1
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Smith BC, Silvers R. 1H, 13C, and 15N resonance assignments of the La Motif of the human La-related protein 1. Biomol NMR Assign 2024; 18:111-118. [PMID: 38691336 DOI: 10.1007/s12104-024-10176-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 04/22/2024] [Indexed: 05/03/2024]
Abstract
Human La-related protein 1 (HsLARP1) is involved in post-transcriptional regulation of certain 5' terminal oligopyrimidine (5'TOP) mRNAs as well as other mRNAs and binds to both the 5'TOP motif and the 3'-poly(A) tail of certain mRNAs. HsLARP1 is heavily involved in cell proliferation, cell cycle defects, and cancer, where HsLARP1 is significantly upregulated in malignant cells and tissues. Like all LARPs, HsLARP1 contains a folded RNA binding domain, the La motif (LaM). Our current understanding of post-transcriptional regulation that emanates from the intricate molecular framework of HsLARP1 is currently limited to small snapshots, obfuscating our understanding of the full picture on HsLARP1 functionality in post-transcriptional events. Here, we present the nearly complete resonance assignment of the LaM of HsLARP1, providing a significant platform for future NMR spectroscopic studies.
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Affiliation(s)
- Benjamin C Smith
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL, 32306, USA
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA
| | - Robert Silvers
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL, 32306, USA.
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA.
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2
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Earwood R, Ninomiya H, Wang H, Shimada I, Stroud M, Perez D, Uuganbayar U, Yamada C, Akiyama-Miyoshi T, Stefanovic B, Kato Y. The binding of LARP6 and DNAAF6 in biomolecular condensates influences ciliogenesis of multi-ciliated cells. J Biol Chem 2024:107373. [PMID: 38762183 DOI: 10.1016/j.jbc.2024.107373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/19/2024] [Accepted: 05/03/2024] [Indexed: 05/20/2024] Open
Abstract
Motile cilia on the cell surface produce fluid flows in the body and abnormalities in motile cilia cause primary ciliary dyskinesia (PCD). Dynein axonemal assembly factors 6 (DNAAF6), a causative gene of PCD, was isolated as an interacting protein with La ribonucleoprotein 6 (LARP6) that regulates ciliogenesis in multi-ciliated cells (MCCs). In MCCs of Xenopus embryos, LARP6 and DNAAF6 were co-localized in biomolecular condensates termed dynein axonemal particles (DynAPs) and synergized to control ciliogenesis. Moreover, Tubulin alpha 1c like (TUBA1CL) mRNA encoding α-Tubulin protein that is a major component of ciliary axoneme was identified as a target mRNA regulated by binding LARP6. While DNAAF6 was necessary for high α-Tubulin protein expression near the apical side of Xenopus MCCs during ciliogenesis, its mutant, which abolishes binding with LARP6, was unable to restore the expression of α-Tubulin protein near the apical side of MCCs in Xenopus DNAAF6 morphant. These results indicated that the binding of LARP6 and DNAAF6 in DynAPs regulates highly expressed α-Tubulin protein near the apical side of Xenopus MCCs during ciliogenesis.
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Affiliation(s)
- Ryan Earwood
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, Florida, USA 32306-4300
| | - Hiromasa Ninomiya
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan 467-8601
| | - Hao Wang
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, Florida, USA 32306-4300
| | - Issei Shimada
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan 467-8601
| | - Mia Stroud
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, Florida, USA 32306-4300
| | - Diana Perez
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, Florida, USA 32306-4300
| | - Udval Uuganbayar
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan 467-8601
| | - Chisato Yamada
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan 467-8601
| | - Toru Akiyama-Miyoshi
- Pathogenic Microbe Laboratory, Research Institute, National Center for Global Health and Medicine, Shinjuku, Tokyo, Japan 162-8655
| | - Branko Stefanovic
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, Florida, USA 32306-4300.
| | - Yoichi Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, Florida, USA 32306-4300; Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan 467-8601.
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3
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Xiang X, Deng Q, Zheng Y, He Y, Ji D, Vejlupkova Z, Fowler JE, Zhou L. Genome-wide investigation of the LARP gene family: focus on functional identification and transcriptome profiling of ZmLARP6c1 in maize pollen. BMC Plant Biol 2024; 24:348. [PMID: 38684961 PMCID: PMC11057080 DOI: 10.1186/s12870-024-05054-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/19/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND The La-related proteins (LARPs) are a superfamily of RNA-binding proteins associated with regulation of gene expression. Evidence points to an important role for post-transcriptional control of gene expression in germinating pollen tubes, which could be aided by RNA-binding proteins. RESULTS In this study, a genome-wide investigation of the LARP proteins in eight plant species was performed. The LARP proteins were classified into three families based on a phylogenetic analysis. The gene structure, conserved motifs, cis-acting elements in the promoter, and gene expression profiles were investigated to provide a comprehensive overview of the evolutionary history and potential functions of ZmLARP genes in maize. Moreover, ZmLARP6c1 was specifically expressed in pollen and ZmLARP6c1 was localized to the nucleus and cytoplasm in maize protoplasts. Overexpression of ZmLARP6c1 enhanced the percentage pollen germination compared with that of wild-type pollen. In addition, transcriptome profiling analysis revealed that differentially expressed genes included PABP homologous genes and genes involved in jasmonic acid and abscisic acid biosynthesis, metabolism, signaling pathways and response in a Zmlarp6c1::Ds mutant and ZmLARP6c1-overexpression line compared with the corresponding wild type. CONCLUSIONS The findings provide a basis for further evolutionary and functional analyses, and provide insight into the critical regulatory function of ZmLARP6c1 in maize pollen germination.
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Affiliation(s)
- Xiaoqin Xiang
- College of Agronomy and Biotechnology, Maize Research Institute, Southwest University, Beibei, Chongqing, 400715, China
| | - Qianxia Deng
- College of Agronomy and Biotechnology, Maize Research Institute, Southwest University, Beibei, Chongqing, 400715, China
| | - Yi Zheng
- College of Agronomy and Biotechnology, Maize Research Institute, Southwest University, Beibei, Chongqing, 400715, China
| | - Yi He
- College of Agronomy and Biotechnology, Maize Research Institute, Southwest University, Beibei, Chongqing, 400715, China
| | - Dongpu Ji
- College of Agronomy and Biotechnology, Maize Research Institute, Southwest University, Beibei, Chongqing, 400715, China
| | - Zuzana Vejlupkova
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - John E Fowler
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Lian Zhou
- College of Agronomy and Biotechnology, Maize Research Institute, Southwest University, Beibei, Chongqing, 400715, China.
- Engineering Research Center of South Upland Agriculture, Ministry of Education, Chongqing, 400715, China.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Bley H, Krisp C, Schöbel A, Hehner J, Schneider L, Becker M, Stegmann C, Heidenfels E, Nguyen-Dinh V, Schlüter H, Gerold G, Herker E. Proximity labeling of host factor ANXA3 in HCV infection reveals a novel LARP1 function in viral entry. J Biol Chem 2024; 300:107286. [PMID: 38636657 PMCID: PMC11101947 DOI: 10.1016/j.jbc.2024.107286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/20/2024] Open
Abstract
Hepatitis C virus (HCV) infection is tightly connected to the lipid metabolism with lipid droplets (LDs) serving as assembly sites for progeny virions. A previous LD proteome analysis identified annexin A3 (ANXA3) as an important HCV host factor that is enriched at LDs in infected cells and required for HCV morphogenesis. To further characterize ANXA3 function in HCV, we performed proximity labeling using ANXA3-BioID2 as bait in HCV-infected cells. Two of the top proteins identified proximal to ANXA3 during HCV infection were the La-related protein 1 (LARP1) and the ADP ribosylation factor-like protein 8B (ARL8B), both of which have been previously described to act in HCV particle production. In follow-up experiments, ARL8B functioned as a pro-viral HCV host factor without localizing to LDs and thus likely independent of ANXA3. In contrast, LARP1 interacts with HCV core protein in an RNA-dependent manner and is translocated to LDs by core protein. Knockdown of LARP1 decreased HCV spreading without altering HCV RNA replication or viral titers. Unexpectedly, entry of HCV particles and E1/E2-pseudotyped lentiviral particles was reduced by LARP1 depletion, whereas particle production was not altered. Using a recombinant vesicular stomatitis virus (VSV)ΔG entry assay, we showed that LARP1 depletion also decreased entry of VSV with VSV, MERS, and CHIKV glycoproteins. Therefore, our data expand the role of LARP1 as an HCV host factor that is most prominently involved in the early steps of infection, likely contributing to endocytosis of viral particles through the pleiotropic effect LARP1 has on the cellular translatome.
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Affiliation(s)
- Hanna Bley
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Christoph Krisp
- Section Mass Spectrometry and Proteomics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anja Schöbel
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Julia Hehner
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Laura Schneider
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Miriam Becker
- Institute for Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hanover, Hanover, Germany
| | - Cora Stegmann
- Institute for Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hanover, Hanover, Germany
| | - Elisa Heidenfels
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Van Nguyen-Dinh
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Hartmut Schlüter
- Section Mass Spectrometry and Proteomics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gisa Gerold
- Institute for Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hanover, Hanover, Germany; Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden; Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden
| | - Eva Herker
- Institute of Virology, Philipps-University Marburg, Marburg, Germany.
