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Li X, Su Y, Xu Y, Hu T, Lu X, Sun J, Li W, Zhou J, Ma X, Yang Y, Bao Y. Adipocyte-Specific Hnrnpa1 Knockout Aggravates Obesity-Induced Metabolic Dysfunction via Upregulation of CCL2. Diabetes 2024; 73:713-727. [PMID: 38320300 PMCID: PMC11043064 DOI: 10.2337/db23-0609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 01/28/2024] [Indexed: 02/08/2024]
Abstract
Heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) is involved in lipid and glucose metabolism via mRNA processing. However, whether and how HNRNPA1 alters adipocyte function in obesity remain obscure. Here, we found that the obese state downregulated HNRNPA1 expression in white adipose tissue (WAT). The depletion of adipocyte HNRNPA1 promoted markedly increased macrophage infiltration and expression of proinflammatory and fibrosis genes in WAT of obese mice, eventually leading to exacerbated insulin sensitivity, glucose tolerance, and hepatic steatosis. Mechanistically, HNRNPA1 interacted with Ccl2 and regulated its mRNA stability. Intraperitoneal injection of CCL2-CCR2 signaling antagonist improved adipose tissue inflammation and systemic glucose homeostasis. Furthermore, HNRNPA1 expression in human WAT was negatively correlated with BMI, fat percentage, and subcutaneous fat area. Among individuals with 1-year metabolic surgery follow-up, HNRNPA1 expression was positively related to percentage of total weight loss. These findings identify adipocyte HNRNPA1 as a link between adipose tissue inflammation and systemic metabolic homeostasis, which might be a promising therapeutic target for obesity-related disorders. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Xiaoya Li
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Yingying Su
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Yiting Xu
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Tingting Hu
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Xuhong Lu
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Jingjing Sun
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Wenfei Li
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Jian Zhou
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Xiaojing Ma
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Ying Yang
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
| | - Yuqian Bao
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Clinical Center for Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital, Shanghai, China
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Shehata SI, Watkins JM, Burke JM, Parker R. Mechanisms and consequences of mRNA destabilization during viral infections. Virol J 2024; 21:38. [PMID: 38321453 PMCID: PMC10848536 DOI: 10.1186/s12985-024-02305-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 01/29/2024] [Indexed: 02/08/2024] Open
Abstract
During viral infection there is dynamic interplay between the virus and the host to regulate gene expression. In many cases, the host induces the expression of antiviral genes to combat infection, while the virus uses "host shut-off" systems to better compete for cellular resources and to limit the induction of the host antiviral response. Viral mechanisms for host shut-off involve targeting translation, altering host RNA processing, and/or inducing the degradation of host mRNAs. In this review, we discuss the diverse mechanisms viruses use to degrade host mRNAs. In addition, the widespread degradation of host mRNAs can have common consequences including the accumulation of RNA binding proteins in the nucleus, which leads to altered RNA processing, mRNA export, and changes to transcription.
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Affiliation(s)
- Soraya I Shehata
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - J Monty Watkins
- Department of Molecular Medicine, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, Jupiter, FL, USA
- Department of Immunology and Microbiology, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, Jupiter, FL, USA
- Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, Jupiter, FL, USA
| | - James M Burke
- Department of Molecular Medicine, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, Jupiter, FL, USA
- Department of Immunology and Microbiology, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, Jupiter, FL, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA.
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Liao Y, Wang H, Liao H, Sun Y, Tan L, Song C, Qiu X, Ding C. Classification, replication, and transcription of Nidovirales. Front Microbiol 2024; 14:1291761. [PMID: 38328580 PMCID: PMC10847374 DOI: 10.3389/fmicb.2023.1291761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/06/2023] [Indexed: 02/09/2024] Open
Abstract
Nidovirales is one order of RNA virus, with the largest single-stranded positive sense RNA genome enwrapped with membrane envelope. It comprises four families (Arterividae, Mesoniviridae, Roniviridae, and Coronaviridae) and has been circulating in humans and animals for almost one century, posing great threat to livestock and poultry,as well as to public health. Nidovirales shares similar life cycle: attachment to cell surface, entry, primary translation of replicases, viral RNA replication in cytoplasm, translation of viral proteins, virion assembly, budding, and release. The viral RNA synthesis is the critical step during infection, including genomic RNA (gRNA) replication and subgenomic mRNAs (sg mRNAs) transcription. gRNA replication requires the synthesis of a negative sense full-length RNA intermediate, while the sg mRNAs transcription involves the synthesis of a nested set of negative sense subgenomic intermediates by a discontinuous strategy. This RNA synthesis process is mediated by the viral replication/transcription complex (RTC), which consists of several enzymatic replicases derived from the polyprotein 1a and polyprotein 1ab and several cellular proteins. These replicases and host factors represent the optimal potential therapeutic targets. Hereby, we summarize the Nidovirales classification, associated diseases, "replication organelle," replication and transcription mechanisms, as well as related regulatory factors.
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Affiliation(s)
- Ying Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Huan Wang
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Huiyu Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yingjie Sun
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Lei Tan
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Cuiping Song
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xusheng Qiu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chan Ding
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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Abedeera SM, Davila-Calderon J, Haddad C, Henry B, King J, Penumutchu S, Tolbert BS. The Repurposing of Cellular Proteins during Enterovirus A71 Infection. Viruses 2023; 16:75. [PMID: 38257775 PMCID: PMC10821071 DOI: 10.3390/v16010075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
Viruses pose a great threat to people's lives. Enterovirus A71 (EV-A71) infects children and infants all over the world with no FDA-approved treatment to date. Understanding the basic mechanisms of viral processes aids in selecting more efficient drug targets and designing more effective antivirals to thwart this virus. The 5'-untranslated region (5'-UTR) of the viral RNA genome is composed of a cloverleaf structure and an internal ribosome entry site (IRES). Cellular proteins that bind to the cloverleaf structure regulate viral RNA synthesis, while those that bind to the IRES also known as IRES trans-acting factors (ITAFs) regulate viral translation. In this review, we survey the cellular proteins currently known to bind the 5'-UTR and influence viral gene expression with emphasis on comparing proteins' functions and localizations pre- and post-(EV-A71) infection. A comprehensive understanding of how the host cell's machinery is hijacked and reprogrammed by the virus to facilitate its replication is crucial for developing effective antivirals.
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Affiliation(s)
- Sudeshi M. Abedeera
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
| | - Jesse Davila-Calderon
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA; (J.D.-C.); (C.H.); (J.K.)
| | - Christina Haddad
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA; (J.D.-C.); (C.H.); (J.K.)
| | - Barrington Henry
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
| | - Josephine King
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA; (J.D.-C.); (C.H.); (J.K.)
| | - Srinivasa Penumutchu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
| | - Blanton S. Tolbert
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.M.A.); (B.H.); (S.P.)
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
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5
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Zhang W, Zhou B, Yang X, Zhao J, Hu J, Ding Y, Zhan S, Yang Y, Chen J, Zhang F, Zhao B, Deng F, Lin Z, Sun Q, Zhang F, Yao Z, Liu W, Li C, Liu KX. Exosomal circEZH2_005, an intestinal injury biomarker, alleviates intestinal ischemia/reperfusion injury by mediating Gprc5a signaling. Nat Commun 2023; 14:5437. [PMID: 37673874 PMCID: PMC10482849 DOI: 10.1038/s41467-023-41147-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 08/24/2023] [Indexed: 09/08/2023] Open
Abstract
Intestinal ischemia/reperfusion (I/R) injury is a severe clinical condition without optimal diagnostic markers nor clear molecular etiological insights. Plasma exosomal circular RNAs (circRNAs) are valuable biomarkers and therapeutic targets for various diseases, but their role in intestinal I/R injury remains unknown. Here we screen the expression profile of circRNAs in intestinal tissue exosomes collected from intestinal I/R mice and identify circEZH2_005 as a significantly downregulated exosomal circRNA. In parallel, circEZH2_005 is also reduced in the plasma of clinical cardiac surgery patients who developed postoperative intestinal I/R injury. Exosomal circEZH2_005 displays a significant diagnostic value for intestinal injury induced by I/R. Mechanistically, circEZH2_005 is highly expressed in intestinal crypt cells. CircEZH2_005 upregulation promotes the proliferation of Lgr5+ stem cells by direct interaction with hnRNPA1, and enhanced Gprc5a stability, thereby alleviating I/R-induced intestinal mucosal damage. Hence, exosomal circEZH2_005 may serve as a biomarker for intestinal I/R injury and targeting the circEZH2_005/hnRNPA1/Gprc5a axis may be a potential therapeutic strategy for intestinal I/R injury.
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Affiliation(s)
- Wenjuan Zhang
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Bowei Zhou
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Xiao Yang
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Jin Zhao
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Jingjuan Hu
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Yuqi Ding
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Shuteng Zhan
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Yifeng Yang
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Jun Chen
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Fu Zhang
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Bingcheng Zhao
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Fan Deng
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Zebin Lin
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Qishun Sun
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Fangling Zhang
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Zhiwen Yao
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Weifeng Liu
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Cai Li
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China.
| | - Ke-Xuan Liu
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 1838 Guangzhou Avenue North, Guangzhou, 510515, China.
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Feng J, Zhou J, Lin Y, Huang W. hnRNP A1 in RNA metabolism regulation and as a potential therapeutic target. Front Pharmacol 2022; 13:986409. [PMID: 36339596 PMCID: PMC9634572 DOI: 10.3389/fphar.2022.986409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/10/2022] [Indexed: 11/22/2022] Open
Abstract
Abnormal RNA metabolism, regulated by various RNA binding proteins, can have functional consequences for multiple diseases. Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is an important RNA binding protein, that regulates various RNA metabolic processes, including transcription, alternative splicing of pre-mRNA, translation, miRNA processing and mRNA stability. As a potent splicing factor, hnRNP A1 can regulate multiple splicing events, including itself, collaborating with other cooperative or antagonistical splicing factors by binding to splicing sites and regulatory elements in exons or introns. hnRNP A1 can modulate gene transcription by directly interacting with promoters or indirectly impacting Pol II activities. Moreover, by interacting with the internal ribosome entry site (IRES) or 3′-UTR of mRNAs, hnRNP A1 can affect mRNA translation. hnRNP A1 can alter the stability of mRNAs by binding to specific locations of 3′-UTR, miRNAs biogenesis and Nonsense-mediated mRNA decay (NMD) pathway. In this review, we conclude the selective sites where hnRNP A1 binds to RNA and DNA, and the co-regulatory factors that interact with hnRNP A1. Given the dysregulation of hnRNP A1 in diverse diseases, especially in cancers and neurodegeneration diseases, targeting hnRNP A1 for therapeutic treatment is extremely promising. Therefore, this review also provides the small-molecule drugs, biomedicines and novel strategies targeting hnRNP A1 for therapeutic purposes.
