pattern of secretion with a new set of bioactive molecules synthesized before ovulation. Using interleukin 7 (IL7) as a prototypic secreted factor, we show that its secretion is dependent on activation of mRNA translation in synchrony with the cell cycle and that its translation is under the control of somatic cells. IL7 is part of a local feedback loop with the soma because it regulates cumulus cell replication. Similar conclusions are reached when IL7 secretion is measured in human follicular fluid during in vitro fertilization cycles. IL7 concentration in the follicular fluid correlates with the oocyte ability to reach the MII stage of maturation. These findings are consistent with the hypothesis that a new set of local factors is secreted by the oocyte during ovulation. These dynamic secretions are likely critical for promoting the final stages of maturation and oocyte developmental competence.
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Liu B, Qian SB. Characterizing inactive ribosomes in translational profiling. ACTA ACUST UNITED AC 2016; 4:e1138018. [PMID: 27335722 DOI: 10.1080/21690731.2015.1138018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/20/2015] [Accepted: 12/28/2015] [Indexed: 01/10/2023]
Abstract
The broad impact of translational regulation has emerged explosively in the last few years in part due to the technological advance in genome-wide interrogation of gene expression. During mRNA translation, the majority of actively translating ribosomes exist as polysomes in cells with multiple ribosomes loaded on a single transcript. The importance of the monosome, however, has been less appreciated in translational profiling analysis. Here we report that the monosome fraction isolated by sucrose sedimentation contains a large quantity of inactive ribosomes that do not engage on mRNAs to direct translation. We found that the elongation factor eEF2, but not eEF1A, stably resides in these non-translating ribosomes. This unique feature permits direct evaluation of ribosome status under various stress conditions and in the presence of translation inhibitors. Ribosome profiling reveals that the monosome has a similar but not identical pattern of ribosome footprints compared to the polysome. We show that the association of free ribosomal subunits minimally contributes to ribosome occupancy outside of the coding region. Our results not only offer a quantitative method to monitor ribosome availability, but also uncover additional layers of ribosome status needed to be considered in translational profiling analysis.
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Affiliation(s)
- Botao Liu
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA; Graduate Field of Genetics, Genomics, and Development, Cornell University, Ithaca, NY, USA; Present address: Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA; Graduate Field of Genetics, Genomics, and Development, Cornell University, Ithaca, NY, USA
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Abstract
Among the multiple modes of regulation of gene expression, translational control is arguably the least investigated and understood, and its role in vascular biology and pathobiology is not an exception. Here, we review recent studies that have revealed exciting translational regulatory phenomena and mechanisms involving novel RNA binding proteins and microRNA machinery in vascular biology. From these studies, the importance of translational regulation in angiogenesis, atherosclerosis, and blood pressure maintenance is beginning to emerge. We believe that the recent development of powerful techniques such as ribosome profiling and translating ribosome affinity purification (TRAP) will motivate and facilitate additional research in these areas.
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Bilanchone V, Clemens K, Kaake R, Dawson AR, Matheos D, Nagashima K, Sitlani P, Patterson K, Chang I, Huang L, Sandmeyer S. Ty3 Retrotransposon Hijacks Mating Yeast RNA Processing Bodies to Infect New Genomes. PLoS Genet 2015; 11:e1005528. [PMID: 26421679 PMCID: PMC4589538 DOI: 10.1371/journal.pgen.1005528] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/24/2015] [Indexed: 01/15/2023] Open
Abstract
Retrotransposition of the budding yeast long terminal repeat retrotransposon Ty3 is activated during mating. In this study, proteins that associate with Ty3 Gag3 capsid protein during virus-like particle (VLP) assembly were identified by mass spectrometry and screened for roles in mating-stimulated retrotransposition. Components of RNA processing bodies including DEAD box helicases Dhh1/DDX6 and Ded1/DDX3, Sm-like protein Lsm1, decapping protein Dcp2, and 5' to 3' exonuclease Xrn1 were among the proteins identified. These proteins associated with Ty3 proteins and RNA, and were required for formation of Ty3 VLP retrosome assembly factories and for retrotransposition. Specifically, Dhh1/DDX6 was required for normal levels of Ty3 genomic RNA, and Lsm1 and Xrn1 were required for association of Ty3 protein and RNA into retrosomes. This role for components of RNA processing bodies in promoting VLP assembly and retrotransposition during mating in a yeast that lacks RNA interference, contrasts with roles proposed for orthologous components in animal germ cell ribonucleoprotein granules in turnover and epigenetic suppression of retrotransposon RNAs.
