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Temaj G, Chichiarelli S, Telkoparan-Akillilar P, Saha S, Nuhii N, Hadziselimovic R, Saso L. Advances in molecular function of UPF1 in Cancer. Arch Biochem Biophys 2024; 756:109989. [PMID: 38621446 DOI: 10.1016/j.abb.2024.109989] [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: 02/06/2024] [Revised: 03/23/2024] [Accepted: 04/10/2024] [Indexed: 04/17/2024]
Abstract
It is known that more than 10 % of genetic diseases are caused by a mutation in protein-coding mRNA (premature termination codon; PTC). mRNAs with an early stop codon are degraded by the cellular surveillance process known as nonsense-mediated mRNA decay (NMD), which prevents the synthesis of C-terminally truncated proteins. Up-frameshift-1 (UPF1) has been reported to be involved in the downregulation of various cancers, and low expression of UPF1 was shown to correlate with poor prognosis. It is known that UPF1 is a master regulator of nonsense-mediated mRNA decay (NMD). UPF1 may also function as an E3 ligase and degrade target proteins without using mRNA decay mechanisms. Increasing evidence indicates that UPF1 could serve as a good biomarker for cancer diagnosis and treatment for future therapeutic applications. Long non-coding RNAs (lncRNAs) have the ability to bind different proteins and regulate gene expression; this role in cancer cells has already been identified by different studies. This article provides an overview of the aberrant expression of UPF1, its functional properties, and molecular processes during cancer for clinical applications in cancer. We also discussed the interactions of lncRNA with UPF1 for cell growth during tumorigenesis.
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Affiliation(s)
- Gazmend Temaj
- Faculty of Pharmacy, College UBT, 10000, Prishtina, Republic of Kosovo.
| | - Silvia Chichiarelli
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, 00185, Rome, Italy.
| | | | - Sarmistha Saha
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura, Uttar Pradesh, India.
| | - Nexhibe Nuhii
- Department of Pharmacy, Faculty of Medical Sciences, State University of Tetovo, 1200, Tetovo, Macedonia.
| | - Rifat Hadziselimovic
- Faculty of Science, University of Sarajevo, 71000, Sarajevo, Bosnia and Herzegovina.
| | - Luciano Saso
- Department of Physiology and Pharmacology "Vittorio Erspamer", La Sapienza University, 00185, Rome, Italy.
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2
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Rahmati M, Chebli J, Kumar Banote R, Roselli S, Agholme L, Zetterberg H, Abramsson A. Fine-Tuning Amyloid Precursor Protein Expression through Nonsense-Mediated mRNA Decay. eNeuro 2024; 11:ENEURO.0034-24.2024. [PMID: 38789273 PMCID: PMC11164851 DOI: 10.1523/eneuro.0034-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/22/2024] [Accepted: 04/16/2024] [Indexed: 05/26/2024] Open
Abstract
Studies on genetic robustness recently revealed transcriptional adaptation (TA) as a mechanism by which an organism can compensate for genetic mutations through activation of homologous genes. Here, we discovered that genetic mutations, introducing a premature termination codon (PTC) in the amyloid precursor protein-b (appb) gene, activated TA of two other app family members, appa and amyloid precursor-like protein-2 (aplp2), in zebrafish. The observed transcriptional response of appa and aplp2 required degradation of mutant mRNA and did not depend on Appb protein level. Furthermore, TA between amyloid precursor protein (APP) family members was observed in human neuronal progenitor cells; however, compensation was only present during early neuronal differentiation and could not be detected in a more differentiated neuronal stage or adult zebrafish brain. Using knockdown and chemical inhibition, we showed that nonsense-mediated mRNA decay (NMD) is involved in degradation of mutant mRNA and that Upf1 and Upf2, key proteins in the NMD pathway, regulate the endogenous transcript levels of appa, appb, aplp1, and aplp2 In conclusion, our results suggest that the expression level of App family members is regulated by the NMD pathway and that mutations destabilizing app/APP mRNA can induce genetic compensation by other family members through TA in both zebrafish and human neuronal progenitors.
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Affiliation(s)
- Maryam Rahmati
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
| | - Jasmine Chebli
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
| | - Rakesh Kumar Banote
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
| | - Sandra Roselli
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
| | - Lotta Agholme
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N #BG, United Kingdom
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 431 41, Sweden
- United Kingdom Dementia Research Institute, London W1T 7NF, United Kingdom
- Hong Kong Center for Neurodegenerative Diseases, 17 Science Park W Ave, Hong Kong, China
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53792
| | - Alexandra Abramsson
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
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Ma Z, Sharma R, Rogers AN. Physiological Consequences of Nonsense-Mediated Decay and Its Role in Adaptive Responses. Biomedicines 2024; 12:1110. [PMID: 38791071 PMCID: PMC11117581 DOI: 10.3390/biomedicines12051110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 04/30/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
The evolutionarily conserved nonsense-mediated mRNA decay (NMD) pathway is a quality control mechanism that degrades aberrant mRNA containing one or more premature termination codons (PTCs). Recent discoveries indicate that NMD also differentially regulates mRNA from wild-type protein-coding genes despite lacking PTCs. Together with studies showing that NMD is involved in development and adaptive responses that influence health and longevity, these findings point to an expanded role of NMD that adds a new layer of complexity in the post-transcriptional regulation of gene expression. However, the extent of its control, whether different types of NMD play different roles, and the resulting physiological outcomes remain unclear and need further elucidation. Here, we review different branches of NMD and what is known of the physiological outcomes associated with this type of regulation. We identify significant gaps in the understanding of this process and the utility of genetic tools in accelerating progress in this area.
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Affiliation(s)
- Zhengxin Ma
- MDI Biological Laboratory, Bar Harbor, ME 04609, USA
| | - Ratna Sharma
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA;
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4
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Kolakada D, Campbell AE, Galvis LB, Li Z, Lore M, Jagannathan S. A system of reporters for comparative investigation of EJC-independent and EJC-enhanced nonsense-mediated mRNA decay. Nucleic Acids Res 2024; 52:e34. [PMID: 38375914 PMCID: PMC11014337 DOI: 10.1093/nar/gkae121] [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: 06/28/2023] [Revised: 01/05/2024] [Accepted: 02/07/2024] [Indexed: 02/21/2024] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a network of pathways that degrades transcripts that undergo premature translation termination. In mammals, NMD can be divided into the exon junction complex (EJC)-enhanced and EJC-independent branches. Fluorescence- and luminescence-based reporters have long been effective tools to investigate NMD, yet existing reporters largely focus on the EJC-enhanced pathway. Here, we present a system of reporters for comparative studies of EJC-independent and EJC-enhanced NMD. This system also enables the study of NMD-associated outcomes such as premature termination codon (PTC) readthrough and truncated protein degradation. These reporters are compatible with fluorescence or luminescence-based readouts via transient transfection or stable integration. Using this reporter system, we show that EJC-enhanced NMD RNA levels are reduced by 2- or 9-fold and protein levels are reduced by 7- or 12-fold compared to EJC-independent NMD, depending on the reporter gene used. Additionally, the extent of readthrough induced by G418 and an NMD inhibitor (SMG1i), alone and in combination, varies across NMD substrates. When combined, G418 and SMG1i increase readthrough product levels in an additive manner for EJC-independent reporters, while EJC-enhanced reporters show a synergistic effect. We present these reporters as a valuable toolkit to deepen our understanding of NMD and its associated mechanisms.
