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Whitworth IT, Romero S, Kissi-Twum A, Knoener R, Scalf M, Sherer NM, Smith LM. Identification of Host Proteins Involved in Hepatitis B Virus Genome Packaging. J Proteome Res 2024. [PMID: 39078123 DOI: 10.1021/acs.jproteome.4c00505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
A critical part of the hepatitis B virus (HBV) life cycle is the packaging of the pregenomic RNA (pgRNA) into nucleocapsids. While this process is known to involve several viral elements, much less is known about the identities and roles of host proteins in this process. To better understand the role of host proteins, we isolated pgRNA and characterized its protein interactome in cells expressing either packaging-competent or packaging-incompetent HBV genomes. We identified over 250 host proteins preferentially associated with pgRNA from the packaging-competent version of the virus. These included proteins already known to support capsid formation, enhance viral gene expression, catalyze nucleocapsid dephosphorylation, and bind to the viral genome, demonstrating the ability of the approach to effectively reveal functionally significant host-virus interactors. Three of these host proteins, AURKA, YTHDF2, and ATR, were selected for follow-up analysis. RNA immunoprecipitation qPCR (RIP-qPCR) confirmed pgRNA-protein association in cells, and siRNA knockdown of the proteins showed decreased encapsidation efficiency. This study provides a template for the use of comparative RNA-protein interactome analysis in conjunction with virus engineering to reveal functionally significant host-virus interactions.
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Affiliation(s)
- Isabella T Whitworth
- Department of Chemistry, University of Wisconsin-Madison College of Letters and Sciences, Madison, Wisconsin 53706, United States
| | - Sofia Romero
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53705, United States
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Abena Kissi-Twum
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53705, United States
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Rachel Knoener
- Department of Chemistry, University of Wisconsin-Madison College of Letters and Sciences, Madison, Wisconsin 53706, United States
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53705, United States
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-Madison College of Letters and Sciences, Madison, Wisconsin 53706, United States
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53705, United States
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-Madison College of Letters and Sciences, Madison, Wisconsin 53706, United States
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2
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Giraud G, Rodà M, Huchon P, Michelet M, Maadadi S, Jutzi D, Montserret R, Ruepp MD, Parent R, Combet C, Zoulim F, Testoni B. G-quadruplexes control hepatitis B virus replication by promoting cccDNA transcription and phase separation in hepatocytes. Nucleic Acids Res 2024; 52:2290-2305. [PMID: 38113270 PMCID: PMC10954475 DOI: 10.1093/nar/gkad1200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 11/12/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023] Open
Abstract
Phase separation regulates fundamental processes in gene expression and is mediated by the local concentration of proteins and nucleic acids, as well as nucleic acid secondary structures such as G-quadruplexes (G4s). These structures play fundamental roles in both host gene expression and in viral replication due to their peculiar localisation in regulatory sequences. Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is an episomal minichromosome whose persistence is at the basis of chronic infection. Identifying the mechanisms controlling its transcriptional activity is indispensable to develop new therapeutic strategies against chronic hepatitis B. The aim of this study was to determine whether G4s are formed in cccDNA and regulate viral replication. Combining biochemistry and functional studies, we demonstrate that cccDNA indeed contains ten G4s structures. Furthermore, mutations disrupting two G4s located in the enhancer I HBV regulatory region altered cccDNA transcription and viral replication. Finally, we showed for the first time that cccDNA undergoes phase separation in a G4-dependent manner to promote its transcription in infected hepatocytes. Altogether, our data give new insight in the transcriptional regulation of the HBV minichromosome that might pave the way for the identification of novel targets to destabilize or silence cccDNA.