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Affiliation(s)
- Virginia Bilanchone
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Kristina Clemens
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Robyn Kaake
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California, United States of America
| | - Anthony R. Dawson
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Dina Matheos
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Kunio Nagashima
- Electron Microscope Laboratory, NCI-Frederick, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Parth Sitlani
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Kurt Patterson
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Ivan Chang
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California, United States of America
| | - Suzanne Sandmeyer
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
- Institute for Genomics and Bioinformatics, University of California, Irvine, Irvine, California, United States of America
- * E-mail:
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Vernekar DV, Bhargava P. Yeast Bud27 modulates the biogenesis of Rpc128 and Rpc160 subunits and the assembly of RNA polymerase III. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:1340-53. [PMID: 26423792 DOI: 10.1016/j.bbagrm.2015.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 01/22/2023]
Abstract
Yeast Bud27, an unconventional prefoldin is reported to affect the expression of nutrient-responsive genes, translation initiation and assembly of the multi-subunit eukaryotic RNA polymerases (pols), at a late step. We found that Bud27 associates with pol III in active as well as repressed states. Pol III transcription and occupancy at the target genes reduce with the deletion of BUD27. It promotes the interaction of pol III with the chromatin remodeler RSC found on most of the pol III targets, and with the heat shock protein Ssa4, which helps in nuclear import of the assembled pol III. Under nutrient-starvation, Ssa4-pol III interaction increases, while pol III remains inside the nucleus. Bud27 but not Ssa4 is required for RSC-pol III interaction, which reduces under nutrient-starvation. In the bud27Δ cells, total protein level of the largest pol III subunit Rpc160 but not of Rpc128, Rpc34 and Rpc53 subunits is reduced. This is accompanied by lower transcription of RPC128 gene and lower RPC160 translation due to reduced association of mRNA with the ribosomes. The resultant alteration in the normal cellular ratio of the two largest subunits of pol III core leads to reduced association of other pol III subunits and hampers the normal assembly of pol III at an early step in the cytoplasm. Our results show that Bud27 is required in multiple activities responsible for pol III biogenesis and activity.
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Affiliation(s)
- Dipti Vinayak Vernekar
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India
| | - Purnima Bhargava
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India.
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Mammalian target of rapamycin complex 1 (mTORC1) Is required for mouse spermatogonial differentiation in vivo. Dev Biol 2015; 407:90-102. [PMID: 26254600 DOI: 10.1016/j.ydbio.2015.08.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 08/02/2015] [Accepted: 08/03/2015] [Indexed: 12/19/2022]
Abstract
Spermatogonial stem cells (SSCs) must balance self-renewal with production of transit-amplifying progenitors that differentiate in response to retinoic acid (RA) before entering meiosis. This self-renewal vs. differentiation spermatogonial fate decision is critical for maintaining tissue homeostasis, as imbalances cause spermatogenesis defects that can lead to human testicular cancer or infertility. A great deal of effort has been exerted to understand how the SSC population is maintained. In contrast, little is known about the essential program of differentiation initiated by retinoic acid (RA) that precedes meiosis, and the pathways and proteins involved are poorly defined. We recently reported a novel role for RA in stimulating the PI3/AKT/mTOR kinase signaling pathway to activate translation of repressed mRNAs such as Kit. Here, we examined the requirement for mTOR complex 1 (mTORC1) in mediating the RA signal to direct spermatogonial differentiation in the neonatal testis. We found that in vivo inhibition of mTORC1 by rapamycin blocked spermatogonial differentiation, which led to an accumulation of undifferentiated spermatogonia. In addition, rapamycin also blocked the RA-induced translational activation of mRNAs encoding KIT, SOHLH1, and SOHLH2 without affecting expression of STRA8. These findings highlight dual roles for RA in germ cell development - transcriptional activation of genes, and kinase signaling to stimulate translation of repressed messages required for spermatogonial differentiation.
