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Coleman JC, Tattersall L, Yianni V, Knight L, Yu H, Hallett SR, Johnson P, Caetano AJ, Cosstick C, Ridley AJ, Gartland A, Conte MR, Grigoriadis AE. The RNA binding proteins LARP4A and LARP4B promote sarcoma and carcinoma growth and metastasis. iScience 2024; 27:109288. [PMID: 38532886 PMCID: PMC10963253 DOI: 10.1016/j.isci.2024.109288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/01/2023] [Accepted: 02/16/2024] [Indexed: 03/28/2024] Open
Abstract
RNA-binding proteins (RBPs) are emerging as important regulators of cancer pathogenesis. We reveal that the RBPs LARP4A and LARP4B are differentially overexpressed in osteosarcoma and osteosarcoma lung metastases, as well as in prostate cancer. Depletion of LARP4A and LARP4B reduced tumor growth and metastatic spread in xenografts, as well as inhibiting cell proliferation, motility, and migration. Transcriptomic profiling and high-content multiparametric analyses unveiled a central role for LARP4B, but not LARP4A, in regulating cell cycle progression in osteosarcoma and prostate cancer cells, potentially through modulating key cell cycle proteins such as Cyclins B1 and E2, Aurora B, and E2F1. This first systematic comparison between LARP4A and LARP4B assigns new pro-tumorigenic functions to LARP4A and LARP4B in bone and prostate cancer, highlighting their similarities while also indicating distinct functional differences. Uncovering clear biological roles for these paralogous proteins provides new avenues for identifying tissue-specific targets and potential druggable intervention.
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Affiliation(s)
- Jennifer C. Coleman
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, SE1 1UL UK
| | - Luke Tattersall
- The Mellanby Centre for Musculoskeletal Research, Department of Oncology and Metabolism, The University of Sheffield, Sheffield, S10 2RX UK
| | - Val Yianni
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
| | - Laura Knight
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
| | - Hongqiang Yu
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
| | - Sadie R. Hallett
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, SE1 1UL UK
| | - Philip Johnson
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
| | - Ana J. Caetano
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
| | - Charlie Cosstick
- Centre for Craniofacial & Regenerative Biology, King’s College London, London, SE1 9RT UK
| | - Anne J. Ridley
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD UK
| | - Alison Gartland
- The Mellanby Centre for Musculoskeletal Research, Department of Oncology and Metabolism, The University of Sheffield, Sheffield, S10 2RX UK
| | - Maria R. Conte
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, SE1 1UL UK
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2
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Lewis BM, Cho CY, Her HL, Mizrahi O, Hunter T, Yeo GW. LARP4 is an RNA-binding protein that binds nuclear-encoded mitochondrial mRNAs to promote mitochondrial function. RNA (NEW YORK, N.Y.) 2024; 30:223-239. [PMID: 38164626 PMCID: PMC10870378 DOI: 10.1261/rna.079799.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/25/2023] [Indexed: 01/03/2024]
Abstract
Mitochondria-associated RNA-binding proteins (RBPs) have emerged as key contributors to mitochondrial biogenesis and homeostasis. With few examples known, we set out to identify RBPs that regulate nuclear-encoded mitochondrial mRNAs (NEMmRNAs). Our systematic analysis of RNA targets of 150 RBPs identified RBPs with a preference for binding NEMmRNAs, including LARP4, a La RBP family member. We show that LARP4's targets are particularly enriched in mRNAs that encode respiratory chain complex proteins (RCCPs) and mitochondrial ribosome proteins (MRPs) across multiple human cell lines. Through quantitative proteomics, we demonstrate that depletion of LARP4 leads to a significant reduction in RCCP and MRP protein levels. Furthermore, we show that LARP4 depletion reduces mitochondrial function, and that LARP4 re-expression rescues this phenotype. Our findings shed light on a novel function for LARP4 as an RBP that binds to and positively regulates NEMmRNAs to promote mitochondrial respiratory function.
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Affiliation(s)
- Benjamin M Lewis
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Chae Yun Cho
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Hsuan-Lin Her
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, California 92037, USA
| | - Orel Mizrahi
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
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3
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Iben JR, Li T, Mattijssen S, Maraia RJ. Single-Molecule Poly(A) Tail Sequencing (SM-PATseq) Using the PacBio Platform. Methods Mol Biol 2024; 2723:285-301. [PMID: 37824077 DOI: 10.1007/978-1-0716-3481-3_17] [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] [Indexed: 10/13/2023]
Abstract
The polyadenylation of the 3' ends of messenger RNAs is an important regulator of stability and translation. We developed the single-molecule poly(A) tail sequencing method, SM-PATseq, to assay tail lengths of the whole transcriptome at nucleotide resolution using long-read sequencing. This method generates cDNA using an oligo-dT 3' splint adaptor ligation to prime first-strand cDNA synthesis, followed by random hexamer priming for second-strand synthesis. By directly sequencing the cDNA on long-read platforms, we can resolve tail lengths at nucleotide resolution, identify non-A bases within the tail, and quantify transcript abundance analogous to traditional RNAseq methods. Here, we discuss the method for generating, sequencing, and primary analysis of poly(A) tail data from total RNA using the Pacific Biosciences Sequel platform.