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Affiliation(s)
- Guillaume Giraud
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
| | - Mélanie Rodà
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
| | - Pélagie Huchon
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
- Université Claude-Bernard Lyon I, 69003 Lyon, France
| | - Maud Michelet
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
| | - Sarah Maadadi
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 lyon, france; université claude-bernard lyon i, 69003 Lyon, France
| | - Daniel Jutzi
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, WC2R 2LS London, UK
| | - Roland Montserret
- Molecular Microbiology and Structural Biochemistry (MMSB) UMR 5086 CNRS/Université de Lyon, Labex Ecofect, 7 Passage du Vercors 69367Lyon, France
| | - Marc-David Ruepp
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, WC2R 2LS London, UK
| | - Romain Parent
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
| | - Christophe Combet
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
| | - Fabien Zoulim
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
- Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Service, Hospices Civils de Lyon, 69004 Lyon, France
| | - Barbara Testoni
- INSERM U1052, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR)-5286, Cancer Research Center of Lyon, 69003 Lyon, France; Université Claude-Bernard Lyon I, 69003 Lyon, France
- Hepatology Institute of Lyon, 69004 Lyon, France
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3
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Sheng M, Zhang Y, Wang Y, Liu W, Wang X, Ke T, Liu P, Wang S, Shao W. Decoding the role of aberrant RNA alternative splicing in hepatocellular carcinoma: a comprehensive review. J Cancer Res Clin Oncol 2023; 149:17691-17708. [PMID: 37898981 DOI: 10.1007/s00432-023-05474-8] [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: 07/18/2023] [Accepted: 10/10/2023] [Indexed: 10/31/2023]
Abstract
During eukaryotic gene expression, alternative splicing of messenger RNA precursors is critical in increasing protein diversity and regulatory complexity. Multiple transcript isoforms could be produced by alternative splicing from a single gene; they could eventually be translated into protein isoforms with deleted, added, or altered domains or produce transcripts containing premature termination codons that could be targeted by nonsense-mediated mRNA decay. Alternative splicing can generate proteins with similar, different, or even opposite functions. Increasingly strong evidence indicates that abnormal RNA splicing is a prevalent and crucial occurrence in cellular differentiation, tissue advancement, and the development and progression of cancer. Aberrant alternative splicing could affect cancer cell activities such as growth, apoptosis, invasiveness, drug resistance, angiogenesis, and metabolism. This systematic review provides a comprehensive overview of the impact of abnormal RNA alternative splicing on the development and progression of hepatocellular carcinoma.
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Affiliation(s)
- Mengfei Sheng
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yuanyuan Zhang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yaoyun Wang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Weiyi Liu
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Xingyu Wang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Tiaoying Ke
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Pingyang Liu
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Sihan Wang
- Department of Clinical Medicine, Bengbu Medical College, Bengbu, China
| | - Wei Shao
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China.
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4
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Ke H, Liu K, Jiao B, Zhao L. Implications of TDP-43 in non-neuronal systems. Cell Commun Signal 2023; 21:338. [PMID: 37996849 PMCID: PMC10666381 DOI: 10.1186/s12964-023-01336-5] [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: 07/27/2023] [Accepted: 09/26/2023] [Indexed: 11/25/2023] Open
Abstract
TAR DNA-binding protein 43 (TDP-43) is a versatile RNA/DNA-binding protein with multifaceted processes. While TDP-43 has been extensively studied in the context of degenerative diseases, recent evidence has also highlighted its crucial involvement in diverse life processes beyond neurodegeneration. Here, we mainly reviewed the function of TDP-43 in non-neurodegenerative physiological and pathological processes, including spermatogenesis, embryonic development, mammary gland development, tumor formation, and viral infection, highlighting its importance as a key regulatory factor for the maintenance of normal functions throughout life. TDP-43 exhibits diverse and sometimes opposite functionality across different cell types through various mechanisms, and its roles can shift at distinct stages within the same biological system. Consequently, TDP-43 operates in both a context-dependent and a stage-specific manner in response to a variety of internal and external stimuli. Video Abstract.
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Affiliation(s)
- Hao Ke
- Human Aging Research Institute (HARI) and School of Life Science, Nanchang University, and Jiangxi Key Laboratory of Human Aging, Nanchang, 330031, China
| | - Kang Liu
- Ganzhou People's Hospital, Ganzhou, 341000, China
| | - Baowei Jiao
- National Key Laboratory of Genetic Evolution & Animal Models, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
- KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China.
| | - Limin Zhao
- Human Aging Research Institute (HARI) and School of Life Science, Nanchang University, and Jiangxi Key Laboratory of Human Aging, Nanchang, 330031, China.