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Affiliation(s)
- Divya Kolakada
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Amy E Campbell
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Zhongyou Li
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Mlana Lore
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Machida R, Ogawa T, Min Soe K, Moriyama K. Nonsense-mediated mRNA decay affects hyperactive root formation in oculo-facio-cardio-dental syndrome via up-frameshift protein 1. J Oral Biosci 2024; 66:225-231. [PMID: 38244688 DOI: 10.1016/j.job.2024.01.008] [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: 09/11/2023] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 01/22/2024]
Abstract
OBJECTIVES Oculo-facio-cardio-dental (OFCD) syndrome is a rare X-linked genetic disorder caused by mutations in the BCL6 co-repressor (BCOR) and is mainly characterized by radiculomegaly (elongated dental roots). All BCOR mutations reported to date have been associated with premature termination codons, indicating that nonsense-mediated mRNA decay (NMD) might play a vital role in the pathogenesis of OFCD syndrome. However, the molecular mechanisms underlying NMD remain unclear. In this study, we investigated the involvement of up-frameshift protein 1 (UPF1), which plays a central role in NMD, in the hyperactive root formation caused by BCOR mutations. METHODS Periodontal ligament cells, isolated from a Japanese woman with a c.3668delC frameshift mutation in BCOR, and primary human periodontal ligament fibroblasts (HPdLFs) were used for an RNA immunoprecipitation assay to confirm the binding of UPF1 to mutated BCOR. Additionally, the effects of UPF1 on the BCOR transcription levels and corresponding gene expression were determined by performing relative quantitative real-time polymerase chain reactions. RESULTS RNA immunoprecipitation revealed that UPF1 binds to exon 9 of mutated BCOR. Additionally, UPF1 knockdown via siRNA upregulated the transcription of BCOR, whereas overexpression of wild-type and mutated BCOR with the same frameshift mutation in HPdLFs altered bone morphogenetic protein 2 (BMP2) expression. CONCLUSIONS Our findings indicate that BCOR mutations regulate the transcription of BCOR via UPF1, which may in turn regulate the expression of BMP2. NMD, caused by a c.3668delC mutation, potentially leads to an OFCD syndrome phenotype, including elongated dental roots.
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Affiliation(s)
- Ryoto Machida
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Takuya Ogawa
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Kyaw Min Soe
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Keiji Moriyama
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
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6
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Dai Y, Zhang H, Feng S, Guo C, Tian W, Sun Y, Zhang Y. SMG9 is a novel prognostic-related biomarker in glioma correlating with ferroptosis and immune infiltrates. Heliyon 2024; 10:e25716. [PMID: 38384572 PMCID: PMC10878878 DOI: 10.1016/j.heliyon.2024.e25716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 01/19/2024] [Accepted: 02/01/2024] [Indexed: 02/23/2024] Open
Abstract
Background Glioma is the most frequent type of malignancy that may damage the brain with high morbidity and mortality rates and patients' prognoses are still dismal. Ferroptosis, a newly uncovered mode of programmed cell death, may be triggered to destroy glioma cells. Nevertheless, the significance of ferroptosis-related genes (FRGs) in predicting prognosis in glioma individuals is still a mystery. Methods The CGGA (The Chinese Glioma Atlas), GEO (Gene Expression Omnibus), and TCGA (The Cancer Genome Atlas) databases were all searched to obtain the glioma expression dataset. First, TCGA was searched to identify differentially expressed genes (DEGs). This was followed by a machine learning algorithm-based screening of the glioma's most relevant genes. Additionally, these genes were subjected to Gene Ontology (GO) and KEGG (Kyoto Encyclopedia of Genes and Genomes) functional enrichment analyses. The chosen biological markers were then submitted to single-cell, immune function, and gene set enrichment analysis (GSEA). In addition, we performed functional enrichment and Mfuzz expression profile clustering on the most promising biological markers to delve deeper into their regulatory mechanisms and assess their clinical diagnostic capacities. Results We identified 4444 DEGs via differential analysis and 564 FRGs from the FerrDb database. The two were subjected to intersection analysis, which led to the discovery of 143 overlapping genes. After that, glioma biological markers were identified in fourteen genes by the use of machine learning methods. In terms of its use for clinical diagnosis, SMG9 stands out as the most significant among these biomarkers. Conclusion In light of these findings, the identification of SMG9 as a new biological marker has the potential to provide information on the mechanism of action and the effect of the immune milieu in glioma. The promise of SMG9 in glioma prognosis prediction warrants more study.
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Affiliation(s)
- Yong Dai
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute & Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huan Zhang
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute & Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Sujuan Feng
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute & Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chao Guo
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute & Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wenjie Tian
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
- State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute & Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yimei Sun
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
| | - Yi Zhang
- Department of Neurosurgery, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, No. 666 Shengli Road, Nantong 226001, China
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Ottens F, Efstathiou S, Hoppe T. Cutting through the stress: RNA decay pathways at the endoplasmic reticulum. Trends Cell Biol 2023:S0962-8924(23)00236-2. [PMID: 38008608 DOI: 10.1016/j.tcb.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/28/2023]
Abstract
The endoplasmic reticulum (ER) is central to the processing of luminal, transmembrane, and secretory proteins, and maintaining a functional ER is essential for organismal physiology and health. Increased protein-folding load on the ER causes ER stress, which activates quality control mechanisms to restore ER function and protein homeostasis. Beyond protein quality control, mRNA decay pathways have emerged as potent ER fidelity regulators, but their mechanistic roles in ER quality control and their interrelationships remain incompletely understood. Herein, we review ER-associated RNA decay pathways - including regulated inositol-requiring enzyme 1α (IRE1α)-dependent mRNA decay (RIDD), nonsense-mediated mRNA decay (NMD), and Argonaute-dependent RNA silencing - in ER homeostasis, and highlight the intricate coordination of ER-targeted RNA and protein decay mechanisms and their association with antiviral defense.
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Affiliation(s)
- Franziska Ottens
- Institute for Genetics, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Sotirios Efstathiou
- Institute for Genetics, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Thorsten Hoppe
- Institute for Genetics, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital of Cologne, Cologne, Germany.
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Akbari B, Ahmadi E, Zabihi MR, Zamir MR, Shaker MS, Noorbakhsh F. SARS-CoV-2 helicase might interfere with cellular nonsense-mediated RNA decay: insights from a bioinformatics study. BMC Genom Data 2023; 24:68. [PMID: 37980504 PMCID: PMC10657555 DOI: 10.1186/s12863-023-01173-y] [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: 03/15/2023] [Accepted: 11/10/2023] [Indexed: 11/20/2023] Open
Abstract
BACKGROUND Viruses employ diverse strategies to interfere with host defense mechanisms, including the production of proteins that mimic or resemble host proteins. This study aimed to analyze the similarities between SARS-CoV-2 and human proteins, investigate their impact on virus-host interactions, and elucidate underlying mechanisms. RESULTS Comparing the proteins of SARS-CoV-2 with human and mammalian proteins revealed sequence and structural similarities between viral helicase with human UPF1. The latter is a protein that is involved in nonsense-mediated RNA decay (NMD), an mRNA surveillance pathway which also acts as a cellular defense mechanism against viruses. Protein sequence similarities were also observed between viral nsp3 and human Poly ADP-ribose polymerase (PARP) family of proteins. Gene set enrichment analysis on transcriptomic data derived from SARS-CoV-2 positive samples illustrated the enrichment of genes belonging to the NMD pathway compared with control samples. Moreover, comparing transcriptomic data from SARS-CoV-2-infected samples with transcriptomic data derived from UPF1 knockdown cells demonstrated a significant overlap between datasets. CONCLUSIONS These findings suggest that helicase/UPF1 sequence and structural similarity might have the ability to interfere with the NMD pathway with pathogenic and immunological implications.
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Affiliation(s)
- Behnia Akbari
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ehsan Ahmadi
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zabihi
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Roshan Zamir
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Sadeghi Shaker
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Farshid Noorbakhsh
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran.