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Affiliation(s)
- James R Iben
- Molecular Genetics Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
| | - Tianwei Li
- Molecular Genetics Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sandy Mattijssen
- Section on Molecular and Cell Biology, NICHD, NIH, Bethesda, MD, USA
| | - Richard J Maraia
- Section on Molecular and Cell Biology, NICHD, NIH, Bethesda, MD, USA.
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4
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Burgess HM, Grande R, Riccio S, Dinesh I, Winkler GS, Depledge DP, Mohr I. CCR4-NOT differentially controls host versus virus poly(a)-tail length and regulates HCMV infection. EMBO Rep 2023; 24:e56327. [PMID: 37846490 PMCID: PMC10702830 DOI: 10.15252/embr.202256327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/18/2023] Open
Abstract
Unlike most RNA and DNA viruses that broadly stimulate mRNA decay and interfere with host gene expression, human cytomegalovirus (HCMV) extensively remodels the host translatome without producing an mRNA decay enzyme. By performing a targeted loss-of-function screen in primary human fibroblasts, we here identify the host CCR4-NOT deadenylase complex members CNOT1 and CNOT3 as unexpected pro-viral host factors that selectively regulate HCMV reproduction. We find that the scaffold subunit CNOT1 is specifically required for late viral gene expression and genome-wide host responses in CCR4-NOT-disrupted cells. By profiling poly(A)-tail lengths of individual HCMV and host mRNAs using nanopore direct RNA sequencing, we reveal poly(A)-tails of viral messages to be markedly longer than those of cellular mRNAs and significantly less sensitive to CCR4-NOT disruption. Our data establish that mRNA deadenylation by host CCR4-NOT is critical for productive HCMV replication and define a new mechanism whereby herpesvirus infection subverts cellular mRNA metabolism to remodel the gene expression landscape of the infected cell. Moreover, we expose an unanticipated host factor with potential to become a therapeutic anti-HCMV target.
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Affiliation(s)
- Hannah M Burgess
- Department of Microbial SciencesUniversity of SurreyGuildfordUK
- Department of Microbiology, School of MedicineNew York UniversityNew YorkNYUSA
| | - Rebecca Grande
- Department of Microbiology, School of MedicineNew York UniversityNew YorkNYUSA
| | - Sofia Riccio
- Department of Microbial SciencesUniversity of SurreyGuildfordUK
| | - Ikshitaa Dinesh
- Department of Microbial SciencesUniversity of SurreyGuildfordUK
| | | | - Daniel P Depledge
- Department of Microbiology, School of MedicineNew York UniversityNew YorkNYUSA
- Institute of VirologyHannover Medical SchoolHannoverGermany
- German Center for Infection Research (DZIF), partner site Hannover‐BraunschweigHannoverGermany
| | - Ian Mohr
- Department of Microbiology, School of MedicineNew York UniversityNew YorkNYUSA
- Laura and Isaac Perlmutter Cancer Institute, School of MedicineNew York UniversityNew YorkNYUSA
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5
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Su Q, Long Y, Wang J, Gou D. CLT-seq as a universal homopolymer-sequencing concept reveals poly(A)-tail-tuned ncRNA regulation. Brief Bioinform 2023; 24:bbad374. [PMID: 37874949 DOI: 10.1093/bib/bbad374] [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: 05/22/2023] [Revised: 09/07/2023] [Accepted: 09/30/2023] [Indexed: 10/26/2023] Open
Abstract
Dynamic tuning of the poly(A) tail is a crucial mechanism for controlling translation and stability of eukaryotic mRNA. Achieving a comprehensive understanding of how this regulation occurs requires unbiased abundance quantification of poly(A)-tail transcripts and simple poly(A)-length measurement using high-throughput sequencing platforms. Current methods have limitations due to complicated setups and elaborate library preparation plans. To address this, we introduce central limit theorem (CLT)-managed RNA-seq (CLT-seq), a simple and straightforward homopolymer-sequencing method. In CLT-seq, an anchor-free oligo(dT) primer rapidly binds to and unbinds from anywhere along the poly(A) tail string, leading to position-directed reverse transcription with equal probability. The CLT mechanism enables the synthesized poly(T) lengths, which correspond to the templated segment of the poly(A) tail, to distribute normally. Based on a well-fitted pseudogaussian-derived poly(A)-poly(T) conversion model, the actual poly(A)-tail profile is reconstructed from the acquired poly(T)-length profile through matrix operations. CLT-seq follows a simple procedure without requiring RNA-related pre-treatment, enrichment or selection, and the CLT-shortened poly(T) stretches are more compatible with existing sequencing platforms. This proof-of-concept approach facilitates direct homopolymer base-calling and features unbiased RNA-seq. Therefore, CLT-seq provides unbiased, robust and cost-efficient transcriptome-wide poly(A)-tail profiling. We demonstrate that CLT-seq on the most common Illumina platform delivers reliable poly(A)-tail profiling at a transcriptome-wide scale in human cellular contexts. We find that the poly(A)-tail-tuned ncRNA regulation undergoes a dynamic, complex process similar to mRNA regulation. Overall, CLT-seq offers a simplified, effective and economical approach to investigate poly(A)-tail regulation, with potential implications for understanding gene expression and identifying therapeutic targets.