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5
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Guo J, Zhu Y, Ma X, Shang G, Liu B, Zhang K. Virus Infection and mRNA Nuclear Export. Int J Mol Sci 2023; 24:12593. [PMID: 37628773 PMCID: PMC10454920 DOI: 10.3390/ijms241612593] [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: 04/21/2023] [Revised: 07/29/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023] Open
Abstract
Gene expression in eukaryotes begins with transcription in the nucleus, followed by the synthesis of messenger RNA (mRNA), which is then exported to the cytoplasm for its translation into proteins. Along with transcription and translation, mRNA export through the nuclear pore complex (NPC) is an essential regulatory step in eukaryotic gene expression. Multiple factors regulate mRNA export and hence gene expression. Interestingly, proteins from certain types of viruses interact with these factors in infected cells, and such an interaction interferes with the mRNA export of the host cell in favor of viral RNA export. Thus, these viruses hijack the host mRNA nuclear export mechanism, leading to a reduction in host gene expression and the downregulation of immune/antiviral responses. On the other hand, the viral mRNAs successfully evade the host surveillance system and are efficiently exported from the nucleus to the cytoplasm for translation, which enables the continuation of the virus life cycle. Here, we present this review to summarize the mechanisms by which viruses suppress host mRNA nuclear export during infection, as well as the key strategies that viruses use to facilitate their mRNA nuclear export. These studies have revealed new potential antivirals that may be used to inhibit viral mRNA transport and enhance host mRNA nuclear export, thereby promoting host gene expression and immune responses.
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Affiliation(s)
- Jiayin Guo
- University of Chinese Academy of Sciences, Beijing 100049, China; (J.G.); (Y.Z.); (X.M.)
| | - Yaru Zhu
- University of Chinese Academy of Sciences, Beijing 100049, China; (J.G.); (Y.Z.); (X.M.)
| | - Xiaoya Ma
- University of Chinese Academy of Sciences, Beijing 100049, China; (J.G.); (Y.Z.); (X.M.)
| | - Guijun Shang
- Shanxi Provincial Key Laboratory of Protein Structure Determination, Shanxi Academy of Advanced Research and Innovation, Taiyuan 030012, China;
| | - Bo Liu
- Key Laboratory of Molecular Virology and Immunology, Chinese Academy of Sciences, Shanghai 200031, China
- Shanghai Huashen Institute of Microbes and Infections, Shanghai 200052, China
| | - Ke Zhang
- Key Laboratory of Molecular Virology and Immunology, Chinese Academy of Sciences, Shanghai 200031, China
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6
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Makokha GN, Chayama K, Hayes CN, Abe-Chayama H, Abuduwaili M, Hijikata M. Deficiency of SCAP inhibits HBV pathogenesis via activation of the interferon signaling pathway. Virology 2023; 585:248-258. [PMID: 37437369 DOI: 10.1016/j.virol.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/15/2023] [Accepted: 07/03/2023] [Indexed: 07/14/2023]
Abstract
Hepatitis B virus (HBV) infects the liver and is a major risk factor for liver cirrhosis and hepatocellular carcinoma. Approaches for an effective cure are thwarted by limited knowledge of virus-host interactions. Herein, we identified SCAP as a novel host factor that regulates HBV gene expression. SCAP, sterol regulatory element-binding protein (SREBP) cleavage-activating protein, is an integral membrane protein located in the endoplasmic reticulum. The protein plays a central role in controlling lipid synthesis and uptake by cells. We found that gene silencing of SCAP significantly inhibited HBV replication; furthermore, knockdown of SREBP2 but not SREBP1, the downstream effectors of SCAP, reduced HBs antigen production from HBV infected primary hepatocytes. We also demonstrated that knockdown of SCAP resulted in activation of interferons (IFNs) and IFN stimulated genes (ISGs). Conversely, ectopic expression of SREBP2 in SCAP-deficient cells restored expression of IFNs and ISGs. Importantly, expression of SREBP2 restored HBV production in SCAP knockdown cells, suggesting that SCAP participates in HBV replication through an effect on IFN production via its downstream effector SREBP2. This observation was further confirmed by blocking IFN signaling by an anti-IFN antibody, which restored HBV infection in SCAP-deficient cells. This led to the conclusion that SCAP regulates the IFN pathway through SREBP, thereby affecting the HBV lifecycle. This is the first study to reveal the involvement of SCAP in regulation of HBV infection. These results may facilitate development of new antiviral strategies against HBV.