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Translational control of myelin basic protein expression by ERK2 MAP kinase regulates timely remyelination in the adult brain. J Neurosci 2015; 35:7850-65. [PMID: 25995471 DOI: 10.1523/jneurosci.4380-14.2015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Successful myelin repair in the adult CNS requires the robust and timely production of myelin proteins to generate new myelin sheaths. The underlying regulatory mechanisms and complex molecular basis of myelin regeneration, however, remain poorly understood. Here, we investigate the role of ERK MAP kinase signaling in this process. Conditional deletion of Erk2 from cells of the oligodendrocyte lineage resulted in delayed remyelination following demyelinating injury to the adult mouse corpus callosum. The delayed repair occurred as a result of a specific deficit in the translation of the major myelin protein, MBP. In the absence of ERK2, activation of the ribosomal protein S6 kinase (p70S6K) and its downstream target, ribosomal protein S6 (S6RP), was impaired at a critical time when premyelinating oligodendrocytes were transitioning to mature cells capable of generating new myelin sheaths. Thus, we have described an important link between the ERK MAP kinase signaling cascade and the translational machinery specifically in remyelinating oligodendrocytes in vivo. These results suggest an important role for ERK2 in the translational control of MBP, a myelin protein that appears critical for ensuring the timely generation of new myelin sheaths following demyelinating injury in the adult CNS.
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Tourlakis ME, Zhang S, Ball HL, Gandhi R, Liu H, Zhong J, Yuan JS, Guidos CJ, Durie PR, Rommens JM. In Vivo Senescence in the Sbds-Deficient Murine Pancreas: Cell-Type Specific Consequences of Translation Insufficiency. PLoS Genet 2015; 11:e1005288. [PMID: 26057580 PMCID: PMC4461263 DOI: 10.1371/journal.pgen.1005288] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 05/18/2015] [Indexed: 01/01/2023] Open
Abstract
Genetic models of ribosome dysfunction show selective organ failure, highlighting a gap in our understanding of cell-type specific responses to translation insufficiency. Translation defects underlie a growing list of inherited and acquired cancer-predisposition syndromes referred to as ribosomopathies. We sought to identify molecular mechanisms underlying organ failure in a recessive ribosomopathy, with particular emphasis on the pancreas, an organ with a high and reiterative requirement for protein synthesis. Biallelic loss of function mutations in SBDS are associated with the ribosomopathy Shwachman-Diamond syndrome, which is typified by pancreatic dysfunction, bone marrow failure, skeletal abnormalities and neurological phenotypes. Targeted disruption of Sbds in the murine pancreas resulted in p53 stabilization early in the postnatal period, specifically in acinar cells. Decreased Myc expression was observed and atrophy of the adult SDS pancreas could be explained by the senescence of acinar cells, characterized by induction of Tgfβ, p15Ink4b and components of the senescence-associated secretory program. This is the first report of senescence, a tumour suppression mechanism, in association with SDS or in response to a ribosomopathy. Genetic ablation of p53 largely resolved digestive enzyme synthesis and acinar compartment hypoplasia, but resulted in decreased cell size, a hallmark of decreased translation capacity. Moreover, p53 ablation resulted in expression of acinar dedifferentiation markers and extensive apoptosis. Our findings indicate a protective role for p53 and senescence in response to Sbds ablation in the pancreas. In contrast to the pancreas, the Tgfβ molecular signature was not detected in fetal bone marrow, liver or brain of mouse models with constitutive Sbds ablation. Nevertheless, as observed with the adult pancreas phenotype, disease phenotypes of embryonic tissues, including marked neuronal cell death due to apoptosis, were determined to be p53-dependent. Our findings therefore point to cell/tissue-specific responses to p53-activation that include distinction between apoptosis and senescence pathways, in the context of translation disruption. Growth of all living things relies on protein synthesis. Failure of components of the complex protein synthesis machinery underlies a growing list of inherited and acquired multi—organ syndromes referred to as ribosomopathies. While ribosomes, the critical working components of the protein synthesis machinery, are required in all cell types to translate the genetic code, only certain organs manifest clinical symptoms in ribosomopathies, indicating specific cell-type features of protein synthesis control. Further, many of these diseases result in cancer despite an inherent deficit in growth. Here we report a range of consequences of protein synthesis insufficiency with loss of a broadly expressed ribosome factor, leading to growth impairment and cell cycle arrest at different stages. Apparent induction of p53-dependent cell death and arrest pathways included apoptosis in the fetal brain and senescence in the mature exocrine pancreas. The senescence, considered a tumour suppression mechanism, was accompanied by the expression of biomarkers associated with early stages of malignant transformation. These findings inform how cancer may initiate when growth is compromised and provide new insights into cell-type specific consequences of protein synthesis insufficiency.