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Zhao M, Shen L, Ouyang Z, Li M, Deng G, Yang C, Zheng W, Kong L, Wu X, Wu X, Guo W, Yin Y, Xu Q, Sun Y. Loss of hnRNP A1 in murine skeletal muscle exacerbates high-fat diet-induced onset of insulin resistance and hepatic steatosis. J Mol Cell Biol 2021; 12:277-290. [PMID: 31169879 PMCID: PMC7232127 DOI: 10.1093/jmcb/mjz050] [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: 01/23/2019] [Revised: 04/14/2019] [Accepted: 05/20/2019] [Indexed: 12/13/2022] Open
Abstract
Impairment of glucose (Glu) uptake and storage by skeletal muscle is a prime risk factor for the development of metabolic diseases. Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a highly abundant RNA-binding protein that has been implicated in diverse cellular functions. The aim of this study was to investigate the function of hnRNP A1 on muscle tissue insulin sensitivity and systemic Glu homeostasis. Our results showed that conditional deletion of hnRNP A1 in the muscle gave rise to a severe insulin resistance phenotype in mice fed a high-fat diet (HFD). Conditional knockout mice fed a HFD showed exacerbated obesity, insulin resistance, and hepatic steatosis. In vitro interference of hnRNP A1 in C2C12 myotubes impaired insulin signal transduction and inhibited Glu uptake, whereas hnRNP A1 overexpression in C2C12 myotubes protected against insulin resistance induced by supraphysiological concentrations of insulin. The expression and stability of glycogen synthase (gys1) mRNA were also decreased in the absence of hnRNP A1. Mechanistically, hnRNP A1 interacted with gys1 and stabilized its mRNA, thereby promoting glycogen synthesis and maintaining the insulin sensitivity in muscle tissue. Taken together, our findings are the first to show that reduced expression of hnRNP A1 in skeletal muscle affects the metabolic properties and systemic insulin sensitivity by inhibiting glycogen synthesis.
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Affiliation(s)
- Mingxia Zhao
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Lihong Shen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Zijun Ouyang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Manru Li
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Guoliang Deng
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Chenxi Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Wei Zheng
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Lingdong Kong
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Xuefeng Wu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Xudong Wu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Wenjie Guo
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Ye Yin
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, China
| | - Qiang Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Yang Sun
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing 210023, China.,State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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Thibault PA, Ganesan A, Kalyaanamoorthy S, Clarke JPWE, Salapa HE, Levin MC. hnRNP A/B Proteins: An Encyclopedic Assessment of Their Roles in Homeostasis and Disease. BIOLOGY 2021; 10:biology10080712. [PMID: 34439945 PMCID: PMC8389229 DOI: 10.3390/biology10080712] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 12/13/2022]
Abstract
The hnRNP A/B family of proteins is canonically central to cellular RNA metabolism, but due to their highly conserved nature, the functional differences between hnRNP A1, A2/B1, A0, and A3 are often overlooked. In this review, we explore and identify the shared and disparate homeostatic and disease-related functions of the hnRNP A/B family proteins, highlighting areas where the proteins have not been clearly differentiated. Herein, we provide a comprehensive assembly of the literature on these proteins. We find that there are critical gaps in our grasp of A/B proteins' alternative splice isoforms, structures, regulation, and tissue and cell-type-specific functions, and propose that future mechanistic research integrating multiple A/B proteins will significantly improve our understanding of how this essential protein family contributes to cell homeostasis and disease.
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Affiliation(s)
- Patricia A. Thibault
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
| | - Aravindhan Ganesan
- ArGan’s Lab, School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - Subha Kalyaanamoorthy
- Department of Chemistry, Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - Joseph-Patrick W. E. Clarke
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Hannah E. Salapa
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
| | - Michael C. Levin
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Correspondence:
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9
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Ryu HG, Jung Y, Lee N, Seo JY, Kim SW, Lee KH, Kim DY, Kim KT. HNRNP A1 Promotes Lung Cancer Cell Proliferation by Modulating VRK1 Translation. Int J Mol Sci 2021; 22:ijms22115506. [PMID: 34071140 PMCID: PMC8197126 DOI: 10.3390/ijms22115506] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/14/2021] [Accepted: 05/21/2021] [Indexed: 01/12/2023] Open
Abstract
THeterogeneous nuclear ribonucleoprotein (HNRNP) A1 is the most abundant and ubiquitously expressed member of the HNRNP protein family. In recent years, it has become more evident that HNRNP A1 contributes to the development of neurodegenerative diseases. However, little is known about the underlying role of HNRNP A1 in cancer development. Here, we report that HNRNP A1 expression is significantly increased in lung cancer tissues and is negatively correlated with the overall survival of patients with lung cancer. Additionally, HNRNP A1 positively regulates vaccinia-related kinase 1 (VRK1) translation via binding directly to the 3′ untranslated region (UTR) of VRK1 mRNA, thus increasing cyclin D1 (CCND1) expression by VRK1-mediated phosphorylation of the cAMP response element–binding protein (CREB). Furthermore, HNRNP A1 binding to the cis-acting region of the 3′UTR of VRK1 mRNA contributes to increased lung cancer cell proliferation. Thus, our study unveils a novel role of HNRNP A1 in lung carcinogenesis via post-transcriptional regulation of VRK1 expression and suggests its potential as a therapeutic target for patients with lung cancer.
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Affiliation(s)
- Hye Guk Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea;
| | - Youngseob Jung
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (Y.J.); (J.-Y.S.); (S.W.K.)
| | - Namgyu Lee
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01065, USA;
| | - Ji-Young Seo
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (Y.J.); (J.-Y.S.); (S.W.K.)
| | - Sung Wook Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (Y.J.); (J.-Y.S.); (S.W.K.)
| | - Kyung-Ha Lee
- Division of Cosmetic Science and Technology, Daegu Haany University, Gyeongsan 38610, Korea;
| | - Do-Yeon Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea;
| | - Kyong-Tai Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea;
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (Y.J.); (J.-Y.S.); (S.W.K.)
- Correspondence: ; Tel.: +82-54-279-2297
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10
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Multiple Sclerosis-Associated hnRNPA1 Mutations Alter hnRNPA1 Dynamics and Influence Stress Granule Formation. Int J Mol Sci 2021; 22:ijms22062909. [PMID: 33809384 PMCID: PMC7998649 DOI: 10.3390/ijms22062909] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022] Open
Abstract
Evidence indicates that dysfunctional heterogeneous ribonucleoprotein A1 (hnRNPA1; A1) contributes to the pathogenesis of neurodegeneration in multiple sclerosis. Understanding molecular mechanisms of neurodegeneration in multiple sclerosis may result in novel therapies that attenuate neurodegeneration, thereby improving the lives of MS patients with multiple sclerosis. Using an in vitro, blue light induced, optogenetic protein expression system containing the optogene Cryptochrome 2 and a fluorescent mCherry reporter, we examined the effects of multiple sclerosis-associated somatic A1 mutations (P275S and F281L) in A1 localization, cluster kinetics and stress granule formation in real-time. We show that A1 mutations caused cytoplasmic mislocalization, and significantly altered the kinetics of A1 cluster formation/dissociation, and the quantity and size of clusters. A1 mutations also caused stress granule formation to occur more quickly and frequently in response to blue light stimulation. This study establishes a live cell optogenetics imaging system to probe localization and association characteristics of A1. It also demonstrates that somatic mutations in A1 alter its function and promote stress granule formation, which supports the hypothesis that A1 dysfunction may exacerbate neurodegeneration in multiple sclerosis.
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11
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Pham TN, Spaulding C, Munshi HG. Controlling TIME: How MNK Kinases Function to Shape Tumor Immunity. Cancers (Basel) 2020; 12:cancers12082096. [PMID: 32731503 PMCID: PMC7465005 DOI: 10.3390/cancers12082096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 12/16/2022] Open
Abstract
A number of studies have clearly established the oncogenic role for MAPK-interacting protein kinases (MNK) in human malignancies. Modulation of MNK activity affects translation of mRNAs involved in cancer development, progression, and resistance to therapies. As a result, there are ongoing efforts to develop and evaluate MNK inhibitors for cancer treatment. However, it is important to recognize that MNK activity also plays an important role in regulating the innate and adaptive immune systems. A better understanding of the role of MNK kinases and MNK-mediated signals in regulating the immune system could help mitigate undesired side effects while maximizing therapeutic efficacy of MNK inhibitors. Here, we provide a systematic review on the function of MNK kinases and their substrates in immune cells.
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Affiliation(s)
- Thao N.D. Pham
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
- Jesse Brown VA Medical Center, Chicago, IL 60612, USA
- Correspondence: (T.N.D.P.); (H.G.M.); Tel.: +312-503-0312 (T.N.D.P.); +312-503-2301 (H.G.M.)
| | - Christina Spaulding
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
- Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Hidayatullah G. Munshi
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
- Jesse Brown VA Medical Center, Chicago, IL 60612, USA
- Robert H. Lurie Comprehensive Cancer Center, Chicago, IL 60611, USA
- Correspondence: (T.N.D.P.); (H.G.M.); Tel.: +312-503-0312 (T.N.D.P.); +312-503-2301 (H.G.M.)
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12
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Abstract
The proper regulation of mRNA processing, localization, translation, and degradation occurs on mRNPs. However, the global principles of mRNP organization are poorly understood. We utilize the limited, but existing, information available to present a speculative synthesis of mRNP organization with the following key points. First, mRNPs form a compacted structure due to the inherent folding of RNA. Second, the ribosome is the principal mechanism by which mRNA regions are partially decompacted. Third, mRNPs are 50%-80% protein by weight, consistent with proteins modulating mRNP organization, but also suggesting the majority of mRNA sequences are not directly interacting with RNA-binding proteins. Finally, the ratio of mRNA-binding proteins to mRNAs is higher in the nucleus to allow effective RNA processing and limit the potential for nuclear RNA based aggregation. This synthesis of mRNP understanding provides a model for mRNP biogenesis, structure, and regulation with multiple implications.