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Khalifah BA, Alghamdi SA, Alhasan AH. Unleashing the potential of catalytic RNAs to combat mis-spliced transcripts. Front Bioeng Biotechnol 2023; 11:1244377. [PMID: 38047291 PMCID: PMC10690607 DOI: 10.3389/fbioe.2023.1244377] [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: 06/22/2023] [Accepted: 10/23/2023] [Indexed: 12/05/2023] Open
Abstract
Human transcriptome can undergo RNA mis-splicing due to spliceopathies contributing to the increasing number of genetic diseases including muscular dystrophy (MD), Alzheimer disease (AD), Huntington disease (HD), myelodysplastic syndromes (MDS). Intron retention (IR) is a major inducer of spliceopathies where two or more introns remain in the final mature mRNA and account for many intronic expansion diseases. Potential removal of such introns for therapeutic purposes can be feasible when utilizing bioinformatics, catalytic RNAs, and nano-drug delivery systems. Overcoming delivery challenges of catalytic RNAs was discussed in this review as a future perspective highlighting the significance of utilizing synthetic biology in addition to high throughput deep sequencing and computational approaches for the treatment of mis-spliced transcripts.
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Affiliation(s)
- Bashayer A. Khalifah
- Institute for Bioengineering, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
- Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Ali H. Alhasan
- Institute for Bioengineering, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
- College of Science and General Studies, Alfaisal University, Riyadh, Saudi Arabia
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Kolakada D, Campbell AE, Baquero Galvis L, Li Z, Lore M, Jagannathan S. A system of reporters for comparative investigation of EJC-independent and EJC-enhanced nonsense-mediated mRNA decay. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567061. [PMID: 38014198 PMCID: PMC10680754 DOI: 10.1101/2023.11.14.567061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is a network of pathways that degrades transcripts that undergo premature translation termination. In mammals, NMD can be divided into the exon junction complex (EJC)-enhanced and EJC-independent branches. Fluorescence- and luminescence-based reporters have long been effective tools to investigate NMD, yet existing reporters largely focus on the EJC-enhanced pathway. Here, we present a system of reporters for comparative studies of EJC-independent and EJC-enhanced NMD. This system also enables the study of NMD-associated outcomes such as premature termination codon (PTC) readthrough and truncated protein degradation. These reporters are compatible with fluorescence or luminescence-based readouts via transient transfection or stable integration. Using this reporter system, we show that EJC-enhanced NMD RNA levels are reduced by 2- or 9-fold and protein levels are reduced by 7- or 12-fold compared to EJC-independent NMD, depending on the reporter gene used. Additionally, the extent of readthrough induced by G418 and SMG1i, alone and in combination, varies across NMD substrates. When combined, G418 and SMG1i increase readthrough product levels in an additive manner for EJC-independent reporters, while EJC-enhanced reporters show a synergistic effect. We present these reporters as a valuable toolkit to deepen our understanding of NMD and its associated mechanisms.
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Affiliation(s)
- Divya Kolakada
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Amy E. Campbell
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Zhongyou Li
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Mlana Lore
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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11
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Patro I, Sahoo A, Nayak BR, Das R, Majumder S, Panigrahi GK. Nonsense-Mediated mRNA Decay: Mechanistic Insights and Physiological Significance. Mol Biotechnol 2023:10.1007/s12033-023-00927-4. [PMID: 37930508 DOI: 10.1007/s12033-023-00927-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/28/2023] [Indexed: 11/07/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved surveillance mechanism across eukaryotes and also regulates the expression of physiological transcripts, thus involved in gene regulation. It essentially ensures recognition and removal of aberrant transcripts. Therefore, the NMD protects the cellular system by restricting the synthesis of truncated proteins, potentially by eliminating the faulty mRNAs. NMD is an evolutionarily conserved surveillance mechanism across eukaryotes and also regulates the expression of physiological transcripts, thus involved in gene regulation as well. Primarily, the NMD machinery scans and differentiates the aberrant and non-aberrant transcripts. A myriad of cellular dysfunctions arise due to production of truncated proteins, so the NMD core proteins, the up-frameshift factors (UPFs) recognizes the faulty mRNAs and further recruits factors resulting in the mRNA degradation. NMD exhibits astounding variability in its ability in regulating cellular mechanisms including both pathological and physiological events. But, the detailed underlying molecular mechanisms in NMD remains blurred and require extensive investigation to gain insights on cellular homeostasis. The complexity in understanding of NMD pathway arises due to the involvement of numerous proteins, molecular interactions and their functioning in different steps of this process. Moreover methods such as alternative splicing generates numerous isoforms of mRNA, so it makes difficulties in understanding the impact of alternative splicing on the efficiency of NMD functioning. Role of NMD in cancer development is very complex. Studies have shown that in some cases cancer cells use NMD pathway as a tool to exploit the NMD mechanism to maintain tumor microenvironment. A greater level of understanding about the intricate mechanism of how tumor used NMD pathway for their benefits, a strategy can be developed for targeting and inhibiting NMD factors involved in pro-tumor activity. There are very little amount of information available about the NMD pathway, how it discriminate mRNAs that are targeted by NMD from those that are not. This review highlights our current understanding of NMD, specifically the regulatory mechanisms and attempts to outline less explored questions that warrant further investigations. Taken as a whole, a detailed molecular understanding of the NMD mechanism could lead to wide-ranging applications for improving cellular homeostasis and paving out strategies in combating pathological disorders leaping forward toward achieving United Nations sustainable development goals (SDG 3: Good health and well-being).
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Affiliation(s)
- Ipsita Patro
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha, India
| | - Annapurna Sahoo
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha, India.
| | - Bilash Ranjan Nayak
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha, India
| | - Rutupurna Das
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha, India
| | - Sanjoy Majumder
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha, India
| | - Gagan Kumar Panigrahi
- School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha, India.
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Fair B, Najar CBA, Zhao J, Lozano S, Reilly A, Mossian G, Staley JP, Wang J, Li YI. Global impact of aberrant splicing on human gene expression levels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.13.557588. [PMID: 37745605 PMCID: PMC10515962 DOI: 10.1101/2023.09.13.557588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Alternative splicing (AS) is pervasive in human genes, yet the specific function of most AS events remains unknown. It is widely assumed that the primary function of AS is to diversify the proteome, however AS can also influence gene expression levels by producing transcripts rapidly degraded by nonsense-mediated decay (NMD). Currently, there are no precise estimates for how often the coupling of AS and NMD (AS-NMD) impacts gene expression levels because rapidly degraded NMD transcripts are challenging to capture. To better understand the impact of AS on gene expression levels, we analyzed population-scale genomic data in lymphoblastoid cell lines across eight molecular assays that capture gene regulation before, during, and after transcription and cytoplasmic decay. Sequencing nascent mRNA transcripts revealed frequent aberrant splicing of human introns, which results in remarkably high levels of mRNA transcripts subject to NMD. We estimate that ~15% of all protein-coding transcripts are degraded by NMD, and this estimate increases to nearly half of all transcripts for lowly-expressed genes with many introns. Leveraging genetic variation across cell lines, we find that GWAS trait-associated loci explained by AS are similarly likely to associate with NMD-induced expression level differences as with differences in protein isoform usage. Additionally, we used the splice-switching drug risdiplam to perturb AS at hundreds of genes, finding that ~3/4 of the splicing perturbations induce NMD. Thus, we conclude that AS-NMD substantially impacts the expression levels of most human genes. Our work further suggests that much of the molecular impact of AS is mediated by changes in protein expression levels rather than diversification of the proteome.