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Affiliation(s)
- Grace Naswa Makokha
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
| | - Kazuaki Chayama
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - C Nelson Hayes
- Department of Gastroenterology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hiromi Abe-Chayama
- Center for Medical Specialist Graduate Education and Research, Hiroshima University, Hiroshima, Japan
| | - Maidina Abuduwaili
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Makoto Hijikata
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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7
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Emerging Therapies for Chronic Hepatitis B and the Potential for a Functional Cure. Drugs 2023; 83:367-388. [PMID: 36906663 DOI: 10.1007/s40265-023-01843-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2023] [Indexed: 03/13/2023]
Abstract
Worldwide, an estimated 296 million people are living with chronic hepatitis B virus (HBV) infection, with a significant risk of morbidity and mortality. Current therapy with pegylated interferon (Peg-IFN) and indefinite or finite therapy with nucleoside/nucleotide analogues (Nucs) are effective in HBV suppression, hepatitis resolution, and prevention of disease progression. However, few achieve hepatitis B surface antigen (HBsAg) loss (functional cure), and relapse often occurs after the end of therapy (EOT) because these agents have no direct effect on durable template: covalently closed circular DNA (cccDNA) and integrated HBV DNA. Hepatitis B surface antigen loss rate increases slightly by adding or switching to Peg-IFN in Nuc-treated patients and this loss rate greatly increases up to 39% in 5 years with finite Nuc therapy with currently available Nuc(s). For this, great effort has been made to develop novel direct-acting antivirals (DAAs) and immunomodulators. Among the DAAs, entry inhibitors and capsid assembly modulators have little effect on reducing HBsAg levels; small interfering RNA, antisense oligonucleotides, and nucleic acid polymers in combination with Peg-IFN and Nuc may reduce HBsAg levels significantly, even a rate of HBsAg loss sustained for > 24 weeks after EOT up to 40%. Novel immunomodulators, including T-cell receptor agonists, check-point inhibitors, therapeutic vaccines, and monoclonal antibodies may restore HBV-specific T-cell response but not sustained HBsAg loss. The safety issues and the durability of HBsAg loss warrant further investigation. Combining agents of different classes has the potential to enhance HBsAg loss. Compounds directly targeting cccDNA would be more effective but are still in the early stage of development. More effort is required to achieve this goal.
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8
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Reviewing the Potential Links between Viral Infections and TDP-43 Proteinopathies. Int J Mol Sci 2023; 24:ijms24021581. [PMID: 36675095 PMCID: PMC9867397 DOI: 10.3390/ijms24021581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 01/15/2023] Open
Abstract
Transactive response DNA binding protein 43 kDa (TDP-43) was discovered in 2001 as a cellular factor capable to inhibit HIV-1 gene expression. Successively, it was brought to new life as the most prevalent RNA-binding protein involved in several neurological disorders, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Despite the fact that these two research areas could be considered very distant from each other, in recent years an increasing number of publications pointed out the existence of a potentially important connection. Indeed, the ability of TDP-43 to act as an important regulator of all aspects of RNA metabolism makes this protein also a critical factor during expression of viral RNAs. Here, we summarize all recent observations regarding the involvement of TDP-43 in viral entry, replication and latency in several viruses that include enteroviruses (EVs), Theiler's murine encephalomyelitis virus (TMEV), human immunodeficiency virus (HIV), human endogenous retroviruses (HERVs), hepatitis B virus (HBV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), West Nile virus (WNV), and herpes simplex virus-2 (HSV). In particular, in this work, we aimed to highlight the presence of similarities with the most commonly studied TDP-43 related neuronal dysfunctions.
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9
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Wei XF, Fan SY, Wang YW, Li S, Long SY, Gan CY, Li J, Sun YX, Guo L, Wang PY, Yang X, Wang JL, Cui J, Zhang WL, Huang AL, Hu JL. Identification of STAU1 as a regulator of HBV replication by TurboID-based proximity labeling. iScience 2022; 25:104416. [PMID: 35663023 PMCID: PMC9156947 DOI: 10.1016/j.isci.2022.104416] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 04/21/2022] [Accepted: 05/12/2022] [Indexed: 11/17/2022] Open
Abstract
The core promoter (CP) of hepatitis B virus (HBV) is critical for HBV replication by controlling the transcription of pregenomic RNA (pgRNA). Host factors regulating the activity of the CP can be identified by different methods. Biotin-based proximity labeling, a powerful method with the capability to capture weak or dynamic interactions, has not yet been used to map proteins interacting with the CP. Here, we established a strategy, based on the newly evolved promiscuous enzyme TurboID, for interrogating host factors regulating the activity of HBV CP. Using this strategy, we identified STAU1 as an important factor involved in the regulation of HBV CP. Mechanistically, STAU1 indirectly binds to CP mediated by TARDBP, and recruits the SAGA transcription coactivator complex to the CP to upregulate its activity. Moreover, STAU1 binds to HBx and enhances the level of HBx by stabilizing it in a ubiquitin-independent manner. HBV core promoter binding factors were interrogated by a proximity labeling method STAU1 enhances HBV transcription and replication STAU1 indirectly binds to core promoter via TARDBP and recruits SAGA complex STAU1 binds to HBx and increases its stability
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Affiliation(s)
- Xia-Fei Wei
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China.,Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Shu-Ying Fan
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Yu-Wei Wang
- Department of Laboratory Medicine, Chongqing Hospital of Traditional Chinese Medicine, Chongqing, China
| | - Shan Li
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Shao-Yuan Long
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Chun-Yang Gan
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jie Li
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Yu-Xue Sun
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Lin Guo
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Pei-Yun Wang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Xue Yang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jin-Lan Wang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jing Cui
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Wen-Lu Zhang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Ai-Long Huang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jie-Li Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
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10
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TARDBP Inhibits Porcine Epidemic Diarrhea Virus Replication through Degrading Viral Nucleocapsid Protein and Activating Type I Interferon Signaling. J Virol 2022; 96:e0007022. [DOI: 10.1128/jvi.00070-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PEDV refers to the highly contagious enteric coronavirus that has quickly spread globally and generated substantial financial damage to the global swine industry. During virus infection, the host regulates the innate immunity and autophagy process to inhibit virus infection.