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Affiliation(s)
- Anthony Khong
- Department of Biochemistry and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Roy Parker
- Department of Biochemistry and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
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13
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Levengood JD, Tolbert BS. Idiosyncrasies of hnRNP A1-RNA recognition: Can binding mode influence function. Semin Cell Dev Biol 2019; 86:150-161. [PMID: 29625167 PMCID: PMC6177329 DOI: 10.1016/j.semcdb.2018.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/27/2018] [Accepted: 04/03/2018] [Indexed: 12/21/2022]
Abstract
The heterogeneous nuclear ribonucleoproteins (hnRNPs) are a diverse family of RNA binding proteins that function in most stages of RNA metabolism. The prototypical member, hnRNP A1, is composed of three major domains; tandem N-terminal RNA Recognition Motifs (RRMs) and a C-terminal mostly intrinsically disordered region. HnRNP A1 is broadly implicated in basic cellular RNA processing events such as splicing, stability, nuclear export and translation. Due to its ubiquity and abundance, hnRNP A1 is also frequently usurped to control viral gene expression. Deregulation of the RNA metabolism functions of hnRNP A1 in neuronal cells contributes to several neurodegenerative disorders. Because of these roles in human pathologies, the study of hnRNP A1 provides opportunities for the development of novel therapeutics, with disruption of its RNA binding capabilities being the most promising target. The functional diversity of hnRNP A1 is reflected in the complex nature by which it interacts with various RNA targets. Indeed, hnRNP A1 binds both structured and unstructured RNAs with binding affinities that span several magnitudes. Available structures of hnRNP A1-RNA complexes also suggest a degree of plasticity in molecular recognition. Given the reinvigoration in hnRNP A1, the goal of this review is to use the available structural biochemical developments as a framework to interpret its wide-range of RNA functions.
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Affiliation(s)
- Jeffrey D Levengood
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, United States
| | - Blanton S Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, United States.
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14
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Hsu MC, Pan MR, Chu PY, Tsai YL, Tsai CH, Shan YS, Chen LT, Hung WC. Protein Arginine Methyltransferase 3 Enhances Chemoresistance in Pancreatic Cancer by Methylating hnRNPA1 to Increase ABCG2 Expression. Cancers (Basel) 2018; 11:cancers11010008. [PMID: 30577570 PMCID: PMC6356582 DOI: 10.3390/cancers11010008] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/11/2018] [Accepted: 12/17/2018] [Indexed: 01/27/2023] Open
Abstract
Pancreatic cancer is poorly responsive to chemotherapy due to intrinsic or acquired resistance. Our previous study showed that epigenetic modifying enzymes including protein arginine methyltransferase 3 (PRMT3) are dysregulated in gemcitabine (GEM)-resistant pancreatic cancer cells. Here, we attempt to elucidate the role of PRMT3 in chemoresistance. Overexpression of PRMT3 led to increased resistance to GEM in pancreatic cancer cells, whereas reduction of PRMT3 restored GEM sensitivity in resistant cells. We identified a novel PRMT3 target, ATP-binding cassette subfamily G member 2 (ABCG2), which is known to play a critical role in drug resistance. PRMT3 overexpression upregulated ABCG2 expression by increasing its mRNA stability. Mass spectrometric analysis identified hnRNPA1 as a PRMT3 interacting protein, and methylation of hnRNPA1 at R31 by PRMT3 in vivo and in vitro. The expression of methylation-deficient hnRNPA1-R31K mutant reduced the RNA binding activity of hnRNPA1 and the expression of ABCG2 mRNA. Taken together, this provides the first evidence that PRMT3 methylates the RNA recognition motif (RRM) of hnRNPA1 and promotes the binding between hnRNPA1 and ABCG2 to enhance drug resistance. Inhibition of PRMT3 could be a novel strategy for the treatment of GEM-resistant pancreatic cancer.
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Affiliation(s)
- Ming-Chuan Hsu
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.
| | - Mei-Ren Pan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
| | - Pei-Yi Chu
- Department of Pathology, Show Chwan Memorial Hospital, Changhua City 500, Taiwan.
| | - Ya-Li Tsai
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.
| | - Chia-Hua Tsai
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.
| | - Yan-Shen Shan
- Department of Surgery, National Cheng Kung University Hospital, Tainan 704, Taiwan.
- Insitute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan.
| | - Li-Tzong Chen
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.
- Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan.
- Graduate Institute of Medicine, College of Medicine Kaohsiung Medical University, Kaohsiung 807, Taiwan.
| | - Wen-Chun Hung
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.
- Graduate Institute of Medicine, College of Medicine Kaohsiung Medical University, Kaohsiung 807, Taiwan.
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15
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β-Hydroxybutyrate Prevents Vascular Senescence through hnRNP A1-Mediated Upregulation of Oct4. Mol Cell 2018; 71:1064-1078.e5. [PMID: 30197300 DOI: 10.1016/j.molcel.2018.07.036] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 04/02/2018] [Accepted: 07/24/2018] [Indexed: 12/16/2022]
Abstract
β-hydroxybutyrate (β-HB) elevation during fasting or caloric restriction is believed to induce anti-aging effects and alleviate aging-related neurodegeneration. However, whether β-HB alters the senescence pathway in vascular cells remains unknown. Here we report that β-HB promotes vascular cell quiescence, which significantly inhibits both stress-induced premature senescence and replicative senescence through p53-independent mechanisms. Further, we identify heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) as a direct binding target of β-HB. β-HB binding to hnRNP A1 markedly enhances hnRNP A1 binding with Octamer-binding transcriptional factor (Oct) 4 mRNA, which stabilizes Oct4 mRNA and Oct4 expression. Oct4 increases Lamin B1, a key factor against DNA damage-induced senescence. Finally, fasting and intraperitoneal injection of β-HB upregulate Oct4 and Lamin B1 in both vascular smooth muscle and endothelial cells in mice in vivo. We conclude that β-HB exerts anti-aging effects in vascular cells by upregulating an hnRNP A1-induced Oct4-mediated Lamin B1 pathway.
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16
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Structural basis for terminal loop recognition and stimulation of pri-miRNA-18a processing by hnRNP A1. Nat Commun 2018; 9:2479. [PMID: 29946118 PMCID: PMC6018666 DOI: 10.1038/s41467-018-04871-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 05/23/2018] [Indexed: 02/07/2023] Open
Abstract
Post-transcriptional mechanisms play a predominant role in the control of microRNA (miRNA) production. Recognition of the terminal loop of precursor miRNAs by RNA-binding proteins (RBPs) influences their processing; however, the mechanistic basis for how levels of individual or subsets of miRNAs are regulated is mostly unexplored. We previously showed that hnRNP A1, an RBP implicated in many aspects of RNA processing, acts as an auxiliary factor that promotes the Microprocessor-mediated processing of pri-mir-18a. Here, by using an integrative structural biology approach, we show that hnRNP A1 forms a 1:1 complex with pri-mir-18a where both RNA recognition motifs (RRMs) bind to cognate RNA sequence motifs in the terminal loop of pri-mir-18a. Terminal loop binding induces an allosteric destabilization of base-pairing in the pri-mir-18a stem that promotes its downstream processing. Our results highlight terminal loop RNA recognition by RBPs as a potential general principle of miRNA biogenesis and regulation. hnRNP A1 is an auxiliary factor that promotes the Microprocessor-mediated processing of pri-mir-18a, of the oncomiR-1 cluster. Here the authors employ an integrative structural biology approach and provide insights into the molecular mechanism of how hnRNP A1 facilitates pri-mir-18a biogenesis.
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17
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Suess B, Kemmerer K, Weigand JE. Splicing and Alternative Splicing Impact on Gene Design. Synth Biol (Oxf) 2018. [DOI: 10.1002/9783527688104.ch7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Beatrix Suess
- Department of Biology; Technische Universität Darmstadt; Schnittspahnstraße 10 64287 Darmstadt Germany
| | - Katrin Kemmerer
- Department of Biology; Technische Universität Darmstadt; Schnittspahnstraße 10 64287 Darmstadt Germany
| | - Julia E. Weigand
- Department of Biology; Technische Universität Darmstadt; Schnittspahnstraße 10 64287 Darmstadt Germany
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18
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Zhang L, Chen Q, An W, Yang F, Maguire EM, Chen D, Zhang C, Wen G, Yang M, Dai B, Luong LA, Zhu J, Xu Q, Xiao Q. Novel Pathological Role of hnRNPA1 (Heterogeneous Nuclear Ribonucleoprotein A1) in Vascular Smooth Muscle Cell Function and Neointima Hyperplasia. Arterioscler Thromb Vasc Biol 2017; 37:2182-2194. [PMID: 28912364 PMCID: PMC5660626 DOI: 10.1161/atvbaha.117.310020] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 09/05/2017] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. Objective— hnRNPA1 (heterogeneous nuclear ribonucleoprotein A1) plays a variety of roles in gene expression. However, little is known about the functional involvement of hnRNPA1 in vascular smooth muscle cell (VSMC) function and neointima hyperplasia. In this study, we have attempted to investigate the functional roles of hnRNPA1 in the contexts of VSMC function, injury-induced vessel remodeling, and human atherosclerotic lesions, as well as discern the molecular mechanisms involved. Approach and Results— hnRNPA1 expression levels were consistently modulated during VSMC phenotype switching and neointimal lesion formation induced by wire injury. Functional studies showed that VSMC-specific gene expression, proliferation, and migration were regulated by hnRNPA1. Our data show that hnRNPA1 exerts its effects on VSMC functions through modulation of IQGAP1 (IQ motif containing GTPase activating protein 1). Mechanistically, hnRNPA1 regulates IQGAP1 mRNA degradation through 2 mechanisms: upregulating microRNA-124 (miR-124) and binding to AU-rich element of IQGAP1 gene. Further evidence suggests that hnRNPA1 upregulates miR-124 by modulating miR-124 biogenesis and that IQGAP1 is the authentic target gene of miR-124. Importantly, ectopic overexpression of hnRNPA1 greatly reduced VSMC proliferation and inhibited neointima formation in wire-injured carotid arteries. Finally, lower expression levels of hnRNPA1 and miR-124, while higher expression levels of IQGAP1, were observed in human atherosclerotic lesions. Conclusions— Our data show that hnRNPA1 is a critical regulator of VSMC function and behavior in the context of neointima hyperplasia, and the hnRNPA1/miR-124/IQGAP1 regulatory axis represents a novel therapeutic target for the prevention of cardiovascular diseases.
