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Liu R, Zhao E, Yu H, Yuan C, Abbas MN, Cui H. Methylation across the central dogma in health and diseases: new therapeutic strategies. Signal Transduct Target Ther 2023; 8:310. [PMID: 37620312 PMCID: PMC10449936 DOI: 10.1038/s41392-023-01528-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 08/26/2023] Open
Abstract
The proper transfer of genetic information from DNA to RNA to protein is essential for cell-fate control, development, and health. Methylation of DNA, RNAs, histones, and non-histone proteins is a reversible post-synthesis modification that finetunes gene expression and function in diverse physiological processes. Aberrant methylation caused by genetic mutations or environmental stimuli promotes various diseases and accelerates aging, necessitating the development of therapies to correct the disease-driver methylation imbalance. In this Review, we summarize the operating system of methylation across the central dogma, which includes writers, erasers, readers, and reader-independent outputs. We then discuss how dysregulation of the system contributes to neurological disorders, cancer, and aging. Current small-molecule compounds that target the modifiers show modest success in certain cancers. The methylome-wide action and lack of specificity lead to undesirable biological effects and cytotoxicity, limiting their therapeutic application, especially for diseases with a monogenic cause or different directions of methylation changes. Emerging tools capable of site-specific methylation manipulation hold great promise to solve this dilemma. With the refinement of delivery vehicles, these new tools are well positioned to advance the basic research and clinical translation of the methylation field.
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Affiliation(s)
- Ruochen Liu
- State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400715, China
- Jinfeng Laboratory, Chongqing, 401329, China
- Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing, 400716, China
- Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, 400715, China
| | - Erhu Zhao
- State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400715, China
- Jinfeng Laboratory, Chongqing, 401329, China
- Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing, 400716, China
- Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, 400715, China
| | - Huijuan Yu
- State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400715, China
| | - Chaoyu Yuan
- State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400715, China
| | - Muhammad Nadeem Abbas
- State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400715, China
- Jinfeng Laboratory, Chongqing, 401329, China
- Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing, 400716, China
- Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, 400715, China
| | - Hongjuan Cui
- State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400715, China.
- Jinfeng Laboratory, Chongqing, 401329, China.
- Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing, 400716, China.
- Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, 400715, China.
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2
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Dong R, Li X, Flores AD, Lai KO. The translation initiating factor eIF4E and arginine methylation underlie G3BP1 function in dendritic spine development of neurons. J Biol Chem 2023; 299:105029. [PMID: 37442236 PMCID: PMC10432808 DOI: 10.1016/j.jbc.2023.105029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 07/02/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
Communication between neurons relies on neurotransmission that takes place at synapses. Excitatory synapses are located primarily on dendritic spines that possess diverse morphologies, ranging from elongated filopodia to mushroom-shaped spines. Failure in the proper development of dendritic spines has detrimental consequences on neuronal connectivity, but the molecular mechanism that controls the balance of filopodia and mushroom spines is not well understood. G3BP1 is the key RNA-binding protein that assembles the stress granules in non-neuronal cells to adjust protein synthesis upon exogenous stress. Emerging evidence suggests that the biological significance of G3BP1 extends beyond its role in stress response, especially in the nervous system. However, the mechanism underlying the regulation and function of G3BP1 in neurons remains elusive. Here we found that G3BP1 suppresses protein synthesis and binds to the translation initiation factor eIF4E via its NTF2-like domain. Notably, the over-production of filopodia caused by G3BP1 depletion can be alleviated by blocking the formation of the translation initiation complex. We further found that the interaction of G3BP1 with eIF4E is regulated by arginine methylation. Knockdown of the protein arginine methyltransferase PRMT8 leads to elevated protein synthesis and filopodia production, which is reversed by the expression of methylation-mimetic G3BP1. Our study, therefore, reveals arginine methylation as a key regulatory mechanism of G3BP1 during dendritic spine morphogenesis and identifies eIF4E as a novel downstream target of G3BP1 in neuronal development independent of stress response.
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Affiliation(s)
- Rui Dong
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China
| | - Xuejun Li
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China; Hong Kong Institute for Advanced Study, City University of Hong Kong, Hong Kong, China
| | - Angelo D Flores
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China
| | - Kwok-On Lai
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China; Hong Kong Institute for Advanced Study, City University of Hong Kong, Hong Kong, China.
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3
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Asano-Inami E, Yokoi A, Sugiyama M, Hyodo T, Hamaguchi T, Kajiyama H. The association of UBAP2L and G3BP1 mediated by small nucleolar RNA is essential for stress granule formation. Commun Biol 2023; 6:415. [PMID: 37059803 PMCID: PMC10104854 DOI: 10.1038/s42003-023-04754-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 03/24/2023] [Indexed: 04/16/2023] Open
Abstract
Stress granules (SGs) are dynamic, non-membranous structures composed of non-translating mRNAs and various proteins and play critical roles in cell survival under stressed conditions. Extensive proteomics analyses have been performed to identify proteins in SGs; however, the molecular functions of these components in SG formation remain unclear. In this report, we show that ubiquitin-associated protein 2-like (UBAP2L) is a crucial component of SGs. UBAP2L localized to SGs in response to various stresses, and its depletion significantly suppressed SG organization. Proteomics and RNA sequencing analyses found that UBAP2L formed a protein-RNA complex with Ras-GTP-activating protein SH3 domain binding protein 1 (G3BP1) and small nucleolar RNAs (snoRNAs). In vitro binding analysis demonstrated that snoRNAs were required for UBAP2L association with G3BP1. In addition, decreased expression of snoRNAs reduced the interaction between UBAP2L and G3BP1 and suppressed SG formation. Our results reveal a critical role of SG component, the UBAP2L/snoRNA/G3BP1 protein-RNA complex, and provide new insights into the regulation of SG assembly.
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Affiliation(s)
- Eri Asano-Inami
- Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya, 466-8550, Japan.
- Bell Research Center for Reproductive Health and Cancer, Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya, 466-8550, Japan.
| | - Akira Yokoi
- Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya, 466-8550, Japan.
- Institute for Advanced Research, Nagoya University, Nagoya, Japan.
| | - Mai Sugiyama
- Bell Research Center for Reproductive Health and Cancer, Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya, 466-8550, Japan
| | - Toshinori Hyodo
- Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan
| | - Tomonari Hamaguchi
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya, 466-8550, Japan
| | - Hiroaki Kajiyama
- Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya, 466-8550, Japan
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Chowdhury MN, Jin H. The RGG motif proteins: Interactions, functions, and regulations. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1748. [PMID: 35661420 PMCID: PMC9718894 DOI: 10.1002/wrna.1748] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 01/31/2023]
Abstract
Proteins with motifs rich in arginines and glycines were discovered decades ago and are functionally involved in a staggering range of essential processes in the cell. Versatile, specific, yet adaptable molecular interactions enabled by the unique combination of arginine and glycine, combined with multiplicity of molecular recognition conferred by repeated di-, tri-, and multiple peptide motifs, allow RGG motif proteins to interact with a broad range of proteins and nucleic acids. Furthermore, posttranslational modifications at the arginines in the motif extend the RGG protein's capacity for a fine-tuned regulation. In this review, we focus on the biochemical properties of the RGG motif, its molecular interactions with RNAs and proteins, and roles of the posttranslational modification in modulating their interactions. We discuss current knowledge of the RGG motif proteins involved in mRNA transport and translation, highlight our merging understanding of their molecular functions in translational regulation and summarize areas of research in the future critical in understanding this important family of proteins. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Translation > Mechanisms.
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Affiliation(s)
- Mashiat N. Chowdhury
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801
| | - Hong Jin
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801,Carl R. Woese Institute for Genomic Biology, 1206 West Gregory Drive, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801,Corresponding author: Phone: (217)244-9493, Fax: (217)244-5858,
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5
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Ren J, Zhang Z, Zong Z, Zhang L, Zhou F. Emerging Implications of Phase Separation in Cancer. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202855. [PMID: 36117111 PMCID: PMC9631093 DOI: 10.1002/advs.202202855] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 08/26/2022] [Indexed: 05/19/2023]
Abstract
In eukaryotic cells, biological activities are executed in distinct cellular compartments or organelles. Canonical organelles with membrane-bound structures are well understood. Cells also inherently contain versatile membrane-less organelles (MLOs) that feature liquid or gel-like bodies. A biophysical process termed liquid-liquid phase separation (LLPS) elucidates how MLOs form through dynamic biomolecule assembly. LLPS-related molecules often have multivalency, which is essential for low-affinity inter- or intra-molecule interactions to trigger phase separation. Accumulating evidence shows that LLPS concentrates and organizes desired molecules or segregates unneeded molecules in cells. Thus, MLOs have tunable functional specificity in response to environmental stimuli and metabolic processes. Aberrant LLPS is widely associated with several hallmarks of cancer, including sustained proliferative signaling, growth suppressor evasion, cell death resistance, telomere maintenance, DNA damage repair, etc. Insights into the molecular mechanisms of LLPS provide new insights into cancer therapeutics. Here, the current understanding of the emerging concepts of LLPS and its involvement in cancer are comprehensively reviewed.
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Affiliation(s)
- Jiang Ren
- School of MedicineZhejiang University City CollegeHangzhou215123China
- The Eighth Affiliated HospitalSun Yat‐sen UniversityShenzhen518033China
| | - Zhenyu Zhang
- Department of NeurosurgeryThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan450003China
| | - Zhi Zong
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Long Zhang
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
- International Biomed‐X Research Center, Second Affiliated Hospital of Zhejiang University School of MedicineZhejiang UniversityHangzhouChina
- Cancer CenterZhejiang UniversityHangzhou215123China
| | - Fangfang Zhou
- School of MedicineZhejiang University City CollegeHangzhou215123China
- Institutes of Biology and Medical SciencesSoochow UniversitySuzhou215123China
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6
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Bhat VD, Jayaraj J, Babu K. RNA and neuronal function: the importance of post-transcriptional regulation. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac011. [PMID: 38596700 PMCID: PMC10913846 DOI: 10.1093/oons/kvac011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/03/2022] [Accepted: 05/28/2022] [Indexed: 04/11/2024]
Abstract
The brain represents an organ with a particularly high diversity of genes that undergo post-transcriptional gene regulation through multiple mechanisms that affect RNA metabolism and, consequently, brain function. This vast regulatory process in the brain allows for a tight spatiotemporal control over protein expression, a necessary factor due to the unique morphologies of neurons. The numerous mechanisms of post-transcriptional regulation or translational control of gene expression in the brain include alternative splicing, RNA editing, mRNA stability and transport. A large number of trans-elements such as RNA-binding proteins and micro RNAs bind to specific cis-elements on transcripts to dictate the fate of mRNAs including its stability, localization, activation and degradation. Several trans-elements are exemplary regulators of translation, employing multiple cofactors and regulatory machinery so as to influence mRNA fate. Networks of regulatory trans-elements exert control over key neuronal processes such as neurogenesis, synaptic transmission and plasticity. Perturbations in these networks may directly or indirectly cause neuropsychiatric and neurodegenerative disorders. We will be reviewing multiple mechanisms of gene regulation by trans-elements occurring specifically in neurons.