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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 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] [What about the content of this article? (0)] [Affiliation(s)] [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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7
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Saba JA, Huang Z, Schole KL, Ye X, Bhatt SD, Li Y, Timp W, Cheng J, Green R. LARP1 senses free ribosomes to coordinate supply and demand of ribosomal proteins. bioRxiv 2023:2023.11.01.565189. [PMID: 37961604 PMCID: PMC10635049 DOI: 10.1101/2023.11.01.565189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Terminal oligopyrimidine motif-containing mRNAs (TOPs) encode all ribosomal proteins in mammals and are regulated to tune ribosome synthesis to cell state. Previous studies implicate LARP1 in 40S- or 80S-ribosome complexes that repress and stabilize TOPs. However, a mechanistic understanding of how LARP1 and TOPs interact with these complexes to coordinate TOP outcomes is lacking. Here, we show that LARP1 senses the cellular supply of ribosomes by directly binding non-translating ribosomal subunits. Cryo-EM structures reveal a previously uncharacterized domain of LARP1 bound to and occluding the 40S mRNA channel. Free cytosolic ribosomes induce sequestration of TOPs in repressed 80S-LARP1-TOP complexes independent of alterations in mTOR signaling. Together, this work demonstrates a general ribosome-sensing function of LARP1 that allows it to tune ribosome protein synthesis to cellular demand.
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Affiliation(s)
- James A. Saba
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- These authors contributed equally
| | - Zixuan Huang
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Dong’an Road 131, 200032, Shanghai, China
- These authors contributed equally
| | - Kate L. Schole
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xianwen Ye
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Dong’an Road 131, 200032, Shanghai, China
| | - Shrey D. Bhatt
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yi Li
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Dong’an Road 131, 200032, Shanghai, China
| | - Winston Timp
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jingdong Cheng
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Dong’an Road 131, 200032, Shanghai, China
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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8
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Mansouri-Noori F, Pircher A, Bilodeau D, Siniavskaia L, Grigull J, Rissland OS, Bayfield MA. The LARP1 homolog Slr1p controls the stability and expression of proto-5'TOP mRNAs in fission yeast. Cell Rep 2023; 42:113226. [PMID: 37851576 DOI: 10.1016/j.celrep.2023.113226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/09/2023] [Accepted: 09/22/2023] [Indexed: 10/20/2023] Open
Abstract
Messenger RNAs (mRNAs) in higher eukaryotes that encode proteins important for the assembly of the translational apparatus (e.g., ribosomal proteins) often harbor a pyrimidine-rich motif at the extreme 5' end known as a 5' terminal oligopyrimidine (5'TOP) sequence. Members of the La-related protein 1 (LARP1) family control 5'TOP expression through a conserved DM15 motif, but the mechanism is not well understood. 5'TOP motifs have not been described in many lower organisms, and fission yeast harbors a LARP1 homolog that also lacks a DM15 motif. In this work, we show that the fission yeast LARP1 homolog, Slr1p, controls the translation and stability of mRNAs encoding proteins analogous to 5'TOP mRNAs in higher eukaryotes, which we thus refer to as proto-5'TOPs. Our data suggest that the LARP1 DM15 motif and the mRNA 5'TOP motif may be features that were scaffolded over a more fundamental mechanism of LARP1-associated control of gene expression.
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Affiliation(s)
| | | | - Danielle Bilodeau
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | | | - Jörg Grigull
- Department of Mathematics and Statistics, York University, Toronto, Canada
| | - Olivia S Rissland
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
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9
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Coleman JC, Hallett SR, Grigoriadis AE, Conte MR. LARP4A and LARP4B in cancer: The new kids on the block. Int J Biochem Cell Biol 2023; 161:106441. [PMID: 37356415 DOI: 10.1016/j.biocel.2023.106441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/09/2023] [Accepted: 06/17/2023] [Indexed: 06/27/2023]
Abstract
Recent developments have mounted a stunning body of evidence underlying the importance of RNA binding proteins (RBPs) in cancer research. In this minireview we focus on LARP4A and LARP4B, two paralogs belonging to the superfamily of La-related proteins, and provide a critical overview of current research, including their roles in cancer pathogenesis and cell proliferation, migration, cell cycle and apoptosis. We highlight current controversies surrounding LARP4A and LARP4B and conclude that their complex roles in tumorigenesis are cell-, tissue- and context-dependent, warning that caution must be exercised before categorising either protein as an oncoprotein or tumour-suppressor. We also reveal that LARP4A and LARP4B have often been confused with one another, adding uncertainty in delineating their functions. We suggest that further functional and mechanistic studies of LARP4 proteins present significant challenges for future investigations to recognise the vital contributions of these RBPs in cancer research.
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Affiliation(s)
- Jennifer C Coleman
- 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
| | | | - Maria R Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK.
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10
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Smith BC, Silvers R. NMR Resonance Assignment of the LA Motif of Human LA-Related Protein 1. bioRxiv 2023:2023.05.09.539749. [PMID: 37214987 PMCID: PMC10197598 DOI: 10.1101/2023.05.09.539749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Human La-related protein 1 (HsLARP1) is involved in post-transcriptional regulation of certain 5' s terminal oligopyrimidine (5'TOP) mRNAs as well as other mRNAs and binds to both the 5'TOP motif and the 3'-poly(A) tail of certain mRNAs. HsLARP1 is heavily involved in cell proliferation, cell cycle defects, and cancer, where HsLARP1 is significantly upregulated in malignant cells and tissues. Like all LARPs, HsLARP1 contains a folded RNA binding domain, the La motif (LaM). Our current understanding of post-transcriptional regulation that emanates from the intricate molecular framework of HsLARP1 is currently limited to small snapshots, obfuscating our understanding of the full picture on HsLARP1 functionality in post-transcriptional events. Here, we present the nearly complete resonance assignment of the LaM of HsLARP1, providing a significant platform for future NMR spectroscopic studies.
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Argyriou AI, Machaliotis GA, Makrynitsa GI, Kaliatsi EG, Stathopoulos C, Spyroulias GA. NMR Analysis Suggests Synergy between the RRM2 and the Carboxy-Terminal Segment of Human La Protein in the Recognition and Interaction with HCV IRES. Int J Mol Sci 2023; 24. [PMID: 36768895 DOI: 10.3390/ijms24032572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 01/31/2023] Open
Abstract
The La protein (lupus antigen) is a ubiquitous RNA-binding protein found in all human cells. It is mainly localized in the nucleus, associates with all RNA polymerase III (Pol III) transcripts, as the first factor they interact with, and modulates subsequent processing events. Export of La to the cytoplasm has been reported to stimulate the decoding of specific cellular and viral mRNAs through IRES-dependent (Internal ribosome entry site) binding and translation. Using NMR (Nuclear Magnetic Resonance) spectroscopy, we provide atomic-level-resolution structural insights on the dynamical properties of human La (hLa) protein in solution. Moreover, using a combination of NMR spectroscopy and isothermal titration calorimetry (ITC), we provide evidence about the role and ligand specificity of the C-terminal domain of the La protein (RRM2 and C-terminal region) that could mediate the recognition of HCV-IRES.
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12
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Long X, Liu X, Deng T, Chen J, Lan J, Zhang S, Zhou M, Guo D, Zhou J. LARP6 suppresses colorectal cancer progression through ZNF267/SGMS2-mediated imbalance of sphingomyelin synthesis. J Exp Clin Cancer Res 2023; 42:33. [PMID: 36691044 PMCID: PMC9872320 DOI: 10.1186/s13046-023-02605-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/18/2023] [Indexed: 01/25/2023]
Abstract
BACKGROUND With increasing incidence and mortality, colorectal cancer (CRC) seriously endangers human health. LARP6, a member of La-related protein (LARP) family, is a RNA binding protein and probably associates with CRC progression, but its specific roles and mechanisms in CRC still remain unknown. METHOD Quantitative real-time PCR (qPCR), western blot, and immunohistochemistry were employed to examine LARP6 expression in CRC tissues. Using the stable LARP6 overexpression or interference CRC cell lines, the effect of LARP6 on CRC progression were evaluated. High-throughput RNA immunoprecipitation sequencing (RIP-seq) and a series of relevant experiments were conducted to explain how LARP6 functions. SPSS software was used for statistical analysis. RESULT In this study, we found that LARP6 expression is downregulated in CRC and correlates with patients' overall survival and relapse-free survival. Furthermore, altered LARP6 expression influences CRC cells invasion and metastasis. Mechanically, we discovered that LARP6 bind ZNF267 mRNA and regulated its stability and translation. LARP6 inhibited expression of SGMS2, a downstream target of ZNF267, resulting in ceramide and sphingomyelin imbalance in CRC cells. Interestingly, LARP6 also enhances autophagy activity of CRC cells, and the effect was at least partially determined by the inhibition of SGMS2-mediated sphingomyelin synthesis. CONCLUSION Our study showed how LARP6/ZNF267/SGMS2 axis influence CRC progression, which contributes to further understanding of the molecular mechanisms underlying CRC development.
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Affiliation(s)
- Xiaoli Long
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Xunhua Liu
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Ting Deng
- Department of Pathology, YunFu People’s Hospital, Yunfu, 527300 China
| | - Jianxiong Chen
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Jiawen Lan
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Sijing Zhang
- grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Miao Zhou
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Dan Guo
- grid.284723.80000 0000 8877 7471Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Jun Zhou
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China ,Department of Pathology, YunFu People’s Hospital, Yunfu, 527300 China
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Abstract
Mammalian poly A-binding proteins (PABPs) are highly conserved multifunctional RNA-binding proteins primarily involved in the regulation of mRNA translation and stability, of which PABPC1 is considered a central regulator of cytoplasmic mRNA homing and is involved in a wide range of physiological and pathological processes by regulating almost every aspect of RNA metabolism. Alterations in its expression and function disrupt intra-tissue homeostasis and contribute to the development of various tumors. There is increasing evidence that PABPC1 is aberrantly expressed in a variety of tumor tissues and cancers such as lung, gastric, breast, liver, and esophageal cancers, and PABPC1 might be used as a potential biomarker for tumor diagnosis, treatment, and clinical application in the future. In this paper, we review the abnormal expression, functional role, and molecular mechanism of PABPC1 in tumorigenesis and provide directions for further understanding the regulatory role of PABPC1 in tumor cells.