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Affiliation(s)
- Li Zhang
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu).
| | - Qishan Chen
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Weiwei An
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Feng Yang
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Eithne Margaret Maguire
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Dan Chen
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Cheng Zhang
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Guanmei Wen
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Mei Yang
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Bin Dai
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Le Anh Luong
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Jianhua Zhu
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Qingbo Xu
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu)
| | - Qingzhong Xiao
- From the Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China (L.Z., Q.C., F.Y., M.Y., B.D., J.Z., Q. Xu); Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (Q.C., W.A., F.Y., E.M.M., D.C., C.Z., G.W., L.A.L., Q. Xiao); Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, China (D.C., C.Z.); Key Laboratory of Cardiovascular Diseases, The Second Affiliated Hospital and Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences (G.W., Q. Xiao), Guangzhou Medical University, Guangdong, China; and Cardiovascular Division, King's College London British Heart Foundation Centre, United Kingdom (Q. Xu).
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19
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Kapeli K, Martinez FJ, Yeo GW. Genetic mutations in RNA-binding proteins and their roles in ALS. Hum Genet 2017; 136:1193-1214. [PMID: 28762175 PMCID: PMC5602095 DOI: 10.1007/s00439-017-1830-7] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 07/17/2017] [Indexed: 12/11/2022]
Abstract
Mutations in genes that encode RNA-binding proteins (RBPs) have emerged as critical determinants of neurological diseases, especially motor neuron disorders such as amyotrophic lateral sclerosis (ALS). RBPs are involved in all aspects of RNA processing, controlling the life cycle of RNAs from synthesis to degradation. Hallmark features of RBPs in neuron dysfunction include misregulation of RNA processing, mislocalization of RBPs to the cytoplasm, and abnormal aggregation of RBPs. Much progress has been made in understanding how ALS-associated mutations in RBPs drive pathogenesis. Here, we focus on several key RBPs involved in ALS—TDP-43, HNRNP A2/B1, HNRNP A1, FUS, EWSR1, and TAF15—and review our current understanding of how mutations in these proteins cause disease.
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Affiliation(s)
- Katannya Kapeli
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Fernando J Martinez
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Gene W Yeo
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore.
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, 92093, USA.
- Molecular Engineering Laboratory, A*STAR, Singapore, 138673, Singapore.
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20
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Song L, Lin HS, Gong JN, Han H, Wang XS, Su R, Chen MT, Shen C, Ma YN, Yu J, Zhang JW. microRNA-451-modulated hnRNP A1 takes a part in granulocytic differentiation regulation and acute myeloid leukemia. Oncotarget 2017; 8:55453-55466. [PMID: 28903433 PMCID: PMC5589672 DOI: 10.18632/oncotarget.19325] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/11/2017] [Indexed: 01/22/2023] Open
Abstract
Myelopoiesis is under the control of a complex network containing various regulation factors. Deregulation of any important regulation factors may result in serious consequences including acute myeloid leukemia (AML). In order to find out the genes that may take a part in AML development, we analyzed data from AML cDNA microarray (GSE2191) in the NCBI data pool and noticed that heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is abnormally over-expressed in AML patients. Then we investigated the function and mechanisms of hnRNP A1 in myeloid development. A gradually decreased hnRNP A1 expression was detected during granulocytic differentiation in ATRA-induced-NB4 and HL-60 cells and cytokines-induced hematopoietic stem and progenitor cells. By function-loss and winning experiments we demonstrated hnRNP A1's inhibition role via inhibiting expression of C/EBPα, a key regulator of granulocytic differentiation, in the granulocytic differentiation. During granulocytic differentiation the decrease of hnRNP A1 reduces inhibition on C/EBPα expression, and the increased C/EBPα promotes the differentiation. We also demonstrated that miR-451 promotes granulocytic differentiation via targeting to and down-regulating hnRNP A1, and hnRNP A1 positively regulates c-Myc expression. Summarily, our results revealed new function and mechanisms of hnRNP A1 in normal granulocytiesis and the involvement of a feed-back loop comprising c-Myc, miR-451 and hnRNP A1 in AML development.
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Affiliation(s)
- Li Song
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Hai-Shuang Lin
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Jia-Nan Gong
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Hua Han
- Department of Obstetrics and Gynecology, Hebei General Hospital, Shijiazhuang 050051, China
| | - Xiao-Shuang Wang
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Rui Su
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Ming-Tai Chen
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Chao Shen
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Yan-Ni Ma
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Jia Yu
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Jun-Wu Zhang
- The State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
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21
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Wang H, Han L, Zhao G, Shen H, Wang P, Sun Z, Xu C, Su Y, Li G, Tong T, Chen J. hnRNP A1 antagonizes cellular senescence and senescence-associated secretory phenotype via regulation of SIRT1 mRNA stability. Aging Cell 2016; 15:1063-1073. [PMID: 27613566 PMCID: PMC6398525 DOI: 10.1111/acel.12511] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2016] [Indexed: 12/12/2022] Open
Abstract
Senescent cells display a senescence‐associated secretory phenotype (SASP) which contributes to tumor suppression, aging, and cancer. However, the underlying mechanisms for SASP regulation are not fully elucidated. SIRT1, a nicotinamide adenosine dinucleotide‐dependent deacetylase, plays multiple roles in metabolism, inflammatory response, and longevity, etc. However, its posttranscriptional regulation and its roles in cellular senescence and SASP regulation are still elusive. Here, we identify the RNA‐binding protein hnRNP A1 as a posttranscriptional regulator of SIRT1, as well as cell senescence and SASP regulator. hnRNP A1 directly interacts with the 3′ untranslated region of SIRT1 mRNA, promotes its stability, and increases SIRT1 expression. hnRNP A1 delays replicative cellular senescence and prevents from Ras OIS via upregulation of SIRT1 expression to deacetylate NF‐κB, thus blunting its transcriptional activity and subsequent IL‐6/IL‐8 induction. hnRNP A1 overexpression promotes cell transformation and tumorigenesis in a SIRT1‐dependent manner. Together, our findings unveil a novel posttranscriptional regulation of SIRT1 by hnRNP A1 and uncover a critical role of hnRNP A1‐SIRT1–NF‐κB pathway in regulating cellular senescence and SASP expression.
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Affiliation(s)
- Hui Wang
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Limin Han
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Ganye Zhao
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Hong Shen
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Pengfeng Wang
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Zhaomeng Sun
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Chenzhong Xu
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Yuanyuan Su
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Guodong Li
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Tanjun Tong
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
| | - Jun Chen
- Peking University Research Center on Aging Department of Biochemistry and Molecular Biology Peking University Health Science Center Beijing China
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22
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The cis-acting replication element of the Hepatitis C virus genome recruits host factors that influence viral replication and translation. Sci Rep 2016; 6:25729. [PMID: 27165399 PMCID: PMC4863150 DOI: 10.1038/srep25729] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 04/21/2016] [Indexed: 02/08/2023] Open
Abstract
The cis-acting replication element (CRE) of the hepatitis C virus (HCV) RNA genome is a region of conserved sequence and structure at the 3′ end of the open reading frame. It participates in a complex and dynamic RNA-RNA interaction network involving, among others, essential functional domains of the 3′ untranslated region and the internal ribosome entry site located at the 5′ terminus of the viral genome. A proper balance between all these contacts is critical for the control of viral replication and translation, and is likely dependent on host factors. Proteomic analyses identified a collection of proteins from a hepatoma cell line as CRE-interacting candidates. A large fraction of these were RNA-binding proteins sharing highly conserved RNA recognition motifs. The vast majority of these proteins were validated by bioinformatics tools that consider RNA-protein secondary structure. Further characterization of representative proteins indicated that hnRNPA1 and HMGB1 exerted negative effects on viral replication in a subgenomic HCV replication system. Furthermore DDX5 and PARP1 knockdown reduced the HCV IRES activity, suggesting an involvement of these proteins in HCV translation. The identification of all these host factors provides new clues regarding the function of the CRE during viral cycle progression.
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23
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Lee S, Levin M. Novel somatic single nucleotide variants within the RNA binding protein hnRNP A1 in multiple sclerosis patients. F1000Res 2014; 3:132. [PMID: 25254102 PMCID: PMC4168748 DOI: 10.12688/f1000research.4436.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/16/2014] [Indexed: 03/22/2024] Open
Abstract
Some somatic single nucleotide variants (SNVs) are thought to be pathogenic, leading to neurological disease. We hypothesized that heterogeneous nuclear ribonuclear protein A1 (hnRNP A1), an autoantigen associated with multiple sclerosis (MS) would contain SNVs. MS patients develop antibodies to hnRNP A1 (293-304), an epitope within the M9 domain (AA (268-305)) of hnRNP A1. M9 is hnRNP A1's nucleocytoplasmic transport domain, which binds transportin-1 (TPNO-1) and allows for hnRNP A1's transport into and out of the nucleus. Genomic DNA sequencing of M9 revealed nine novel SNVs that resulted in an amino acid substitution in MS patients that were not present in controls. SNVs occurred within the TPNO-1 binding domain (hnRNP A1 (268-289)) and the MS IgG epitope (hnRNP A1 (293-304)), within M9. In contrast to the nuclear localization of wild type (WT) hnRNP A1, mutant hnRNP A1 mis-localized to the cytoplasm, co-localized with stress granules and caused cellular apoptosis. Whilst WT hnRNP A1 bound TPNO-1, mutant hnRNP A1 showed reduced TPNO-1 binding. These data suggest SNVs in hnRNP A1 might contribute to pathogenesis of MS.
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Affiliation(s)
- Sangmin Lee
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michael Levin
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy/Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
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24
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Lee S, Levin M. Novel somatic single nucleotide variants within the RNA binding protein hnRNP A1 in multiple sclerosis patients. F1000Res 2014; 3:132. [PMID: 25254102 PMCID: PMC4168748 DOI: 10.12688/f1000research.4436.2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/16/2014] [Indexed: 12/13/2022] Open
Abstract
Some somatic single nucleotide variants (SNVs) are thought to be pathogenic, leading to neurological disease. We hypothesized that heterogeneous nuclear ribonuclear protein A1 (hnRNP A1), an autoantigen associated with multiple sclerosis (MS) would contain SNVs. MS patients develop antibodies to hnRNP A1 (293-304), an epitope within the M9 domain (AA (268-305)) of hnRNP A1. M9 is hnRNP A1's nucleocytoplasmic transport domain, which binds transportin-1 (TPNO-1) and allows for hnRNP A1's transport into and out of the nucleus. Genomic DNA sequencing of M9 revealed nine novel SNVs that resulted in an amino acid substitution in MS patients that were not present in controls. SNVs occurred within the TPNO-1 binding domain (hnRNP A1 (268-289)) and the MS IgG epitope (hnRNP A1 (293-304)), within M9. In contrast to the nuclear localization of wild type (WT) hnRNP A1, mutant hnRNP A1 mis-localized to the cytoplasm, co-localized with stress granules and caused cellular apoptosis. Whilst WT hnRNP A1 bound TPNO-1, mutant hnRNP A1 showed reduced TPNO-1 binding. These data suggest SNVs in hnRNP A1 might contribute to pathogenesis of MS.