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11
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Kamiya N, Sugimoto T, Abe-Chayama H, Akiyama R, Tsuboi Y, Mogami A, Imamura M, Hayes CN, Chayama K. Untying relaxed circular DNA of hepatitis B virus by polymerase reaction provides a new option for accurate quantification and visualization of covalently closed circular DNA. J Gen Virol 2022; 103. [PMID: 35130138 DOI: 10.1099/jgv.0.001591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hepatitis B virus (HBV) is a small hepatotropic DNA virus that replicates via an RNA intermediate. After entry, the virus capsid carries relaxed circular DNA (rcDNA) into the nucleus where the viral genome is converted into covalently closed circular DNA (cccDNA), which serves as the template for all viral transcripts. To monitor cccDNA levels, preprocessing methods to eliminate rcDNA have emerged for quantitative PCR, although Southern blotting is still the only method to discriminate cccDNA from other DNA intermediates. In this study, we have established a robust method for untying mature rcDNA into double stranded linear DNA using specific polymerases. Untying rcDNA provides not only an alternative method for cccDNA quantification but also a sensitive method for visualizing cccDNA. We combined this method with plasmid-safe DNase and T5 exonuclease preprocessing and revealed that accurate quantification requires cccDNA digestion by a restriction enzyme because heat stability of cccDNA increases after T5 exonuclease treatment. In digital PCR using duplex TaqMan probes, fewer than 1000 copies of cccDNA were successfully visualized as double positive spots that were distinct from single positives derived from untied rcDNA. This method was further applied to the infection model of primary hepatocytes treated with nucleoside analogues and a core protein allosteric modulator to monitor cccDNA levels. Relative quantification of cccDNA by human genome copy demonstrated the possibility of precise evaluation of cccDNA level per nucleus. These results clearly indicate that the sequential reaction from untying rcDNA is useful to investigate cccDNA fates in a small fraction of nuclei.
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Affiliation(s)
- Naohiro Kamiya
- Research Unit/Immunology & Inflammation, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan.,Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Takahiko Sugimoto
- Research Unit/Immunology & Inflammation, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Hiromi Abe-Chayama
- Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.,Research Center for Hepatology and Gastroenterology, Hiroshima University, Hiroshima, Japan
| | - Rie Akiyama
- Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.,Research Center for Hepatology and Gastroenterology, Hiroshima University, Hiroshima, Japan
| | - Yasunori Tsuboi
- Research Unit/Immunology & Inflammation, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Akira Mogami
- Research Unit/Immunology & Inflammation, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Michio Imamura
- Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.,Research Center for Hepatology and Gastroenterology, Hiroshima University, Hiroshima, Japan
| | - C Nelson Hayes
- Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.,Research Center for Hepatology and Gastroenterology, Hiroshima University, Hiroshima, Japan
| | - Kazuaki Chayama
- Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.,Research Center for Hepatology and Gastroenterology, Hiroshima University, Hiroshima, Japan.,Institute of Physical and Chemical Research (RIKEN) Center for Integrative Medical Sciences, Yokohama, Japan
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12
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Kremsdorf D, Lekbaby B, Bablon P, Sotty J, Augustin J, Schnuriger A, Pol J, Soussan P. Alternative splicing of viral transcripts: the dark side of HBV. Gut 2021; 70:2373-2382. [PMID: 34535538 DOI: 10.1136/gutjnl-2021-324554] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 09/06/2021] [Indexed: 02/06/2023]
Abstract