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Affiliation(s)
- Ya Qi
- Department of Gynecology and Obstetrics, Shengjing Hospital Affiliated of China Medical University, Shenyang, Liaoning, China
| | - Min Wang
- Department of Gynecology and Obstetrics, Shengjing Hospital Affiliated of China Medical University, Shenyang, Liaoning, China
| | - Qi Jiang
- Second Department of Clinical Medicine, China Medical University, Shenyang, Liaoning, China
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14
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Kerkhofs K, Garg J, Fafard-Couture É, Abou Elela S, Scott MS, Pearlman RE, Bayfield MA. Altered tRNA processing is linked to a distinct and unusual La protein in Tetrahymena thermophila. Nat Commun 2022; 13:7332. [PMID: 36443289 DOI: 10.1038/s41467-022-34796-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 11/07/2022] [Indexed: 11/29/2022] Open
Abstract
Nascent pre-tRNAs are transcribed by RNA polymerase III and immediately bound by La proteins on the UUU-3'OH sequence, using a tandem arrangement of the La motif and an adjacent RNA recognition motif-1 (RRM1), resulting in protection from 3'-exonucleases and promotion of pre-tRNA folding. The Tetrahymena thermophila protein Mlp1 has been previously classified as a genuine La protein, despite the predicted absence of the RRM1. We find that Mlp1 functions as a La protein through binding of pre-tRNAs, and affects pre-tRNA processing in Tetrahymena thermophila and when expressed in fission yeast. However, unlike in other examined eukaryotes, depletion of Mlp1 results in 3'-trailer stabilization. The 3'-trailers in Tetrahymena thermophila are uniquely short relative to other examined eukaryotes, and 5'-leaders have evolved to disfavour pre-tRNA leader/trailer pairing. Our data indicate that this variant Mlp1 architecture is linked to an altered, novel mechanism of tRNA processing in Tetrahymena thermophila.
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15
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Zhang W, Fang D, Ye Z, Hu F, Cheng X, Cao J. Identification and molecular evolution of the La and LARP genes in 16 plant species: A focus on the Gossypium hirsutum. Int J Biol Macromol 2022. [DOI: 10.1016/j.ijbiomac.2022.10.195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/12/2022] [Accepted: 10/20/2022] [Indexed: 11/05/2022]
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16
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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17
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Duarte-Conde JA, Sans-Coll G, Merchante C. RNA-binding proteins and their role in translational regulation in plants. Essays Biochem 2022:EBC20210069. [PMID: 35612383 DOI: 10.1042/EBC20210069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 12/16/2022]
Abstract
Translation is a fundamental process for life that needs to be finely adapted to the energetical, developmental and environmental conditions; however, the molecular mechanisms behind such adaptation are not yet fully understood. By directly recognizing and binding to cis-elements present in their target mRNAs, RBPs govern all post-transcriptional regulatory processes. They orchestrate the balance between mRNA stability, storage, decay, and translation of their client mRNAs, playing a crucial role in the modulation of gene expression. In the last years exciting discoveries have been made regarding the roles of RBPs in fine-tuning translation. In this review, we focus on how these RBPs recognize their targets and modulate their translation, highlighting the complex and diverse molecular mechanisms implicated. Since the repertoire of RBPs keeps growing, future research promises to uncover new fascinating means of translational modulation, and thus, of gene expression.
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18
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Desi N, Tong QY, Teh V, Chan JJ, Zhang B, Tabatabaeian H, Tan HQ, Kapeli K, Jin W, Lim CY, Kwok ZH, Tan HT, Wang S, Siew BE, Lee KC, Chong CS, Tan KK, Yang H, Kappei D, Yeo GW, Chung MCM, Tay Y. Global analysis of RNA-binding proteins identifies a positive feedback loop between LARP1 and MYC that promotes tumorigenesis. Cell Mol Life Sci 2022; 79:147. [PMID: 35195778 PMCID: PMC11072786 DOI: 10.1007/s00018-021-04093-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 11/03/2022]
Abstract
In addition to genomic alterations, aberrant changes in post-transcriptional regulation can modify gene function and drive cancer development. RNA-binding proteins (RBPs) are a large class of post-transcriptional regulators that have been increasingly implicated in carcinogenesis. By integrating multi-omics data, we identify LARP1 as one of the most upregulated RBPs in colorectal cancer (CRC) and demonstrate its oncogenic properties. We perform LARP1:RNA interactome profiling and unveil a previously unexplored role for LARP1 in targeting the 3'UTR of oncogenes in CRC. Notably, we identify the proto-oncogenic transcription factor MYC as a key LARP1-regulated target. Our data show that LARP1 positively modulates MYC expression by associating with its 3'UTR. In addition, antisense oligonucleotide-mediated blocking of the interaction between LARP1 and the MYC 3'UTR reduces MYC expression and in vitro CRC growth. Furthermore, a systematic analysis of LARP1:protein interactions reveals IGF2BP3 and YBX1 as LARP1-interacting proteins that also regulate MYC expression and CRC development. Finally, we demonstrate that MYC reciprocally modulates LARP1 expression by targeting its enhancer. In summary, our data reveal a critical, previously uncharacterized role of LARP1 in promoting CRC tumorigenesis, validate its direct regulation of the proto-oncogene MYC and delineate a model of the positive feedback loop between MYC and LARP1 that promotes CRC growth and development.
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Affiliation(s)
- Ng Desi
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore
| | - Qing Yun Tong
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Velda Teh
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Jia Jia Chan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Bin Zhang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Hossein Tabatabaeian
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Hui Qing Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Katannya Kapeli
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Wenhao Jin
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Chun You Lim
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Zhi Hao Kwok
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
- Division of Pulmonary and Critical Care, Boston University, Boston, MA, 02118, USA
| | - Hwee Tong Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore
| | - Shi Wang
- Department of Pathology, National University Health System, Singapore, Singapore
| | - Bei-En Siew
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Kuok-Chung Lee
- Division of Colorectal Surgery, University Surgical Cluster, National University Health System, Singapore, Singapore
| | - Choon-Seng Chong
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Division of Colorectal Surgery, University Surgical Cluster, National University Health System, Singapore, Singapore
| | - Ker-Kan Tan
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Division of Colorectal Surgery, University Surgical Cluster, National University Health System, Singapore, Singapore
| | - Henry Yang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore
| | - Dennis Kappei
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore
| | - Gene W Yeo
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, La Jolla, San Diego, USA
| | - Maxey Ching Ming Chung
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore
| | - Yvonne Tay
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore.
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19
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Stefanovic L, Gordon BH, Silvers R, Stefanovic B. Characterization of Sequence-Specific Binding of LARP6 to the 5' Stem-Loop of Type I Collagen mRNAs and Implications for Rational Design of Antifibrotic Drugs. J Mol Biol 2022; 434:167394. [PMID: 34896113 PMCID: PMC8752511 DOI: 10.1016/j.jmb.2021.167394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 02/01/2023]
Abstract
Excessive synthesis of type I collagen is a hallmark of fibrotic diseases. Binding of La-related protein 6 (LARP6) to the 5' stem-loop (5'SL) of collagen mRNAs regulates their translation leading to an unnaturally elevated rate of collagen biosynthesis in fibrosis. Previous work suggested that LARP6 needs two domains to form stable complex with 5'SL RNA, the La domain and the juxtaposed RNA recognition motif (RRM), jointly called the La-module. Here we describe that La domain of LARP6 is necessary and sufficient for recognition of 5'SL in RNA sequence specific manner. A three-amino-acid motif located in the flexible loop connecting the second α-helix to the β-sheet of the La domain, called the RNK-motif, is critical for binding. Mutation of any of these three amino acids abolishes the binding of the La domain to 5'SL. The major site of crosslinking of LARP6 to 5'SL RNA was mapped to this motif, as well. The RNK-motif is not found in other LARPs, which cannot bind 5'SL. Presence of RRM increases the stability of complex between La domain and 5'SL RNA and RRM domain does not make extensive contacts with 5'SL RNA. We propose a model in which the initial recognition of 5'SL by LARP6 is mediated by the RNK epitope and further stabilized by the RRM domain. This discovery suggests that the interaction between LARP6 and collagen mRNAs can be blocked by small molecules that target the RNK epitope and will help rational design of the LARP6 binding inhibitors as specific antifibrotic drugs.
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Affiliation(s)
- Lela Stefanovic
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
| | - Blaine H Gordon
- Department of Chemistry and Biochemistry, College of Arts and Sciences, Florida State University, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, College of Arts and Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Robert Silvers
- Department of Chemistry and Biochemistry, College of Arts and Sciences, Florida State University, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, College of Arts and Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Branko Stefanovic
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA.