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Affiliation(s)
- Sangmin Lee
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michael Levin
- Research Service, Veterans Affairs Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy/Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
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25
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Levin MC, Douglas JN, Meyers L, Lee S, Shin Y, Gardner LA. Neurodegeneration in multiple sclerosis involves multiple pathogenic mechanisms. Degener Neurol Neuromuscul Dis 2014; 4:49-63. [PMID: 32669900 PMCID: PMC7337253 DOI: 10.2147/dnnd.s54391] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/06/2014] [Indexed: 12/18/2022] Open
Abstract
Multiple sclerosis (MS) is a complex autoimmune disease that impairs the central nervous system (CNS). The neurological disability and clinical course of the disease is highly variable and unpredictable from one patient to another. The cause of MS is still unknown, but it is thought to occur in genetically susceptible individuals who develop disease due to a nongenetic trigger, such as altered metabolism, a virus, or other environmental factors. MS patients develop progressive, irreversible, neurological disability associated with neuronal and axonal damage, collectively known as neurodegeneration. Neurodegeneration was traditionally considered as a secondary phenomenon to inflammation and demyelination. However, recent data indicate that neurodegeneration develops along with inflammation and demyelination. Thus, MS is increasingly recognized as a neurodegenerative disease triggered by an inflammatory attack of the CNS. While both inflammation and demyelination are well described and understood cellular processes, neurodegeneration might be defined by a diverse pool of any of the following: neuronal cell death, apoptosis, necrosis, and virtual hypoxia. In this review, we present multiple theories and supporting evidence that identify common biological processes that contribute to neurodegeneration in MS.
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Affiliation(s)
- Michael C Levin
- Veterans Administration Medical Center.,Department of Neuroscience, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Joshua N Douglas
- Veterans Administration Medical Center.,Department of Neuroscience, University of Tennessee Health Science Center, Memphis, TN, USA
| | | | - Sangmin Lee
- Veterans Administration Medical Center.,Department of Neurology
| | - Yoojin Shin
- Veterans Administration Medical Center.,Department of Neurology
| | - Lidia A Gardner
- Veterans Administration Medical Center.,Department of Neurology
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26
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Jean-Philippe J, Paz S, Caputi M. hnRNP A1: the Swiss army knife of gene expression. Int J Mol Sci 2013; 14:18999-9024. [PMID: 24065100 PMCID: PMC3794818 DOI: 10.3390/ijms140918999] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/02/2013] [Accepted: 09/04/2013] [Indexed: 12/31/2022] Open
Abstract
Eukaryotic cells express a large variety of RNA binding proteins (RBPs), with diverse affinities and specificities towards target RNAs. These proteins play a crucial role in almost every aspect of RNA biogenesis, expression and function. The heterogeneous nuclear ribonucleoproteins (hnRNPs) are a complex and diverse family of RNA binding proteins. hnRNPs display multiple functions in the processing of heterogeneous nuclear RNAs into mature messenger RNAs. hnRNP A1 is one of the most abundant and ubiquitously expressed members of this protein family. hnRNP A1 plays multiple roles in gene expression by regulating major steps in the processing of nascent RNA transcripts. The transcription, splicing, stability, export through nuclear pores and translation of cellular and viral transcripts are all mechanisms modulated by this protein. The diverse functions played by hnRNP A1 are not limited to mRNA biogenesis, but extend to the processing of microRNAs, telomere maintenance and the regulation of transcription factor activity. Genomic approaches have recently uncovered the extent of hnRNP A1 roles in the development and differentiation of living organisms. The aim of this review is to highlight recent developments in the study of this protein and to describe its functions in cellular and viral gene expression and its role in human pathologies.
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Affiliation(s)
- Jacques Jean-Philippe
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA.
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27
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Yu CY, Theusch E, Lo K, Mangravite LM, Naidoo D, Kutilova M, Medina MW. HNRNPA1 regulates HMGCR alternative splicing and modulates cellular cholesterol metabolism. Hum Mol Genet 2013; 23:319-32. [PMID: 24001602 DOI: 10.1093/hmg/ddt422] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGCR) encodes the rate-limiting enzyme in the cholesterol biosynthesis pathway and is inhibited by statins, a class of cholesterol-lowering drugs. Expression of an alternatively spliced HMGCR transcript lacking exon 13, HMGCR13(-), has been implicated in the variation of plasma LDL-cholesterol (LDL-C) and is the single most informative molecular marker of LDL-C response to statins. Given the physiological importance of this transcript, our goal was to identify molecules that regulate HMGCR alternative splicing. We recently reported gene expression changes in 480 lymphoblastoid cell lines (LCLs) after in vitro simvastatin treatment, and identified a number of statin-responsive genes involved in mRNA splicing. Heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) was chosen for follow-up since rs3846662, an HMGCR SNP that regulates exon 13 skipping, was predicted to alter an HNRNPA1 binding motif. Here, we not only demonstrate that rs3846662 modulates HNRNPA1 binding, but also that sterol depletion of human hepatoma cell lines reduced HNRNPA1 mRNA levels, an effect that was reversed with sterol add-back. Overexpression of HNRNPA1 increased the ratio of HMGCR13(-) to total HMGCR transcripts by both directly increasing exon 13 skipping in an allele-related manner and specifically stabilizing the HMGCR13(-) transcript. Importantly, HNRNPA1 overexpression also diminished HMGCR enzyme activity, enhanced LDL-C uptake and increased cellular apolipoprotein B (APOB). rs1920045, an SNP associated with HNRNPA1 exon 8 alternative splicing, was also associated with smaller statin-induced reduction in total cholesterol from two independent clinical trials. These results suggest that HNRNPA1 plays a role in the variation of cardiovascular disease risk and statin response.
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Affiliation(s)
- Chi-Yi Yu
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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28
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Norovirus genome circularization and efficient replication are facilitated by binding of PCBP2 and hnRNP A1. J Virol 2013; 87:11371-87. [PMID: 23946460 DOI: 10.1128/jvi.03433-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Sequences and structures within the terminal genomic regions of plus-strand RNA viruses are targets for the binding of host proteins that modulate functions such as translation, RNA replication, and encapsidation. Using murine norovirus 1 (MNV-1), we describe the presence of long-range RNA-RNA interactions that were stabilized by cellular proteins. The proteins potentially responsible for the stabilization were selected based on their ability to bind the MNV-1 genome and/or having been reported to be involved in the stabilization of RNA-RNA interactions. Cell extracts were preincubated with antibodies against the selected proteins and used for coprecipitation reactions. Extracts treated with antibodies to poly(C) binding protein 2 (PCBP2) and heterogeneous nuclear ribonucleoprotein (hnRNP) A1 significantly reduced the 5'-3' interaction. Both PCBP2 and hnRNP A1 recombinant proteins stabilized the 5'-3' interactions and formed ribonucleoprotein complexes with the 5' and 3' ends of the MNV-1 genomic RNA. Mutations within the 3' complementary sequences (CS) that disrupt the 5'-3'-end interactions resulted in a significant reduction of the viral titer, suggesting that the integrity of the 3'-end sequence and/or the lack of complementarity with the 5' end is important for efficient virus replication. Small interfering RNA-mediated knockdown of PCBP2 or hnRNP A1 resulted in a reduction in virus yield, confirming a role for the observed interactions in efficient viral replication. PCBP2 and hnRNP A1 induced the circularization of MNV-1 RNA, as revealed by electron microscopy. This study provides evidence that PCBP2 and hnRNP A1 bind to the 5' and 3' ends of the MNV-1 viral RNA and contribute to RNA circularization, playing a role in the virus life cycle.
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29
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Papadopoulou C, Ganou V, Patrinou-Georgoula M, Guialis A. HuR-hnRNP interactions and the effect of cellular stress. Mol Cell Biochem 2012; 372:137-47. [PMID: 22983828 DOI: 10.1007/s11010-012-1454-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 09/05/2012] [Indexed: 12/11/2022]
Abstract
The heterogeneous nuclear ribonucleoproteins (hnRNPs) constitute an important group of RNA-binding proteins (RBPs) that play an active role in post-transcriptional gene regulation. Here, we focus on representative members of the hnRNP group of RBPs, namely hnRNP A1 and hnRNP C1/C2, which participate mainly in RNA splicing, as well as on HuR, a prototype of the AU-rich element-binding proteins (ARE-BP), which has an established role in regulating the stability and translation of target mRNAs. HuR and most hnRNPs are primarily localized in the nucleoplasm, and they can shuttle between the nucleus and the cytoplasm. Herein, we have extended our recently reported findings on the ability of HuR to associate with the immunopurified from mammalian cell extracts hnRNP and mRNP complexes by the application of an anti-HuR antibody that selects HuR-RNP complexes. We find that the protein components precipitated by the anti-HuR antibody are very similar to the hnRNP-HuR complexes reported previously. The in vivo association of HuR and hnRNP proteins is examined in the presence and the absence of thermal stress by confocal microscopy of intact cells and by in situ nuclear matrix preparation. We find notable heat-induced changes of HuR and of hnRNP A1, which exit the nucleus and co-localize to large cytoplasmic foci that represent heat-induced stress granules. The functional implications of HuR-hnRNP interactions in stressed and unstressed cells are discussed.
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Affiliation(s)
- Christina Papadopoulou
- RNA Processing Program, Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
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30
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Aksaas AK, Eikvar S, Akusjärvi G, Skålhegg BS, Kvissel AK. Protein kinase a-dependent phosphorylation of serine 119 in the proto-oncogenic serine/arginine-rich splicing factor 1 modulates its activity as a splicing enhancer protein. Genes Cancer 2012; 2:841-51. [PMID: 22393468 DOI: 10.1177/1947601911430226] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 10/27/2011] [Indexed: 11/17/2022] Open
Abstract
Serine/arginine-rich splicing factor 1 (SRSF1), previously designated SF2/ASF, belongs to a family of SR proteins that regulate constitutive and alternative splicing. SRSF1 expression is increased in tumors from several tissues and elicits changes in key target genes involved in tumor genesis. Several protein kinases phosphorylate SRSF1, which regulates its localization and function. It is previously reported that protein kinase A (PKA) phosphorylates SRSF1, but the importance of this modification is not well characterized. Here, we show that PKA phosphorylates SRSF1 on serine 119 in vitro. Phosphorylation of SRSF1 on this site enhanced the RNA binding capacity of SRSF1 in vivo and reduced the protein's capacity to activate splicing of the Minx transcript in vitro. We also confirm an interaction between SRSF1 and PKA Cα1 and demonstrate that this interaction is not dependent on serine 119 phosphorylation but requires active PKA Cα1. We conclude that PKA phosphorylation of SRSF1 at serine 119 regulates SFRS1-dependent RNA binding and processing but not its interaction with PKA.