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Affiliation(s)
- Benjamin Fair
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Carlos Buen Abad Najar
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Junxing Zhao
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Stephanie Lozano
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
- Present address: Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - Austin Reilly
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Gabriela Mossian
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Yang I Li
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
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Petrić Howe M, Patani R. Nonsense-mediated mRNA decay in neuronal physiology and neurodegeneration. Trends Neurosci 2023; 46:879-892. [PMID: 37543480 DOI: 10.1016/j.tins.2023.07.001] [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: 03/02/2023] [Revised: 06/19/2023] [Accepted: 07/09/2023] [Indexed: 08/07/2023]
Abstract
The processes of mRNA export from the nucleus and subsequent mRNA translation in the cytoplasm are of particular relevance in eukaryotic cells. In highly polarised cells such as neurons, finely-tuned molecular regulation of these processes serves to safeguard the spatiotemporal fidelity of gene expression. Nonsense-mediated mRNA decay (NMD) is a cytoplasmic translation-dependent quality control process that regulates gene expression in a wide range of scenarios in the nervous system, including neurodevelopment, learning, and memory formation. Moreover, NMD dysregulation has been implicated in a broad range of neurodevelopmental and neurodegenerative disorders. We discuss how NMD and related aspects of mRNA translation regulate key neuronal functions and, in particular, we focus on evidence implicating these processes in the molecular pathogenesis of neurodegeneration. Finally, we discuss the therapeutic potential and challenges of targeting mRNA translation and NMD across the spectrum of largely untreatable neurological diseases.
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Affiliation(s)
- Marija Petrić Howe
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London (UCL), Queen Square, WC1N 3BG London, UK.
| | - Rickie Patani
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London (UCL), Queen Square, WC1N 3BG London, UK.
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Yang L, Wei J, Ma X, Cheng R, Zhang H, Jin T. Pan-Cancer Analysis of the Prognostic and Immunological Role of SMG5: A Biomarker for Cancers. Oncology 2023; 102:168-182. [PMID: 37699361 DOI: 10.1159/000533421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/29/2023] [Indexed: 09/14/2023]
Abstract
INTRODUCTION SMG5 is involved in tumor cell development and viewed as a potential target for immunotherapy. The purpose of this study was to systematically analyze the expression level, function, and prognostic value of SMG5 in pan-cancers. METHODS Differential expression of SMG5 in normal and tumor tissues was analyzed using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression Database (GTEx) data. Survival analysis was performed by Kaplan-Meier method and Cox risk regression. The relationship between SMG5 expression and lymphocyte abundance, tumor cell immune infiltration level, molecular and immune subtypes as well as immune checkpoints was analyzed by tumor-immune system interactions database (TISIDB), Tumor Immune Estimation Resource (TIMER), and Sangerbox databases. The correlation between SMG5 and immune scores was studied using the Estimation of Stromal and Immune Cells in Malignant Tumours using Expression (ESTIMATE) data algorithm. Further, drug sensitivity analysis of SMG5 with low-grade glioma (LGG) was conducted using the CellMiner database. RESULTS SMG5 was highly expressed in 23 tumors and only had a significant impact on the prognosis of patients with LGG only. In addition, in tumor microenvironment and tumor immune analysis, we found that the level of immune infiltration, tumor mutational load, microsatellite instability, and immune checkpoints of LGG were significantly correlated with SMG5 expression. Furthermore, SMG5 was significantly associated with immune scores, stromal scores, and sensitivity of some drugs in LGG. CONCLUSION SMG5 is differentially expressed in several cancers and is significantly associated with prognosis, immune microenvironment, and immune checkpoints in LGG patients. Therefore, SMG5 could be a potential pan-cancer biomarker and an immunotherapeutic target for LGG.
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Affiliation(s)
- Leteng Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
- College of Life Science, Northwest University, Xi'an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi'an, China
| | - Jie Wei
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
- College of Life Science, Northwest University, Xi'an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi'an, China
| | - Xiaoya Ma
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
- College of Life Science, Northwest University, Xi'an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi'an, China
| | - Rui Cheng
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
| | - Huan Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
- College of Life Science, Northwest University, Xi'an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi'an, China
| | - Tianbo Jin
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
- College of Life Science, Northwest University, Xi'an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi'an, China
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Nasif S, Colombo M, Uldry AC, Schröder M, de Brot S, Mühlemann O. Inhibition of nonsense-mediated mRNA decay reduces the tumorigenicity of human fibrosarcoma cells. NAR Cancer 2023; 5:zcad048. [PMID: 37681034 PMCID: PMC10480688 DOI: 10.1093/narcan/zcad048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/08/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a eukaryotic RNA decay pathway with roles in cellular stress responses, differentiation, and viral defense. It functions in both quality control and post-transcriptional regulation of gene expression. NMD has also emerged as a modulator of cancer progression, although available evidence supports both a tumor suppressor and a pro-tumorigenic role, depending on the model. To further investigate the role of NMD in cancer, we knocked out the NMD factor SMG7 in the HT1080 human fibrosarcoma cell line, resulting in suppression of NMD function. We then compared the oncogenic properties of the parental cell line, the SMG7-knockout, and a rescue cell line in which we re-introduced both isoforms of SMG7. We also tested the effect of a drug inhibiting the NMD factor SMG1 to distinguish NMD-dependent effects from putative NMD-independent functions of SMG7. Using cell-based assays and a mouse xenograft tumor model, we showed that suppression of NMD function severely compromises the oncogenic phenotype. Molecular pathway analysis revealed that NMD suppression strongly reduces matrix metalloprotease 9 (MMP9) expression and that MMP9 re-expression partially rescues the oncogenic phenotype. Since MMP9 promotes cancer cell migration and invasion, metastasis and angiogenesis, its downregulation may contribute to the reduced tumorigenicity of NMD-suppressed cells. Collectively, our results highlight the potential value of NMD inhibition as a therapeutic approach.
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Affiliation(s)
- Sofia Nasif
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Switzerland
| | - Martino Colombo
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Switzerland
| | - Anne-Christine Uldry
- Proteomics & Mass Spectrometry Core Facility, Department for BioMedical Research, University of Bern, Switzerland
| | - Markus S Schröder
- NCCR RNA & Disease Bioinformatics Support,Department of Biology, ETH Zürich, Switzerland
| | - Simone de Brot
- COMPATH, Institute of Animal Pathology, University of Bern, Switzerland
| | - Oliver Mühlemann
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Switzerland
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Halbout M, Bury M, Hanet A, Gerin I, Graff J, Killian T, Gatto L, Vertommen D, Bommer GT. SUZ domain-containing proteins have multiple effects on nonsense-mediated decay target transcripts. J Biol Chem 2023; 299:105095. [PMID: 37507022 PMCID: PMC10470013 DOI: 10.1016/j.jbc.2023.105095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Many transcripts are targeted by nonsense-mediated decay (NMD), leading to their degradation and the inhibition of their translation. We found that the protein SUZ domain-containing protein 1 (SZRD1) interacts with the key NMD factor up-frameshift 1. When recruited to NMD-sensitive reporter gene transcripts, SZRD1 increased protein production, at least in part, by relieving translational inhibition. The conserved SUZ domain in SZRD1 was required for this effect. The SUZ domain is present in only three other human proteins besides SZRD1: R3H domain-containing protein 1 and 2 (R3HDM1, R3HDM2) and cAMP-regulated phosphoprotein 21 (ARPP21). We found that ARPP21, similarly to SZRD1, can increase protein production from NMD-sensitive reporter transcripts in an SUZ domain-dependent manner. This indicated that the SUZ domain-containing proteins could prevent translational inhibition of transcripts targeted by NMD. Consistent with the idea that SZRD1 mainly prevents translational inhibition, we did not observe a systematic decrease in the abundance of NMD targets when we knocked down SZRD1. Surprisingly, knockdown of SZRD1 in two different cell lines led to reduced levels of the NMD component UPF3B, which was accompanied by increased levels in a subset of NMD targets. This suggests that SZRD1 is required to maintain normal UPF3B levels and indicates that the effect of SZRD1 on NMD targets is not limited to a relief from translational inhibition. Overall, our study reveals that human SUZ domain-containing proteins play a complex role in regulating protein output from transcripts targeted by NMD.