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20
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Abstract
RNA binding proteins, through control of mRNA fate and expression, are key players of organism development. The LARP family of RBPs sharing the La motif, are largely present in eukaryotes. They classify into five subfamilies which members acquired specific additional domains, including the RRM1 moiety which teams up with the La motif to form a versatile RNA binding unit. The LARP6 subfamily has had a peculiar history during plant evolution. While containing a single LARP6 in algae and non-vascular plants, they expanded and neofunctionalized into three subclusters in vascular plants. Studies from Arabidopsis thaliana, support that they acquired specific RNA binding properties and physiological roles. In particular LARP6C participates, through spatiotemporal control of translation, to male fertilization, a role seemingly conserved in maize. Interestingly, human LARP6 also acts in translation control and mRNA transport and similarly to LARP6C which is required for pollen tube guided elongation, is necessary to cell migration, through protrusion extension. This opens the possibility that some cellular and molecular functions of LARP6 were retained across eukaryote evolution. With their peculiar evolutionary history, plants provide a unique opportunity to uncover how La-module RNA binding properties evolved and identify species specific and basal roles of the LARP6 function. Deciphering of how LARP6, in particular LARP6C, acts at the molecular level, will foster novel knowledge on translation regulation and dynamics in changing cellular contexts. Considering the seemingly conserved function of LARP6C in male reproduction, it should fuel studies aimed at deriving crop species with improved seed yields.
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Affiliation(s)
- Cécile Bousquet-Antonelli
- CNRS LGDP-UMR5096, 58 Av. Paul Alduy, 66860 Perpignan, France
- Université de Perpignan Via Domitia, LGDP-UMR5096, 58 Av. Paul Alduy, 66860 Perpignan, France
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21
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Billey E, Hafidh S, Cruz-Gallardo I, Litholdo CG, Jean V, Carpentier MC, Picart C, Kumar V, Kulichova K, Maréchal E, Honys D, Conte MR, Deragon JM, Bousquet-Antonelli C. LARP6C orchestrates posttranscriptional reprogramming of gene expression during hydration to promote pollen tube guidance. Plant Cell 2021; 33:2637-2661. [PMID: 34124761 DOI: 10.1101/2020.11.27.401307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/06/2021] [Indexed: 05/19/2023]
Abstract
Increasing evidence suggests that posttranscriptional regulation is a key player in the transition between mature pollen and the progamic phase (from pollination to fertilization). Nonetheless, the actors in this messenger RNA (mRNA)-based gene expression reprogramming are poorly understood. We demonstrate that the evolutionarily conserved RNA-binding protein LARP6C is necessary for the transition from dry pollen to pollen tubes and the guided growth of pollen tubes towards the ovule in Arabidopsis thaliana. In dry pollen, LARP6C binds to transcripts encoding proteins that function in lipid synthesis and homeostasis, vesicular trafficking, and polarized cell growth. LARP6C also forms cytoplasmic granules that contain the poly(A) binding protein and possibly represent storage sites for translationally silent mRNAs. In pollen tubes, the loss of LARP6C negatively affects the quantities and distribution of storage lipids, as well as vesicular trafficking. In Nicotiana benthamiana leaf cells and in planta, analysis of reporter mRNAs designed from the LARP6C target MGD2 provided evidence that LARP6C can shift from a repressor to an activator of translation when the pollen grain enters the progamic phase. We propose that LARP6C orchestrates the timely posttranscriptional regulation of a subset of mRNAs in pollen during the transition from the quiescent to active state and along the progamic phase to promote male fertilization in plants.
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Affiliation(s)
- Elodie Billey
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Isabel Cruz-Gallardo
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Celso G Litholdo
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Viviane Jean
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Katarina Kulichova
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, 38054 Grenoble, France
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Maria R Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Jean-Marc Deragon
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Institut Universitaire de France, 75231 Paris Cedex 5, France
| | - Cécile Bousquet-Antonelli
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
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Billey E, Hafidh S, Cruz-Gallardo I, Litholdo CG, Jean V, Carpentier MC, Picart C, Kumar V, Kulichova K, Maréchal E, Honys D, Conte MR, Deragon JM, Bousquet-Antonelli C. LARP6C orchestrates posttranscriptional reprogramming of gene expression during hydration to promote pollen tube guidance. Plant Cell 2021; 33:2637-2661. [PMID: 34124761 PMCID: PMC8408461 DOI: 10.1093/plcell/koab131] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/06/2021] [Indexed: 05/15/2023]
Abstract
Increasing evidence suggests that posttranscriptional regulation is a key player in the transition between mature pollen and the progamic phase (from pollination to fertilization). Nonetheless, the actors in this messenger RNA (mRNA)-based gene expression reprogramming are poorly understood. We demonstrate that the evolutionarily conserved RNA-binding protein LARP6C is necessary for the transition from dry pollen to pollen tubes and the guided growth of pollen tubes towards the ovule in Arabidopsis thaliana. In dry pollen, LARP6C binds to transcripts encoding proteins that function in lipid synthesis and homeostasis, vesicular trafficking, and polarized cell growth. LARP6C also forms cytoplasmic granules that contain the poly(A) binding protein and possibly represent storage sites for translationally silent mRNAs. In pollen tubes, the loss of LARP6C negatively affects the quantities and distribution of storage lipids, as well as vesicular trafficking. In Nicotiana benthamiana leaf cells and in planta, analysis of reporter mRNAs designed from the LARP6C target MGD2 provided evidence that LARP6C can shift from a repressor to an activator of translation when the pollen grain enters the progamic phase. We propose that LARP6C orchestrates the timely posttranscriptional regulation of a subset of mRNAs in pollen during the transition from the quiescent to active state and along the progamic phase to promote male fertilization in plants.
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Affiliation(s)
- Elodie Billey
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Isabel Cruz-Gallardo
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Celso G. Litholdo
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Viviane Jean
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Katarina Kulichova
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, 38054 Grenoble, France
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Maria R. Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Jean-Marc Deragon
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Institut Universitaire de France, 75231 Paris Cedex 5, France
| | - Cécile Bousquet-Antonelli
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
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23
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Song J, Castillo-González C, Ma Z, Shippen DE. Arabidopsis retains vertebrate-type telomerase accessory proteins via a plant-specific assembly. Nucleic Acids Res 2021; 49:9496-9507. [PMID: 34403479 PMCID: PMC8450087 DOI: 10.1093/nar/gkab699] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/08/2021] [Accepted: 08/11/2021] [Indexed: 11/17/2022] Open
Abstract
The recent discovery of the bona-fide telomerase RNA (TR) from plants reveals conserved and unique secondary structure elements and the opportunity for new insight into the telomerase RNP. Here we examine how two highly conserved proteins previously implicated in Arabidopsis telomere maintenance, AtPOT1a and AtNAP57 (dyskerin), engage plant telomerase. We report that AtPOT1a associates with Arabidopsis telomerase via interaction with TERT. While loss of AtPOT1a does not impact AtTR stability, the templating domain is more accessible in pot1a mutants, supporting the conclusion that AtPOT1a stimulates telomerase activity but does not facilitate telomerase RNP assembly. We also show, that despite the absence of a canonical H/ACA binding motif within AtTR, dyskerin binds AtTR with high affinity and specificity in vitro via a plant specific three-way junction (TWJ). A core element of the TWJ is the P1a stem, which unites the 5′ and 3′ ends of AtTR. P1a is required for dyskerin-mediated stimulation of telomerase repeat addition processivity in vitro, and for AtTR accumulation and telomerase activity in vivo. The deployment of vertebrate-like accessory proteins and unique RNA structural elements by Arabidopsis telomerase provides a new platform for exploring telomerase biogenesis and evolution.
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Affiliation(s)
- Jiarui Song
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA
| | - Claudia Castillo-González
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA
| | - Zeyang Ma
- National Maize Improvement Center of China, China Agricultural University, 100193 Beijing, China
- College of Agronomy and Biotechnology, China Agricultural University, 100193 Beijing, China
| | - Dorothy E Shippen
- To whom correspondence should be addressed. Tel: +1 979 862 2342; Fax: +1 979 862 7638;
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24
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Chang Y, Lim G, Huh WK. Analysis of the TORC1 interactome reveals a spatially distinct function of TORC1 in mRNP complexes. J Cell Biol 2021; 220:211781. [PMID: 33566094 PMCID: PMC7879482 DOI: 10.1083/jcb.201912060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 11/15/2020] [Accepted: 01/06/2021] [Indexed: 11/22/2022] Open
Abstract
The target of rapamycin complex 1 (TORC1) is mainly localized to the vacuolar membrane and regulates eukaryotic cell growth in response to nutrient availability. To obtain deeper insights into the functional roles of TORC1, we performed a genome-wide analysis of the TORC1 interactome in yeast using the bimolecular fluorescence complementation (BiFC) assay. We found that while most of the BiFC signals are observed at the vacuolar membrane, a fraction of them are detected at cytoplasmic messenger ribonucleoprotein (mRNP) granules. Moreover, mRNA-binding proteins are enriched in the TORC1 interactome, suggesting a functional relationship between TORC1 and mRNA metabolism. We show that a portion of TORC1 is consistently associated with mRNP complexes and interacts with a specific subset of mRNAs. We also demonstrate that TORC1 directly targets a translational repressor Scd6 and that the activity of Scd6 is inhibited by TORC1-dependent phosphorylation. Collectively, our data suggest that TORC1 plays a novel role in posttranscriptional regulation by controlling the activity of Scd6.