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Affiliation(s)
- Marina E. Tourlakis
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Siyi Zhang
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Heather L. Ball
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Rikesh Gandhi
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Hongrui Liu
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Jian Zhong
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Julie S. Yuan
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Department of Immunology, University of Toronto, Toronto, Canada
| | - Cynthia J. Guidos
- Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Department of Immunology, University of Toronto, Toronto, Canada
| | - Peter R. Durie
- Program in Physiology & Experimental Medicine, Research Institute, Division of Gastroenterology & Nutrition, The Hospital for Sick Children, Department of Paediatrics, University of Toronto, Toronto, Canada
| | - Johanna M. Rommens
- Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
- * E-mail:
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Guan Z, Liu H. The WOR1 5' untranslated region regulates white-opaque switching in Candida albicans by reducing translational efficiency. Mol Microbiol 2015; 97:125-38. [PMID: 25831958 PMCID: PMC4552353 DOI: 10.1111/mmi.13014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2015] [Indexed: 12/25/2022]
Abstract
The human fungal pathogen Candida albicans undergoes white‐opaque phenotypic switching, which enhances its adaptation to host niches. Switching is controlled by a transcriptional regulatory network of interlocking feedback loops acting on the transcription of WOR1, the master regulator of white‐opaque switching, but regulation of the network on the translational level is not yet explored. Here, we show that the long 5′ untranslated region of WOR1 regulates the white‐opaque phenotype. Deletion of the WOR1 5′ UTR promotes white‐to‐opaque switching and stabilizes the opaque state. The WOR1 5′ UTR reduces translational efficiency and the association of the transcript with polysomes. Reduced polysome association was observed for additional key regulators of cell fate and morphology with long 5′ UTR as well. Overall, we find a novel regulatory step of white‐opaque switching at the translational level. This translational regulation is implicated for many key regulators of cell fate and morphology in C. albicans.
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Affiliation(s)
- Zhiyun Guan
- Department of Biological Chemistry, University of California, Irvine, CA, USA
| | - Haoping Liu
- Department of Biological Chemistry, University of California, Irvine, CA, USA
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Lenarcic EM, Ziehr BJ, Moorman NJ. An unbiased proteomics approach to identify human cytomegalovirus RNA-associated proteins. Virology 2015; 481:13-23. [PMID: 25765003 DOI: 10.1016/j.virol.2015.02.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/18/2014] [Accepted: 02/06/2015] [Indexed: 12/13/2022]
Abstract
Post-transcriptional events regulate herpesvirus gene expression, yet few herpesvirus RNA-binding proteins have been identified. We used an unbiased approach coupling oligo(dT) affinity capture with proteomics to identify viral RNA-associated proteins during infection. Using this approach, we identified and confirmed changes in the abundance or activity of two host RNA-associated proteins, DHX9 and DDX3, in cells infected with human cytomegalovirus (HCMV). We also identified and confirmed previously unreported activities for the HCMV US22 and pp71 proteins as RNA-associated viral proteins and confirmed that a known viral RNA-binding protein, pTRS1, associates with RNA in infected cells. Further, we found that HCMV pp71 co-sedimented with polysomes, associated with host and viral RNAs, and stimulated the overall rate of protein synthesis. These results demonstrate that oligo(dT) affinity capture coupled with proteomics provides a rapid and straightforward means to identify RNA-associated viral proteins during infection that may participate in the post-transcriptional control of gene expression.