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31
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Vázquez-Iglesias L, Lostalé-Seijo I, Martínez-Costas J, Benavente J. Different intracellular distribution of avian reovirus core protein sigmaA in cells of avian and mammalian origin. Virology 2012; 432:495-504. [PMID: 22832119 DOI: 10.1016/j.virol.2012.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 06/19/2012] [Accepted: 07/05/2012] [Indexed: 11/26/2022]
Abstract
A comparative analysis of the intracellular distribution of avian reovirus (ARV) core protein sigmaA in cells of avian and mammalian origin revealed that, whereas the viral protein accumulates in the cytoplasm and nucleolus of avian cells, most sigmaA concentrates in the nucleoplasm of mammalian cells in tight association with the insoluble nuclear matrix fraction. Our results further showed that sigmaA becomes arrested in the nucleoplasm of mammalian cells via association with mammalian cell-specific factors and that this association prevents nucleolar targeting. Inhibition of RNA polymerase II activity, but not of RNA polymerase I activity, in infected mammalian cells induces nucleus-to-cytoplasm sigmaA translocation through a CRM1- and RanGTP-dependent mechanism, yet a heterokaryon assay suggests that sigmaA does not shuttle between the nucleus and cytoplasm. The scarcity of sigmaA in cytoplasmic viral factories of infected mammalian cells could be one of the factors contributing to limited ARV replication in mammalian cells.
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Affiliation(s)
- Lorena Vázquez-Iglesias
- Departamento de Bioquímica y Biología Molecular, y Centro Singular de Investigación en Química Biológica y Materiales Moleculares, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
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Ufer C, Wang CC, Borchert A, Heydeck D, Kuhn H. Redox control in mammalian embryo development. Antioxid Redox Signal 2010; 13:833-75. [PMID: 20367257 DOI: 10.1089/ars.2009.3044] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The development of an embryo constitutes a complex choreography of regulatory events that underlies precise temporal and spatial control. Throughout this process the embryo encounters ever changing environments, which challenge its metabolism. Oxygen is required for embryogenesis but it also poses a potential hazard via formation of reactive oxygen and reactive nitrogen species (ROS/RNS). These metabolites are capable of modifying macromolecules (lipids, proteins, nucleic acids) and altering their biological functions. On one hand, such modifications may have deleterious consequences and must be counteracted by antioxidant defense systems. On the other hand, ROS/RNS function as essential signal transducers regulating the cellular phenotype. In this context the combined maternal/embryonic redox homeostasis is of major importance and dysregulations in the equilibrium of pro- and antioxidative processes retard embryo development, leading to organ malformation and embryo lethality. Silencing the in vivo expression of pro- and antioxidative enzymes provided deeper insights into the role of the embryonic redox equilibrium. Moreover, novel mechanisms linking the cellular redox homeostasis to gene expression regulation have recently been discovered (oxygen sensing DNA demethylases and protein phosphatases, redox-sensitive microRNAs and transcription factors, moonlighting enzymes of the cellular redox homeostasis) and their contribution to embryo development is critically reviewed.
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Affiliation(s)
- Christoph Ufer
- Institute of Biochemistry, University Medicine Berlin-Charité, Berlin, FR Germany
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Meyuhas O, Dreazen A. Ribosomal protein S6 kinase from TOP mRNAs to cell size. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 90:109-53. [PMID: 20374740 DOI: 10.1016/s1877-1173(09)90003-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ribosomal protein S6 kinase (S6K) has been implicated in the phosphorylation of multiple substrates and is subject to activation by a wide variety of signals that converge at mammalian target of rapamycin (mTOR). In the course of the search for its physiological role, it was proposed that S6K activation and ribosomal protein S6 (rpS6) phosphorylation account for the translational activation of a subgroup of transcripts, the TOP mRNAs. The structural hallmark of these mRNAs is an oligopyrimidine tract at their 5'-terminus, known as the 5'-TOP motif. TOP mRNAs consists of about 90 members that encode multiple components of the translational machinery, such as ribosomal proteins and translation factors. The translation efficiency of TOP mRNAs indeed correlates with S6K activation and rpS6 phosphorylation, yet recent biochemical and genetic studies have established that, although S6K and TOP mRNAs respond to similar signals and are regulated by mTOR, they maintain no cause and effect relationship. Instead, S6K is primarily involved in regulation of cell size, and affects glucose homeostasis, but is dispensable for global protein synthesis, whereas translational efficiency of TOP mRNAs is a determinant of the cellular protein synthesis capacity. Despite extensive studies of their function and mode of regulation, the mechanism underlying the effect of S6K on the cell size, as well as the trans-acting factor that mediates the translational control of TOP mRNAs, still await their identification.
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Affiliation(s)
- Oded Meyuhas
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Monette A, Ajamian L, López-Lastra M, Mouland AJ. Human immunodeficiency virus type 1 (HIV-1) induces the cytoplasmic retention of heterogeneous nuclear ribonucleoprotein A1 by disrupting nuclear import: implications for HIV-1 gene expression. J Biol Chem 2009; 284:31350-62. [PMID: 19737937 DOI: 10.1074/jbc.m109.048736] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) co-opts host proteins and cellular machineries to its advantage at every step of the replication cycle. Here we show that HIV-1 enhances heterogeneous nuclear ribonucleoprotein (hnRNP) A1 expression and promotes the relocalization of hnRNP A1 to the cytoplasm. The latter was dependent on the nuclear export of the unspliced viral genomic RNA (vRNA) and to alterations in the abundance and localization of the FG-repeat nuclear pore glycoprotein p62. hnRNP A1 and vRNA remain colocalized in the cytoplasm supporting a post-nuclear function during the late stages of HIV-1 replication. Consistently, we show that hnRNP A1 acts as an internal ribosomal entry site trans-acting factor up-regulating internal ribosome entry site-mediated translation initiation of the HIV-1 vRNA. The up-regulation and cytoplasmic retention of hnRNP A1 by HIV-1 would ensure abundant expression of viral structural proteins in cells infected with HIV-1.
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Affiliation(s)
- Anne Monette
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute for Medical Research-Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
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Shimada N, Rios I, Moran H, Sayers B, Hubbard K. p38 MAP kinase-dependent regulation of the expression level and subcellular distribution of heterogeneous nuclear ribonucleoprotein A1 and its involvement in cellular senescence in normal human fibroblasts. RNA Biol 2009; 6:293-304. [PMID: 19430204 DOI: 10.4161/rna.6.3.8497] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a RNA binding protein that plays important role in the biogenesis of mRNA, such as alternative splicing and mRNA stability. We have previously demonstrated that hnRNP A1 has diminished protein levels and shows cytoplasmic accumulation in senescent human diploid fibroblasts. Recent reports showed that p38 MAP kinase (p38 MAPK), a member of the MAP kinase family is necessary and sufficient for the cytoplasmic accumulation of hnRNP A1 by stress stimuli such as osmotic shock. p38 MAP kinase has been shown to be involved in cell proliferation and the induction of senescence in response to extracellular stimuli. However, the relationship between hnRNP A1 and p38 MAPK and the roles of hnRNP A1 in cellular senescence have not yet been elucidated. Here we show that hnRNP A1 forms a complex with phospho-p38 MAPK in vivo. Inhibition of p38 MAPK activity with SB203580 elevated hnRNP A1 protein levels and prohibited the cytoplasmic accumulation of the protein, but not hnRNP A2, in senescent cells. The phosphorylation level of hnRNP A1 was elevated in senescent cells. Reduction of hnRNP A1 and A2 levels by siRNA transfection induced a senescence-like morphology and elevated the level of F-actin, a marker of senescence. These results suggest that the expression levels and subcellular distribution of hnRNP A1 are regulated in a p38 MAPK-dependent manner, probably via its phosphorylation. Our results also suggest that hnRNP A2 in addition to hnRNP A1 may play a role in establishing the senescence phenotype.
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Affiliation(s)
- Naoko Shimada
- City College of New York, City University of New York, New York, NY 10031, USA
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Koch L, Linderkamp O, Ittrich C, Benner A, Poeschl J. Gene expression profiles of adult peripheral and cord blood mononuclear cells altered by lipopolysaccharide. Neonatology 2008; 93:87-100. [PMID: 17700033 DOI: 10.1159/000107350] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 05/14/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND Neonatal Gram-negative sepsis is often characterized by a fulminant clinical course, compared to adults, resulting in higher morbidity and mortality. Genome-wide gene expression analysis can provide insights into the molecular alterations in sepsis. OBJECTIVES To evaluate in vitro activation of the neonatal and adult immune system, gene expression patterns were compared in mononuclear cells from cord (CBMNC) and adult peripheral blood (APBMNC). METHODS To better understand the influence of early molecular signals on the effects of sepsis, Affymetrix gene profiling (8,475 genes) was done on RNA isolated from CBMNC and APBMNC without and after incubation with 100 ng/ml lipopolysaccharide (LPS). RESULTS We demonstrated significant alterations in the expression of 108 CBMNC and APBMNC genes compared with basal levels, 188 significant changes in CBMNC and 97 in APBMNC, including cytokines, chemokines and immunoregulatory genes. Furthermore, we found 5 genes showing a significant interaction effect between cell type and LPS stimulation, including tumor necrosis factor receptor superfamily, member 6 (FAS), absent in melanoma 2, malic enzyme 1, hemoglobin epsilon 1, and trans-prenyltransferase. CONCLUSIONS These results provide further support for a marked difference in the pathogenesis of neonatal and adult sepsis and may stimulate additional studies to investigate some of the altered genes as potential new targets for diagnostic tools and therapeutic strategies.
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Affiliation(s)
- Lutz Koch
- Division of Neonatology, Department of Pediatrics, University of Heidelberg Medical School, Heidelberg, Germany.