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Affiliation(s)
- Yeonji Chang
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,Institute of Microbiology, Seoul National University, Seoul, Republic of Korea
| | - Gyubum Lim
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Won-Ki Huh
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,Institute of Microbiology, Seoul National University, Seoul, Republic of Korea
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25
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Stefanovic B, Michaels HA, Nefzi A. Discovery of a Lead Compound for Specific Inhibition of Type I Collagen Production in Fibrosis. ACS Med Chem Lett 2021; 12:477-484. [PMID: 33738075 DOI: 10.1021/acsmedchemlett.1c00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/23/2021] [Indexed: 02/06/2023] Open
Abstract
Fibrosis is a major medical problem caused by excessive synthesis of the extracellular matrix, composed predominantly of type I collagen, in various tissues. There are no approved antifibrotic drugs, and the major obstacle in finding clinically relevant compounds is the lack of specificity of current experimental drugs for type I collagen. Here we describe the discovery of a lead compound that specifically inhibited secretion of type I collagen by fibroblasts in culture at IC50 = 4.5 μM. The inhibition was specific for type I collagen, because secretion of fibronectin was not affected. In vitro, the compound inhibited binding of LARP6, the master regulator of translation of type I collagen mRNAs, to the 5' stem-loop sequence element which regulates their translation. Because binding of LARP6 to collagen mRNAs is crucial for the development of fibrosis, this inhibitor represents a promising lead for optimization into specific antifibrotic drugs.
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Affiliation(s)
- Branko Stefanovic
- Florida State University, 1115 West Call Street, Tallahassee, Florida 32306, United States
| | | | - Adel Nefzi
- Florida International University, Port Saint Lucie, Florida 34987, United States
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26
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Yu S, Palanisamy K, Sun K, Li X, Wang Y, Lin F, Chen K, Wang I, Yu T, Li C. Human antigen R regulates hypoxia-induced mitophagy in renal tubular cells through PARKIN/BNIP3L expressions. J Cell Mol Med 2021; 25:2691-2702. [PMID: 33496385 PMCID: PMC7933924 DOI: 10.1111/jcmm.16301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/29/2020] [Accepted: 01/05/2021] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial dysfunction contributes to the pathophysiology of acute kidney injury (AKI). Mitophagy selectively degrades damaged mitochondria and thereby regulates cellular homeostasis. RNA-binding proteins (RBPs) regulate RNA processing at multiple levels and thereby control cellular function. In this study, we aimed to understand the role of human antigen R (HuR) in hypoxia-induced mitophagy process in the renal tubular cells. Mitophagy marker expressions (PARKIN, p-PARKIN, PINK1, BNIP3L, BNIP3, LC3) were determined by western blot analysis. Immunofluorescence studies were performed to analyze mitophagosome, mitolysosome, co-localization of p-PARKIN/TOMM20 and BNIP3L/TOMM20. HuR-mediated regulation of PARKIN/BNIP3L expressions was determined by RNA-immunoprecipitation analysis and RNA stability experiments. Hypoxia induced mitochondrial dysfunction by increased ROS, decline in membrane potential and activated mitophagy through up-regulated PARKIN, PINK1, BNIP3 and BNIP3L expressions. HuR knockdown studies revealed that HuR regulates hypoxia-induced mitophagosome and mitolysosome formation. HuR was significantly bound to PARKIN and BNIP3L mRNA under hypoxia and thereby up-regulated their expressions through mRNA stability. Altogether, our data highlight the importance of HuR in mitophagy regulation through up-regulating PARKIN/BNIP3L expressions in renal tubular cells.
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Affiliation(s)
- Shao‐Hua Yu
- Graduate Institute of Biomedical SciencesChina Medical UniversityTaichungTaiwan
- Department of Emergency MedicineChina Medical University HospitalTaichungTaiwan
| | | | - Kuo‐Ting Sun
- Department of Pediatric DentistryChina Medical University HospitalTaichungTaiwan
- School of Dentistry, College of DentistryChina Medical UniversityTaichungTaiwan
| | - Xin Li
- Graduate Institute of Biomedical SciencesChina Medical UniversityTaichungTaiwan
| | - Yao‐Ming Wang
- Department of RadiologyTaichung Tzu Chi HospitalBuddhist Tzu Chi Medical FoundationTaichungTaiwan
| | - Feng‐Yen Lin
- Department of Internal MedicineSchool of MedicineCollege of MedicineTaipei Medical UniversityTaipeiTaiwan
- Division of Cardiology and Cardiovascular Research CenterTaipei Medical University HospitalTaipeiTaiwan
| | - Kuen‐Bao Chen
- School of MedicineChina Medical UniversityTaichungTaiwan
- Department of AnesthesiologyChina Medical University HospitalTaichungTaiwan
| | - I‐Kuan Wang
- Graduate Institute of Biomedical SciencesChina Medical UniversityTaichungTaiwan
- School of MedicineChina Medical UniversityTaichungTaiwan
- Division of NephrologyChina Medical University HospitalTaichungTaiwan
| | - Tung‐Min Yu
- Graduate Institute of Biomedical SciencesChina Medical UniversityTaichungTaiwan
- Division of NephrologyDepartment of Internal MedicineTaichung Veterans General HospitalTaichungTaiwan
| | - Chi‐Yuan Li
- Graduate Institute of Biomedical SciencesChina Medical UniversityTaichungTaiwan
- Department of AnesthesiologyChina Medical University HospitalTaichungTaiwan
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27
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Zhou L, Vejlupkova Z, Warman C, Fowler JE. A Maize Male Gametophyte-Specific Gene Encodes ZmLARP6c1, a Potential RNA-Binding Protein Required for Competitive Pollen Tube Growth. Front Plant Sci 2021; 12:635244. [PMID: 33719310 PMCID: PMC7947365 DOI: 10.3389/fpls.2021.635244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Members of the La-related protein family (LARPs) contain a conserved La module, which has been associated with RNA-binding activity. Expression of the maize gene GRMZM2G323499/Zm00001d018613, a member of the LARP family, is highly specific to pollen, based on both transcriptomic and proteomic assays. This suggests a pollen-specific RNA regulatory function for the protein, designated ZmLARP6c1 based on sequence similarity to the LARP6 subfamily in Arabidopsis. To test this hypothesis, a Ds-GFP transposable element insertion in the ZmLarp6c1 gene (tdsgR82C05) was obtained from the Dooner/Du mutant collection. Sequencing confirmed that the Ds-GFP insertion is in an exon, and thus likely interferes with ZmLARP6c1 function. Tracking inheritance of the insertion via its endosperm-expressed GFP indicated that the mutation was associated with reduced transmission from a heterozygous plant when crossed as a male (ranging from 0.5 to 26.5% transmission), but not as a female. Furthermore, this transmission defect was significantly alleviated when less pollen was applied to the silk, reducing competition between mutant and wild-type pollen. Pollen grain diameter measurements and nuclei counts showed no significant differences between wild-type and mutant pollen. However, in vitro, mutant pollen tubes were significantly shorter than those from sibling wild-type plants, and also displayed altered germination dynamics. These results are consistent with the idea that ZmLARP6c1 provides an important regulatory function during the highly competitive progamic phase of male gametophyte development following arrival of the pollen grain on the silk. The conditional, competitive nature of the Zmlarp6c1::Ds male sterility phenotype (i.e., reduced ability to produce progeny seed) points toward new possibilities for genetic control of parentage in crop production.
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Affiliation(s)
- Lian Zhou
- Maize Research Institute, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Zuzana Vejlupkova
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
| | - Cedar Warman
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
| | - John E Fowler
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
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28
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Bitaraf A, Razmara E, Bakhshinejad B, Yousefi H, Vatanmakanian M, Garshasbi M, Cho WC, Babashah S. The oncogenic and tumor suppressive roles of RNA-binding proteins in human cancers. J Cell Physiol 2021; 236:6200-6224. [PMID: 33559213 DOI: 10.1002/jcp.30311] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 01/14/2021] [Accepted: 01/22/2021] [Indexed: 12/17/2022]
Abstract
Posttranscriptional regulation is a mechanism for the cells to control gene regulation at the RNA level. In this process, RNA-binding proteins (RBPs) play central roles and orchestrate the function of RNA molecules in multiple steps. Accumulating evidence has shown that the aberrant regulation of RBPs makes contributions to the initiation and progression of tumorigenesis via numerous mechanisms such as genetic changes, epigenetic alterations, and noncoding RNA-mediated regulations. In this article, we review the effects caused by RBPs and their functional diversity in the malignant transformation of cancer cells that occurs through the involvement of these proteins in various stages of RNA regulation including alternative splicing, stability, polyadenylation, localization, and translation. Besides this, we review the various interactions between RBPs and other crucial posttranscriptional regulators such as microRNAs and long noncoding RNAs in the pathogenesis of cancer. Finally, we discuss the potential approaches for targeting RBPs in human cancers.