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Affiliation(s)
- Erik M Lenarcic
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
| | - Benjamin J Ziehr
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
| | - Nathaniel J Moorman
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States.
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45
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Insel PA, Wilderman A, Zambon AC, Snead AN, Murray F, Aroonsakool N, McDonald DS, Zhou S, McCann T, Zhang L, Sriram K, Chinn AM, Michkov AV, Lynch RM, Overland AC, Corriden R. G Protein-Coupled Receptor (GPCR) Expression in Native Cells: "Novel" endoGPCRs as Physiologic Regulators and Therapeutic Targets. Mol Pharmacol 2015; 88:181-7. [PMID: 25737495 DOI: 10.1124/mol.115.098129] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/02/2015] [Indexed: 12/24/2022] Open
Abstract
G protein-coupled receptors (GPCRs), the largest family of signaling receptors in the human genome, are also the largest class of targets of approved drugs. Are the optimal GPCRs (in terms of efficacy and safety) currently targeted therapeutically? Especially given the large number (∼ 120) of orphan GPCRs (which lack known physiologic agonists), it is likely that previously unrecognized GPCRs, especially orphan receptors, regulate cell function and can be therapeutic targets. Knowledge is limited regarding the diversity and identity of GPCRs that are activated by endogenous ligands and that native cells express. Here, we review approaches to define GPCR expression in tissues and cells and results from studies using these approaches. We identify problems with the available data and suggest future ways to identify and validate the physiologic and therapeutic roles of previously unrecognized GPCRs. We propose that a particularly useful approach to identify functionally important GPCRs with therapeutic potential will be to focus on receptors that show selective increases in expression in diseased cells from patients and experimental animals.
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Affiliation(s)
- Paul A Insel
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Andrea Wilderman
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Alexander C Zambon
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Aaron N Snead
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Fiona Murray
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Nakon Aroonsakool
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Daniel S McDonald
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Shu Zhou
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Thalia McCann
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Lingzhi Zhang
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Krishna Sriram
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Amy M Chinn
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Alexander V Michkov
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Rebecca M Lynch
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Aaron C Overland
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
| | - Ross Corriden
- Departments of Pharmacology (P.A.I., A.W., A.C.Z., A.N.S., N.A., D.S.M., S.Z., T.M., L.Z., K.S., A.M.C., A.V.M., R.M.L., A.C.O., R.C.) and Medicine (P.A.I., F.M.), University of California, San Diego, La Jolla, California
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Translating Ribosome Affinity Purification (TRAP) followed by RNA sequencing technology (TRAP-SEQ) for quantitative assessment of plant translatomes. Methods Mol Biol 2015; 1284:185-207. [PMID: 25757773 DOI: 10.1007/978-1-4939-2444-8_9] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Translating Ribosome Affinity Purification (TRAP) is a technology to isolate the population of mRNAs associated with at least one 80S ribosome, referred as the translatome. TRAP is based on the expression of an epitope-tagged version of a ribosomal protein and the affinity purification of ribosomes and associated mRNAs using antibodies conjugated to agarose beads. Quantitative assessment of the translatome is achieved by direct RNA sequencing (RNA-SEQ), which provides accurate quantitation of ribosome-associated mRNAs and reveals alternatively spliced isoforms. Here we present a detailed procedure for TRAP, as well as a guide for preparation of RNA-SEQ libraries (TRAP-SEQ) and a primary data analysis. This methodology enables the study of translational dynamic by assessing rapid changes in translatomes, at organ or cell-type level, during development or in response to endogenous or exogenous stimuli.