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Affiliation(s)
- Vandita D Bhat
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
| | - Jagannath Jayaraj
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, CV Raman Road, Bangalore 560012, Karnataka, India
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7
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Sette C, Paronetto MP. Somatic Mutations in Core Spliceosome Components Promote Tumorigenesis and Generate an Exploitable Vulnerability in Human Cancer. Cancers (Basel) 2022; 14:cancers14071827. [PMID: 35406598 PMCID: PMC8997811 DOI: 10.3390/cancers14071827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 12/02/2022] Open
Abstract
Simple Summary High throughput exome sequencing approaches have disclosed recurrent cancer-associated mutations in spliceosomal components, which drive aberrant pre-mRNA processing events and support the tumor phenotype. At the same time, mutations in spliceosome genes and aberrant splicing regulation establish a selective vulnerability of cancer cells to splicing-targeting approaches, which could be exploited therapeutically. It is conceivable that a better understanding of the mechanisms and roles of abnormal splicing in tumor metabolism will facilitate the development of a novel generation of tumor-targeting drugs. In this review, we describe recent advances in the elucidation of the biological impact and biochemical effects of somatic mutations in core spliceosome components on splicing choices and their associated targetable vulnerabilities. Abstract Alternative pre-mRNA processing enables the production of distinct mRNA and protein isoforms from a single gene, thus greatly expanding the coding potential of eukaryotic genomes and fine-tuning gene expression programs. Splicing is carried out by the spliceosome, a complex molecular machinery which assembles step-wise on mRNA precursors in the nucleus of eukaryotic cells. In the last decade, exome sequencing technologies have allowed the identification of point mutations in genes encoding splicing factors as a recurrent hallmark of human cancers, with higher incidence in hematological malignancies. These mutations lead to production of splicing factors that reduce the fidelity of the splicing process and yield splicing variants that are often advantageous for cancer cells. However, at the same time, these mutations increase the sensitivity of transformed cells to splicing inhibitors, thus offering a therapeutic opportunity for novel targeted strategies. Herein, we review the recent literature documenting cancer-associated mutations in components of the early spliceosome complex and discuss novel therapeutic strategies based on small-molecule spliceosome inhibitors that exhibit strong anti-tumor effects, particularly against cancer cells harboring mutations in spliceosomal components.
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Affiliation(s)
- Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy;
- GSTEP-Organoids Core Facility, Fondazione Policlinico Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico”, Piazza Lauro De Bosis, 6, 00135 Rome, Italy
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, IRCCS, Via del Fosso di Fiorano 64, 00143 Rome, Italy
- Correspondence:
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8
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The Novel Protease Activities of JMJD5–JMJD6–JMJD7 and Arginine Methylation Activities of Arginine Methyltransferases Are Likely Coupled. Biomolecules 2022; 12:biom12030347. [PMID: 35327545 PMCID: PMC8945206 DOI: 10.3390/biom12030347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/03/2022] [Accepted: 02/18/2022] [Indexed: 12/23/2022] Open
Abstract
The surreptitious discoveries of the protease activities on arginine-methylated targets of a subfamily of Jumonji domain-containing family including JMJD5, JMJD6, and JMJD7 pose several questions regarding their authenticity, function, purpose, and relations with others. At the same time, despite several decades of efforts and massive accumulating data regarding the roles of the arginine methyltransferase family (PRMTs), the exact function of this protein family still remains a mystery, though it seems to play critical roles in transcription regulation, including activation and inactivation of a large group of genes, as well as other biological activities. In this review, we aim to elucidate that the function of JMJD5/6/7 and PRMTs are likely coupled. Besides roles in the regulation of the biogenesis of membrane-less organelles in cells, they are major players in regulating stimulating transcription factors to control the activities of RNA Polymerase II in higher eukaryotes, especially in the animal kingdom. Furthermore, we propose that arginine methylation by PRMTs could be a ubiquitous action marked for destruction after missions by a subfamily of the Jumonji protein family.
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9
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Luo YY, Wu JJ, Li YM. Regulation of liquid-liquid phase separation with focus on post-translational modifications. Chem Commun (Camb) 2021; 57:13275-13287. [PMID: 34816836 DOI: 10.1039/d1cc05266g] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Liquid-liquid phase separation (LLPS), a type of phase transition that is important in organisms, is a unique means of forming biomolecular condensates. LLPS plays a significant role in transcription, genome organisation, immune response and cell signaling, and its dysregulation may cause neurodegenerative diseases and cancers. Exploring the regulatory mechanism of LLPS contributes to the understanding of the pathogenic mechanism of abnormal phase transition and enables potential therapeutic targets to be proposed. Many factors have been found to regulate LLPS, of which post-translational modification (PTM) is among the most important. PTMs can change the structure, charge, hydrophobicity and other properties of the proteins involved in phase separation and thereby affect the phase transition behaviour. In this review, we discuss LLPS and the regulatory effects of PTMs, RNA and molecular chaperones in a phase separation system. We introduce several common PTMs (including phosphorylation, arginine methylation, arginine citrullination, acetylation, ubiquitination and poly(ADP-ribosyl)ation), highlight recent advances regarding their roles in LLPS and describe the regulatory mechanisms behind these features. This review provides a detailed overview of the field that will help further the understanding of and interventions in LLPS.
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Affiliation(s)
- Yun-Yi Luo
- Key Lab of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
| | - Jun-Jun Wu
- Key Lab of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China. .,Biomedical Research Center of South China, College of Life Sciences, Fujian Normal University, Fuzhou, Fujian, P. R. China
| | - Yan-Mei Li
- Key Lab of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China. .,Beijing Institute for Brain Disorders, Beijing 100069, P. R. China.,Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, P. R. China
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10
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Lenard AJ, Hutten S, Zhou Q, Usluer S, Zhang F, Bourgeois BMR, Dormann D, Madl T. Phosphorylation Regulates CIRBP Arginine Methylation, Transportin-1 Binding and Liquid-Liquid Phase Separation. Front Mol Biosci 2021; 8:689687. [PMID: 34738012 PMCID: PMC8562343 DOI: 10.3389/fmolb.2021.689687] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 10/01/2021] [Indexed: 12/20/2022] Open
Abstract
Arginine-glycine(-glycine) (RG/RGG) regions are highly abundant in RNA-binding proteins and involved in numerous physiological processes. Aberrant liquid-liquid phase separation (LLPS) and stress granule (SGs) association of RG/RGG regions in the cytoplasm have been implicated in several neurodegenerative disorders. LLPS and SG association of these proteins is regulated by the interaction with nuclear import receptors, such as transportin-1 (TNPO1), and by post-translational arginine methylation. Strikingly, many RG/RGG proteins harbour potential phosphorylation sites within or close to their arginine methylated regions, indicating a regulatory role. Here, we studied the role of phosphorylation within RG/RGG regions on arginine methylation, TNPO1-binding and LLPS using the cold-inducible RNA-binding protein (CIRBP) as a paradigm. We show that the RG/RGG region of CIRBP is in vitro phosphorylated by serine-arginine protein kinase 1 (SRPK1), and discovered two novel phosphorylation sites in CIRBP. SRPK1-mediated phosphorylation of the CIRBP RG/RGG region impairs LLPS and binding to TNPO1 in vitro and interferes with SG association in cells. Furthermore, we uncovered that arginine methylation of the CIRBP RG/RGG region regulates in vitro phosphorylation by SRPK1. In conclusion, our findings indicate that LLPS and TNPO1-mediated chaperoning of RG/RGG proteins is regulated through an intricate interplay of post-translational modifications.
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Affiliation(s)
- Aneta J Lenard
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Saskia Hutten
- Johannes Gutenberg-Universität (JGU) Mainz, Faculty of Biology, Mainz, Germany.,BioMedical Center, Cell Biology, Ludwig-Maximilians-Universität (LMU) München, Martinsried, Germany
| | - Qishun Zhou
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Sinem Usluer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Fangrong Zhang
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Benjamin M R Bourgeois
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dorothee Dormann
- Johannes Gutenberg-Universität (JGU) Mainz, Faculty of Biology, Mainz, Germany.,BioMedical Center, Cell Biology, Ludwig-Maximilians-Universität (LMU) München, Martinsried, Germany.,Institute of Molecular Biology (IMB), Mainz, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
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11
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Dong R, Li X, Lai KO. Activity and Function of the PRMT8 Protein Arginine Methyltransferase in Neurons. Life (Basel) 2021; 11:life11111132. [PMID: 34833008 PMCID: PMC8621972 DOI: 10.3390/life11111132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 12/13/2022] Open
Abstract
Among the nine mammalian protein arginine methyltransferases (PRMTs), PRMT8 is unusual because it has restricted expression in the nervous system and is the only membrane-bound PRMT. Emerging studies have demonstrated that this enzyme plays multifaceted roles in diverse processes in neurons. Here we will summarize the unique structural features of PRMT8 and describe how it participates in various neuronal functions such as dendritic growth, synapse maturation, and synaptic plasticity. Recent evidence suggesting the potential role of PRMT8 function in neurological diseases will also be discussed.
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12
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PRMT5: An Emerging Target for Pancreatic Adenocarcinoma. Cancers (Basel) 2021; 13:cancers13205136. [PMID: 34680285 PMCID: PMC8534199 DOI: 10.3390/cancers13205136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The burden of pancreatic ductal adenocarcinoma (PDAC) increases with rising incidence, yet 5-year overall survival remains poor at 17%. Routine comprehensive genomic profiling of PDAC only finds 2.5% of patients who may benefit and receive matched targeted therapy. Protein arginine methyltransferase 5 (PRMT5) as an anti-cancer target has gained significant interest in recent years and high levels of PRMT5 protein are associated with worse survival outcomes across multiple cancer types. Inhibition of PRMT5 in pre-clinical models can lead to cancer growth inhibition. However, PRMT5 is involved in multiple cellular processes, thus determining its mechanism of action is challenging. While past reviews on PRMT5 have focused on its role in diverse cellular processes and past research studies have focused mainly on haematological malignancies and glioblastoma, this review provides an overview of the possible biological mechanisms of action of PRMT5 inhibition and its potential as a treatment in pancreatic cancer. Abstract The overall survival of pancreatic ductal adenocarcinoma (PDAC) remains poor and its incidence is rising. Targetable mutations in PDAC are rare, thus novel therapeutic approaches are needed. Protein arginine methyltransferase 5 (PRMT5) overexpression is associated with worse survival and inhibition of PRMT5 results in decreased cancer growth across multiple cancers, including PDAC. Emerging evidence also suggests that altered RNA processing is a driver in PDAC tumorigenesis and creates a partial dependency on this process. PRMT5 inhibition induces altered splicing and this vulnerability can be exploited as a novel therapeutic approach. Three possible biological pathways underpinning the action of PRMT5 inhibitors are discussed; c-Myc regulation appears central to its action in the PDAC setting. Whilst homozygous MTAP deletion and symmetrical dimethylation levels are associated with increased sensitivity to PRMT5 inhibition, neither measure robustly predicts its growth inhibitory response. The immunomodulatory effect of PRMT5 inhibitors on the tumour microenvironment will also be discussed, based on emerging evidence that PDAC stroma has a significant bearing on disease behaviour and response to therapy. Lastly, with the above caveats in mind, current knowledge gaps and the implications and rationales for PRMT5 inhibitor development in PDAC will be explored.