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Affiliation(s)
- Amirreza Bitaraf
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ehsan Razmara
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Babak Bakhshinejad
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hassan Yousefi
- Department of Biochemistry and Molecular Biology, LSUHSC School of Medicine, New Orleans, Louisiana, USA
| | - Mousa Vatanmakanian
- Department of Biochemistry and Molecular Biology, LSUHSC School of Medicine, New Orleans, Louisiana, USA
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - William C Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong
| | - Sadegh Babashah
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
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29
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Bayfield MA, Vinayak J, Kerkhofs K, Mansouri-Noori F. La proteins couple use of sequence-specific and non-specific binding modes to engage RNA substrates. RNA Biol 2021; 18:168-177. [PMID: 30777481 PMCID: PMC7928037 DOI: 10.1080/15476286.2019.1582955] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/05/2019] [Accepted: 02/05/2019] [Indexed: 12/31/2022] Open
Abstract
La shuttles between the nucleus and cytoplasm where it binds nascent RNA polymerase III (pol III) transcripts and mRNAs, respectively. La protects the 3' end of pol III transcribed RNA precursors, such as pre-tRNAs, through the use of a well-characterized UUU-3'OH binding mode. La proteins are also RNA chaperones, and La-dependent RNA chaperone activity is hypothesized to promote pre-tRNA maturation and translation at cellular and viral internal ribosome entry sites via binding sites distinct from those used for UUU-3'OH recognition. Since the publication of La-UUU-3'OH co-crystal structures, biochemical and genetic experiments have expanded our understanding of how La proteins use UUU-3'OH-independent binding modes to make sequence-independent contacts that can increase affinity for ligands and promote RNA remodeling. Other recent work has also expanded our understanding of how La binds mRNAs through contacts to the poly(A) tail. In this review, we focus on advances in the study of La protein-RNA complex surfaces beyond the description of the La-UUU-3'OH binding mode. We highlight recent advances in the functions of expected canonical nucleic acid interaction surfaces, a heightened appreciation of disordered C-terminal regions, and the nature of sequence-independent RNA determinants in La-RNA target binding. We further discuss how these RNA binding modes may have relevance to the function of the La-related proteins.
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Affiliation(s)
- Mark A. Bayfield
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Jyotsna Vinayak
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Kyra Kerkhofs
- Department of Biology, York University, Toronto, Ontario, Canada
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30
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Berman AJ, Thoreen CC, Dedeic Z, Chettle J, Roux PP, Blagden SP. Controversies around the function of LARP1. RNA Biol 2021; 18:207-217. [PMID: 32233986 PMCID: PMC7928164 DOI: 10.1080/15476286.2020.1733787] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/06/2020] [Accepted: 02/11/2020] [Indexed: 12/21/2022] Open
Abstract
The RNA-binding protein LARP1 has generated interest in recent years for its role in the mTOR signalling cascade and its regulation of terminal oligopyrimidine (TOP) mRNA translation. Paradoxically, some scientists have shown that LARP1 represses TOP translation while others that LARP1 activates it. Here, we present opinions from four leading scientists in the field to discuss these and other contradictory findings.
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Affiliation(s)
- Andrea J. Berman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, USA
| | - Carson C. Thoreen
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, USA
| | - Zinaida Dedeic
- Department of Oncology, University of Oxford, Oxford, UK
| | - James Chettle
- Department of Oncology, University of Oxford, Oxford, UK
| | - Philippe P. Roux
- Institute for Research in Immunology and Cancer (IRIC), Université De Montréal, Montreal, Quebec, Canada
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31
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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32
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Schwenzer H, Abdel Mouti M, Neubert P, Morris J, Stockton J, Bonham S, Fellermeyer M, Chettle J, Fischer R, Beggs AD, Blagden SP. LARP1 isoform expression in human cancer cell lines. RNA Biol 2021; 18:237-247. [PMID: 32286153 PMCID: PMC7928056 DOI: 10.1080/15476286.2020.1744320] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/09/2020] [Accepted: 03/14/2020] [Indexed: 01/07/2023] Open
Abstract
LARP1 is an oncogenic RNA-binding protein required for ribosome biogenesis and cancer cell survival. From published in vitro studies, there is disparity over which of two different LARP1 protein isoforms (termed the long LI-LARP1 and short SI-LARP1) is the canonical. Here, after conducting a series of biochemical and cellular assays, we conclude that LI-LARP1 (NM_033551.3 > NP_056130.2) is the dominantly expressed form. We observe that SI-LARP1 (NM_015315.5> NP_056130.2) is epigenetically repressed and that this repression is evolutionarily conserved in all but a small subclade of mammalian species. As with other LARP family members, there are multiple potential LARP1 mRNA isoforms that appear to be censored within the nucleus. The capacity of the cell to modulate splicing and expression of these apparently 'redundant' mRNAs hints at contextually specific mechanisms of LARP1 expression.
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Affiliation(s)
| | | | - Pia Neubert
- Department of Oncology, University of Oxford, Oxford, UK
| | | | - Joanne Stockton
- Institute of Cancer & Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Sarah Bonham
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - James Chettle
- Department of Oncology, University of Oxford, Oxford, UK
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrew D. Beggs
- Institute of Cancer & Genomic Sciences, University of Birmingham, Birmingham, UK
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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34
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Abstract
La-Related Protein 1 (LARP1) is an RNA-binding protein that regulates the stability and translation of mRNAs encoding the translation machinery, including ribosomal proteins and translation factors. These mRNAs are characterized by a 5'-terminal oligopyrimidine (TOP) motif that coordinates their temporal and stoichiometric expression. While LARP1 represses TOP mRNA translation via the C-terminal DM15 region, the role of the N-terminal La-Module in the recognition and translational regulation of TOP mRNAs remains elusive. Herein we show that the LARP1 La-Module also binds TOP motifs, although in a cap-independent manner. We also demonstrate that it recognizes poly(A) RNA. Further, our data reveal that the LARP1 La-Module can simultaneously engage TOP motifs and poly(A) RNA. These results evoke an intriguing molecular mechanism whereby LARP1 could regulate translation and stabilization of TOP transcripts.
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Affiliation(s)
- Hiba A. Al-Ashtal
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Courtney M. Rubottom
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Thomas C. Leeper
- Department of Chemistry & Biochemistry, Kennesaw State University, Kennesaw, GA, USA
| | - Andrea J. Berman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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35
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Blagden SP, Bayfield M, Bousquet-Antonelli C. A decade of LARP society. RNA Biol 2021; 18:157-158. [PMID: 33651971 PMCID: PMC7928030 DOI: 10.1080/15476286.2020.1755505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
| | - Mark Bayfield
- Department of Biology, York University, Toronto, ON, Canada
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36
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Abstract
The fate of any cellular RNA is largely influenced by the nature and diversity of its interactions with various RNA-binding proteins (RBPs) leading to the formation of a biologically significant ribonucleoprotein (RNP) complex. La motif-containing proteins (composed of genuine La and La-related proteins (LARPs)) represent an evolutionary conserved family of RBPs that encompass a large range of crucial functions, involving coding and non-coding RNAs. In this work, we provide data that extend our previous knowledge on the distribution, organization and evolutionary history of this important protein family. Using a repertoire of 345 La motif-containing proteins from 135 species representing all major eukaryotic lineages, we were able to pinpoint many lineage-specific variations in the structural organization of La and LARPs and propose new evolutive scenarios to explain their modern genomic distribution.
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Affiliation(s)
- Jean-Marc Deragon
- LGDP-UMR5096, Université de Perpignan Via Domitia, Perpignan, France
- CNRS LGDP-UMR5096, Perpignan, France
- Institut Universitaire de France, Paris, France
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37
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Werneck-de-Castro JP, Peçanha FLM, Silvestre DH, Bernal-Mizrachi E. The RNA-binding protein LARP1 is dispensable for pancreatic β-cell function and mass. Sci Rep 2021; 11:2079. [PMID: 33483593 PMCID: PMC7822907 DOI: 10.1038/s41598-021-81457-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/07/2020] [Indexed: 12/28/2022] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) deficiency or chronic hyperactivation in pancreatic β-cells leads to diabetes. mTORC1 complexes with La-related protein 1 (LARP1) to specifically regulate the expression of 5' terminal oligopyrimidine tract (5'TOP) mRNAs which encode proteins of the translation machinery and ribosome biogenesis. Here we show that LARP1 is the most expressed LARP in mouse islets and human β-cells, being 2-4-fold more abundant than LARP1B, a member of the family that also interacts with mTORC1. Interestingly, β-cells from diabetic patients have higher LARP1 and LARP1B expression. However, specific deletion of Larp1 gene in β-cells (β-Larp1KO mice) did not impair insulin secretion and glucose metabolism in male and female mice. High fat or high branched-chain amino acid (BCAA) diets did not disturb glucose homeostasis compared to control littermates up to 8 weeks; BCAA diet slightly impaired glucose tolerance in the β-Larp1KO mice at 16 weeks. However, no differences in plasma insulin levels, non-fasting glycemia and β-cell mass were observed in the β-Larp1KO mice. In conclusion, LARP1 is the most abundant LARP in mouse islets and human β-cells, and it is upregulated in diabetic subjects. However, genetically disruption of Larp1 gene did not impact glucose homeostasis in basal and diabetogenic conditions, suggesting no major role for LARP1 in β-cells.
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Affiliation(s)
- Joao Pedro Werneck-de-Castro
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
- Miami VA Health Care System, Miami, FL, 33136, USA
| | - Flavia Leticia Martins Peçanha
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Diego Henrique Silvestre
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, 21941090, Brazil
| | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
- Miami VA Health Care System, Miami, FL, 33136, USA.