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King HA, Gerber AP. Translatome profiling: methods for genome-scale analysis of mRNA translation. Brief Funct Genomics 2014; 15:22-31. [PMID: 25380596 DOI: 10.1093/bfgp/elu045] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During the past decade, there has been a rapidly increased appreciation of the role of translation as a key regulatory node in gene expression. Thereby, the development of methods to infer the translatome, which refers to the entirety of mRNAs associated with ribosomes for protein synthesis, has facilitated the discovery of new principles and mechanisms of translation and expanded our view of the underlying logic of protein synthesis. Here, we review the three main methodologies for translatome analysis, and we highlight some of the recent discoveries made using each technique. We first discuss polysomal profiling, a classical technique that involves the separation of mRNAs depending on the number of bound ribosomes using a sucrose gradient, and which has been combined with global analysis tools such as DNA microarrays or high-throughput RNA sequencing to identify the RNAs in polysomal fractions. We then introduce ribosomal profiling, a recently established technique that enables the mapping of ribosomes along mRNAs at near-nucleotide resolution on a global scale. We finally refer to ribosome affinity purification techniques that are based on the cell-type-specific expression of tagged ribosomal proteins, allowing the capture of translatomes from specialized cells in organisms. We discuss the advantages and disadvantages of these three main techniques in the pursuit of defining the translatome, and we speculate about future developments.
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Gigova A, Duggimpudi S, Pollex T, Schaefer M, Koš M. A cluster of methylations in the domain IV of 25S rRNA is required for ribosome stability. RNA (NEW YORK, N.Y.) 2014; 20:1632-44. [PMID: 25125595 PMCID: PMC4174444 DOI: 10.1261/rna.043398.113] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In all three domains of life ribosomal RNAs are extensively modified at functionally important sites of the ribosome. These modifications are believed to fine-tune the ribosome structure for optimal translation. However, the precise mechanistic effect of modifications on ribosome function remains largely unknown. Here we show that a cluster of methylated nucleotides in domain IV of 25S rRNA is critical for integrity of the large ribosomal subunit. We identified the elusive cytosine-5 methyltransferase for C2278 in yeast as Rcm1 and found that a combined loss of cytosine-5 methylation at C2278 and ribose methylation at G2288 caused dramatic ribosome instability, resulting in loss of 60S ribosomal subunits. Structural and biochemical analyses revealed that this instability was caused by changes in the structure of 25S rRNA and a consequent loss of multiple ribosomal proteins from the large ribosomal subunit. Our data demonstrate that individual RNA modifications can strongly affect structure of large ribonucleoprotein complexes.
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Affiliation(s)
- Andriana Gigova
- Biochemistry Center and Cluster of Excellence CellNetworks, University of Heidelberg, 69120 Heidelberg, Germany
| | - Sujitha Duggimpudi
- Biochemistry Center and Cluster of Excellence CellNetworks, University of Heidelberg, 69120 Heidelberg, Germany
| | - Tim Pollex
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Matthias Schaefer
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Martin Koš
- Biochemistry Center and Cluster of Excellence CellNetworks, University of Heidelberg, 69120 Heidelberg, Germany
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49
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Boddu R, Yang C, O’Connor AK, Hendrickson RC, Boone B, Cui X, Garcia-Gonzalez M, Igarashi P, Onuchic LF, Germino GG, Guay-Woodford LM. Intragenic motifs regulate the transcriptional complexity of Pkhd1/PKHD1. J Mol Med (Berl) 2014; 92:1045-56. [PMID: 24984783 PMCID: PMC4197071 DOI: 10.1007/s00109-014-1185-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/05/2014] [Accepted: 06/16/2014] [Indexed: 11/26/2022]
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) results from mutations in the human PKHD1 gene. Both this gene, and its mouse ortholog, Pkhd1, are primarily expressed in renal and biliary ductal structures. The mouse protein product, fibrocystin/polyductin complex (FPC), is a 445-kDa protein encoded by a 67-exon transcript that spans >500 kb of genomic DNA. In the current study, we observed multiple alternatively spliced Pkhd1 transcripts that varied in size and exon composition in embryonic mouse kidney, liver, and placenta samples, as well as among adult mouse pancreas, brain, heart, lung, testes, liver, and kidney. Using reverse transcription PCR and RNASeq, we identified 22 novel Pkhd1 kidney transcripts with unique exon junctions. Various mechanisms of alternative splicing were observed, including exon skipping, use of alternate acceptor/donor splice sites, and inclusion of novel exons. Bioinformatic analyses identified, and exon-trapping minigene experiments validated, consensus binding sites for serine/arginine-rich proteins that modulate alternative splicing. Using site-directed mutagenesis, we examined the functional importance of selected splice enhancers. In addition, we demonstrated that many of the novel transcripts were polysome bound, thus likely translated. Finally, we determined that the human PKHD1 R760H missense variant alters a splice enhancer motif that disrupts exon splicing in vitro and is predicted to truncate the protein. Taken together, these data provide evidence of the complex transcriptional regulation of Pkhd1/PKHD1 and identified motifs that regulate its splicing. Our studies indicate that Pkhd1/PKHD1 transcription is modulated, in part by intragenic factors, suggesting that aberrant PKHD1 splicing represents an unappreciated pathogenic mechanism in ARPKD. Key messages: Multiple mRNA transcripts are generated for Pkhd1 in renal tissues Pkhd1 transcription is modulated by standard splice elements and effectors Mutations in splice motifs may alter splicing to generate nonfunctional peptides.