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13
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Giuliani V, Miller MA, Liu CY, Hartono SR, Class CA, Bristow CA, Suzuki E, Sanz LA, Gao G, Gay JP, Feng N, Rose JL, Tomihara H, Daniele JR, Peoples MD, Bardenhagen JP, Geck Do MK, Chang QE, Vangamudi B, Vellano C, Ying H, Deem AK, Do KA, Genovese G, Marszalek JR, Kovacs JJ, Kim M, Fleming JB, Guccione E, Viale A, Maitra A, Emilia Di Francesco M, Yap TA, Jones P, Draetta G, Carugo A, Chedin F, Heffernan TP. PRMT1-dependent regulation of RNA metabolism and DNA damage response sustains pancreatic ductal adenocarcinoma. Nat Commun 2021; 12:4626. [PMID: 34330913 PMCID: PMC8324870 DOI: 10.1038/s41467-021-24798-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 07/05/2021] [Indexed: 12/11/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that has remained clinically challenging to manage. Here we employ an RNAi-based in vivo functional genomics platform to determine epigenetic vulnerabilities across a panel of patient-derived PDAC models. Through this, we identify protein arginine methyltransferase 1 (PRMT1) as a critical dependency required for PDAC maintenance. Genetic and pharmacological studies validate the role of PRMT1 in maintaining PDAC growth. Mechanistically, using proteomic and transcriptomic analyses, we demonstrate that global inhibition of asymmetric arginine methylation impairs RNA metabolism, which includes RNA splicing, alternative polyadenylation, and transcription termination. This triggers a robust downregulation of multiple pathways involved in the DNA damage response, thereby promoting genomic instability and inhibiting tumor growth. Taken together, our data support PRMT1 as a compelling target in PDAC and informs a mechanism-based translational strategy for future therapeutic development.Statement of significancePDAC is a highly lethal cancer with limited therapeutic options. This study identified and characterized PRMT1-dependent regulation of RNA metabolism and coordination of key cellular processes required for PDAC tumor growth, defining a mechanism-based translational hypothesis for PRMT1 inhibitors.
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Affiliation(s)
- Virginia Giuliani
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
| | - Meredith A Miller
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Chiu-Yi Liu
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Stella R Hartono
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Caleb A Class
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Pharmaceutical Sciences, Butler University, Indianapolis, IN, USA
| | | | - Erika Suzuki
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Lionel A Sanz
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Guang Gao
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jason P Gay
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ningping Feng
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Johnathon L Rose
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Hideo Tomihara
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Surgery, Kindai University Nara Hospital, Nara, JP, USA
| | - Joseph R Daniele
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Michael D Peoples
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jennifer P Bardenhagen
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Mary K Geck Do
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Qing E Chang
- ORBIT, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Bhavatarini Vangamudi
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Exo Therapeutics, Cambridge, MA, USA
| | - Christopher Vellano
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Haoqiang Ying
- Department of Cellular and Molecular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Angela K Deem
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kim-Anh Do
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Giannicola Genovese
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Joseph R Marszalek
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jeffrey J Kovacs
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Michael Kim
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jason B Fleming
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Division of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA
| | - Ernesto Guccione
- Department of Oncological Sciences and Pharmacological Sciences at Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Andrea Viale
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Anirban Maitra
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - M Emilia Di Francesco
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Timothy A Yap
- Department of Investigational Cancer Therapeutics (Phase I Program), The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Philip Jones
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Giulio Draetta
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Alessandro Carugo
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Frederic Chedin
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Timothy P Heffernan
- Traction, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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14
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Lo LHY, Dong R, Lyu Q, Lai KO. The Protein Arginine Methyltransferase PRMT8 and Substrate G3BP1 Control Rac1-PAK1 Signaling and Actin Cytoskeleton for Dendritic Spine Maturation. Cell Rep 2021; 31:107744. [PMID: 32521269 DOI: 10.1016/j.celrep.2020.107744] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/01/2020] [Accepted: 05/18/2020] [Indexed: 01/25/2023] Open
Abstract
Excitatory synapses of neurons are located on dendritic spines. Spine maturation is essential for the stability of synapses and memory consolidation, and overproduction of the immature filopodia is associated with brain disorders. The structure and function of synapses can be modulated by protein post-translational modification (PTM). Arginine methylation is a major PTM that regulates chromatin structure, transcription, and splicing within the nucleus. Here we find that the protein arginine methyltransferase PRMT8 is present at neuronal synapses and its expression is upregulated in the hippocampus when dendritic spine maturation occurs. Depletion of PRMT8 leads to overabundance of filopodia and mis-localization of excitatory synapses. Mechanistically, PRMT8 promotes dendritic spine morphology through methylation of the dendritic RNA-binding protein G3BP1 and suppression of the Rac1-PAK1 signaling pathway to control synaptic actin dynamics. Our findings unravel arginine methylation as a crucial regulatory mechanism for actin cytoskeleton during synapse development.
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Affiliation(s)
- Louisa Hoi-Ying Lo
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Rui Dong
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Quanwei Lyu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-On Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China.
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15
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Gill AL, Premasiri AS, Vieira FG. Hypothesis and Theory: Roles of Arginine Methylation in C9orf72-Mediated ALS and FTD. Front Cell Neurosci 2021; 15:633668. [PMID: 33833668 PMCID: PMC8021787 DOI: 10.3389/fncel.2021.633668] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/09/2021] [Indexed: 12/11/2022] Open
Abstract
Hexanucleotide repeat expansion (G4C2n) mutations in the gene C9ORF72 account for approximately 30% of familial cases of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), as well as approximately 7% of sporadic cases of ALS. G4C2n mutations are known to result in the production of five species of dipeptide repeat proteins (DRPs) through non-canonical translation processes. Arginine-enriched dipeptide repeat proteins, glycine-arginine (polyGR), and proline-arginine (polyPR) have been demonstrated to be cytotoxic and deleterious in multiple experimental systems. Recently, we and others have implicated methylation of polyGR/polyPR arginine residues in disease processes related to G4C2n mutation-mediated neurodegeneration. We previously reported that inhibition of asymmetric dimethylation (ADMe) of arginine residues is protective in cell-based models of polyGR/polyPR cytotoxicity. These results are consistent with the idea that PRMT-mediated arginine methylation in the context of polyGR/polyPR exposure is harmful. However, it remains unclear why. Here we discuss the influence of arginine methylation on diverse cellular processes including liquid-liquid phase separation, chromatin remodeling, transcription, RNA processing, and RNA-binding protein localization, and we consider how methylation of polyGR/polyPR may disrupt processes essential for normal cellular function and survival.
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Affiliation(s)
- Anna L Gill
- ALS Therapy Development Institute, Cambridge, MA, United States
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16
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Hofmann S, Kedersha N, Anderson P, Ivanov P. Molecular mechanisms of stress granule assembly and disassembly. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118876. [PMID: 33007331 DOI: 10.1016/j.bbamcr.2020.118876] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 12/11/2022]
Abstract
Stress granules (SGs) are membrane-less ribonucleoprotein (RNP)-based cellular compartments that form in the cytoplasm of a cell upon exposure to various environmental stressors. SGs contain a large set of proteins, as well as mRNAs that have been stalled in translation as a result of stress-induced polysome disassembly. Despite the fact that SGs have been extensively studied for many years, their function is still not clear. They presumably help the cell to cope with the encountered stress, and facilitate the recovery process after stress removal upon which SGs disassemble. Aberrant formation of SGs and impaired SG disassembly majorly contribute to various pathological phenomena in cancer, viral infections, and neurodegeneration. The assembly of SGs is largely driven by liquid-liquid phase separation (LLPS), however, the molecular mechanisms behind that are not fully understood. Recent studies have proposed a novel mechanism for SG formation that involves the interplay of a large interaction network of mRNAs and proteins. Here, we review this novel concept of SG assembly, and discuss the current insights into SG disassembly.
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Affiliation(s)
- Sarah Hofmann
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nancy Kedersha
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Paul Anderson
- Brigham and Women's Hospital, Harvard Medical School, Harvard Initiative for RNA Medicine, Boston, MA 02115, USA
| | - Pavel Ivanov
- Brigham and Women's Hospital, Harvard Medical School, Harvard Initiative for RNA Medicine, Boston, MA 02115, USA.
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17
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Majumder M, Johnson RH, Palanisamy V. Fragile X-related protein family: a double-edged sword in neurodevelopmental disorders and cancer. Crit Rev Biochem Mol Biol 2020; 55:409-424. [PMID: 32878499 DOI: 10.1080/10409238.2020.1810621] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The fragile X-related (FXR) family proteins FMRP, FXR1, and FXR2 are RNA binding proteins that play a critical role in RNA metabolism, neuronal plasticity, and muscle development. These proteins share significant homology in their protein domains, which are functionally and structurally similar to each other. FXR family members are known to play an essential role in causing fragile X mental retardation syndrome (FXS), the most common genetic form of autism spectrum disorder. Recent advances in our understanding of this family of proteins have occurred in tandem with discoveries of great importance to neurological disorders and cancer biology via the identification of their novel RNA and protein targets. Herein, we review the FXR family of proteins as they pertain to FXS, other mental illnesses, and cancer. We emphasize recent findings and analyses that suggest contrasting functions of this protein family in FXS and tumorigenesis based on their expression patterns in human tissues. Finally, we discuss current gaps in our knowledge regarding the FXR protein family and their role in FXS and cancer and suggest future studies to facilitate bench to bedside translation of the findings.
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Affiliation(s)
- Mrinmoyee Majumder
- Department of Biochemistry and Molecular Biology, School of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Roger H Johnson
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Viswanathan Palanisamy
- Department of Biochemistry and Molecular Biology, School of Medicine, Medical University of South Carolina, Charleston, SC, USA
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18
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Prieto M, Folci A, Martin S. Post-translational modifications of the Fragile X Mental Retardation Protein in neuronal function and dysfunction. Mol Psychiatry 2020; 25:1688-1703. [PMID: 31822816 DOI: 10.1038/s41380-019-0629-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/22/2019] [Accepted: 11/27/2019] [Indexed: 12/17/2022]
Abstract
The Fragile X Mental Retardation Protein (FMRP) is an RNA-binding protein essential to the regulation of local translation at synapses. In the mammalian brain, synapses are constantly formed and eliminated throughout development to achieve functional neuronal networks. At the molecular level, thousands of proteins cooperate to accomplish efficient neuronal communication. Therefore, synaptic protein levels and their functional interactions need to be tightly regulated. FMRP generally acts as a translational repressor of its mRNA targets. FMRP is the target of several post-translational modifications (PTMs) that dynamically regulate its function. Here we provide an overview of the PTMs controlling the FMRP function and discuss how their spatiotemporal interplay contributes to the physiological regulation of FMRP. Importantly, FMRP loss-of-function leads to Fragile X syndrome (FXS), a rare genetic developmental condition causing a range of neurological alterations including intellectual disability (ID), learning and memory impairments, autistic-like features and seizures. Here, we also explore the possibility that recently reported missense mutations in the FMR1 gene disrupt the PTM homoeostasis of FMRP, thus participating in the aetiology of FXS. This suggests that the pharmacological targeting of PTMs may be a promising strategy to develop innovative therapies for patients carrying such missense mutations.