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Affiliation(s)
- Qiang Su
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, 1066 Xueyuan Street, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Yi Long
- The School of Medicine, Life and Health Sciences (MED | LHS), Chinese University of Hong Kong, Shenzhen, No. 2001 Longxiang Blvd., Longgang District, Shenzhen 518172, Guangdong, China
| | - Jun Wang
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, 1066 Xueyuan Street, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Deming Gou
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, 1066 Xueyuan Street, Nanshan District, Shenzhen 518055, Guangdong, China
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6
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Baptissart M, Papas BN, Chi RPA, Li Y, Lee D, Puviindran B, Morgan M. A unique poly(A) tail profile uncovers the stability and translational activation of TOP transcripts during neuronal differentiation. iScience 2023; 26:107511. [PMID: 37636056 PMCID: PMC10448114 DOI: 10.1016/j.isci.2023.107511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 05/15/2023] [Accepted: 07/25/2023] [Indexed: 08/29/2023] Open
Abstract
Cell differentiation is associated with global changes in translational activity. Here, we characterize how mRNA poly(A) tail processing supports this dynamic. We observe that decreased translation during neuronal differentiation of P19 cells correlates with the downregulation of 5'-terminal oligopyrimidine (TOP) transcripts which encode the translational machinery. Despite their downregulation, TOP transcripts remain highly stable and show increased translation as cells differentiate. Changes in TOP mRNA metabolism are reflected by their accumulation with poly(A) tails ∼60-nucleotide (nt) long. The dynamic changes in poly(A) processing can be partially recapitulated by depleting LARP1 or activating the mTOR pathway in undifferentiated cells. Although mTOR-induced accumulation of TOP mRNAs with tails ∼60-nt long does not trigger differentiation, it is associated with reduced proliferation of neuronal progenitors. We propose that while TOP mRNAs are transcriptionally silenced, their post-transcriptional regulation mediated by a specific poly(A) processing ensures an adequate supply of ribosomes to complete differentiation.
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Affiliation(s)
- Marine Baptissart
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
| | - Brian N. Papas
- Integrative Bioinformatics, Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
| | - Ru-pin Alicia Chi
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
| | - Yin Li
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
| | - Dongwon Lee
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
| | - Bhairavy Puviindran
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
| | - Marcos Morgan
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 27709, USA
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7
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Dhungel P, Brahim Belhaouari D, Yang Z. La-related protein 4 is enriched in vaccinia virus factories and is required for efficient viral replication in primary human fibroblasts. Microbiol Spectr 2023; 11:e0139023. [PMID: 37594266 PMCID: PMC10581054 DOI: 10.1128/spectrum.01390-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 07/06/2023] [Indexed: 08/19/2023] Open
Abstract
In addition to the 3'-poly(A) tail, vaccinia virus mRNAs synthesized after viral DNA replication (post-replicative mRNAs) possess a 5'-poly(A) leader that confers a translational advantage in virally infected cells. These mRNAs are synthesized in viral factories, the cytoplasmic compartment where vaccinia virus DNA replication, mRNA synthesis, and translation occur. However, a previous study indicates that the poly(A)-binding protein (PABPC1)-which has a well-established role in RNA stability and translation-is absent in the viral factories. This prompts the question of whether other poly(A)-binding proteins engage vaccinia virus post-replicative mRNA in viral factories. Here, in this study, we found that La-related protein 4 (LARP4), a poly(A) binding protein, was enriched in viral factories in multiple types of cells during vaccinia virus infection. Further studies showed that LARP4 enrichment in the viral factories required viral post-replicative gene expression and functional decapping enzymes encoded by vaccinia virus. We further showed that knockdown of LARP4 expression in human foreskin fibroblasts (HFFs) reduced vaccinia virus DNA replication, post-replicative protein levels, and viral production. Interestingly, the knockdown of LARP4 expression also reduced protein levels from transfected mRNA containing a 5'-poly(A) leader in vaccinia virus-infected and uninfected HFFs. Taken together, our results identified a poly(A)-binding protein, LARP4, being enriched in the vaccinia virus viral factories and facilitating viral replication in HFFs. IMPORTANCE Vaccinia virus, the prototype poxvirus, encodes over 200 open reading frames (ORFs). Over 90 of vaccinia virus ORFs are transcribed post-viral DNA replication. All these mRNAs contain a 5'-poly(A) leader, as well as a 3'-poly(A) tail. They are synthesized in viral factories, where vaccinia virus DNA replication, mRNA synthesis, and translation occur. However, surprisingly, the poly(A) binding protein, PABPC1, that is important for mRNA metabolism and translation is not present in the viral factories, suggesting other poly(A) binding protein(s) may be present in viral factories. Here, we found another poly(A)-binding protein, La-related protein 4 (LARP4), enriched in viral factories during vaccinia virus infection. We also showed that LARP4 enrichment in the viral factories depends on viral post-replicative gene expression and functional viral decapping enzymes. The knockdown of LARP4 expression in human foreskin fibroblasts reduced vaccinia virus DNA replication, post-replicative gene expression, and viral production.