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Affiliation(s)
- Ravindra Boddu
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chaozhe Yang
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
| | - Amber K. O’Connor
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
| | | | - Braden Boone
- Hudson Alpha Institute, Huntsville, AL 35806, USA
| | - Xiangqin Cui
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Miguel Garcia-Gonzalez
- Complexo Hospitalario de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - Peter Igarashi
- Department of Medicine, University of Texas Southwestern School of Medicine, Dallas, TX 75235, USA
| | - Luiz F. Onuchic
- Department of Medicine, University of Sao Paulo, Sao Paulo, Brazil 01246-903
| | - Gregory G. Germino
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lisa M. Guay-Woodford
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
- Children’s National Medical Center, 6th Floor Main Hospital, Center 6, 111 Michigan Ave NW, Washington, DC 20010, USA
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50
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Wu X, He WT, Tian S, Meng D, Li Y, Chen W, Li L, Tian L, Zhong CQ, Han F, Chen J, Han J. pelo is required for high efficiency viral replication. PLoS Pathog 2014; 10:e1004034. [PMID: 24722736 PMCID: PMC3983054 DOI: 10.1371/journal.ppat.1004034] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 02/14/2014] [Indexed: 11/18/2022] Open
Abstract
Viruses hijack host factors for their high speed protein synthesis, but information about these factors is largely unknown. In searching for genes that are involved in viral replication, we carried out a forward genetic screen for Drosophila mutants that are more resistant or sensitive to Drosophila C virus (DCV) infection-caused death, and found a virus-resistant line in which the expression of pelo gene was deficient. Our mechanistic studies excluded the viral resistance of pelo deficient flies resulting from the known Drosophila anti-viral pathways, and revealed that pelo deficiency limits the high level synthesis of the DCV capsid proteins but has no or very little effect on the expression of some other viral proteins, bulk cellular proteins, and transfected exogenous genes. The restriction of replication of other types of viruses in pelo deficient flies was also observed, suggesting pelo is required for high level production of capsids of all kinds of viruses. We show that both pelo deficiency and high level DCV protein synthesis increase aberrant 80S ribosomes, and propose that the preferential requirement of pelo for high level synthesis of viral capsids is at least partly due to the role of pelo in dissociation of stalled 80S ribosomes and clearance of aberrant viral RNA and proteins. Our data demonstrated that pelo is a host factor that is required for high efficiency translation of viral capsids and targeting pelo could be a strategy for general inhibition of viral infection.
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Affiliation(s)
- Xiurong Wu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Wan-Ting He
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Shuye Tian
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Dan Meng
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yuanyue Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Wanze Chen
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Lisheng Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Lili Tian
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Chuan-Qi Zhong
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Felicia Han
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Jianming Chen
- The Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography, State Oceanic Administration of China, Xiamen, Fujian, China
| | - Jiahuai Han
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
- * E-mail: ,
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