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Affiliation(s)
- Marta Prieto
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | | | - Stéphane Martin
- Université Côte d'Azur, INSERM, CNRS, IPMC, Valbonne, France.
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19
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Zhu J, Zhou X, Huang X, Du Z. Crystal structure of a 123 amino acids dimerization domain of Drosophila Caprin. Proteins 2020; 88:1701-1711. [PMID: 32725918 DOI: 10.1002/prot.25987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/12/2020] [Accepted: 07/26/2020] [Indexed: 11/12/2022]
Abstract
Cytoplasmic activation/proliferation-associated protein (Caprin) proteins assume diverse functions in many important biological processes, including synaptic plasticity, stress response, innate immune response, and cellular proliferation. The Caprin family members are characterized by the presence of a highly conserved homologous region (HR1) at the N-terminus and arginine-glycine-rich (RGG) boxes at the C-terminus. We had previously determined the crystal structures of human Caprin-1 and Caprin-2 fragments corresponding to the C-terminal 2/3 of HR1. Both fragments adopt homodimeric structures. Based on sequence conservation, we speculated that all Caprin proteins should have similar homodimeric structures. Here we report the crystal structure of a fragment (residues 187-309) of Drosophila melanogaster Caprin (dCaprin). The dCaprin fragment adopts an all α-helical fold which self-associates to form a homodimer. The overall dCaprin homodimeric structure is similar to the Caprin-1 and Caprin-2 homodimeric structures. Most of the amino acids residues mediating homodimerization in the three structures are conserved among all Caprin family members. These structural and sequence data suggest that homodimerization through a conserved dimerization domain is a common structural feature of the Caprin protein family. The dimeric structures may also be involved in interaction with Caprin partners. Dimer formation creates a V-shape concave surface that may serve as a protein binding groove. The concave surfaces in Caprin-1, Caprin-2, and dCaprin should have different and specific binding partners due to the large difference in electrostatic potentials. We propose the existence of a multi-functional domain in Caprin proteins, which not only mediate homodimerization but also involve in interaction with specific Caprin partners.
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Affiliation(s)
- Jiang Zhu
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Xia Zhou
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Xiaolan Huang
- Department of Computer Science, Southern Illinois University, Carbondale, Illinois, USA
| | - Zhihua Du
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
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20
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Frydrýšková K, Mašek T, Pospíšek M. Changing faces of stress: Impact of heat and arsenite treatment on the composition of stress granules. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1596. [PMID: 32362075 DOI: 10.1002/wrna.1596] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 03/19/2020] [Accepted: 03/23/2020] [Indexed: 11/07/2022]
Abstract
Stress granules (SGs), hallmarks of the cellular adaptation to stress, promote survival, conserve cellular energy, and are fully dissolved upon the cessation of stress treatment. Different stresses can initiate the assembly of SGs, but arsenite and heat are the best studied of these stresses. The composition of SGs and posttranslational modifications of SG proteins differ depending on the type and severity of the stress insult, methodology used, cell line, and presence of overexpressed and tagged proteins. A group of 18 proteins showing differential localization to SGs in heat- and arsenite-stressed mammalian cell lines is described. Upon severe and prolonged stress, physiological SGs transform into more solid protein aggregates that are no longer reversible and do not contain mRNA. Similar pathological inclusions are hallmarks of neurodegenerative diseases. SGs induced by heat stress are less dynamic than SGs induced by arsenite and contain a set of unique proteins and linkage-specific polyubiquitinated proteins. The same types of ubiquitin linkages have been found to contribute to the development of neurodegenerative disorders such as Parkinson disease, Alzheimer disease, and amyotrophic lateral sclerosis (ALS). We propose heat stress-induced SGs as a possible model of an intermediate stage along the transition from dynamic, fully reversible arsenite stress-induced SGs toward aberrant SGs, the hallmark of neurodegenerative diseases. Stress- and methodology-specific differences in the compositions of SGs and the transition of SGs to aberrant protein aggregates are discussed. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Export and Localization > RNA Localization.
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Affiliation(s)
| | | | - Martin Pospíšek
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
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21
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Sanders DW, Kedersha N, Lee DSW, Strom AR, Drake V, Riback JA, Bracha D, Eeftens JM, Iwanicki A, Wang A, Wei MT, Whitney G, Lyons SM, Anderson P, Jacobs WM, Ivanov P, Brangwynne CP. Competing Protein-RNA Interaction Networks Control Multiphase Intracellular Organization. Cell 2020; 181:306-324.e28. [PMID: 32302570 PMCID: PMC7816278 DOI: 10.1016/j.cell.2020.03.050] [Citation(s) in RCA: 426] [Impact Index Per Article: 106.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 10/24/2019] [Accepted: 03/20/2020] [Indexed: 12/22/2022]
Abstract
Liquid-liquid phase separation (LLPS) mediates formation of membraneless condensates such as those associated with RNA processing, but the rules that dictate their assembly, substructure, and coexistence with other liquid-like compartments remain elusive. Here, we address the biophysical mechanism of this multiphase organization using quantitative reconstitution of cytoplasmic stress granules (SGs) with attached P-bodies in human cells. Protein-interaction networks can be viewed as interconnected complexes (nodes) of RNA-binding domains (RBDs), whose integrated RNA-binding capacity determines whether LLPS occurs upon RNA influx. Surprisingly, both RBD-RNA specificity and disordered segments of key proteins are non-essential, but modulate multiphase condensation. Instead, stoichiometry-dependent competition between protein networks for connecting nodes determines SG and P-body composition and miscibility, while competitive binding of unconnected proteins disengages networks and prevents LLPS. Inspired by patchy colloid theory, we propose a general framework by which competing networks give rise to compositionally specific and tunable condensates, while relative linkage between nodes underlies multiphase organization.
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Affiliation(s)
- David W Sanders
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Nancy Kedersha
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Daniel S W Lee
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Amy R Strom
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Victoria Drake
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Joshua A Riback
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Dan Bracha
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Jorine M Eeftens
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Allana Iwanicki
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Alicia Wang
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Ming-Tzo Wei
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Gena Whitney
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Shawn M Lyons
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Paul Anderson
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - William M Jacobs
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Pavel Ivanov
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Princeton, NJ 08544, USA.
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22
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Cao X, Jin X, Liu B. The involvement of stress granules in aging and aging-associated diseases. Aging Cell 2020; 19:e13136. [PMID: 32170904 PMCID: PMC7189987 DOI: 10.1111/acel.13136] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Stress granules (SGs) are nonmembrane assemblies formed in cells in response to stress conditions. SGs mainly contain untranslated mRNA and a variety of proteins. RNAs and scaffold proteins with intrinsically disordered regions or RNA-binding domains are essential for the assembly of SGs, and multivalent macromolecular interactions among these components are thought to be the driving forces for SG assembly. The SG assembly process includes regulation through post-translational modification and involvement of the cytoskeletal system. During aging, many intracellular bioprocesses become disrupted by factors such as cellular environmental changes, mitochondrial dysfunction, and decline in the protein quality control system. Such changes could lead to the formation of aberrant SGs, as well as alterations in their maintenance, disassembly, and clearance. These aberrant SGs might in turn promote aging and aging-associated diseases. In this paper, we first review the latest progress on the molecular mechanisms underlying SG assembly and SG functioning under stress conditions. Then, we provide a detailed discussion of the relevance of SGs to aging and aging-associated diseases.
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Affiliation(s)
- Xiuling Cao
- State Key Laboratory of Subtropical Silviculture School of Forestry and Biotechnology Zhejiang A&F University Hangzhou China
| | - Xuejiao Jin
- State Key Laboratory of Subtropical Silviculture School of Forestry and Biotechnology Zhejiang A&F University Hangzhou China
| | - Beidong Liu
- State Key Laboratory of Subtropical Silviculture School of Forestry and Biotechnology Zhejiang A&F University Hangzhou China
- Department of Chemistry and Molecular Biology University of Gothenburg Goteborg Sweden
- Center for Large‐scale Cell‐based Screening Faculty of Science University of Gothenburg Goteborg Sweden
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23
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Gao X, Jiang L, Gong Y, Chen X, Ying M, Zhu H, He Q, Yang B, Cao J. Stress granule: A promising target for cancer treatment. Br J Pharmacol 2019; 176:4421-4433. [PMID: 31301065 DOI: 10.1111/bph.14790] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/26/2019] [Accepted: 07/02/2019] [Indexed: 12/14/2022] Open
Abstract
Stress granules (SGs) are primarily composed of mRNAs that stall at translation initiation and usually appear in the cytoplasm under unusual physiological or pathological conditions such as hypoxia, oxidative stress, and viral infection. Recent studies have indicated that several components of SGs participate in tumourigenesis and cancer metastasis through tumour-associated signalling pathways as well as other mechanisms. Furthermore, some chemotherapy drugs have been reported to induce SGs. Thus, the roles of SGs in cancer treatment have attracted considerable interest. Importantly, disturbing the recruitment of SGs components or microtubule polymerization, as well as other strategies that can abolish SGs formation, is reported to inhibit tumour progression, suggesting that targeting SGs could be a promising strategy for cancer treatment. In this review, we summarize the relationship between SGs and cancer, as well as recent advances in targeting SGs, in the interest of providing new opportunities for cancer treatment.