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Affiliation(s)
- Pragyesh Dhungel
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Djamal Brahim Belhaouari
- Department of Veterinary Pathobiology, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Zhilong Yang
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
- Department of Veterinary Pathobiology, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, USA
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8
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Kumar S, Verma R, Saha S, Agrahari AK, Shukla S, Singh ON, Berry U, Anurag, Maiti TK, Asthana S, Ranjith-Kumar CT, Surjit M. RNA-Protein Interactome at the Hepatitis E Virus Internal Ribosome Entry Site. Microbiol Spectr 2023; 11:e0282722. [PMID: 37382527 PMCID: PMC10434006 DOI: 10.1128/spectrum.02827-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/11/2023] [Indexed: 06/30/2023] Open
Abstract
Multiple processes exist in a cell to ensure continuous production of essential proteins either through cap-dependent or cap-independent translation processes. Viruses depend on the host translation machinery for viral protein synthesis. Therefore, viruses have evolved clever strategies to use the host translation machinery. Earlier studies have shown that genotype 1 hepatitis E virus (g1-HEV) uses both cap-dependent and cap-independent translation machineries for its translation and proliferation. Cap-independent translation in g1-HEV is driven by an 87-nucleotide-long RNA element that acts as a noncanonical, internal ribosome entry site-like (IRESl) element. Here, we have identified the RNA-protein interactome of the HEV IRESl element and characterized the functional significance of some of its components. Our study identifies the association of HEV IRESl with several host ribosomal proteins, demonstrates indispensable roles of ribosomal protein RPL5 and DHX9 (RNA helicase A) in mediating HEV IRESl activity, and establishes the latter as a bona fide internal translation initiation site. IMPORTANCE Protein synthesis is a fundamental process for survival and proliferation of all living organisms. The majority of cellular proteins are produced through cap-dependent translation. Cells also use a variety of cap-independent translation processes to synthesize essential proteins during stress. Viruses depend on the host cell translation machinery to synthesize their own proteins. Hepatitis E virus (HEV) is a major cause of hepatitis worldwide and has a capped positive-strand RNA genome. Viral nonstructural and structural proteins are synthesized through a cap-dependent translation process. An earlier study from our laboratory reported the presence of a fourth open reading frame (ORF) in genotype 1 HEV, which produces the ORF4 protein using a cap-independent internal ribosome entry site-like (IRESl) element. In the current study, we identified the host proteins that associate with the HEV-IRESl RNA and generated the RNA-protein interactome. Through a variety of experimental approaches, our data prove that HEV-IRESl is a bona fide internal translation initiation site.
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Affiliation(s)
- Shiv Kumar
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Rohit Verma
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Sandhini Saha
- Laboratory of Functional Proteomics, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| | - Ashish Kumar Agrahari
- Noncommunicable Disease Group, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Shivangi Shukla
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Oinam Ningthemmani Singh
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Umang Berry
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Anurag
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Tushar Kanti Maiti
- Laboratory of Functional Proteomics, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| | - Shailendra Asthana
- Noncommunicable Disease Group, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - C. T. Ranjith-Kumar
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Milan Surjit
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
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9
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Ogami K, Oishi Y, Hoshino SI. Protocol for analyzing intact mRNA poly(A) tail length using nanopore direct RNA sequencing. STAR Protoc 2023; 4:102340. [PMID: 37243600 DOI: 10.1016/j.xpro.2023.102340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/20/2023] [Accepted: 05/09/2023] [Indexed: 05/29/2023] Open
Abstract
Poly(A) tail metabolism contributes to post-transcriptional regulation of gene expression. Here, we present a protocol for analyzing intact mRNA poly(A) tail length using nanopore direct RNA sequencing, which excludes truncated RNAs from the measurement. We describe steps for preparing recombinant eIF4E mutant protein, purifying m7G- capped RNAs, library preparation, and sequencing. Resulting data can be used not only for expression profiling and poly(A) tail length estimation but also for detecting alternative splicing and polyadenylation events and RNA base modification. For complete details on the use and execution of this protocol, please refer to Ogami et al. (2022).1.
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Affiliation(s)
- Koichi Ogami
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 Japan; Division of Molecular Oncology, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Yuka Oishi
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 Japan
| | - Shin-Ichi Hoshino
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 Japan.
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10
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Turner M. Regulation and function of poised mRNAs in lymphocytes. Bioessays 2023; 45:e2200236. [PMID: 37009769 DOI: 10.1002/bies.202200236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 04/04/2023]
Abstract
Pre-existing but untranslated or 'poised' mRNA exists as a means to rapidly induce the production of specific proteins in response to stimuli and as a safeguard to limit the actions of these proteins. The translation of poised mRNA enables immune cells to express quickly genes that enhance immune responses. The molecular mechanisms that repress the translation of poised mRNA and, upon stimulation, enable translation have yet to be elucidated. They likely reflect intrinsic properties of the mRNAs and their interactions with trans-acting factors that direct poised mRNAs away from or into the ribosome. Here, I discuss mechanisms by which this might be regulated.