Regulation of alternative splicing is one of the most efficient mechanisms to enlarge the proteomic diversity in eukaryotic organisms. Many viruses hijack the splicing machinery following infection to accomplish their replication cycle. Regarding the HBV, numerous reports have described alternative splicing events of the long viral transcript (pregenomic RNA), which also acts as a template for viral genome replication. Alternative splicing of HBV pregenomic RNAs allows the synthesis of at least 20 spliced variants. In addition, almost all these spliced forms give rise to defective particles, detected in the blood of infected patients. HBV-spliced RNAs have long been unconsidered, probably due to their uneasy detection in comparison to unspliced forms as well as for their dispensable role during viral replication. However, recent data highlighted the relevance of these HBV-spliced variants through (1) the trans-regulation of the alternative splicing of viral transcripts along the course of liver disease; (2) the ability to generate defective particle formation, putative biomarker of the liver disease progression; (3) modulation of viral replication; and (4) their intrinsic propensity to encode for novel viral proteins involved in liver pathogenesis and immune response. Altogether, tricky regulation of HBV alternative splicing may contribute to modulate multiple viral and cellular processes all along the course of HBV-related liver disease.
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Affiliation(s)
- Dina Kremsdorf
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France
| | - Bouchra Lekbaby
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France
| | - Pierre Bablon
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France
| | - Jules Sotty
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France
| | - Jérémy Augustin
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France
| | - Aurélie Schnuriger
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France.,Assistance Publique - Hôpitaux de Paris, Département de Virologie, GHU Paris-Est, Paris, France
| | - Jonathan Pol
- Institut National de la Santé et de la Recherche Médicale U1138, Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Paris, France.,Metabolomics ann Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
| | - Patrick Soussan
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche de Saint Antoine, Sorbonne Université-Faculté Saint Antoine, Paris, France .,Assistance Publique - Hôpitaux de Paris, Département de Virologie, GHU Paris-Est, Paris, France
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13
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Van Damme E, Vanhove J, Severyn B, Verschueren L, Pauwels F. The Hepatitis B Virus Interactome: A Comprehensive Overview. Front Microbiol 2021; 12:724877. [PMID: 34603251 PMCID: PMC8482013 DOI: 10.3389/fmicb.2021.724877] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/17/2021] [Indexed: 12/19/2022] Open
Abstract
Despite the availability of a prophylactic vaccine, chronic hepatitis B (CHB) caused by the hepatitis B virus (HBV) is a major health problem affecting an estimated 292 million people globally. Current therapeutic goals are to achieve functional cure characterized by HBsAg seroclearance and the absence of HBV-DNA after treatment cessation. However, at present, functional cure is thought to be complicated due to the presence of covalently closed circular DNA (cccDNA) and integrated HBV-DNA. Even if the episomal cccDNA is silenced or eliminated, it remains unclear how important the high level of HBsAg that is expressed from integrated HBV DNA is for the pathology. To identify therapies that could bring about high rates of functional cure, in-depth knowledge of the virus' biology is imperative to pinpoint mechanisms for novel therapeutic targets. The viral proteins and the episomal cccDNA are considered integral for the control and maintenance of the HBV life cycle and through direct interaction with the host proteome they help create the most optimal environment for the virus whilst avoiding immune detection. New HBV-host protein interactions are continuously being identified. Unfortunately, a compendium of the most recent information is lacking and an interactome is unavailable. This article provides a comprehensive review of the virus-host relationship from viral entry to release, as well as an interactome of cccDNA, HBc, and HBx.