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Affiliation(s)
- Xiaomeng Gao
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Li Jiang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yanling Gong
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xiaobing Chen
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Meidan Ying
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Hong Zhu
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Qiaojun He
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Bo Yang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Ji Cao
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
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24
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Fong JY, Pignata L, Goy PA, Kawabata KC, Lee SCW, Koh CM, Musiani D, Massignani E, Kotini AG, Penson A, Wun CM, Shen Y, Schwarz M, Low DH, Rialdi A, Ki M, Wollmann H, Mzoughi S, Gay F, Thompson C, Hart T, Barbash O, Luciani GM, Szewczyk MM, Wouters BJ, Delwel R, Papapetrou EP, Barsyte-Lovejoy D, Arrowsmith CH, Minden MD, Jin J, Melnick A, Bonaldi T, Abdel-Wahab O, Guccione E. Therapeutic Targeting of RNA Splicing Catalysis through Inhibition of Protein Arginine Methylation. Cancer Cell 2019; 36:194-209.e9. [PMID: 31408619 PMCID: PMC7194031 DOI: 10.1016/j.ccell.2019.07.003] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/02/2019] [Accepted: 07/08/2019] [Indexed: 12/16/2022]
Abstract
Cancer-associated mutations in genes encoding RNA splicing factors (SFs) commonly occur in leukemias, as well as in a variety of solid tumors, and confer dependence on wild-type splicing. These observations have led to clinical efforts to directly inhibit the spliceosome in patients with refractory leukemias. Here, we identify that inhibiting symmetric or asymmetric dimethylation of arginine, mediated by PRMT5 and type I protein arginine methyltransferases (PRMTs), respectively, reduces splicing fidelity and results in preferential killing of SF-mutant leukemias over wild-type counterparts. These data identify genetic subsets of cancer most likely to respond to PRMT inhibition, synergistic effects of combined PRMT5 and type I PRMT inhibition, and a mechanistic basis for the therapeutic efficacy of PRMT inhibition in cancer.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacokinetics
- Antineoplastic Agents/pharmacology
- Catalysis
- Enzyme Inhibitors/pharmacokinetics
- Enzyme Inhibitors/pharmacology
- Ethylenediamines/pharmacokinetics
- Ethylenediamines/pharmacology
- Gene Expression Regulation, Neoplastic
- Gene Regulatory Networks
- Humans
- K562 Cells
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Mice, Inbred C57BL
- Mice, Transgenic
- Protein-Arginine N-Methyltransferases/antagonists & inhibitors
- Protein-Arginine N-Methyltransferases/genetics
- Protein-Arginine N-Methyltransferases/metabolism
- Pyrroles/pharmacokinetics
- Pyrroles/pharmacology
- RNA Splicing/drug effects
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Repressor Proteins/antagonists & inhibitors
- Repressor Proteins/metabolism
- THP-1 Cells
- Tumor Cells, Cultured
- U937 Cells
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Jia Yi Fong
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore
| | - Luca Pignata
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | - Pierre-Alexis Goy
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | | | - Stanley Chun-Wei Lee
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Cheryl M Koh
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore
| | - Daniele Musiani
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20146 Milan, Italy
| | - Enrico Massignani
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20146 Milan, Italy
| | - Andriana G Kotini
- Department of Oncological Sciences and Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Alex Penson
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Cheng Mun Wun
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore
| | - Yudao Shen
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Megan Schwarz
- Department of Oncological Sciences and Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Diana Hp Low
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore
| | - Alexander Rialdi
- Department of Oncological Sciences and Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michelle Ki
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Heike Wollmann
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore
| | - Slim Mzoughi
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore
| | - Florence Gay
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore
| | | | - Timothy Hart
- Epigenetics Research Unit, GlaxoSmithKline, Collegeville, PA 19426, USA
| | - Olena Barbash
- Epigenetics Research Unit, GlaxoSmithKline, Collegeville, PA 19426, USA
| | - Genna M Luciani
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Magdalena M Szewczyk
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Bas J Wouters
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Medical College of Cornell University, New York, NY 10065, USA; Department of Hematology, Erasmus University Medical Center, 3015 GD Rotterdam, Netherlands
| | - Ruud Delwel
- Department of Hematology, Erasmus University Medical Center, 3015 GD Rotterdam, Netherlands
| | - Eirini P Papapetrou
- Department of Oncological Sciences and Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Cheryl H Arrowsmith
- Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada; Ontario Cancer Institute/Princess Margaret Hospital, Toronto, ON M5G 2M9, Canada
| | - Mark D Minden
- Ontario Cancer Institute/Princess Margaret Hospital, Toronto, ON M5G 2M9, Canada
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ari Melnick
- Departments of Medicine and Pharmacology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Tiziana Bonaldi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20146 Milan, Italy
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Ernesto Guccione
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A(∗)STAR), Singapore 138673, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore; Department of Oncological Sciences and Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pharmacological Sciences and Mount Sinai Center for Therapeutics Discovery, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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25
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Kinase pathway inhibition restores PSD95 induction in neurons lacking fragile X mental retardation protein. Proc Natl Acad Sci U S A 2019; 116:12007-12012. [PMID: 31118285 DOI: 10.1073/pnas.1812056116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fragile X syndrome (FXS) is the leading monogenic cause of autism and intellectual disability. FXS is caused by loss of expression of fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates translation of numerous mRNA targets, some of which are present at synapses. While protein synthesis deficits have long been postulated as an etiology of FXS, how FMRP loss affects distributions of newly synthesized proteins is unknown. Here we investigated the role of FMRP in regulating expression of new copies of the synaptic protein PSD95 in an in vitro model of synaptic plasticity. We find that local BDNF application promotes persistent accumulation of new PSD95 at stimulated synapses and dendrites of cultured neurons, and that this accumulation is absent in FMRP-deficient mouse neurons. New PSD95 accumulation at sites of BDNF stimulation does not require known mechanisms regulating FMRP-mRNA interactions but instead requires the PI3K-mTORC1-S6K1 pathway. Surprisingly, in FMRP-deficient neurons, BDNF induction of new PSD95 accumulation can be restored by mTORC1-S6K1 blockade, suggesting that constitutively high mTORC1-S6K1 activity occludes PSD95 regulation by BDNF and that alternative pathways exist to mediate induction when mTORC1-S6K1 is inhibited. This study provides direct evidence for deficits in local protein synthesis and accumulation of newly synthesized protein in response to local stimulation in FXS, and supports mTORC1-S6K1 pathway inhibition as a potential therapeutic approach for FXS.
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26
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Post-transcriptional regulatory patterns revealed by protein-RNA interactions. Sci Rep 2019; 9:4302. [PMID: 30867517 PMCID: PMC6416249 DOI: 10.1038/s41598-019-40939-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 02/26/2019] [Indexed: 02/07/2023] Open
Abstract
The coordination of the synthesis of functionally-related proteins can be achieved at the post-transcriptional level by the action of common regulatory molecules, such as RNA–binding proteins (RBPs). Despite advances in the genome-wide identification of RBPs and their binding transcripts, the protein–RNA interaction space is still largely unexplored, thus hindering a broader understanding of the extent of the post-transcriptional regulation of related coding RNAs. Here, we propose a computational approach that combines protein–mRNA interaction networks and statistical analyses to provide an inferred regulatory landscape for more than 800 human RBPs and identify the cellular processes that can be regulated at the post-transcriptional level. We show that 10% of the tested sets of functionally-related mRNAs can be post-transcriptionally regulated. Moreover, we propose a classification of (i) the RBPs and (ii) the functionally-related mRNAs, based on their distinct behaviors in the functional landscape, hinting towards mechanistic regulatory hypotheses. In addition, we demonstrate the usefulness of the inferred functional landscape to investigate the cellular role of both well-characterized and novel RBPs in the context of human diseases.
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27
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Phosphoregulated FMRP phase separation models activity-dependent translation through bidirectional control of mRNA granule formation. Proc Natl Acad Sci U S A 2019; 116:4218-4227. [PMID: 30765518 DOI: 10.1073/pnas.1814385116] [Citation(s) in RCA: 201] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Activity-dependent translation requires the transport of mRNAs within membraneless protein assemblies known as neuronal granules from the cell body toward synaptic regions. Translation of mRNA is inhibited in these granules during transport but quickly activated in response to neuronal stimuli at the synapse. This raises an important question: how does synaptic activity trigger translation of once-silenced mRNAs? Here, we demonstrate a strong connection between phase separation, the process underlying the formation of many different types of cellular granules, and in vitro inhibition of translation. By using the Fragile X Mental Retardation Protein (FMRP), an abundant neuronal granule component and translational repressor, we show that FMRP phase separates in vitro with RNA into liquid droplets mediated by its C-terminal low-complexity disordered region (i.e., FMRPLCR). FMRPLCR posttranslational modifications by phosphorylation and methylation have opposing effects on in vitro translational regulation, which corroborates well with their critical concentrations for phase separation. Our results, combined with bioinformatics evidence, are supportive of phase separation as a general mechanism controlling activity-dependent translation.
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28
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Hofweber M, Dormann D. Friend or foe-Post-translational modifications as regulators of phase separation and RNP granule dynamics. J Biol Chem 2018; 294:7137-7150. [PMID: 30587571 DOI: 10.1074/jbc.tm118.001189] [Citation(s) in RCA: 222] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ribonucleoprotein (RNP) granules are membrane-less organelles consisting of RNA-binding proteins (RBPs) and RNA. RNA granules form through liquid-liquid phase separation (LLPS), whereby weak promiscuous interactions among RBPs and/or RNAs create a dense network of interacting macromolecules and drive the phase separation. Post-translational modifications (PTMs) of RBPs have emerged as important regulators of LLPS and RNP granule dynamics, as they can directly weaken or enhance the multivalent interactions between phase-separating macromolecules or can recruit or exclude certain macromolecules into or from condensates. Here, we review recent insights into how PTMs regulate phase separation and RNP granule dynamics, in particular arginine (Arg)-methylation and phosphorylation. We discuss how these PTMs regulate the phase behavior of prototypical RBPs and how, as "friend or foe," they might influence the assembly, disassembly, or material properties of cellular RNP granules, such as stress granules or amyloid-like condensates. We particularly highlight how PTMs control the phase separation and aggregation behavior of disease-linked RBPs. We also review how disruptions of PTMs might be involved in aberrant phase transitions and the formation of amyloid-like protein aggregates as observed in neurodegenerative diseases.
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Affiliation(s)
- Mario Hofweber
- From the BioMedical Center, Cell Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 9, 82152 Planegg-Martinsried.,the Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, and
| | - Dorothee Dormann
- From the BioMedical Center, Cell Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 9, 82152 Planegg-Martinsried, .,the Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, and.,the Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Strasse 17, 81377 Munich, Germany
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29
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Ravanidis S, Kattan FG, Doxakis E. Unraveling the Pathways to Neuronal Homeostasis and Disease: Mechanistic Insights into the Role of RNA-Binding Proteins and Associated Factors. Int J Mol Sci 2018; 19:ijms19082280. [PMID: 30081499 PMCID: PMC6121432 DOI: 10.3390/ijms19082280] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/13/2022] Open
Abstract
The timing, dosage and location of gene expression are fundamental determinants of brain architectural complexity. In neurons, this is, primarily, achieved by specific sets of trans-acting RNA-binding proteins (RBPs) and their associated factors that bind to specific cis elements throughout the RNA sequence to regulate splicing, polyadenylation, stability, transport and localized translation at both axons and dendrites. Not surprisingly, misregulation of RBP expression or disruption of its function due to mutations or sequestration into nuclear or cytoplasmic inclusions have been linked to the pathogenesis of several neuropsychiatric and neurodegenerative disorders such as fragile-X syndrome, autism spectrum disorders, spinal muscular atrophy, amyotrophic lateral sclerosis and frontotemporal dementia. This review discusses the roles of Pumilio, Staufen, IGF2BP, FMRP, Sam68, CPEB, NOVA, ELAVL, SMN, TDP43, FUS, TAF15, and TIA1/TIAR in RNA metabolism by analyzing their specific molecular and cellular function, the neurological symptoms associated with their perturbation, and their axodendritic transport/localization along with their target mRNAs as part of larger macromolecular complexes termed ribonucleoprotein (RNP) granules.