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Affiliation(s)
- Martin Turner
- Immunology Programme, The Babraham Institute, Cambridge, UK
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11
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Dhungel P, Brahim Belhaouari D, Yang Z. La-related protein 4 is enriched in vaccinia virus factories and is required for efficient viral replication in primary human fibroblasts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.10.532125. [PMID: 36945573 PMCID: PMC10029068 DOI: 10.1101/2023.03.10.532125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
In addition to the 3'-poly(A) tail, vaccinia virus mRNAs synthesized after viral DNA replication (post-replicative mRNAs) possess a 5'-poly(A) leader that confers a translational advantage in virally infected cells. These mRNAs are synthesized in viral factories, the cytoplasmic compartment where vaccinia virus DNA replication, mRNA synthesis, and translation occur. However, a previous study indicates that the poly(A)-binding protein (PABPC1)-which has a well-established role in RNA stability and translation-is not present in the viral factories. This prompts the question of whether another poly(A)-binding protein engages vaccinia virus post-replicative mRNA in viral factories. In this study, we found that La-related protein 4 (LARP4), a poly(A) binding protein, was enriched in viral factories in multiple types of cells during vaccinia virus infection. Further studies showed that LARP4 enrichment in the viral factories required viral post-replicative gene expression and functional decapping enzymes encoded by vaccinia virus. We further showed that knockdown of LARP4 expression in human foreskin fibroblasts (HFFs) significantly reduced vaccinia virus post-replicative gene expression and viral replication. Interestingly, the knockdown of LARP4 expression also reduced 5'-poly(A) leader-mediated mRNA translation in vaccinia virus-infected and uninfected HFFs. Together, our results identified a poly(A)-binding protein, LARP4, enriched in the vaccinia virus viral factories and facilitates viral replication and mRNA translation. Importance Poxviruses are a family of large DNA viruses comprising members infecting a broad range of hosts, including many animals and humans. Poxvirus infections can cause deadly diseases in humans and animals. Vaccinia virus, the prototype poxvirus, encodes over 200 open reading frames (ORFs). Over 90 of vaccinia virus ORFs are transcribed post-viral DNA replication. All these mRNAs contain a 5'-poly(A) leader, as well as a 3'-poly(A) tail. They are synthesized in viral factories, where vaccinia virus DNA replication, mRNA synthesis and translation occur. However, surprisingly, the poly(A) binding protein (PABPC1) that is important for mRNA metabolism and translation is not present in the viral factories, suggesting other poly(A) binding protein(s) may be present in viral factories. Here we found another poly(A)-binding protein, La-related protein 4 (LARP4), is enriched in viral factories during vaccinia virus infection. We also showed that LARP4 enrichment in the viral factories depends on viral post-replicative gene expression and functional viral decapping enzymes. The knockdown of LARP4 expression in human foreskin fibroblasts (HFFs) significantly reduced vaccinia virus post-replicative gene expression and viral replication. Overall, this study identified a poly(A)-binding protein that plays an important role in vaccinia virus replication.
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Affiliation(s)
- Pragyesh Dhungel
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Djamal Brahim Belhaouari
- Department of Veterinary Pathobiology, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Zhilong Yang
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Department of Veterinary Pathobiology, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
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12
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Park J, Kim M, Yi H, Baeg K, Choi Y, Lee YS, Lim J, Kim VN. Short poly(A) tails are protected from deadenylation by the LARP1-PABP complex. Nat Struct Mol Biol 2023; 30:330-338. [PMID: 36849640 DOI: 10.1038/s41594-023-00930-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 01/10/2023] [Indexed: 03/01/2023]
Abstract
Deadenylation generally constitutes the first and pivotal step in eukaryotic messenger RNA decay. Despite its importance in posttranscriptional regulations, the kinetics of deadenylation and its regulation remain largely unexplored. Here we identify La ribonucleoprotein 1, translational regulator (LARP1) as a general decelerator of deadenylation, which acts mainly in the 30-60-nucleotide (nt) poly(A) length window. We measured the steady-state and pulse-chased distribution of poly(A)-tail length, and found that deadenylation slows down in the 30-60-nt range. LARP1 associates preferentially with short tails and its depletion results in accelerated deadenylation specifically in the 30-60-nt range. Consistently, LARP1 knockdown leads to a global reduction of messenger RNA abundance. LARP1 interferes with the CCR4-NOT-mediated deadenylation in vitro by forming a ternary complex with poly(A)-binding protein (PABP) and poly(A). Together, our work reveals a dynamic nature of deadenylation kinetics and a role of LARP1 as a poly(A) length-specific barricade that creates a threshold for deadenylation.
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Affiliation(s)
- Joha Park
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Myeonghwan Kim
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Hyerim Yi
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
- Stanford University School of Medicine, Stanford, CA, USA
| | - Kyungmin Baeg
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
| | - Yongkuk Choi
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Young-Suk Lee
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Jaechul Lim
- Center for RNA Research, Institute for Basic Science, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
- Yale School of Medicine, New Haven, CT, USA
| | - V Narry Kim
- Center for RNA Research, Institute for Basic Science, Seoul, Korea.