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Yang F, Jaitly N, Jayachandran H, Luo Q, Monroe ME, Du X, Gritsenko MA, Zhang R, Anderson DJ, Purvine SO, Adkins JN, Moore RJ, Ding SJ, Mottaz HM, Lipton MS, Camp DG, Udseth HR, Smith RD, Rossie S. Applying a targeted label-free approach using LC-MS AMT tags to evaluate changes in protein phosphorylation following phosphatase inhibition. J Proteome Res 2007; 6:4489-97. [PMID: 17929957 PMCID: PMC2516346 DOI: 10.1021/pr070068e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
To identify phosphoproteins regulated by the phosphoprotein phosphatase (PPP) family of S/T phosphatases, we performed a large-scale characterization of changes in protein phosphorylation on extracts from HeLa cells treated with or without calyculin A, a potent PPP enzyme inhibitor. A label-free comparative phosphoproteomics approach using immobilized metal ion affinity chromatography and targeted tandem mass spectrometry was employed to discover and identify signatures based upon distinctive changes in abundance. Overall, 232 proteins were identified as either direct or indirect targets for PPP enzyme regulation. Most of the present identifications represent novel PPP enzyme targets at the level of both phosphorylation site and protein. These include phosphorylation sites within signaling proteins such as p120 Catenin, A Kinase Anchoring Protein 8, JunB, and Type II Phosphatidyl Inositol 4 Kinase. These data can be used to define underlying signaling pathways and events regulated by the PPP family of S/T phosphatases.
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Affiliation(s)
- Feng Yang
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Navdeep Jaitly
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Hemalatha Jayachandran
- Department of Biochemistry and Purdue Cancer Center, Purdue University West Lafayette, Indiana 47907-2084
| | - Quanzhou Luo
- Biological Sciences Division, Pacific Northwest National Laboratory
| | | | - Xiuxia Du
- Biological Sciences Division, Pacific Northwest National Laboratory
| | | | - Rui Zhang
- Biological Sciences Division, Pacific Northwest National Laboratory
| | | | | | - Joshua N. Adkins
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Ronald J. Moore
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Shi-Jian Ding
- Biological Sciences Division, Pacific Northwest National Laboratory
| | | | - Mary S. Lipton
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - David G. Camp
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Harold R. Udseth
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Richard D. Smith
- Biological Sciences Division, Pacific Northwest National Laboratory
| | - Sandra Rossie
- Department of Biochemistry and Purdue Cancer Center, Purdue University West Lafayette, Indiana 47907-2084
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The alternative splicing factor hnRNP A1 is up-regulated during virus-infected epithelial cell differentiation and binds the human papillomavirus type 16 late regulatory element. Virus Res 2007; 131:189-98. [PMID: 17950949 PMCID: PMC2635527 DOI: 10.1016/j.virusres.2007.09.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 09/10/2007] [Accepted: 09/10/2007] [Indexed: 01/06/2023]
Abstract
Human papillomavirus type 16 (HPV16) infects anogenital epithelia and is the etiological agent of cervical cancer. We showed previously that HPV16 infection regulates the key splicing/alternative splicing factor SF2/ASF and that virus late transcripts are extensively alternatively spliced. hnRNP A1 is the antagonistic counterpart of SF2/ASF in alternative splicing. We show here that hnRNP A1 is also up-regulated during differentiation of virus-infected epithelial cells in monolayer and organotypic raft culture. Taken together with our previous data on SF2/ASF, this comprises the first report of HPV-mediated regulation of expression of two functionally related cellular proteins during epithelial differentiation. Further, using electrophoretic mobility shift assays and UV crosslinking we demonstrate that hnRNP A1 binds the HPV16 late regulatory element (LRE) in differentiated HPV16 infected cells. The LRE has been shown to be important in temporally controlling virus late gene expression during epithelial differentiation. We suggest that increased levels of these cellular RNA processing factors facilitate appropriate alternative splicing necessary for production of virus late transcripts in differentiated epithelial cells.
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Nielsen AF, Leuschner PJF, Martinez J. Not miR-ly a splicing factor: hnRNP A1 succumbs to microRNA temptation. Nat Struct Mol Biol 2007; 14:572-3. [PMID: 17611594 DOI: 10.1038/nsmb0707-572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Barrandon C, Bonnet F, Nguyen VT, Labas V, Bensaude O. The transcription-dependent dissociation of P-TEFb-HEXIM1-7SK RNA relies upon formation of hnRNP-7SK RNA complexes. Mol Cell Biol 2007; 27:6996-7006. [PMID: 17709395 PMCID: PMC2168891 DOI: 10.1128/mcb.00975-07] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The positive transcription elongation factor P-TEFb controls the elongation of transcription by RNA polymerase II. P-TEFb is inactivated upon binding to HEXIM1 or HEXIM2 proteins associated with a noncoding RNA, 7SK. In response to the inhibition of transcription, 7SK RNA, as well as HEXIM proteins, is released by an unknown mechanism and P-TEFb is activated. New partners of 7SK RNA were searched for as potential players in this feedback process. A subset of heterogeneous ribonuclear proteins, hnRNPs Q and R and hnRNPs A1 and A2, were thus identified as major 7SK RNA-associated proteins. The degree of association of 7SK RNA with these hnRNPs increased when P-TEFb-HEXIM1-7SK was dissociated following the inhibition of transcription or HEXIM1 knockdown. This finding suggested that 7SK RNA shuttles from HEXIM1-P-TEFb complexes to hnRNPs. The transcription-dependent dissociation of P-TEFb-HEXIM1-7SK complexes was attenuated when both hnRNPs A1 and A2 were knocked down by small interfering RNA. As hnRNPs are known to interact transiently with RNA while it is synthesized, hnRNPs released from nascent transcripts may trap 7SK RNA and thereby contribute to the activation of P-TEFb.
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Affiliation(s)
- Charlotte Barrandon
- UMR 8541 CNRS, Ecole Normale Supérieure, 46 rue d'Ulm, 75230 Paris Cedex 05, France
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Guil S, Cáceres JF. The multifunctional RNA-binding protein hnRNP A1 is required for processing of miR-18a. Nat Struct Mol Biol 2007; 14:591-6. [PMID: 17558416 DOI: 10.1038/nsmb1250] [Citation(s) in RCA: 418] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Accepted: 04/09/2007] [Indexed: 12/19/2022]
Abstract
hnRNP A1 is an RNA-binding protein involved in various aspects of RNA processing. Use of an in vivo cross-linking and immunoprecipitation protocol to find hnRNP A1 RNA targets resulted in the identification of a microRNA (miRNA) precursor, pre-miR-18a. This microRNA is expressed as part of a cluster of intronic RNAs, including miR-17, miR-18a, miR-19a, miR-20a, miR-19b-1 and miR-92, and potentially acts as an oncogene. Here we show that hnRNP A1 binds specifically to the primary RNA sequence pri-miR-18a before Drosha processing. HeLa cells depleted of hnRNP A1 have reduced in vitro processing activity with pri-miR-18a and also show reduced abundances of endogenous pre-miR-18a. Furthermore, we show that hnRNP A1 is required for miR-18a-mediated repression of a target reporter in vivo. These results underscore a previously uncharacterized role for general RNA-binding proteins as auxiliary factors that facilitate the processing of specific miRNAs.
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Affiliation(s)
- Sonia Guil
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh EH4 2XU, Scotland, UK
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Identification of a set of KSRP target transcripts upregulated by PI3K-AKT signaling. BMC Mol Biol 2007; 8:28. [PMID: 17437629 PMCID: PMC1858702 DOI: 10.1186/1471-2199-8-28] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Accepted: 04/16/2007] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND KSRP is a AU-rich element (ARE) binding protein that causes decay of select sets of transcripts in different cell types. We have recently described that phosphatidylinositol 3-kinase/AKT (PI3K-AKT) activation induces stabilization and accumulation of the labile beta-catenin mRNA through an impairment of KSRP function. RESULTS Aim of this study was to identify additional KSRP targets whose stability and steady-state levels are enhanced by PI3K-AKT activation. First, through microarray analyses of the AU-rich transcriptome in pituitary alphaT3-1 cells, we identified 34 ARE-containing transcripts upregulated in cells expressing a constitutively active form of AKT1. In parallel, by an affinity chromatography-based technique followed by microarray analyses, 12 mRNAs target of KSRP, additional to beta-catenin, were identified. Among them, seven mRNAs were upregulated in cells expressing activated AKT1. Both steady-state levels and stability of these new KSRP targets were consistently increased by either KSRP knock-down or PI3K-AKT activation. CONCLUSION Our study identified a set of transcripts that are targets of KSRP and whose expression is increased by PI3K-AKT activation. These mRNAs encode RNA binding proteins, signaling molecules and a replication-independent histone. The increased expression of these gene products upon PI3K-AKT activation could play a role in the cellular events initiated by this signaling pathway.
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Lawrence S, Tang Y, Frank MB, Dozmorov I, Jiang K, Chen Y, Cadwell C, Turner S, Centola M, Jarvis JN. A dynamic model of gene expression in monocytes reveals differences in immediate/early response genes between adult and neonatal cells. JOURNAL OF INFLAMMATION-LONDON 2007; 4:4. [PMID: 17306030 PMCID: PMC1803772 DOI: 10.1186/1476-9255-4-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Accepted: 02/16/2007] [Indexed: 11/30/2022]
Abstract
Neonatal monocytes display immaturity of numerous functions compared with adult cells. Gene expression arrays provide a promising tool for elucidating mechanisms underlying neonatal immune function. We used a well-established microarray to analyze differences between LPS-stimulated human cord blood and adult monocytes to create dynamic models for interactions to elucidate observed deficiencies in neonatal immune responses. We identified 168 genes that were differentially expressed between adult and cord monocytes after 45 min incubation with LPS. Of these genes, 95% (159 of 167) were over-expressed in adult relative to cord monocytes. Differentially expressed genes could be sorted into nine groups according to their kinetics of activation. Functional modelling suggested differences between adult and cord blood in the regulation of apoptosis, a finding confirmed using annexin binding assays. We conclude that kinetic studies of gene expression reveal potentially important differences in gene expression dynamics that may provide insight into neonatal innate immunity.