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Affiliation(s)
- Stylianos Ravanidis
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
| | - Fedon-Giasin Kattan
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
| | - Epaminondas Doxakis
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
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30
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Chitiprolu M, Jagow C, Tremblay V, Bondy-Chorney E, Paris G, Savard A, Palidwor G, Barry FA, Zinman L, Keith J, Rogaeva E, Robertson J, Lavallée-Adam M, Woulfe J, Couture JF, Côté J, Gibbings D. A complex of C9ORF72 and p62 uses arginine methylation to eliminate stress granules by autophagy. Nat Commun 2018; 9:2794. [PMID: 30022074 PMCID: PMC6052026 DOI: 10.1038/s41467-018-05273-7] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/21/2018] [Indexed: 12/12/2022] Open
Abstract
Mutations in proteins like FUS which cause Amyotrophic Lateral Sclerosis (ALS) result in the aberrant formation of stress granules while ALS-linked mutations in other proteins impede elimination of stress granules. Repeat expansions in C9ORF72, the major cause of ALS, reduce C9ORF72 levels but how this impacts stress granules is uncertain. Here, we demonstrate that C9ORF72 associates with the autophagy receptor p62 and controls elimination of stress granules by autophagy. This requires p62 to associate via the Tudor protein SMN with proteins, including FUS, that are symmetrically methylated on arginines. Mice lacking p62 accumulate arginine-methylated proteins and alterations in FUS-dependent splicing. Patients with C9ORF72 repeat expansions accumulate symmetric arginine dimethylated proteins which co-localize with p62. This suggests that C9ORF72 initiates a cascade of ALS-linked proteins (C9ORF72, p62, SMN, FUS) to recognize stress granules for degradation by autophagy and hallmarks of a defect in this process are observable in ALS patients. Many Amyotrophic Lateral Sclerosis (ALS)-linked mutations cause accumulation of stress granules, and most ALS cases are caused by repeat expansions in C9ORF72. Here the authors show that C9ORF72 and the autophagy receptor p62 interact to associate with proteins symmetrically dimethylated on arginines such as FUS, to eliminate stress granules by autophagy.
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Affiliation(s)
- Maneka Chitiprolu
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Chantal Jagow
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Veronique Tremblay
- Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Emma Bondy-Chorney
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Geneviève Paris
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Alexandre Savard
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Gareth Palidwor
- Ottawa Bioinformatics Core Facility, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, K1H 8L6, Canada
| | - Francesca A Barry
- Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Lorne Zinman
- Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
| | - Julia Keith
- Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, Ontario, M5T 2S8, Canada
| | - Janice Robertson
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, Ontario, M5T 2S8, Canada
| | - Mathieu Lavallée-Adam
- Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - John Woulfe
- Department of Pathology and Laboratory Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Ontario, K1H 8L6, Canada
| | - Jean-François Couture
- Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada
| | - Derrick Gibbings
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada. .,Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.
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31
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Chong PA, Vernon RM, Forman-Kay JD. RGG/RG Motif Regions in RNA Binding and Phase Separation. J Mol Biol 2018; 430:4650-4665. [PMID: 29913160 DOI: 10.1016/j.jmb.2018.06.014] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/02/2018] [Accepted: 06/06/2018] [Indexed: 12/29/2022]
Abstract
RGG/RG motifs are RNA binding segments found in many proteins that can partition into membraneless organelles. They occur in the context of low-complexity disordered regions and often in multiple copies. Although short RGG/RG-containing regions can sometimes form high-affinity interactions with RNA structures, multiple RGG/RG repeats are generally required for high-affinity binding, suggestive of the dynamic, multivalent interactions that are thought to underlie phase separation in formation of cellular membraneless organelles. Arginine can interact with nucleotide bases via hydrogen bonding and π-stacking; thus, nucleotide conformers that provide access to the bases provide enhanced opportunities for RGG interactions. Methylation of RGG/RG regions, which is accomplished by protein arginine methyltransferase enzymes, occurs to different degrees in different cell types and may regulate the behavior of proteins containing these regions.
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Affiliation(s)
- P Andrew Chong
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Robert M Vernon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Julie D Forman-Kay
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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32
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Qie S, Majumder M, Mackiewicz K, Howley BV, Peterson YK, Howe PH, Palanisamy V, Diehl JA. Fbxo4-mediated degradation of Fxr1 suppresses tumorigenesis in head and neck squamous cell carcinoma. Nat Commun 2017; 8:1534. [PMID: 29142209 PMCID: PMC5688124 DOI: 10.1038/s41467-017-01199-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 08/29/2017] [Indexed: 02/07/2023] Open
Abstract
The Fbxo4 tumour suppressor is a component of an Skp1-Cul1-F-box E3 ligase for which two substrates are known. Here we show purification of SCFFbxo4 complexes results in the identification of fragile X protein family (FMRP, Fxr1 and Fxr2) as binding partners. Biochemical and functional analyses reveal that Fxr1 is a direct substrate of SCFFbxo4. Consistent with a substrate relationship, Fxr1 is overexpressed in Fbxo4 knockout cells, tissues and in human cancer cells, harbouring inactivating Fbxo4 mutations. Critically, in head and neck squamous cell carcinoma, Fxr1 overexpression correlates with reduced Fbxo4 levels in the absence of mutations or loss of mRNA, suggesting the potential for feedback regulation. Direct analysis reveals that Fbxo4 translation is attenuated by Fxr1, indicating the existence of a feedback loop that contributes to Fxr1 overexpression and the loss of Fbxo4. Ultimately, the consequence of Fxr1 overexpression is the bypass of senescence and neoplastic progression.
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MESH Headings
- Amino Acid Sequence
- Animals
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Line, Tumor
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cells, Cultured
- F-Box Proteins/chemistry
- F-Box Proteins/genetics
- F-Box Proteins/metabolism
- Gene Expression Regulation, Neoplastic
- HEK293 Cells
- Head and Neck Neoplasms/genetics
- Head and Neck Neoplasms/metabolism
- Head and Neck Neoplasms/pathology
- Humans
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- NIH 3T3 Cells
- Protein Binding
- Protein Domains
- RNA Interference
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Sequence Homology, Amino Acid
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Affiliation(s)
- Shuo Qie
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Mrinmoyee Majumder
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Oral Health Sciences and Centre for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Katarzyna Mackiewicz
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Breege V Howley
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Philip H Howe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Viswanathan Palanisamy
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Oral Health Sciences and Centre for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - J Alan Diehl
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA.
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33
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Mahboubi H, Stochaj U. Cytoplasmic stress granules: Dynamic modulators of cell signaling and disease. Biochim Biophys Acta Mol Basis Dis 2017; 1863:884-895. [PMID: 28095315 DOI: 10.1016/j.bbadis.2016.12.022] [Citation(s) in RCA: 176] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/15/2016] [Accepted: 12/26/2016] [Indexed: 12/14/2022]
Abstract
Stress granule (SG) assembly is a conserved cellular strategy to minimize stress-related damage and promote cell survival. Beyond their fundamental role in the stress response, SGs have emerged as key players for human health. As such, SG assembly is associated with cancer, neurodegenerative disorders, ischemia, and virus infections. SGs and granule-related signaling circuits are therefore promising targets to improve therapeutic intervention for several diseases. This is clinically relevant, because pharmacological drugs can affect treatment outcome by modulating SG formation. As membraneless and highly dynamic compartments, SGs regulate translation, ribostasis and proteostasis. Moreover, they serve as signaling hubs that determine cell viability and stress recovery. Various compounds can modulate SG formation and dynamics. Rewiring cell signaling through SG manipulation thus represents a new strategy to control cell fate under various physiological and pathological conditions.
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Affiliation(s)
- Hicham Mahboubi
- Department of Physiology, McGill University, Montreal, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, Canada.
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Wall ML, Lewis SM. Methylarginines within the RGG-Motif Region of hnRNP A1 Affect Its IRES Trans-Acting Factor Activity and Are Required for hnRNP A1 Stress Granule Localization and Formation. J Mol Biol 2016; 429:295-307. [PMID: 27979648 DOI: 10.1016/j.jmb.2016.12.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/22/2016] [Accepted: 12/08/2016] [Indexed: 12/30/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a stress granule-associated RNA-binding protein that plays a role in apoptosis and cellular stress recovery. HnRNP A1 is a major non-histone target of protein arginine methyltransferase 1, which asymmetrically dimethylates hnRNP A1 at several key arginine residues within its arginine-glycine-glycine (RGG)-motif region. Although arginine methylation is known to regulate general RNA binding of hnRNP A1 in vitro, the functional role of arginine methylation in hnRNP A1 cytoplasmic activity is unknown. To test the impact of key methylarginine residues on hnRNP A1 cytoplasmic activity and stress granule association, cytoplasmically restricted Flag-tagged mutants of hnRNP A1 were generated in which key methylarginine residues within the RGG-motif region were changed to either lysine or alanine. Lysine substitution, which mimics unmethylated arginine, resulted in a 40% increase in internal ribosome entry site trans-acting factor (ITAF) activity and the protein readily associates with stress granules. Alanine substitution resulted in a loss of ITAF activity and reduced mRNA binding. The alanine mutant also displays reduced stress granule association and suppresses stress granule formation. Our data suggest that arginine residues within the RGG-motif region are critical for hnRNP A1 cytoplasmic activities and that endogenous asymmetric dimethylation of the RGG-motif region suppresses hnRNP A1 ITAF activity in cells. Our findings indicate that methylarginine residues within the RGG-motif region of hnRNP A1 are important for its cytoplasmic activities and that hypomethylation and/or mutation of the RGG-motif region may contribute to the role of hnRNP A1 in diseases such as cancer.
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Affiliation(s)
- Michael L Wall
- Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada
| | - Stephen M Lewis
- Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada; Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada; Department of Chemistry & Biochemistry, Université de Moncton, Moncton, New Brunswick, Canada.
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Modulation of the cytoplasmic functions of mammalian post-transcriptional regulatory proteins by methylation and acetylation: a key layer of regulation waiting to be uncovered? Biochem Soc Trans 2016; 43:1285-95. [PMID: 26614674 DOI: 10.1042/bst20150172] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Post-transcriptional control of gene expression is critical for normal cellular function and viability and many of the proteins that mediate post-transcriptional control are themselves subject to regulation by post-translational modification (PTM), e.g. phosphorylation. However, proteome-wide studies are revealing new complexities in the PTM status of mammalian proteins, in particular large numbers of novel methylated and acetylated residues are being identified. Here we review studied examples of methylation/acetylation-dependent regulation of post-transcriptional regulatory protein (PTRP) function and present collated PTM data that points to the huge potential for regulation of mRNA fate by these PTMs.