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Affiliation(s)
- Mathias Halbout
- Department of Physiological Chemistry, de Duve Institute, UCLouvain, Brussels, Belgium; WELBIO, Brussels, Belgium
| | - Marina Bury
- Department of Physiological Chemistry, de Duve Institute, UCLouvain, Brussels, Belgium; WELBIO, Brussels, Belgium
| | - Aoife Hanet
- Department of Physiological Chemistry, de Duve Institute, UCLouvain, Brussels, Belgium
| | - Isabelle Gerin
- Department of Physiological Chemistry, de Duve Institute, UCLouvain, Brussels, Belgium; WELBIO, Brussels, Belgium
| | - Julie Graff
- Department of Physiological Chemistry, de Duve Institute, UCLouvain, Brussels, Belgium; WELBIO, Brussels, Belgium
| | - Theodore Killian
- Computational Biology Laboratory, de Duve Institute, UCLouvain, Bruxelles, Belgium
| | - Laurent Gatto
- Computational Biology Laboratory, de Duve Institute, UCLouvain, Bruxelles, Belgium
| | - Didier Vertommen
- Protein Phosphorylation Unit, de Duve Institute, UCLouvain, Brussels, Belgium
| | - Guido T Bommer
- Department of Physiological Chemistry, de Duve Institute, UCLouvain, Brussels, Belgium; WELBIO, Brussels, Belgium.
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA (NEW YORK, N.Y.) 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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Muñoz O, Lore M, Jagannathan S. The long and short of EJC-independent nonsense-mediated RNA decay. Biochem Soc Trans 2023; 51:1121-1129. [PMID: 37145092 DOI: 10.1042/bst20221131] [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: 01/11/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
Nonsense-mediated RNA decay (NMD) plays a dual role as an RNA surveillance mechanism against aberrant transcripts containing premature termination codons and as a gene regulatory mechanism for normal physiological transcripts. This dual function is possible because NMD recognizes its substrates based on the functional definition of a premature translation termination event. An efficient mode of NMD target recognition involves the presence of exon-junction complexes (EJCs) downstream of the terminating ribosome. A less efficient, but highly conserved, mode of NMD is triggered by long 3' untranslated regions (UTRs) that lack EJCs (termed EJC-independent NMD). While EJC-independent NMD plays an important regulatory role across organisms, our understanding of its mechanism, especially in mammalian cells, is incomplete. This review focuses on EJC-independent NMD and discusses the current state of knowledge and factors that contribute to the variability in the efficiency of this mechanism.
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Affiliation(s)
- Oscar Muñoz
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
| | - Mlana Lore
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
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Huang S, Zhang H, Chen W, Su N, Yuan C, Zhang J, Xiang S, Hu X. CRISPR/Cas9-Mediated Knockout of tnfaip1 in Zebrafish Plays a Role in Early Development. Genes (Basel) 2023; 14:genes14051005. [PMID: 37239365 DOI: 10.3390/genes14051005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
TNF α-induced protein 1 (TNFAIP1) was first identified in human umbilical vein endothelial cells and can be induced by tumor necrosis factor α (TNFα). Early studies have found that TNFAIP1 is involved in the development of many tumors and is closely associated with the neurological disorder Alzheimer's disease. However, little is known about the expression pattern of TNFAIP1 under physiological conditions and its function during embryonic development. In this study, we used zebrafish as a model to illustrate the early developmental expression pattern of tnfaip1 and its role in early development. First, we examined the expression pattern of tnfaip1 during early zebrafish development using quantitative real-time PCR and whole mount in situ hybridization and found that tnfaip1 was highly expressed in early embryonic development and, subsequently, expression became localized to anterior embryonic structures. To investigate the function of tnfaip1 during early development, we constructed a model of a stably inherited tnfaip1 mutant using the CRISPR/Cas9 system. Tnfaip1 mutant embryos showed significant developmental delays as well as microcephaly and microphthalmia. At the same time, we found decreased expression of the neuronal marker genes tuba1b, neurod1, and ccnd1 in tnfaip1 mutants. Analysis of transcriptome sequencing data revealed altered expression of the embryonic development related genes dhx40, hspa13, tnfrsf19, nppa, lrp2b, hspb9, clul1, zbtb47a, cryba1a, and adgrg4a in the tnfaip1 mutants. These findings suggest an important role for tnfaip1 in the early development of zebrafish.
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Affiliation(s)
- Shulan Huang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Hongning Zhang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Wen Chen
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
- Key Laboratory of Vascular Biology and Translational Medicine, Medical School, Hunan University of Chinese Medicine, Changsha 410208, China
| | - Na Su
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Changyue Yuan
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Jian Zhang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Shuanglin Xiang
- Engineering Research Center for Antibodies from Experimental Animals of Hunan Province, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Xiang Hu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China
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McCann JJ, Fleenor DE, Chen J, Lai CH, Bass TE, Kastan MB. Participation of ATM, SMG1, and DDX5 in a DNA Damage-Induced Alternative Splicing Pathway. Radiat Res 2023; 199:406-421. [PMID: 36921295 PMCID: PMC10162594 DOI: 10.1667/rade-22-00219.1] [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: 12/09/2022] [Accepted: 02/03/2023] [Indexed: 03/17/2023]
Abstract
Altered cellular responses to DNA damage can contribute to cancer development, progression, and therapeutic resistance. Mutations in key DNA damage response factors occur across many cancer types, and the DNA damage-responsive gene, TP53, is frequently mutated in a high percentage of cancers. We recently reported that an alternative splicing pathway induced by DNA damage regulates alternative splicing of TP53 RNA and further modulates cellular stress responses. Through damage-induced inhibition of the SMG1 kinase, TP53 pre-mRNA is alternatively spliced to generate TP53b mRNA and p53b protein is required for optimal induction of cellular senescence after ionizing radiation-induced DNA damage. Herein, we confirmed and extended these observations by demonstrating that the ATM protein kinase is required for repression of SMG1 kinase activity after ionizing radiation. We found that the RNA helicase and splicing factor, DDX5, interacts with SMG1, is required for alternative splicing of TP53 pre-mRNA to TP53b and TP53c mRNAs after DNA damage, and contributes to radiation-induced cellular senescence. Interestingly, the role of SMG1 in alternative splicing of p53 appears to be distinguishable from its role in regulating nonsense-mediated RNA decay. Thus, ATM, SMG1, and DDX5 participate in a DNA damage-induced alternative splicing pathway that regulates TP53 splicing and modulates radiation-induced cellular senescence.
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Affiliation(s)
- Jennifer J. McCann
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Donald E. Fleenor
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Jing Chen
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Chun-Hsiang Lai
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Thomas E. Bass
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Michael B. Kastan
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
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Sybilska E, Daszkowska-Golec A. Alternative splicing in ABA signaling during seed germination. FRONTIERS IN PLANT SCIENCE 2023; 14:1144990. [PMID: 37008485 PMCID: PMC10060653 DOI: 10.3389/fpls.2023.1144990] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 03/02/2023] [Indexed: 06/19/2023]
Abstract
Seed germination is an essential step in a plant's life cycle. It is controlled by complex physiological, biochemical, and molecular mechanisms and external factors. Alternative splicing (AS) is a co-transcriptional mechanism that regulates gene expression and produces multiple mRNA variants from a single gene to modulate transcriptome diversity. However, little is known about the effect of AS on the function of generated protein isoforms. The latest reports indicate that alternative splicing (AS), the relevant mechanism controlling gene expression, plays a significant role in abscisic acid (ABA) signaling. In this review, we present the current state of the art about the identified AS regulators and the ABA-related changes in AS during seed germination. We show how they are connected with the ABA signaling and the seed germination process. We also discuss changes in the structure of the generated AS isoforms and their impact on the functionality of the generated proteins. Also, we point out that the advances in sequencing technology allow for a better explanation of the role of AS in gene regulation by more accurate detection of AS events and identification of full-length splicing isoforms.