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Affiliation(s)
- Shelley Lawrence
- Dept. of Pediatrics, Neonatal Section, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
| | - Yuhong Tang
- Arthritis & Immunology Program Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA
| | - M Barton Frank
- Arthritis & Immunology Program Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA
| | - Igor Dozmorov
- Arthritis & Immunology Program Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA
| | - Kaiyu Jiang
- Dept. of Pediatrics, Neonatal Section, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
| | - Yanmin Chen
- Dept. of Pediatrics, Neonatal Section, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
| | - Craig Cadwell
- Arthritis & Immunology Program Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA
| | - Sean Turner
- Arthritis & Immunology Program Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA
| | - Michael Centola
- Arthritis & Immunology Program Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA
| | - James N Jarvis
- Dept. of Pediatrics, Neonatal Section, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
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Tong X, Van Dross RT, Abu-Yousif A, Morrison AR, Pelling JC. Apigenin prevents UVB-induced cyclooxygenase 2 expression: coupled mRNA stabilization and translational inhibition. Mol Cell Biol 2006; 27:283-96. [PMID: 17074806 PMCID: PMC1800648 DOI: 10.1128/mcb.01282-06] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyclooxygenase 2 (COX-2) is a key enzyme in the conversion of arachidonic acid to prostaglandins, and COX-2 overexpression plays an important role in carcinogenesis. Exposure to UVB strongly increased COX-2 protein expression in mouse 308 keratinocytes, and this induction was inhibited by apigenin, a nonmutagenic bioflavonoid that has been shown to prevent mouse skin carcinogenesis induced by both chemical carcinogens and UV exposure. Our previous study suggested that one pathway by which apigenin inhibits UV-induced and basal COX-2 expression is through modulation of USF transcriptional activity in the 5' upstream region of the COX-2 gene. Here, we found that apigenin treatment also increased COX-2 mRNA stability, and the inhibitory effect of apigenin on UVB-induced luciferase reporter gene activity was dependent on the AU-rich element of the COX-2 3'-untranslated region. Furthermore, we identified two RNA-binding proteins, HuR and the T-cell-restricted intracellular antigen 1-related protein (TIAR), which were associated with endogenous COX-2 mRNA in 308 keratinocytes, and apigenin treatment increased their localization to cell cytoplasm. More importantly, reduction of HuR levels by small interfering RNA inhibited apigenin-mediated stabilization of COX-2 mRNA. Cells expressing reduced TIAR showed marked resistance to apigenin's ability to inhibit UVB-induced COX-2 expression. Taken together, these results indicate that in addition to transcriptional regulation, another mechanism by which apigenin prevents COX-2 expression is through mediating TIAR suppression of translation.
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Affiliation(s)
- Xin Tong
- Department of Pathology, Northwestern University, 303 E. Superior Street, Chicago, IL 60611, USA
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Guil S, Long JC, Cáceres JF. hnRNP A1 relocalization to the stress granules reflects a role in the stress response. Mol Cell Biol 2006; 26:5744-58. [PMID: 16847328 PMCID: PMC1592774 DOI: 10.1128/mcb.00224-06] [Citation(s) in RCA: 245] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
hnRNP A1 is a nucleocytoplasmic shuttling protein that is involved in many aspects of mRNA metabolism. We have previously shown that activation of the p38 stress-signaling pathway in mammalian cells results in both hyperphosphorylation and cytoplasmic accumulation of hnRNP A1, affecting alternative splicing regulation in vivo. Here we show that the stress-induced cytoplasmic accumulation of hnRNP A1 occurs in discrete phase-dense particles, the cytoplasmic stress granules (SGs). Interestingly, mRNA-binding activity is required for both phosphorylation of hnRNP A1 and localization to SGs. We also show that these effects are mediated by the Mnk1/2 protein kinases that act downstream of p38. Finally, depletion of hnRNP A1 affects the recovery of cells from stress, suggesting a physiologically significant role for hnRNP A1 in the stress response. Our data are consistent with a model whereby hnRNP A1 recruitment to SGs involves Mnk1/2-dependent phosphorylation of mRNA-bound hnRNP A1.
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Affiliation(s)
- Sonia Guil
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, Scotland, United Kingdom
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46
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Misquitta CM, Chen T, Grover AK. Control of protein expression through mRNA stability in calcium signalling. Cell Calcium 2006; 40:329-46. [PMID: 16765440 DOI: 10.1016/j.ceca.2006.04.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2006] [Revised: 03/22/2006] [Accepted: 04/12/2006] [Indexed: 01/14/2023]
Abstract
Specific sequences (cis-acting elements) in the 3'-untranslated region (UTR) of RNA, together with stabilizing and destabilizing proteins (trans-acting factors), determine the mRNA stability, and consequently, the level of expression of several proteins. Such interactions were discovered initially for short-lived mRNAs encoding cytokines and early genes like c-jun and c-myc. However, they may also determine the fate of more stable mRNAs in a tissue and disease-dependent manner. The interactions between the cis-acting elements and the trans-acting factors may also be modulated by Ca(2+) either directly or via a control of the phosphorylation status of the trans-acting factors. We focus initially on the basic concepts in mRNA stability with the trans-acting factors AUF1 (destabilizing) and HuR (stabilizing). Sarco/endoplasmic reticulum Ca(2+) pumps, SERCA2a (cardiac and slow twitch muscles) and SERCA2b (most cells including smooth muscle cells), are pivotal in Ca(2+) mobilization during signal transduction. SERCA2a and SERCA2b proteins are encoded by relatively stable mRNAs that contain cis-acting stability determinants in their 3'-regions. We present several pathways where 3'-UTR mediated mRNA decay is key to Ca(2+) signalling: SERCA2a and beta-adrenergic receptors in heart failure, renin-angiotensin system, and parathyroid hormones. Other examples discussed include cytokines vascular endothelial growth factor, endothelin and endothelial nitric oxide synthase. Roles of Ca(2+) and Ca(2+)-binding proteins in mRNA stability are also discussed. We anticipate that these novel modes of control of protein expression will form an emerging area of research that may explore the central role of Ca(2+) in cell function during development and in disease.
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Affiliation(s)
- Christine M Misquitta
- Banting and Best Department of Medical Research, 10th floor Donnelly CCBR, University of Toronto, 160 College Street, Toronto, Ont., Canada M5S 3E1
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Chou CF, Mulky A, Maitra S, Lin WJ, Gherzi R, Kappes J, Chen CY. Tethering KSRP, a decay-promoting AU-rich element-binding protein, to mRNAs elicits mRNA decay. Mol Cell Biol 2006; 26:3695-706. [PMID: 16648466 PMCID: PMC1489004 DOI: 10.1128/mcb.26.10.3695-3706.2006] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inherently unstable mRNAs contain AU-rich elements (AREs) in their 3' untranslated regions that act as mRNA stability determinants by interacting with ARE-binding proteins (ARE-BPs). We have destabilized two mRNAs by fusing sequence-specific RNA-binding proteins to KSRP, a decay-promoting ARE-BP, in a tethering assay. These results support a model that KSRP recruits mRNA decay machinery/factors to elicit decay. The ability of tethered KSRP to elicit mRNA decay depends on functions of known mRNA decay enzymes. By targeting the Rev response element of human immunodeficiency virus type 1 by using Rev-KSRP fusion protein, we degraded viral mRNA, resulting in a dramatic reduction of viral replication. These results provide a foundation for the development of novel therapeutic strategies to inhibit specific gene expression in patients with acquired or hereditary diseases.
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Affiliation(s)
- Chu-Fang Chou
- Department of Biochemistry & Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Espel E, Teixé T, Reina M, Vilaró S, Parra JL, Buxadé M. Use of Western blotting filtration to detect UV-cross-linked protein: RNA complexes. Anal Biochem 2006; 353:138-40. [PMID: 16620744 DOI: 10.1016/j.ab.2005.11.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2005] [Revised: 11/11/2005] [Accepted: 11/17/2005] [Indexed: 10/25/2022]
Affiliation(s)
- Enric Espel
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Spain.
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Buxadé M, Parra JL, Rousseau S, Shpiro N, Marquez R, Morrice N, Bain J, Espel E, Proud CG. The Mnks are novel components in the control of TNF alpha biosynthesis and phosphorylate and regulate hnRNP A1. Immunity 2005; 23:177-89. [PMID: 16111636 DOI: 10.1016/j.immuni.2005.06.009] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Revised: 06/08/2005] [Accepted: 06/15/2005] [Indexed: 11/22/2022]
Abstract
Posttranscriptional regulatory mechanisms control TNFalpha expression through AU-rich elements in the 3'UTR of its mRNA. This is mediated through Erk and p38 MAP kinase signaling, although the mechanisms involved remain poorly understood. Here, we show that the MAP kinase signal-integrating kinases (Mnks), which are activated by both these pathways, regulate TNFalpha expression in T cells via the 3'UTR. A selective Mnk inhibitor or siRNA-mediated knockdown of Mnk1 inhibits TNFalpha production in T cells, whereas Mnk1 overexpression enhances expression of a reporter construct containing the TNFalpha 3'UTR. We identify ARE binding proteins that are Mnk substrates, such as hnRNP A1, which they phosphorylate at two sites in vitro. hnRNP A1 is phosphorylated in response to T cell activation, and this is blocked by Mnk inhibition. Moreover, Mnk-mediated phosphorylation decreases binding of hnRNP A1 to TNFalpha-ARE in vitro or TNFalpha-mRNA in vivo. Therefore, Mnks are novel players in cytokine regulation and potential new targets for anti-inflammatory therapy.
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Affiliation(s)
- Maria Buxadé
- Departament de Fisiologia, Universitat de Barcelona, Spain
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Rigby WFC, Roy K, Collins J, Rigby S, Connolly JE, Bloch DB, Brooks SA. Structure/function analysis of tristetraprolin (TTP): p38 stress-activated protein kinase and lipopolysaccharide stimulation do not alter TTP function. THE JOURNAL OF IMMUNOLOGY 2005; 174:7883-93. [PMID: 15944294 DOI: 10.4049/jimmunol.174.12.7883] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tristetraprolin (TTP) is the only trans-acting factor shown to be capable of regulating AU-rich element-dependent mRNA turnover at the level of the intact animal; however, the mechanism by which TTP mediated RNA instability is unknown. Using an established model system, we performed structure/function analysis with TTP as well as examined the current hypothesis that TTP function is regulated by p38-MAPKAP kinase 2 (MK2) activation. Deletion of either the N- or C-terminal domains inhibited TTP function. Extensive mutagenesis, up to 16%, of serines and threonines, some of which were predicted to mediate proteasomal targeting, did not alter human TTP function. Mutation of the conserved MK2 phosphorylation sites enhanced human TTP function in both resting and p38-stress-activated protein kinase-MK2-activated cells. However, p38-stress-activated protein kinase-MK2 activation did not alter the activity of either wild-type or mutant TTP. TTP localized to the stress granules, with arsenite treatment reducing this localization. In contrast, arsenite treatment enhanced stress granule localization of the MK2 mutant, consistent with the involvement of additional pathways regulating this event. Finally, we determined that, in response to LPS stimulation, human TTP moves onto the polysomes, and this movement occurs in the absence of 14-3-3. Taken together, these data indicate that, although p38 activation alters TTP entry into the stress granule, it does not alter TTP function. Moreover, the interaction of TTP with 14-3-3, which may limit entry into the stress granule, is not involved in the downstream message stabilization events.
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