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Tsai WC, Gayatri S, Reineke LC, Sbardella G, Bedford MT, Lloyd RE. Arginine Demethylation of G3BP1 Promotes Stress Granule Assembly. J Biol Chem 2016; 291:22671-22685. [PMID: 27601476 DOI: 10.1074/jbc.m116.739573] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/15/2016] [Indexed: 12/22/2022] Open
Abstract
Stress granules (SGs) are cytoplasmic condensates of stalled messenger ribonucleoprotein complexes (mRNPs) that form when eukaryotic cells encounter environmental stress. RNA-binding proteins are enriched for arginine methylation and facilitate SG assembly through interactions involving regions of low amino acid complexity. How methylation of specific RNA-binding proteins regulates RNA granule assembly has not been characterized. Here, we examined the potent SG-nucleating protein Ras-GAP SH3-binding protein 1 (G3BP1), and found that G3BP1 is differentially methylated on specific arginine residues by protein arginine methyltransferase (PRMT) 1 and PRMT5 in its RGG domain. Several genetic and biochemical interventions that increased methylation repressed SG assembly, whereas interventions that decreased methylation promoted SG assembly. Arsenite stress quickly and reversibly decreased asymmetric arginine methylation on G3BP1. These data indicate that arginine methylation in the RGG domain prevents large SG assembly and rapid demethylation is a novel signal that regulates SG formation.
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Affiliation(s)
- Wei-Chih Tsai
- From the Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030
| | - Sitaram Gayatri
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Science Park, Smithville, Texas 78957, and
| | - Lucas C Reineke
- From the Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030
| | - Gianluca Sbardella
- Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
| | - Mark T Bedford
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Science Park, Smithville, Texas 78957, and
| | - Richard E Lloyd
- From the Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030,
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Herpes Simplex Virus 2 Virion Host Shutoff Endoribonuclease Activity Is Required To Disrupt Stress Granule Formation. J Virol 2016; 90:7943-55. [PMID: 27334584 DOI: 10.1128/jvi.00947-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/20/2016] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED We previously established that cells infected with herpes simplex virus 2 (HSV-2) are disrupted in their ability to form stress granules (SGs) in response to oxidative stress and that this disruption is mediated by virion host shutoff protein (vhs), a virion-associated endoribonuclease. Here, we test the requirement for vhs endoribonuclease activity in disruption of SG formation. We analyzed the ability of HSV-2 vhs carrying the point mutation D215N, which ablates its endoribonuclease activity, to disrupt SG formation in both transfected and infected cells. We present evidence that ablation of vhs endoribonuclease activity results in defects in vhs-mediated disruption of SG formation. Furthermore, we demonstrate that preformed SGs can be disassembled by HSV-2 infection in a manner that requires vhs endoribonuclease activity and that, befitting this ability to promote SG disassembly, vhs is able to localize to SGs. Together these data indicate that endoribonuclease activity must be maintained in order for vhs to disrupt SG formation. We propose a model whereby vhs-mediated destruction of SG mRNA promotes SG disassembly and may also prevent SG assembly. IMPORTANCE Stress granules (SGs) are transient cytoplasmic structures that form when a cell is exposed to stress. SGs are emerging as potential barriers to viral infection, necessitating a more thorough understanding of their basic biology. We identified virion host shutoff protein (vhs) as a herpes simplex virus 2 (HSV-2) protein capable of disrupting SG formation. As mRNA is a central component of SGs and the best-characterized activity of vhs is as an endoribonuclease specific for mRNA in vivo, we investigated the requirement for vhs endoribonuclease activity in disruption of SG formation. Our studies demonstrate that endoribonuclease activity is required for vhs to disrupt SG formation and, more specifically, that SG disassembly can be driven by vhs endoribonuclease activity. Notably, during the course of these studies we discovered that there is an ordered departure of SG components during their disassembly and, furthermore, that vhs itself has the capacity to localize to SGs.
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Finnen RL, Banfield BW. Alphaherpesvirus Subversion of Stress-Induced Translational Arrest. Viruses 2016; 8:81. [PMID: 26999187 PMCID: PMC4810271 DOI: 10.3390/v8030081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/14/2022] Open
Abstract
In this article, we provide an overview of translational arrest in eukaryotic cells in response to stress and the tactics used specifically by alphaherpesviruses to overcome translational arrest. One consequence of translational arrest is the formation of cytoplasmic compartments called stress granules (SGs). Many viruses target SGs for disruption and/or modification, including the alphaherpesvirus herpes simplex virus type 2 (HSV-2). Recently, it was discovered that HSV-2 disrupts SG formation early after infection via virion host shutoff protein (vhs), an endoribonuclease that is packaged within the HSV-2 virion. We review this discovery and discuss the insights it has provided into SG biology as well as its potential significance in HSV-2 infection. A model for vhs-mediated disruption of SG formation is presented.
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Affiliation(s)
- Renée L Finnen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Bruce W Banfield
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
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Post-Translational Modifications and RNA-Binding Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 907:297-317. [PMID: 27256391 DOI: 10.1007/978-3-319-29073-7_12] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
RNA-binding proteins affect cellular metabolic programs through development and in response to cellular stimuli. Though much work has been done to elucidate the roles of a handful of RNA-binding proteins and their effect on RNA metabolism, the progress of studies to understand the effects of post-translational modifications of this class of proteins is far from complete. This chapter summarizes the work that has been done to identify the consequence of post-translational modifications to some RNA-binding proteins. The effects of these modifications have been shown to increase the panoply of functions that a given RNA-binding protein can assume. We will survey the experimental methods that are used to identify the presence of several protein modifications and methods that attempt to discern the consequence of these modifications.
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Kaehler C, Guenther A, Uhlich A, Krobitsch S. PRMT1-mediated arginine methylation controls ATXN2L localization. Exp Cell Res 2015; 334:114-25. [PMID: 25748791 DOI: 10.1016/j.yexcr.2015.02.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/20/2015] [Accepted: 02/25/2015] [Indexed: 01/02/2023]
Abstract
Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine-glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory.
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Affiliation(s)
- Christian Kaehler
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Anika Guenther
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Anja Uhlich
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Sylvia Krobitsch
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany.
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41
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Snijders AP, Hautbergue GM, Bloom A, Williamson JC, Minshull TC, Phillips HL, Mihaylov SR, Gjerde DT, Hornby DP, Wilson SA, Hurd PJ, Dickman MJ. Arginine methylation and citrullination of splicing factor proline- and glutamine-rich (SFPQ/PSF) regulates its association with mRNA. RNA (NEW YORK, N.Y.) 2015; 21:347-59. [PMID: 25605962 PMCID: PMC4338332 DOI: 10.1261/rna.045138.114] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 11/15/2014] [Indexed: 05/19/2023]
Abstract
Splicing factor proline- and glutamine-rich (SFPQ) also commonly known as polypyrimidine tract-binding protein-associated-splicing factor (PSF) and its binding partner non-POU domain-containing octamer-binding protein (NONO/p54nrb), are highly abundant, multifunctional nuclear proteins. However, the exact role of this complex is yet to be determined. Following purification of the endogeneous SFPQ/NONO complex, mass spectrometry analysis identified a wide range of interacting proteins, including those involved in RNA processing, RNA splicing, and transcriptional regulation, consistent with a multifunctional role for SFPQ/NONO. In addition, we have identified several sites of arginine methylation in SFPQ/PSF using mass spectrometry and found that several arginines in the N-terminal domain of SFPQ/PSF are asymmetrically dimethylated. Furthermore, we find that the protein arginine N-methyltransferase, PRMT1, catalyzes this methylation in vitro and that this is antagonized by citrullination of SFPQ. Arginine methylation and citrullination of SFPQ/PSF does not affect complex formation with NONO. However, arginine methylation was shown to increase the association with mRNA in mRNP complexes in mammalian cells. Finally we show that the biochemical properties of the endogenous complex from cell lysates are significantly influenced by the ionic strength during purification. At low ionic strength, the SFPQ/NONO complex forms large heterogeneous protein assemblies or aggregates, preventing the purification of the SFPQ/NONO complex. The ability of the SFPQ/NONO complex to form varying protein assemblies, in conjunction with the effect of post-translational modifications of SFPQ modulating mRNA binding, suggests key roles affecting mRNP dynamics within the cell.
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Affiliation(s)
- Ambrosius P Snijders
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | - Alex Bloom
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - James C Williamson
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Thomas C Minshull
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Helen L Phillips
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Simeon R Mihaylov
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | | | - David P Hornby
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Stuart A Wilson
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Paul J Hurd
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Mark J Dickman
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
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Chen E, Joseph S. Fragile X mental retardation protein: A paradigm for translational control by RNA-binding proteins. Biochimie 2015; 114:147-54. [PMID: 25701550 DOI: 10.1016/j.biochi.2015.02.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 02/09/2015] [Indexed: 10/24/2022]
Abstract
Translational control is a common mechanism used to regulate gene expression and occur in bacteria to mammals. Typically in translational control, an RNA-binding protein binds to a unique sequence in the mRNA to regulate protein synthesis by the ribosomes. Alternatively, a protein may bind to or modify a translation factor to globally regulate protein synthesis by the cell. Here, we review translational control by the fragile X mental retardation protein (FMRP), the absence of which causes the neurological disease, fragile X syndrome (FXS).
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Affiliation(s)
- Eileen Chen
- Department of Chemistry and Biochemistry, University of California at San Diego 9500 Gilman Drive, La Jolla, CA 92093-0314, USA
| | - Simpson Joseph
- Department of Chemistry and Biochemistry, University of California at San Diego 9500 Gilman Drive, La Jolla, CA 92093-0314, USA.
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43
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Trivedi MS, Deth R. Redox-based epigenetic status in drug addiction: a potential contributor to gene priming and a mechanistic rationale for metabolic intervention. Front Neurosci 2015; 8:444. [PMID: 25657617 PMCID: PMC4302946 DOI: 10.3389/fnins.2014.00444] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 12/16/2014] [Indexed: 12/26/2022] Open
Abstract
Alcohol and other drugs of abuse, including psychostimulants and opioids, can induce epigenetic changes: a contributing factor for drug addiction, tolerance, and associated withdrawal symptoms. DNA methylation is a major epigenetic mechanism and it is one of more than 200 methylation reactions supported by methyl donor S-adenosylmethionine (SAM). Levels of SAM are controlled by cellular redox status via the folate and vitamin B12-dependent enzyme methionine synthase (MS). For example, under oxidative conditions MS is inhibited, diverting its substrate homocysteine (HCY) to the trans sulfuration pathway. Alcohol, dopamine, and morphine, can alter intracellular levels of glutathione (GSH)-based cellular redox status, subsequently affecting SAM levels and DNA methylation status. Here, existing evidence is presented in a coherent manner to propose a novel hypothesis implicating the involvement of redox-based epigenetic changes in drug addiction. Further, we discuss how a “gene priming” phenomenon can contribute to the maintenance of redox and methylation status homeostasis under various stimuli including drugs of abuse. Additionally, a new mechanistic rationale for the use of metabolic interventions/redox-replenishers as symptomatic treatment of alcohol and other drug addiction and associated withdrawal symptoms is also provided. Hence, the current review article strengthens the hypothesis that neuronal metabolism has a critical bidirectional coupling with epigenetic changes in drug addiction exemplified by the link between redox-based metabolic changes and resultant epigenetic consequences under the effect of drugs of abuse.