- School of Biological Sciences, Seoul National University, Seoul, Korea.
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13
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Brouze A, Krawczyk PS, Dziembowski A, Mroczek S. Measuring the tail: Methods for poly(A) tail profiling. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1737. [PMID: 35617484 PMCID: PMC10078590 DOI: 10.1002/wrna.1737] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/13/2022] [Accepted: 04/15/2022] [Indexed: 01/31/2023]
Abstract
The 3'-end poly(A) tail is an important and potent feature of most mRNA molecules that affects mRNA fate and translation efficiency. Polyadenylation is a posttranscriptional process that occurs in the nucleus by canonical poly(A) polymerases (PAPs). In some specific instances, the poly(A) tail can also be extended in the cytoplasm by noncanonical poly(A) polymerases (ncPAPs). This epitranscriptomic regulation of mRNA recently became one of the most interesting aspects in the field. Advances in RNA sequencing technologies and software development have allowed the precise measurement of poly(A) tails, identification of new ncPAPs, expansion of the function of known enzymes, discovery and a better understanding of the physiological role of tail heterogeneity, and recognition of a correlation between tail length and RNA translatability. Here, we summarize the development of polyadenylation research methods, including classic low-throughput approaches, Illumina-based genome-wide analysis, and advanced state-of-art techniques that utilize long-read third-generation sequencing with Pacific Biosciences and Oxford Nanopore Technologies platforms. A boost in technical opportunities over recent decades has allowed a better understanding of the regulation of gene expression at the mRNA level. This article is categorized under: RNA Methods > RNA Analyses In Vitro and In Silico.
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Affiliation(s)
- Aleksandra Brouze
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Paweł Szczepan Krawczyk
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Andrzej Dziembowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland.,Department of Embryology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Seweryn Mroczek
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
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14
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mTOR- and LARP1-dependent regulation of TOP mRNA poly(A) tail and ribosome loading. Cell Rep 2022; 41:111548. [DOI: 10.1016/j.celrep.2022.111548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 08/30/2022] [Accepted: 09/30/2022] [Indexed: 11/20/2022] Open
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15
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Kozlov G, Mattijssen S, Jiang J, Nyandwi S, Sprules T, Iben J, Coon S, Gaidamakov S, Noronha AM, Wilds C, Maraia R, Gehring K. Structural basis of 3'-end poly(A) RNA recognition by LARP1. Nucleic Acids Res 2022; 50:9534-9547. [PMID: 35979957 PMCID: PMC9458460 DOI: 10.1093/nar/gkac696] [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: 03/25/2022] [Revised: 07/21/2022] [Accepted: 08/02/2022] [Indexed: 12/24/2022] Open
Abstract
La-related proteins (LARPs) comprise a family of RNA-binding proteins involved in a wide range of posttranscriptional regulatory activities. LARPs share a unique tandem of two RNA-binding domains, La motif (LaM) and RNA recognition motif (RRM), together referred to as a La-module, but vary in member-specific regions. Prior structural studies of La-modules reveal they are pliable platforms for RNA recognition in diverse contexts. Here, we characterize the La-module of LARP1, which plays an important role in regulating synthesis of ribosomal proteins in response to mTOR signaling and mRNA stabilization. LARP1 has been well characterized functionally but no structural information exists for its La-module. We show that unlike other LARPs, the La-module in LARP1 does not contain an RRM domain. The LaM alone is sufficient for binding poly(A) RNA with submicromolar affinity and specificity. Multiple high-resolution crystal structures of the LARP1 LaM domain in complex with poly(A) show that it is highly specific for the RNA 3'-end, and identify LaM residues Q333, Y336 and F348 as the most critical for binding. Use of a quantitative mRNA stabilization assay and poly(A) tail-sequencing demonstrate functional relevance of LARP1 RNA binding in cells and provide novel insight into its poly(A) 3' protection activity.