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Affiliation(s)
- Ellen Van Damme
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium
| | - Jolien Vanhove
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium.,Early Discovery Biology, Charles River Laboratories, Beerse, Belgium
| | - Bryan Severyn
- Janssen Research & Development, Janssen Pharmaceutical Companies, Springhouse, PA, United States
| | - Lore Verschueren
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium
| | - Frederik Pauwels
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium
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14
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Ahluwalia S, Choudhary D, Tyagi P, Kumar V, Vivekanandan P. Vitamin D signaling inhibits HBV activity by directly targeting the HBV core promoter. J Biol Chem 2021; 297:101233. [PMID: 34562448 PMCID: PMC8517215 DOI: 10.1016/j.jbc.2021.101233] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/16/2021] [Accepted: 09/21/2021] [Indexed: 12/12/2022] Open
Abstract
Clinical and epidemiological studies support a role for vitamin D in suppressing hepatitis B virus (HBV). This antiviral role of vitamin D is widely attributed to vitamin D receptor (VDR)/retinoid X receptor-mediated regulation of host immunomodulatory genes through vitamin D response elements (VDREs) in their promoters. Here, we investigated the ability of calcitriol (1α,25-dihydroxyvitamin D3, metabolically activated vitamin D) to directly regulate HBV activity through this signaling pathway. We observed that calcitriol selectively inhibited only the HBV core promoter without affecting the HBV-PreS1, HBV-PreS2/S, or HBx promoters. We then identified a VDRE cluster in the HBV core promoter that is highly conserved across most HBV genotypes. Disruption of this VDRE cluster abrogated calcitriol-mediated suppression of the HBV core promoter. Furthermore, we showed that VDR interacts directly with the VDRE cluster in the HBV core promoter independent of retinoid X receptor. This demonstrates that calcitriol inhibits HBV core promoter activity through a noncanonical calcitriol-activated VDR pathway. Finally, we observed that calcitriol suppressed expression of the canonical HBV core promoter transcripts, pregenomic RNA, and precore RNA in multiple HBV cell culture models. In addition, calcitriol inhibited the secretion of hepatitis B "e" antigen and hepatitis B surface antigen (HBV-encoded proteins linked to poor disease prognosis), without affecting virion secretion. Our findings identify VDR as a novel regulator of HBV core promoter activity and also explain at least in part the correlation of vitamin D levels to HBV activity observed in clinical studies. Furthermore, this study has implications on the potential use of vitamin D along with anti-HBV therapies, and lays the groundwork for studies on vitamin D-mediated regulation of viruses through VDREs in virus promoters.
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Affiliation(s)
- Shivaksh Ahluwalia
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Divya Choudhary
- Department of Chemical Engineering, Indian Institute of Technology Delhi, New Delhi, India
| | - Purnima Tyagi
- Department of Molecular and Cellular Medicine, Institute of Liver and Biliary sciences, New Delhi, India
| | - Vijay Kumar
- Department of Molecular and Cellular Medicine, Institute of Liver and Biliary sciences, New Delhi, India
| | - Perumal Vivekanandan
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
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15
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Hepatitis B virus Core protein nuclear interactome identifies SRSF10 as a host RNA-binding protein restricting HBV RNA production. PLoS Pathog 2020; 16:e1008593. [PMID: 33180834 PMCID: PMC7707522 DOI: 10.1371/journal.ppat.1008593] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/01/2020] [Accepted: 10/04/2020] [Indexed: 12/11/2022] Open
Abstract
Despite the existence of a preventive vaccine, chronic infection with Hepatitis B virus (HBV) affects more than 250 million people and represents a major global cause of hepatocellular carcinoma (HCC) worldwide. Current clinical treatments, in most of cases, do not eliminate viral genome that persists as a DNA episome in the nucleus of hepatocytes and constitutes a stable template for the continuous expression of viral genes. Several studies suggest that, among viral factors, the HBV core protein (HBc), well-known for its structural role in the cytoplasm, could have critical regulatory functions in the nucleus of infected hepatocytes. To elucidate these functions, we performed a proteomic analysis of HBc-interacting host-factors in the nucleus of differentiated HepaRG, a surrogate model of human hepatocytes. The HBc interactome was found to consist primarily of RNA-binding proteins (RBPs), which are involved in various aspects of mRNA metabolism. Among them, we focused our studies on SRSF10, a RBP that was previously shown to regulate alternative splicing (AS) in a phosphorylation-dependent manner and to control stress and DNA damage responses, as well as viral replication. Functional studies combining SRSF10 knockdown and a pharmacological inhibitor of SRSF10 phosphorylation (1C8) showed that SRSF10 behaves as a restriction factor that regulates HBV RNAs levels and that its dephosphorylated form is likely responsible for the anti-viral effect. Surprisingly, neither SRSF10 knock-down nor 1C8 treatment modified the splicing of HBV RNAs but rather modulated the level of nascent HBV RNA. Altogether, our work suggests that in the nucleus of infected cells HBc interacts with multiple RBPs that regulate viral RNA metabolism. Our identification of SRSF10 as a new anti-HBV restriction factor offers new perspectives for the development of new host-targeted antiviral strategies. Chronic infection with Hepatitis B virus (HBV) affects more than 250 million of people world-wide and is a major global cause of liver cancer. Current treatments lead to a significant reduction of viremia in patients. However, viral clearance is rarely obtained and the persistence of the HBV genome in the hepatocyte’s nucleus generates a stable source of viral RNAs and subsequently proteins which play important roles in immune escape mechanisms and liver disease progression. Therapies aiming at efficiently and durably eliminating viral gene expression are still required. In this study, we identified the nuclear partners of the HBV Core protein (HBc) to understand how this structural protein, responsible for capsid assembly in the cytoplasm, could also regulate viral gene expression. The HBc interactome was found to consist primarily of RNA-binding proteins (RBPs). One of these RBPs, SRSF10, was demonstrated to restrict HBV RNA levels and a drug, able to alter its phosphorylation, behaved as an antiviral compound capable of reducing viral gene expression. Altogether, this study sheds new light on novel regulatory functions of HBc and provides information relevant for the development of antiviral strategies aiming at preventing viral gene expression.