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38
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Basu R, Eichhorn CD, Cheng R, Peterson RD, Feigon J. Structure of S. pombe telomerase protein Pof8 C-terminal domain is an xRRM conserved among LARP7 proteins. RNA Biol 2020; 18:1181-1192. [PMID: 33131423 DOI: 10.1080/15476286.2020.1836891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
La-related proteins 7 (LARP7) are a class of RNA chaperones that bind the 3' ends of RNA and are constitutively associated with their specific target RNAs. In metazoa, Larp7 binds to the long non-coding 7SK RNA as a core component of the 7SK RNP, a major regulator of eukaryotic transcription. In the ciliate Tetrahymena the LARP7 protein p65 is a component of telomerase, an essential ribonucleoprotein complex that maintains the telomeric DNA at eukaryotic chromosome ends. p65 is important for the ordered assembly of telomerase RNA (TER) with telomerase reverse transcriptase. Unexpectedly, Schizosaccharomyces pombe Pof8 was recently identified as a LARP7 protein and a core component of fission yeast telomerase essential for biogenesis. LARP7 proteins have a conserved N-terminal La motif and RRM1 (La module) and C-terminal RRM2 with specific RNA substrate recognition attributed to RRM2, first structurally characterized in p65 as an atypical RRM named xRRM. Here we present the X-ray crystal structure and NMR studies of S. pombe Pof8 RRM2. Sequence and structure comparison of Pof8 RRM2 to p65 and human Larp7 xRRMs reveals conserved features for RNA binding with the main variability in the length of the non-canonical helix α3. This study shows that Pof8 has conserved xRRM features, providing insight into TER recognition and the defining characteristics of the xRRM.
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Affiliation(s)
- Ritwika Basu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Catherine D Eichhorn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Ryan Cheng
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Robert D Peterson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
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39
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Abstract
RNA-binding proteins are important regulators of RNA metabolism and are of critical importance in all steps of the gene expression cascade. The role of aberrantly expressed RBPs in human disease is an exciting research field and the potential application of RBPs as a therapeutic target or a diagnostic marker represents a fast-growing area of research.Aberrant overexpression of the human RNA-binding protein La has been found in various cancer entities including lung, cervical, head and neck, and chronic myelogenous leukaemia. Cancer-associated La protein supports tumour-promoting processes such as proliferation, mobility, invasiveness and tumour growth. Moreover, the La protein maintains the survival of cancer cells by supporting an anti-apoptotic state that may cause resistance to chemotherapeutic therapy.The human La protein represents a multifunctional post-translationally modified RNA-binding protein with RNA chaperone activity that promotes processing of non-coding precursor RNAs but also stimulates the translation of selective messenger RNAs encoding tumour-promoting and anti-apoptotic factors. In our model, La facilitates the expression of those factors and helps cancer cells to cope with cellular stress. In contrast to oncogenes, able to initiate tumorigenesis, we postulate that the aberrantly elevated expression of the human La protein contributes to the non-oncogenic addiction of cancer cells. In this review, we summarize the current understanding about the implications of the RNA-binding protein La in cancer progression and therapeutic resistance. The concept of exploiting the RBP La as a cancer drug target will be discussed.
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Affiliation(s)
- Gunhild Sommer
- Department for Pediatric Hematology, Oncology and Stem Cell Transplantation, University Hospital Regensburg, Regensburg, Germany
| | - Tilman Heise
- Department for Pediatric Hematology, Oncology and Stem Cell Transplantation, University Hospital Regensburg, Regensburg, Germany
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40
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Grimm C, Pelz JP, Schneider C, Schäffler K, Fischer U. Crystal Structure of a Variant PAM2 Motif of LARP4B Bound to the MLLE Domain of PABPC1. Biomolecules 2020; 10:E872. [PMID: 32517187 DOI: 10.3390/biom10060872] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/31/2020] [Accepted: 06/04/2020] [Indexed: 12/15/2022] Open
Abstract
Eukaryotic cells determine the protein output of their genetic program by regulating mRNA transcription, localization, translation and turnover rates. This regulation is accomplished by an ensemble of RNA-binding proteins (RBPs) that bind to any given mRNA, thus forming mRNPs. Poly(A) binding proteins (PABPs) are prominent members of virtually all mRNPs that possess poly(A) tails. They serve as multifunctional scaffolds, allowing the recruitment of diverse factors containing a poly(A)-interacting motif (PAM) into mRNPs. We present the crystal structure of the variant PAM motif (termed PAM2w) in the N-terminal part of the positive translation factor LARP4B, which binds to the MLLE domain of the poly(A) binding protein C1 cytoplasmic 1 (PABPC1). The structural analysis, along with mutational studies in vitro and in vivo, uncovered a new mode of interaction between PAM2 motifs and MLLE domains.
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41
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Abstract
La and La-related proteins (LARPs) are characterized by a common RNA interaction platform termed the La module. This structural hallmark allows LARPs to pervade various aspects of RNA biology. The metazoan LARP7 protein binds to the 7SK RNA as part of a 7SK small nuclear ribonucleoprotein (7SK snRNP), which inhibits the transcriptional activity of RNA polymerase II (Pol II). Additionally, recent findings revealed unanticipated roles of LARP7 in the assembly of other RNPs, as well as in the modification, processing and cellular transport of RNA molecules. Reduced levels of functional LARP7 have been linked to cancer and Alazami syndrome, two seemingly unrelated human diseases characterized either by hyperproliferation or growth retardation. Here, we review the intricate regulatory networks centered on LARP7 and assess how malfunction of these networks may relate to the etiology of LARP7-linked diseases.
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Affiliation(s)
- Daniele Hasler
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Gunter Meister
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany
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42
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Abstract
RNA-binding proteins (RBPs) comprise a large class of over 2,000 proteins that interact with transcripts in all manner of RNA-driven processes. The structures and mechanisms that RBPs use to bind and regulate RNA are incredibly diverse. In this review, we take a look at the components of protein-RNA interaction, from the molecular level to multi-component interaction. We first summarize what is known about protein-RNA molecular interactions based on analyses of solved structures. We additionally describe software currently available for predicting protein-RNA interaction and other resources useful for the study of RBPs. We then review the structure and function of seventeen known RNA-binding domains and analyze the hydrogen bonds adopted by protein-RNA structures on a domain-by-domain basis. We conclude with a summary of the higher-level mechanisms that regulate protein-RNA interactions.
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Affiliation(s)
- Meredith Corley
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Margaret C Burns
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA; Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA.
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43
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Abstract
The La-related proteins (LaRPs) are a superfamily of eukaryotic RNA-binding proteins with important and varied roles. To understand LaRP functions it is essential to unravel the divergent features responsible for their RNA target selectivity, which underlie their distinct identities and cellular roles. LaRPs are built on a common structural module called the ‘La-module’ that acts as a main locus for RNA recognition. The La-module is comprised of two tethered domains whose relative structural and dynamic interplay has been proposed to regulate RNA-target selection, albeit the mechanistic underpinning of this recognition remains to be elucidated. A main unsolved conundrum is how conserved La-modules across LaRPs are able to bind to extremely diverse RNA ligands. In this work, we employed Small Angle X-ray Scattering (SAXS) to investigate several human LaRP La-modules in the absence and, where applicable, in the presence of their RNA target, with the aim to explore the structural dynamics of their RNA recognition and provide information on the architectural landscape accessible to these proteins. Integration of these SAXS experiments with prior X-ray crystallography and NMR data suggests that RNA binding is generally accompanied by a compaction and loss of flexibility of the La-module. Nonetheless, the La-modules appear to experience a considerably different degree of inherent flexibility in their apo state. Furthermore, although they all exist in discrete subsets of accessible populations in equilibrium, these vary from LaRP to LaRP and can be either extended or compact. We propose that these divergent features may be critical for RNA substrate discrimination.
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Affiliation(s)
- Javier Lizarrondo
- Randall Centre for Cell & Molecular Biophysics, King's College London, Guy's Campus, London, UK
| | - Anne-Catherine Dock-Bregeon
- Laboratoire De Biologie Intégrative Des Modèles Marins, Station Biologique De Roscoff, CNRS-Sorbonne Université, Roscoff, France
| | - Luigi Martino
- The Francis Crick Institute, Molecular Structure of Cell Signalling Laboratory, London, UK
| | - Maria R Conte
- Randall Centre for Cell & Molecular Biophysics, King's College London, Guy's Campus, London, UK
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44
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Philippe L, van den Elzen AMG, Watson MJ, Thoreen CC. Global analysis of LARP1 translation targets reveals tunable and dynamic features of 5' TOP motifs. Proc Natl Acad Sci U S A 2020; 117:5319-5328. [PMID: 32094190 PMCID: PMC7071917 DOI: 10.1073/pnas.1912864117] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Terminal oligopyrimidine (TOP) motifs are sequences at the 5' ends of mRNAs that link their translation to the mTOR Complex 1 (mTORC1) nutrient-sensing signaling pathway. They are commonly regarded as discrete elements that reside on ∼100 mRNAs that mostly encode translation factors. However, the full spectrum of TOP sequences and their prevalence throughout the transcriptome remain unclear, primarily because of uncertainty over the mechanism that detects them. Here, we globally analyzed translation targets of La-related protein 1 (LARP1), an RNA-binding protein and mTORC1 effector that has been shown to repress TOP mRNA translation in a few specific cases. We establish that LARP1 is the primary translation regulator of mRNAs with classical TOP motifs genome-wide, and also that these motifs are extreme instances of a broader continuum of regulatory sequences. We identify the features of TOP sequences that determine their potency and quantify these as a metric that accurately predicts mTORC1/LARP1 regulation called a TOPscore. Analysis of TOPscores across the transcriptomes of 16 mammalian tissues defines a constitutive "core" set of TOP mRNAs, but also identifies tissue-specific TOP mRNAs produced via alternative transcription initiation sites. These results establish the central role of LARP1 in TOP mRNA regulation on a transcriptome scale and show how it connects mTORC1 to a tunable and dynamic program of gene expression that is tailored to specific biological contexts.