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Affiliation(s)
- Guennadi Kozlov
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Sandy Mattijssen
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Jianning Jiang
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Samuel Nyandwi
- Department of Biochemistry, McGill University, Montréal, Canada,Centre de recherche en biologie structurale, McGill University, Montréal, Canada
| | - Tara Sprules
- Centre de recherche en biologie structurale, McGill University, Montréal, Canada,Quebec/Eastern Canada NMR Centre, McGill University, Montréal, Canada
| | - James R Iben
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Steven L Coon
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Sergei Gaidamakov
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Anne M Noronha
- Department of Chemistry and Biochemistry, Concordia University, Montréal, Canada
| | - Christopher J Wilds
- Department of Chemistry and Biochemistry, Concordia University, Montréal, Canada
| | - Richard J Maraia
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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16
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Roles of mRNA poly(A) tails in regulation of eukaryotic gene expression. Nat Rev Mol Cell Biol 2022; 23:93-106. [PMID: 34594027 PMCID: PMC7614307 DOI: 10.1038/s41580-021-00417-y] [Citation(s) in RCA: 139] [Impact Index Per Article: 69.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 02/06/2023]
Abstract
In eukaryotes, poly(A) tails are present on almost every mRNA. Early experiments led to the hypothesis that poly(A) tails and the cytoplasmic polyadenylate-binding protein (PABPC) promote translation and prevent mRNA degradation, but the details remained unclear. More recent data suggest that the role of poly(A) tails is much more complex: poly(A)-binding protein can stimulate poly(A) tail removal (deadenylation) and the poly(A) tails of stable, highly translated mRNAs at steady state are much shorter than expected. Furthermore, the rate of translation elongation affects deadenylation. Consequently, the interplay between poly(A) tails, PABPC, translation and mRNA decay has a major role in gene regulation. In this Review, we discuss recent work that is revolutionizing our understanding of the roles of poly(A) tails in the cytoplasm. Specifically, we discuss the roles of poly(A) tails in translation and control of mRNA stability and how poly(A) tails are removed by exonucleases (deadenylases), including CCR4-NOT and PAN2-PAN3. We also discuss how deadenylation rate is determined, the integration of deadenylation with other cellular processes and the function of PABPC. We conclude with an outlook for the future of research in this field.
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17
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Decoupling of degradation from deadenylation reshapes poly(A) tail length in yeast meiosis. Nat Struct Mol Biol 2021; 28:1038-1049. [PMID: 34887567 DOI: 10.1038/s41594-021-00694-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 10/28/2021] [Indexed: 12/13/2022]
Abstract
Nascent messenger RNA is endowed with a poly(A) tail that is subject to gradual deadenylation and subsequent degradation in the cytoplasm. Deadenylation and degradation rates are typically correlated, rendering it difficult to dissect the determinants governing each of these processes and the mechanistic basis of their coupling. Here we developed an approach that allows systematic, robust and multiplexed quantification of poly(A) tails in Saccharomyces cerevisiae. Our results suggest that mRNA deadenylation and degradation rates are decoupled during meiosis, and that transcript length is a major determinant of deadenylation rates and a key contributor to reshaping of poly(A) tail lengths. Meiosis-specific decoupling also leads to unique positive associations between poly(A) tail length and gene expression. The decoupling is associated with a focal localization pattern of the RNA degradation factor Xrn1, and can be phenocopied by Xrn1 deletion under nonmeiotic conditions. Importantly, the association of transcript length with deadenylation rates is conserved across eukaryotes. Our study uncovers a factor that shapes deadenylation rate and reveals a unique context in which degradation is decoupled from deadenylation.
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18
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Novel insights into the molecular mechanisms underlying risk of colorectal cancer from smoking and red/processed meat carcinogens by modeling exposure in normal colon organoids. Oncotarget 2021; 12:1863-1877. [PMID: 34548904 PMCID: PMC8448508 DOI: 10.18632/oncotarget.28058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/13/2021] [Indexed: 12/23/2022] Open
Abstract
Tobacco smoke and red/processed meats are well-known risk factors for colorectal cancer (CRC). Most research has focused on studies of normal colon biopsies in epidemiologic studies or treatment of CRC cell lines in vitro. These studies are often constrained by challenges with accuracy of self-report data or, in the case of CRC cell lines, small sample sizes and lack of relationship to normal tissue at risk. In an attempt to address some of these limitations, we performed a 24-hour treatment of a representative carcinogens cocktail in 37 independent organoid lines derived from normal colon biopsies. Machine learning algorithms were applied to bulk RNA-sequencing and revealed cellular composition changes in colon organoids. We identified 738 differentially expressed genes in response to carcinogens exposure. Network analysis identified significantly different modules of co-expression, that included genes related to MSI-H tumor biology, and genes previously implicated in CRC through genome-wide association studies. Our study helps to better define the molecular effects of representative carcinogens from smoking and red/processed meat in normal colon epithelial cells and in the etiology of the MSI-H subtype of CRC, and suggests an overlap between molecular mechanisms involved in inherited and environmental CRC risk.
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19
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Coon SL, Li T, Iben JR, Mattijssen S, Maraia RJ. Single-molecule polyadenylated tail sequencing (SM-PAT-Seq) to measure polyA tail lengths transcriptome-wide. Methods Enzymol 2021; 655:119-137. [PMID: 34183118 DOI: 10.1016/bs.mie.2021.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Polyadenylation of the 3' end of mRNAs is an important mechanism for regulating their stability and translation. We developed a nucleotide-resolution, transcriptome-wide, single-molecule SM-PAT-Seq method to accurately measure the polyA tail lengths of individual transcripts using long-read sequencing. The method generates cDNA using a double stranded splint adaptor targeting the far 3' end of the polyA tail for first strand synthesis along with random hexamers for second strand synthesis. This straight-forward method yields accurate polyA tail sequence lengths, can identify non-A residues in those tails, and quantitate transcript abundance.
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Affiliation(s)
- Steven L Coon
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Tianwei Li
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - James R Iben
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Sandy Mattijssen
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Richard J Maraia
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States.