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22
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Regulation of Arp5 expression by alternative splicing coupled to nonsense-mediated RNA decay. Biochem Biophys Res Commun 2023; 657:50-58. [PMID: 36977368 DOI: 10.1016/j.bbrc.2023.03.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 03/16/2023] [Indexed: 03/19/2023]
Abstract
Actin-related protein 5 (ARP5) inhibits the differentiation of skeletal, smooth, and cardiac muscle tissues, and ARP5 expression increases or decreases according to physiological and pathological changes in the muscle differentiation status. However, the regulatory mechanisms of ARP5 expression are largely unknown. Here, we identified a novel Arp5 mRNA isoform that contains premature termination codons in alternative exon 7b and is thus targeted by nonsense-mediated mRNA decay (NMD). In mouse skeletal muscle cells, switching from the canonical Arp5 isoform, i.e., Arp5(7a), to the NMD-targeted isoform Arp5(7b) occurred during differentiation, suggesting that Arp5 expression is regulated by alternative splicing coupled to NMD (AS-NMD). We developed an original method to accurately quantify the proportion of both Arp5 isoforms and measured higher levels of Arp5(7b) in muscle and brain tissues, where ARP5 is less expressed. The 3' splice site in Arp5 exon 7 has an unusual acceptor sequence that often leads to the skip of the authentic splice site and the use of the cryptic splice site localized 16 bases downstream. When the unusual acceptor sequence was mutated to the usual one, the Arp5(7b) isoform was barely detectable. The expression of several splicing factors involved in 3' splice site recognition was reduced after muscle differentiation. Additionally, knockdown of splicing factors increased the levels of Arp5(7b) and decreased the expression of Arp5(7a). Furthermore, strong positive correlations were found between Arp5 expression and the levels of these splicing factors in human skeletal and cardiac muscle tissues. Thus, Arp5 expression in muscle tissues is most likely regulated by the AS-NMD pathway.
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Sun L, Mailliot J, Schaffitzel C. Nonsense-Mediated mRNA Decay Factor Functions in Human Health and Disease. Biomedicines 2023; 11:722. [PMID: 36979701 PMCID: PMC10045457 DOI: 10.3390/biomedicines11030722] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/06/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a cellular surveillance mechanism that degrades mRNAs with a premature stop codon, avoiding the synthesis of C-terminally truncated proteins. In addition to faulty mRNAs, NMD recognises ~10% of endogenous transcripts in human cells and downregulates their expression. The up-frameshift proteins are core NMD factors and are conserved from yeast to human in structure and function. In mammals, NMD diversified into different pathways that target different mRNAs employing additional NMD factors. Here, we review our current understanding of molecular mechanisms and cellular roles of NMD pathways and the involvement of more specialised NMD factors. We describe the consequences of mutations in NMD factors leading to neurodevelopmental diseases, and the role of NMD in cancer. We highlight strategies of RNA viruses to evade recognition and decay by the NMD machinery.
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Affiliation(s)
- Lingling Sun
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Justine Mailliot
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Christiane Schaffitzel
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
- Bristol Engineering Biology Centre BrisEngBio, 24 Tyndall Ave, Bristol BS8 1TQ, UK
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24
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Nonsense-Mediated mRNA Decay as a Mediator of Tumorigenesis. Genes (Basel) 2023; 14:genes14020357. [PMID: 36833284 PMCID: PMC9956241 DOI: 10.3390/genes14020357] [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: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/03/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved and well-characterized biological mechanism that ensures the fidelity and regulation of gene expression. Initially, NMD was described as a cellular surveillance or quality control process to promote selective recognition and rapid degradation of erroneous transcripts harboring a premature translation-termination codon (PTC). As estimated, one-third of mutated and disease-causing mRNAs were reported to be targeted and degraded by NMD, suggesting the significance of this intricate mechanism in maintaining cellular integrity. It was later revealed that NMD also elicits down-regulation of many endogenous mRNAs without mutations (~10% of the human transcriptome). Therefore, NMD modulates gene expression to evade the generation of aberrant truncated proteins with detrimental functions, compromised activities, or dominant-negative effects, as well as by controlling the abundance of endogenous mRNAs. By regulating gene expression, NMD promotes diverse biological functions during development and differentiation, and facilitates cellular responses to adaptation, physiological changes, stresses, environmental insults, etc. Mutations or alterations (such as abnormal expression, degradation, post-translational modification, etc.) that impair the function or expression of proteins associated with the NMD pathway can be deleterious to cells and may cause pathological consequences, as implicated in developmental and intellectual disabilities, genetic defects, and cancer. Growing evidence in past decades has highlighted NMD as a critical driver of tumorigenesis. Advances in sequencing technologies provided the opportunity to identify many NMD substrate mRNAs in tumor samples compared to matched normal tissues. Interestingly, many of these changes are tumor-specific and are often fine-tuned in a tumor-specific manner, suggesting the complex regulation of NMD in cancer. Tumor cells differentially exploit NMD for survival benefits. Some tumors promote NMD to degrade a subset of mRNAs, such as those encoding tumor suppressors, stress response proteins, signaling proteins, RNA binding proteins, splicing factors, and immunogenic neoantigens. In contrast, some tumors suppress NMD to facilitate the expression of oncoproteins or other proteins beneficial for tumor growth and progression. In this review, we discuss how NMD is regulated as a critical mediator of oncogenesis to promote the development and progression of tumor cells. Understanding how NMD affects tumorigenesis differentially will pave the way for the development of more effective and less toxic, targeted therapeutic opportunities in the era of personalized medicine.
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Modulation of NBAS-Related Functions in the Early Response to SARS-CoV-2 Infection. Int J Mol Sci 2023; 24:ijms24032634. [PMID: 36768954 PMCID: PMC9916797 DOI: 10.3390/ijms24032634] [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: 12/16/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
Upon infection, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is predicted to interact with diverse cellular functions, such as the nonsense-mediated decay (NMD) pathway, as suggested by the identification of the core NMD factor upframeshift-1 (UPF1) in the SARS-CoV-2 interactome, and the retrograde transport from the Golgi to the endoplasmic reticulum (ER) through the endoplasmic reticulum-Golgi intermediate compartment (ERGIC), where coronavirus assembly occurs. Here, we investigated the expression and localization of the neuroblastoma-amplified sequence (NBAS) protein, a UPF1 partner for the NMD at the ER, participating also in retrograde transport, and of its functional partners, at early time points after SARS-CoV-2 infection of the human lung epithelial cell line Calu3. We found a significant decrease of DExH-Box Helicase 34 (DHX34), suppressor with morphogenetic effect on genitalia 5 (SMG5), and SMG7 expression at 6 h post-infection, followed by a significant increase of these genes and also UPF1 and UPF2 at 9 h post-infection. Conversely, NBAS and other genes coding for NMD factors were not modulated. Known NMD substrates related to cell stress (Growth Arrest Specific 5, GAS5; transducin beta-like 2, TBL2; and DNA damage-inducible transcript 3, DDIT3) were increased in infected cells, possibly as a result of alterations in the NMD pathway and of a direct effect of the infection. We also found that the expression of unconventional SNARE in the ER 1, USE1 (p31) and Zeste White 10 homolog, ZW10, partners of NBAS in the retrograde transport function, significantly increased over time in infected cells. Co-localization of NBAS and UPF1 proteins did not change within 24 h of infection nor did it differ in infected versus non-infected cells at 1 and 24 h after infection; similarly, the co-localization of NBAS and p31 proteins was not altered by infection in this short time frame. Finally, both NBAS and UPF1 were found to co-localize with SARS-CoV-2 S and N proteins. Overall, these data are preliminary evidence of an interaction between NBAS and NBAS-related functions and SARS-CoV-2 in infected cells, deserving further investigation.