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Affiliation(s)
- Lucas Philippe
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510
| | | | - Maegan J Watson
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510
| | - Carson C Thoreen
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510
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45
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Wang X, Li ZT, Yan Y, Lin P, Tang W, Hasler D, Meduri R, Li Y, Hua MM, Qi HT, Lin DH, Shi HJ, Hui J, Li J, Li D, Yang JH, Lin J, Meister G, Fischer U, Liu MF. LARP7-Mediated U6 snRNA Modification Ensures Splicing Fidelity and Spermatogenesis in Mice. Mol Cell 2020; 77:999-1013.e6. [PMID: 32017896 DOI: 10.1016/j.molcel.2020.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 11/19/2019] [Accepted: 12/26/2019] [Indexed: 12/13/2022]
Abstract
U6 snRNA, as an essential component of the catalytic core of the pre-mRNA processing spliceosome, is heavily modified post-transcriptionally, with 2'-O-methylation being most common. The role of these modifications in pre-mRNA splicing as well as their physiological function in mammals have remained largely unclear. Here we report that the La-related protein LARP7 functions as a critical cofactor for 2'-O-methylation of U6 in mouse male germ cells. Mechanistically, LARP7 promotes U6 loading onto box C/D snoRNP, facilitating U6 2'-O-methylation by box C/D snoRNP. Importantly, ablation of LARP7 in the male germline causes defective U6 2'-O-methylation, massive alterations in pre-mRNA splicing, and spermatogenic failure in mice, which can be rescued by ectopic expression of wild-type LARP7 but not an U6-loading-deficient mutant LARP7. Our data uncover a novel role of LARP7 in regulating U6 2'-O-methylation and demonstrate the functional requirement of such modification for splicing fidelity and spermatogenesis in mice.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhi-Tong Li
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Yue Yan
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Penghui Lin
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Wei Tang
- Animal Core Facility, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Daniele Hasler
- Laboratory for RNA Biology, Biochemistry Center Regensburg (BZR), University of Regensburg, Regensburg, Germany
| | | | - Ye Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China
| | - Min-Min Hua
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China; NHC Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Pharmacy School, Fudan University, Shanghai 200032, China
| | - Hui-Tao Qi
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Di-Hang Lin
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Hui-Juan Shi
- NHC Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Pharmacy School, Fudan University, Shanghai 200032, China
| | - Jingyi Hui
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Jinsong Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; School of Life Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Dangsheng Li
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Jian-Hua Yang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China
| | - Gunter Meister
- Laboratory for RNA Biology, Biochemistry Center Regensburg (BZR), University of Regensburg, Regensburg, Germany
| | - Utz Fischer
- Department of Biochemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Mo-Fang Liu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences - University of Chinese Academy of Sciences, Shanghai 200031, China; School of Life Science and Technology, Shanghai Tech University, Shanghai 201210, China.
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46
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Abstract
In Neurospora and other fungi, the protein frequency (FRQ) is an integral part and a negative element in the fungal circadian oscillator. In Drosophila and many other higher organisms, the protein period (PER) is an integral part and a negative element of their circadian oscillator. Employing bioinformatic techniques, such as BLAST, CLUSTAL, and MEME (Multiple Em for Motif Elicitation), 11 regions (sequences) of potential similarity were found between the fungal FRQ and the Drosophila PER. Many of these FRQ regions are conserved in many fungal FRQ(s). Many of these PER regions are conserved in many insects. In addition, these regions are also of biological significance since mutations in these regions lead to changes in the circadian clock of Neurospora and Drosophila. Many of these regions of similarity between FRQ and PER are also conserved between the Drosophila PER and the mouse PER (mPER2). This suggests conserved and important regions for all 3 proteins and a common ancestor, possibly in those amoeba, such as Capsaspora, that sits at the base of the phylogenetic tree where fungi and animals diverged. Two additional examples of a possible common ancestor between Neurospora and Drosophila were found. One, the white collar (WC-1) protein of Neurospora and the Drosophila PER, shows significant similarity in its Per/Arnt/Sim (PAS) motifs to the PAS motif of an ARNT-like protein found in the amoeba, Capsaspora. Two, both of the positive elements in each system (i.e., WC-1 in Neurospora and cycle [CYC] in Drosophila), show significant similarity to this Capsaspora ARNT protein. A discussion of these findings centers on the long-time debate about the origins of the many different clock systems (i.e., independent evolution or common ancestor as well as to the question of how new genes are formed).
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Affiliation(s)
- Stuart Brody
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, and Center for Circadian Biology, UCSD, La Jolla, California
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47
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Desi N, Tay Y. The Butterfly Effect of RNA Alterations on Transcriptomic Equilibrium. Cells 2019; 8:E1634. [PMID: 31847302 DOI: 10.3390/cells8121634] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/11/2019] [Accepted: 12/11/2019] [Indexed: 12/17/2022] Open
Abstract
: Post-transcriptional regulation plays a key role in modulating gene expression, and the perturbation of transcriptomic equilibrium has been shown to drive the development of multiple diseases including cancer. Recent studies have revealed the existence of multiple post-transcriptional processes that coordinatively regulate the expression and function of each RNA transcript. In this review, we summarize the latest research describing various mechanisms by which small alterations in RNA processing or function can potentially reshape the transcriptomic landscape, and the impact that this may have on cancer development.
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Dock-Bregeon AC, Lewis KA, Conte MR. The La-related proteins: structures and interactions of a versatile superfamily of RNA-binding proteins. RNA Biol 2019; 18:178-193. [PMID: 31752575 DOI: 10.1080/15476286.2019.1695712] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The La-related proteins (LaRPs) are an ancient superfamily of RNA-binding proteins orchestrating the major fates of RNA, from processing and maturation to regulation of mRNA translation. LaRPs are instrumental in modulating complex assemblies where the RNA is bound, folded, processed, escorted and presented to the functional effectors often through recruitment of protein partners. This intricate web of protein-RNA and protein-protein interactions is enabled by the modular nature of the LaRPs, comprising several structured domains connected by flexible linkers, and other sequences lacking recognizable folded motifs. Recent structures, together with biochemical and biophysical studies, have provided insights into how each LaRP family has evolved unique mechanisms of RNA recognition, not only through the conserved RNA-binding unit, the La-module, but also mediated by other family-specific motifs. Furthermore, in a series of unexpected twists and turns, they have revealed that the dynamic and conformational interplay of multi-structured domains and disordered regions operate in unison to achieve RNA substrate discrimination. This review proposes a perspective of our current knowledge of the structure-function relationship of the LaRP superfamily.
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Affiliation(s)
| | - Karen A Lewis
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | - Maria R Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
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Cho H, Lee W, Kim GW, Lee SH, Moon JS, Kim M, Kim HS, Oh JW. Regulation of La/SSB-dependent viral gene expression by pre-tRNA 3' trailer-derived tRNA fragments. Nucleic Acids Res 2019; 47:9888-9901. [PMID: 31504775 PMCID: PMC6765225 DOI: 10.1093/nar/gkz732] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 07/29/2019] [Accepted: 08/16/2019] [Indexed: 12/19/2022] Open
Abstract
tRNA-derived RNA fragments (tRFs) have emerged as a new class of functional RNAs implicated in cancer, metabolic and neurological disorders, and viral infection. Yet our understanding of their biogenesis and functions remains limited. In the present study, through analysis of small RNA profile we have identified a distinct set of tRFs derived from pre-tRNA 3′ trailers in the hepatocellular carcinoma cell line Huh7. Among those tRFs, tRF_U3_1, which is a 19-nucleotide-long chr10.tRNA2-Ser(TGA)-derived trailer, was expressed most abundantly in both Huh7 and cancerous liver tissues, being present primarily in the cytoplasm. We show that genetic loss of tRF_U3_1 does not affect cell growth and it is not involved in Ago2-mediated gene silencing. Using La/SSB knockout Huh7 cell lines, we demonstrate that this nuclear-cytoplasmic shuttling protein directly binds to the 3′ U-tail of tRF_U3_1 and other abundantly expressed trailers and plays a critical role in their stable cytoplasmic accumulation. The pre-tRNA trailer-derived tRFs capable of sequestering the limiting amounts of La/SSB in the cytoplasm rendered cells resistant to various RNA viruses, which usurp La/SSB with RNA chaperone activity for their gene expression. Collectively, our results establish the trailer-derived tRF-La/SSB interface, regulating viral gene expression.
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Affiliation(s)
- Hee Cho
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Wooseong Lee
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Geon-Woo Kim
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Seung-Hoon Lee
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Jae-Su Moon
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Minwoo Kim
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Hyun Seok Kim
- Severance Biomedical Science Institute, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Jong-Won Oh
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
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Abstract
Telomerase is a DNA polymerase that extends the 3' ends of chromosomes by processively synthesizing multiple telomeric repeats. It is a unique ribonucleoprotein (RNP) containing a specialized telomerase reverse transcriptase (TERT) and telomerase RNA (TER) with its own template and other elements required with TERT for activity (catalytic core), as well as species-specific TER-binding proteins important for biogenesis and assembly (core RNP); other proteins bind telomerase transiently or constitutively to allow association of telomerase and other proteins with telomere ends for regulation of DNA synthesis. Here we describe how nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography of TER and protein domains helped define the structure and function of the core RNP, laying the groundwork for interpreting negative-stain and cryo electron microscopy (cryo-EM) density maps of Tetrahymena thermophila and human telomerase holoenzymes. As the resolution has improved from ∼30 Å to ∼5 Å, these studies have provided increasingly detailed information on telomerase architecture and mechanism.
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Affiliation(s)
- Yaqiang Wang
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, California 90095-1569
| | - Lukas Sušac
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, California 90095-1569
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, California 90095-1569
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