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Affiliation(s)
- Malav S Trivedi
- Department of Pharmaceutical Sciences, Northeastern University Boston, MA, USA
| | - Richard Deth
- Department of Pharmaceutical Sciences, Northeastern University Boston, MA, USA
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44
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Fragile X mental retardation protein regulates translation by binding directly to the ribosome. Mol Cell 2014; 54:407-417. [PMID: 24746697 DOI: 10.1016/j.molcel.2014.03.023] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 02/18/2014] [Accepted: 03/10/2014] [Indexed: 11/23/2022]
Abstract
Fragile X syndrome (FXS) is the most common form of inherited mental retardation, and it is caused by loss of function of the fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that is involved in the translational regulation of several neuronal mRNAs. However, the precise mechanism of translational inhibition by FMRP is unknown. Here, we show that FMRP inhibits translation by binding directly to the L5 protein on the 80S ribosome. Furthermore, cryoelectron microscopic reconstruction of the 80S ribosome⋅FMRP complex shows that FMRP binds within the intersubunit space of the ribosome such that it would preclude the binding of tRNA and translation elongation factors on the ribosome. These findings suggest that FMRP inhibits translation by blocking the essential components of the translational machinery from binding to the ribosome.
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45
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Taha MS, Nouri K, Milroy LG, Moll JM, Herrmann C, Brunsveld L, Piekorz RP, Ahmadian MR. Subcellular fractionation and localization studies reveal a direct interaction of the fragile X mental retardation protein (FMRP) with nucleolin. PLoS One 2014; 9:e91465. [PMID: 24658146 PMCID: PMC3962360 DOI: 10.1371/journal.pone.0091465] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 02/11/2014] [Indexed: 12/31/2022] Open
Abstract
Fragile X mental Retardation Protein (FMRP) is a well-known regulator of local translation of its mRNA targets in neurons. However, despite its ubiquitous expression, the role of FMRP remains ill-defined in other cell types. In this study we investigated the subcellular distribution of FMRP and its protein complexes in HeLa cells using confocal imaging as well as detergent-free fractionation and size exclusion protocols. We found FMRP localized exclusively to solid compartments, including cytosolic heavy and light membranes, mitochondria, nuclear membrane and nucleoli. Interestingly, FMRP was associated with nucleolin in both a high molecular weight ribosomal and translation-associated complex (≥6 MDa) in the cytosol, and a low molecular weight complex (∼200 kDa) in the nucleoli. Consistently, we identified two functional nucleolar localization signals (NoLSs) in FMRP that are responsible for a strong nucleolar colocalization of the C-terminus of FMRP with nucleolin, and a direct interaction of the N-terminus of FMRP with the arginine-glycine-glycine (RGG) domain of nucleolin. Taken together, we propose a novel mechanism by which a transient nucleolar localization of FMRP underlies a strong nucleocytoplasmic translocation, most likely in a complex with nucleolin and possibly ribosomes, in order to regulate translation of its target mRNAs.
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Affiliation(s)
- Mohamed S. Taha
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine-University, Düsseldorf, Germany
| | - Kazem Nouri
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine-University, Düsseldorf, Germany
| | - Lech G. Milroy
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems, Department of Biomedical Engineering, Technische Universiteit Eindhoven, Eindhoven, the Netherlands
| | - Jens M. Moll
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine-University, Düsseldorf, Germany
| | - Christian Herrmann
- Department of Physical Chemistry I, Ruhr University Bochum, Bochum, Germany
| | - Luc Brunsveld
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems, Department of Biomedical Engineering, Technische Universiteit Eindhoven, Eindhoven, the Netherlands
| | - Roland P. Piekorz
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine-University, Düsseldorf, Germany
| | - Mohammad R. Ahmadian
- Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine-University, Düsseldorf, Germany
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46
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Raymond LJ, Deth RC, Ralston NVC. Potential Role of Selenoenzymes and Antioxidant Metabolism in relation to Autism Etiology and Pathology. AUTISM RESEARCH AND TREATMENT 2014; 2014:164938. [PMID: 24734177 PMCID: PMC3966422 DOI: 10.1155/2014/164938] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 01/07/2014] [Accepted: 01/27/2014] [Indexed: 11/17/2022]
Abstract
Autism and autism spectrum disorders (ASDs) are behaviorally defined, but the biochemical pathogenesis of the underlying disease process remains uncharacterized. Studies indicate that antioxidant status is diminished in autistic subjects, suggesting its pathology is associated with augmented production of oxidative species and/or compromised antioxidant metabolism. This suggests ASD may result from defects in the metabolism of cellular antioxidants which maintain intracellular redox status by quenching reactive oxygen species (ROS). Selenium-dependent enzymes (selenoenzymes) are important in maintaining intercellular reducing conditions, particularly in the brain. Selenoenzymes are a family of ~25 genetically unique proteins, several of which have roles in preventing and reversing oxidative damage in brain and endocrine tissues. Since the brain's high rate of oxygen consumption is accompanied by high ROS production, selenoenzyme activities are particularly important in this tissue. Because selenoenzymes can be irreversibly inhibited by many electrophiles, exposure to these organic and inorganic agents can diminish selenoenzyme-dependent antioxidant functions. This can impair brain development, particularly via the adverse influence of oxidative stress on epigenetic regulation. Here we review the physiological roles of selenoproteins in relation to potential biochemical mechanisms of ASD etiology and pathology.
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Affiliation(s)
- Laura J. Raymond
- Energy & Environmental Research Center, University of North Dakota, 15 North 23rd Street, Stop 9018, Grand Forks, ND 58202, USA
| | - Richard C. Deth
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Nicholas V. C. Ralston
- Energy & Environmental Research Center, University of North Dakota, 15 North 23rd Street, Stop 9018, Grand Forks, ND 58202, USA
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47
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Lee YJ, Wei HM, Chen LY, Li C. Localization of SERBP1 in stress granules and nucleoli. FEBS J 2013; 281:352-64. [DOI: 10.1111/febs.12606] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 11/06/2013] [Indexed: 12/24/2022]
Affiliation(s)
- Yu-Jen Lee
- Institute of Biochemistry and Biotechnology; Chung Shan Medical University; Taichung Taiwan
| | - Hung-Ming Wei
- Department of Biomedical Sciences; Chung Shan Medical University; Taichung Taiwan
| | - Ling-Yun Chen
- Institute of Biochemistry and Biotechnology; Chung Shan Medical University; Taichung Taiwan
| | - Chuan Li
- Department of Biomedical Sciences; Chung Shan Medical University; Taichung Taiwan
- Department of Medical Research; Chung Shan Medical University Hospital; Taichung Taiwan
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48
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Sama RRK, Ward CL, Kaushansky LJ, Lemay N, Ishigaki S, Urano F, Bosco DA. FUS/TLS assembles into stress granules and is a prosurvival factor during hyperosmolar stress. J Cell Physiol 2013; 228:2222-31. [PMID: 23625794 DOI: 10.1002/jcp.24395] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 04/17/2013] [Indexed: 12/14/2022]
Abstract
FUsed in Sarcoma/Translocated in LipoSarcoma (FUS/TLS or FUS) has been linked to several biological processes involving DNA and RNA processing, and has been associated with multiple diseases, including myxoid liposarcoma and amyotrophic lateral sclerosis (ALS). ALS-associated mutations cause FUS to associate with stalled translational complexes called stress granules under conditions of stress. However, little is known regarding the normal role of endogenous (non-disease linked) FUS in cellular stress response. Here, we demonstrate that endogenous FUS exerts a robust response to hyperosmolar stress induced by sorbitol. Hyperosmolar stress causes an immediate re-distribution of nuclear FUS to the cytoplasm, where it incorporates into stress granules. The redistribution of FUS to the cytoplasm is modulated by methyltransferase activity, whereas the inhibition of methyltransferase activity does not affect the incorporation of FUS into stress granules. The response to hyperosmolar stress is specific, since endogenous FUS does not redistribute to the cytoplasm in response to sodium arsenite, hydrogen peroxide, thapsigargin, or heat shock, all of which induce stress granule assembly. Intriguingly, cells with reduced expression of FUS exhibit a loss of cell viability in response to sorbitol, indicating a prosurvival role for endogenous FUS in the cellular response to hyperosmolar stress.
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Affiliation(s)
- Reddy Ranjith K Sama
- Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Thapar R, Denmon AP. Signaling pathways that control mRNA turnover. Cell Signal 2013; 25:1699-710. [PMID: 23602935 PMCID: PMC3703460 DOI: 10.1016/j.cellsig.2013.03.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Accepted: 03/29/2013] [Indexed: 02/06/2023]
Abstract
Cells regulate their genomes mainly at the level of transcription and at the level of mRNA decay. While regulation at the level of transcription is clearly important, the regulation of mRNA turnover by signaling networks is essential for a rapid response to external stimuli. Signaling pathways result in posttranslational modification of RNA binding proteins by phosphorylation, ubiquitination, methylation, acetylation etc. These modifications are important for rapid remodeling of dynamic ribonucleoprotein complexes and triggering mRNA decay. Understanding how these posttranslational modifications alter gene expression is therefore a fundamental question in biology. In this review we highlight recent findings on how signaling pathways and cell cycle checkpoints involving phosphorylation, ubiquitination, and arginine methylation affect mRNA turnover.
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Affiliation(s)
- Roopa Thapar
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA.
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Cook D, Nuro E, Murai KK. Increasing our understanding of human cognition through the study of Fragile X Syndrome. Dev Neurobiol 2013; 74:147-77. [PMID: 23723176 PMCID: PMC4216185 DOI: 10.1002/dneu.22096] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 05/17/2013] [Indexed: 12/16/2022]
Abstract
Fragile X Syndrome (FXS) is considered the most common form of inherited intellectual disability. It is caused by reductions in the expression level or function of a single protein, the Fragile X Mental Retardation Protein (FMRP), a translational regulator which binds to approximately 4% of brain messenger RNAs. Accumulating evidence suggests that FXS is a complex disorder of cognition, involving interactions between genetic and environmental influences, leading to difficulties in acquiring key life skills including motor skills, language, and proper social behaviors. Since many FXS patients also present with one or more features of autism spectrum disorders (ASDs), insights gained from studying the monogenic basis of FXS could pave the way to a greater understanding of underlying features of multigenic ASDs. Here we present an overview of the FXS and FMRP field with the goal of demonstrating how loss of a single protein involved in translational control affects multiple stages of brain development and leads to debilitating consequences on human cognition. We also focus on studies which have rescued or improved FXS symptoms in mice using genetic or therapeutic approaches to reduce protein expression. We end with a brief description of how deficits in translational control are implicated in FXS and certain cases of ASDs, with many recent studies demonstrating that ASDs are likely caused by increases or decreases in the levels of certain key synaptic proteins. The study of FXS and its underlying single genetic cause offers an invaluable opportunity to study how a single gene influences brain development and behavior.
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Affiliation(s)
- Denise Cook
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
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