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16
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Gales JP, Kubina J, Geldreich A, Dimitrova M. Strength in Diversity: Nuclear Export of Viral RNAs. Viruses 2020; 12:E1014. [PMID: 32932882 PMCID: PMC7551171 DOI: 10.3390/v12091014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/03/2020] [Accepted: 09/09/2020] [Indexed: 12/11/2022] Open
Abstract
The nuclear export of cellular mRNAs is a complex process that requires the orchestrated participation of many proteins that are recruited during the early steps of mRNA synthesis and processing. This strategy allows the cell to guarantee the conformity of the messengers accessing the cytoplasm and the translation machinery. Most transcripts are exported by the exportin dimer Nuclear RNA export factor 1 (NXF1)-NTF2-related export protein 1 (NXT1) and the transcription-export complex 1 (TREX1). Some mRNAs that do not possess all the common messenger characteristics use either variants of the NXF1-NXT1 pathway or CRM1, a different exportin. Viruses whose mRNAs are synthesized in the nucleus (retroviruses, the vast majority of DNA viruses, and influenza viruses) exploit both these cellular export pathways. Viral mRNAs hijack the cellular export machinery via complex secondary structures recognized by cellular export factors and/or viral adapter proteins. This way, the viral transcripts succeed in escaping the host surveillance system and are efficiently exported for translation, allowing the infectious cycle to proceed. This review gives an overview of the cellular mRNA nuclear export mechanisms and presents detailed insights into the most important strategies that viruses use to export the different forms of their RNAs from the nucleus to the cytoplasm.
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Affiliation(s)
- Jón Pol Gales
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
| | - Julie Kubina
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
- SVQV UMR-A 1131, INRAE, Université de Strasbourg, F-68000 Colmar, France
| | - Angèle Geldreich
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
| | - Maria Dimitrova
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
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17
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mRNA Post-Transcriptional Regulation by AU-Rich Element-Binding Proteins in Liver Inflammation and Cancer. Int J Mol Sci 2020; 21:ijms21186648. [PMID: 32932781 PMCID: PMC7554771 DOI: 10.3390/ijms21186648] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/09/2020] [Accepted: 09/09/2020] [Indexed: 12/12/2022] Open
Abstract
AU-rich element-binding proteins (AUBPs) represent important post-transcriptional regulators of gene expression. AUBPs can bind to the AU-rich elements present in the 3'-UTR of more than 8% of all mRNAs and are thereby able to control the stability and/or translation of numerous target mRNAs. The regulation of the stability and the translation of mRNA transcripts by AUBPs are highly complex processes that occur through multiple mechanisms depending on the cell type and the cellular context. While AUBPs have been shown to be involved in inflammatory processes and the development of various cancers, their important role and function in the development of chronic metabolic and inflammatory fatty liver diseases (FLDs), as well as in the progression of these disorders toward cancers such as hepatocellular carcinoma (HCC), has recently started to emerge. Alterations of either the expression or activity of AUBPs are indeed significantly associated with FLDs and HCC, and accumulating evidence indicates that several AUBPs are deeply involved in a significant number of cellular processes governing hepatic metabolic disorders, inflammation, fibrosis, and carcinogenesis. Herein, we discuss our current knowledge of the roles and functions of AUBPs in liver diseases and cancer. The relevance of AUBPs as potential biomarkers for different stages of FLD and HCC, or as therapeutic targets for these diseases, are also highlighted.
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