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Huang Z, Peng Y, Wei Y, Tan Y. Nonsense-mediated mRNA decay promote C2C12 cell proliferation by targeting PIK3R5. J Muscle Res Cell Motil 2022; 44:11-23. [PMID: 36512272 DOI: 10.1007/s10974-022-09639-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022]
Abstract
Nonsense mediated mRNA decay (NMD) is a highly conserved RNA quality control system, which can specifically clear abnormal mRNA and play an important role in tumorigenesis. Myoblast proliferation plays an important role in the repair of skeletal muscle injury and the development of myosarcoma, and is controlled by a variety of transcription factors and signals. The molecular mechanism by which NMD regulates the proliferation of myoblast cells is not completely clear. In this study, we found that the NMD activity of skeletal muscle is high in 1-week-old mice but decreases gradually with age, corresponding to a weakening capacity for muscle growth and regeneration. Here, we provide evidence that NMD plays an important role in myoblast proliferation and apoptosis. In addition, we found that PIK3R5 is an NMD substrate gene which can inhibit AKT activity and C2C12 cell proliferation. Therefore, NMD can target PIK3R5 to enhance AKT activity, which in turn promotes C2C12 cell proliferation. This study provides new insights into NMD regulatory mechanisms in muscular development and into potential novel therapeutic strategies for muscle atrophy.
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Affiliation(s)
- Zhenzhou Huang
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Institute of Biomedical Sciences, Shandong Normal University, Jinan, 250014, Shandong, China
| | - Yishu Peng
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Institute of Biomedical Sciences, Shandong Normal University, Jinan, 250014, Shandong, China
| | - Yuhui Wei
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Institute of Biomedical Sciences, Shandong Normal University, Jinan, 250014, Shandong, China
| | - Yanjie Tan
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Institute of Biomedical Sciences, Shandong Normal University, Jinan, 250014, Shandong, China.
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27
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Lehtiniemi T, Bourgery M, Ma L, Ahmedani A, Mäkelä M, Asteljoki J, Olotu O, Laasanen S, Zhang FP, Tan K, Chousal JN, Burow D, Koskinen S, Laiho A, Elo L, Chalmel F, Wilkinson M, Kotaja N. SMG6 localizes to the chromatoid body and shapes the male germ cell transcriptome to drive spermatogenesis. Nucleic Acids Res 2022; 50:11470-11491. [PMID: 36259644 PMCID: PMC9723633 DOI: 10.1093/nar/gkac900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 09/23/2022] [Accepted: 10/03/2022] [Indexed: 12/24/2022] Open
Abstract
Nonsense-mediated RNA decay (NMD) is a highly conserved and selective RNA turnover pathway that depends on the endonuclease SMG6. Here, we show that SMG6 is essential for male germ cell differentiation in mice. Germ-cell conditional knockout (cKO) of Smg6 induces extensive transcriptome misregulation, including a failure to eliminate meiotically expressed transcripts in early haploid cells, and accumulation of NMD target mRNAs with long 3' untranslated regions (UTRs). Loss of SMG6 in the male germline results in complete arrest of spermatogenesis at the early haploid cell stage. We find that SMG6 is strikingly enriched in the chromatoid body (CB), a specialized cytoplasmic granule in male germ cells also harboring PIWI-interacting RNAs (piRNAs) and the piRNA-binding protein PIWIL1. This raises the possibility that SMG6 and the piRNA pathway function together, which is supported by several findings, including that Piwil1-KO mice phenocopy Smg6-cKO mice and that SMG6 and PIWIL1 co-regulate many genes in round spermatids. Together, our results demonstrate that SMG6 is an essential regulator of the male germline transcriptome, and highlight the CB as a molecular platform coordinating RNA regulatory pathways to control sperm production and fertility.
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Affiliation(s)
- Tiina Lehtiniemi
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Matthieu Bourgery
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Lin Ma
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Ammar Ahmedani
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Margareeta Mäkelä
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Juho Asteljoki
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Opeyemi Olotu
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Samuli Laasanen
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
| | - Fu-Ping Zhang
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
- Turku Center for Disease Modeling, University of Turku, Turku, Finland
- GM-Unit, Helsinki Institute of Life Science, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kun Tan
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jennifer N Chousal
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Dana Burow
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Satu Koskinen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Asta Laiho
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Laura L Elo
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Frédéric Chalmel
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France
| | - Miles F Wilkinson
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- Institute for Genomic Medicine (IGM), University of California, San Diego, La Jolla, CA 92093, USA
| | - Noora Kotaja
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Turku, Finland
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Chousal JN, Sohni A, Vitting-Seerup K, Cho K, Kim M, Tan K, Porse B, Wilkinson MF, Cook-Andersen H. Progression of the pluripotent epiblast depends upon the NMD factor UPF2. Development 2022; 149:dev200764. [PMID: 36255229 PMCID: PMC9687065 DOI: 10.1242/dev.200764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/09/2022] [Indexed: 11/09/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is a highly conserved RNA turnover pathway that degrades RNAs harboring in-frame stop codons in specific contexts. Loss of NMD factors leads to embryonic lethality in organisms spanning the phylogenetic scale, but the mechanism remains unknown. Here, we report that the core NMD factor, UPF2, is required for expansion of epiblast cells within the inner cell mass of mice in vivo. We identify NMD target mRNAs in mouse blastocysts - both canonical and alternatively processed mRNAs - including those encoding cell cycle arrest and apoptosis factors, raising the possibility that NMD is essential for embryonic cell proliferation and survival. In support, the inner cell mass of Upf2-null blastocysts rapidly regresses with outgrowth and is incompetent for embryonic stem cell derivation in vitro. In addition, we uncovered concordant temporal- and lineage-specific regulation of NMD factors and mRNA targets, indicative of a shift in NMD magnitude during peri-implantation development. Together, our results reveal developmental and molecular functions of the NMD pathway in the early embryo.
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Affiliation(s)
- Jennifer N. Chousal
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Abhishek Sohni
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kristoffer Vitting-Seerup
- The Bioinformatics Centre, Department of Biology and Biotech Research & Innovation Centre, University of Copenhagen, 2200 Copenhagen, Denmark
- Section for Bioinformatics, Health Technology, Technical University of Denmark (DTU), 2800 Kongens Lyngby, Denmark
| | - Kyucheol Cho
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Matthew Kim
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kun Tan
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Bo Porse
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, DK2200 Copenhagen, Denmark
- Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Miles F. Wilkinson
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heidi Cook-Andersen
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
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29
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Del Giudice M, Foster JG, Peirone S, Rissone A, Caizzi L, Gaudino F, Parlato C, Anselmi F, Arkell R, Guarrera S, Oliviero S, Basso G, Rajan P, Cereda M. FOXA1 regulates alternative splicing in prostate cancer. Cell Rep 2022; 40:111404. [PMID: 36170835 PMCID: PMC9532847 DOI: 10.1016/j.celrep.2022.111404] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/28/2022] [Accepted: 09/01/2022] [Indexed: 11/25/2022] Open
Abstract
Dysregulation of alternative splicing in prostate cancer is linked to transcriptional programs activated by AR, ERG, FOXA1, and MYC. Here, we show that FOXA1 functions as the primary orchestrator of alternative splicing dysregulation across 500 primary and metastatic prostate cancer transcriptomes. We demonstrate that FOXA1 binds to the regulatory regions of splicing-related genes, including HNRNPK and SRSF1. By controlling trans-acting factor expression, FOXA1 exploits an "exon definition" mechanism calibrating alternative splicing toward dominant isoform production. This regulation especially impacts splicing factors themselves and leads to a reduction of nonsense-mediated decay (NMD)-targeted isoforms. Inclusion of the NMD-determinant FLNA exon 30 by FOXA1-controlled oncogene SRSF1 promotes cell growth in vitro and predicts disease recurrence. Overall, we report a role for FOXA1 in rewiring the alternative splicing landscape in prostate cancer through a cascade of events from chromatin access, to splicing factor regulation, and, finally, to alternative splicing of exons influencing patient survival.