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20
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Mattijssen S, Kozlov G, Fonseca BD, Gehring K, Maraia RJ. LARP1 and LARP4: up close with PABP for mRNA 3' poly(A) protection and stabilization. RNA Biol 2021; 18:259-274. [PMID: 33522422 PMCID: PMC7928012 DOI: 10.1080/15476286.2020.1868753] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 12/06/2020] [Accepted: 12/17/2020] [Indexed: 02/06/2023] Open
Abstract
La-related proteins (LARPs) share a La motif (LaM) followed by an RNA recognition motif (RRM). Together these are termed the La-module that, in the prototypical nuclear La protein and LARP7, mediates binding to the UUU-3'OH termination motif of nascent RNA polymerase III transcripts. We briefly review La and LARP7 activities for RNA 3' end binding and protection from exonucleases before moving to the more recently uncovered poly(A)-related activities of LARP1 and LARP4. Two features shared by LARP1 and LARP4 are direct binding to poly(A) and to the cytoplasmic poly(A)-binding protein (PABP, also known as PABPC1). LARP1, LARP4 and other proteins involved in mRNA translation, deadenylation, and decay, contain PAM2 motifs with variable affinities for the MLLE domain of PABP. We discuss a model in which these PABP-interacting activities contribute to poly(A) pruning of active mRNPs. Evidence that the SARS-CoV-2 RNA virus targets PABP, LARP1, LARP 4 and LARP 4B to control mRNP activity is also briefly reviewed. Recent data suggests that LARP4 opposes deadenylation by stabilizing PABP on mRNA poly(A) tails. Other data suggest that LARP1 can protect mRNA from deadenylation. This is dependent on a PAM2 motif with unique characteristics present in its La-module. Thus, while nuclear La and LARP7 stabilize small RNAs with 3' oligo(U) from decay, LARP1 and LARP4 bind and protect mRNA 3' poly(A) tails from deadenylases through close contact with PABP.Abbreviations: 5'TOP: 5' terminal oligopyrimidine, LaM: La motif, LARP: La-related protein, LARP1: La-related protein 1, MLLE: mademoiselle, NTR: N-terminal region, PABP: cytoplasmic poly(A)-binding protein (PABPC1), Pol III: RNA polymerase III, PAM2: PABP-interacting motif 2, PB: processing body, RRM: RNA recognition motif, SG: stress granule.
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Affiliation(s)
- Sandy Mattijssen
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Guennadi Kozlov
- Department of Biochemistry & Centre for Structural Biology, McGill University, Montreal, Canada
| | | | - Kalle Gehring
- Department of Biochemistry & Centre for Structural Biology, McGill University, Montreal, Canada
| | - Richard J. Maraia
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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21
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Mattijssen S, Kozlov G, Gaidamakov S, Ranjan A, Fonseca BD, Gehring K, Maraia RJ. The isolated La-module of LARP1 mediates 3' poly(A) protection and mRNA stabilization, dependent on its intrinsic PAM2 binding to PABPC1. RNA Biol 2021; 18:275-289. [PMID: 33292040 PMCID: PMC7928023 DOI: 10.1080/15476286.2020.1860376] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 12/18/2022] Open
Abstract
The protein domain arrangement known as the La-module, comprised of a La motif (LaM) followed by a linker and RNA recognition motif (RRM), is found in seven La-related proteins: LARP1, LARP1B, LARP3 (La protein), LARP4, LARP4B, LARP6, and LARP7 in humans. Several LARPs have been characterized for their distinct activity in a specific aspect of RNA metabolism. The La-modules vary among the LARPs in linker length and RRM subtype. The La-modules of La protein and LARP7 bind and protect nuclear RNAs with UUU-3' tails from degradation by 3' exonucleases. LARP4 is an mRNA poly(A) stabilization factor that binds poly(A) and the cytoplasmic poly(A)-binding protein PABPC1 (also known as PABP). LARP1 exhibits poly(A) length protection and mRNA stabilization similar to LARP4. Here, we show that these LARP1 activities are mediated by its La-module and dependent on a PAM2 motif that binds PABP. The isolated La-module of LARP1 is sufficient for PABP-dependent poly(A) length protection and mRNA stabilization in HEK293 cells. A point mutation in the PAM2 motif in the La-module impairs mRNA stabilization and PABP binding in vivo but does not impair oligo(A) RNA binding by the purified recombinant La-module in vitro. We characterize the unusual PAM2 sequence of LARP1 and show it may differentially affect stable and unstable mRNAs. The unique LARP1 La-module can function as an autonomous factor to confer poly(A) protection and stabilization to heterologous mRNAs.
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Affiliation(s)
- Sandy Mattijssen
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Guennadi Kozlov
- Department of Biochemistry & Centre for Structural Biology, McGill University, Montreal, Canada
| | - Sergei Gaidamakov
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Amitabh Ranjan
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | | | - Kalle Gehring
- Department of Biochemistry & Centre for Structural Biology, McGill University, Montreal, Canada
| | - Richard J. Maraia
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
- Commissioned Corps, U.S. Public Health Service, Rockville, MD, USA
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