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Affiliation(s)
- Marco Del Giudice
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - John G Foster
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Serena Peirone
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Alberto Rissone
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Livia Caizzi
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Federica Gaudino
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Caterina Parlato
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Francesca Anselmi
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Life Science and System Biology, Università degli Studi di Torino, via Accademia Albertina 13, 10123 Turin, Italy
| | - Rebecca Arkell
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Simonetta Guarrera
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Salvatore Oliviero
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Life Science and System Biology, Università degli Studi di Torino, via Accademia Albertina 13, 10123 Turin, Italy
| | - Giuseppe Basso
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Prabhakar Rajan
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK; Division of Surgery and Interventional Science, University College London, Charles Bell House, 3 Road Floor, 43-45 Foley Street, London W1W 7TS, UK; The Alan Turing Institute, British Library, 96 Euston Road, London NW1 2DB, UK; Department of Urology, Barts Health NHS Trust, the Royal London Hospital, Whitechapel Road, London E1 1BB, UK; Department of Uro-oncology, University College London NHS Foundation Trust, 47 Wimpole Street, London W1G 8SE, UK.
| | - Matteo Cereda
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.
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30
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Gui X, Zhang P, Wang D, Ding Z, Wu X, Shi J, Shen QH, Xu YZ, Ma W, Qiao Y. Phytophthora effector PSR1 hijacks the host pre-mRNA splicing machinery to modulate small RNA biogenesis and plant immunity. THE PLANT CELL 2022; 34:3443-3459. [PMID: 35699507 PMCID: PMC9421478 DOI: 10.1093/plcell/koac176] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 06/06/2022] [Indexed: 05/29/2023]
Abstract
Phytophthora effector PSR1 suppresses small RNA (sRNA)-mediated immunity in plants, but the underlying mechanism remains unknown. Here, we show that Phytophthora suppressor of RNA silencing 1 (PSR1) contributes to the pathogenicity of Phytophthora sojae and specifically binds to three conserved C-terminal domains of the eukaryotic PSR1-Interacting Protein 1 (PINP1). PINP1 encodes PRP16, a core pre-mRNA splicing factor that unwinds RNA duplexes and binds to primary microRNA transcripts and general RNAs. Intriguingly, PSR1 decreased both RNA helicase and RNA-binding activity of PINP1, thereby dampening sRNA biogenesis and RNA metabolism. The PSR1-PINP1 interaction caused global changes in alternative splicing (AS). A total of 5,135 genes simultaneously exhibited mis-splicing in both PSR1-overexpressing and PINP1-silenced plants. AS upregulated many mRNA transcripts that had their introns retained. The high occurrence of intron retention in AS-induced transcripts significantly promoted Phytophthora pathogen infection in Nicotiana benthamiana, and this might be caused by the production of truncated proteins. Taken together, our findings reveal a key role for PINP1 in regulating sRNA biogenesis and plant immunity.
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Affiliation(s)
- Xinmeng Gui
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Peng Zhang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
- College of Agriculture, Yangtze University, Jingzhou 434025, China
| | - Dan Wang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Zhan Ding
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Science, Wuhan University, Hubei 430072, China
| | - Xian Wu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jinxia Shi
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Qian-Hua Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Innovation Academy for Seed Design, Beijing 100101, China
| | - Yong-Zhen Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Science, Wuhan University, Hubei 430072, China
| | - Wenbo Ma
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Yongli Qiao
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
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Cho H, Abshire ET, Popp MW, Pröschel C, Schwartz JL, Yeo GW, Maquat LE. AKT constitutes a signal-promoted alternative exon-junction complex that regulates nonsense-mediated mRNA decay. Mol Cell 2022; 82:2779-2796.e10. [PMID: 35675814 PMCID: PMC9357146 DOI: 10.1016/j.molcel.2022.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/21/2022] [Accepted: 05/10/2022] [Indexed: 11/28/2022]
Abstract
Despite a long appreciation for the role of nonsense-mediated mRNA decay (NMD) in destroying faulty, disease-causing mRNAs and maintaining normal, physiologic mRNA abundance, additional effectors that regulate NMD activity in mammalian cells continue to be identified. Here, we describe a haploid-cell genetic screen for NMD effectors that has unexpectedly identified 13 proteins constituting the AKT signaling pathway. We show that AKT supersedes UPF2 in exon-junction complexes (EJCs) that are devoid of RNPS1 but contain CASC3, defining an unanticipated insulin-stimulated EJC. Without altering UPF1 RNA binding or ATPase activity, AKT-mediated phosphorylation of the UPF1 CH domain at T151 augments UPF1 helicase activity, which is critical for NMD and also decreases the dependence of helicase activity on ATP. We demonstrate that upregulation of AKT signaling contributes to the hyperactivation of NMD that typifies Fragile X syndrome, as exemplified using FMR1-KO neural stem cells derived from induced pluripotent stem cells.
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Affiliation(s)
- Hana Cho
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Elizabeth T Abshire
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Maximilian W Popp
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Christoph Pröschel
- Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Stem Cell and Regenerative Medicine Institute, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - Joshua L Schwartz
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA; Stem Cell Program, University of California, San Diego, La Jolla, CA, USA; Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA; Stem Cell Program, University of California, San Diego, La Jolla, CA, USA; Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.
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Tan K, Stupack DG, Wilkinson MF. Nonsense-mediated RNA decay: an emerging modulator of malignancy. Nat Rev Cancer 2022; 22:437-451. [PMID: 35624152 PMCID: PMC11009036 DOI: 10.1038/s41568-022-00481-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 12/11/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is a highly conserved RNA turnover pathway that selectively degrades RNAs harbouring truncating mutations that prematurely terminate translation, including nonsense, frameshift and some splice-site mutations. Recent studies show that NMD shapes the mutational landscape of tumours by selecting for mutations that tend to downregulate the expression of tumour suppressor genes but not oncogenes. This suggests that NMD can benefit tumours, a notion further supported by the finding that mRNAs encoding immunogenic neoantigen peptides are typically targeted for decay by NMD. Together, this raises the possibility that NMD-inhibitory therapy could be of therapeutic benefit against many tumour types, including those with a high load of neoantigen-generating mutations. Complicating this scenario is the evidence that NMD can also be detrimental for many tumour types, and consequently tumours often have perturbed NMD. NMD may suppress tumour generation and progression by degrading subsets of specific normal mRNAs, including those encoding stress-response proteins, signalling factors and other proteins beneficial for tumours, as well as pro-tumour non-coding RNAs. Together, these findings suggest that NMD-modulatory therapy has the potential to provide widespread therapeutic benefit against diverse tumour types. However, whether NMD should be stimulated or repressed requires careful analysis of the tumour to be treated.
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Affiliation(s)
- Kun Tan
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Dwayne G Stupack
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA.
- UCSD Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA.
| | - Miles F Wilkinson
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA.
- Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA, USA.
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Karousis ED, Mühlemann O. The broader sense of nonsense. Trends Biochem Sci 2022; 47:921-935. [PMID: 35780009 DOI: 10.1016/j.tibs.2022.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/30/2022] [Accepted: 06/08/2022] [Indexed: 12/21/2022]
Abstract
The term 'nonsense-mediated mRNA decay' (NMD) was initially coined to describe the translation-dependent degradation of mRNAs harboring premature termination codons (PTCs), but it is meanwhile known that NMD also targets many canonical mRNAs with numerous biological implications. The molecular mechanisms determining on which RNAs NMD ensues are only partially understood. Considering the broad range of NMD-sensitive RNAs and the variable degrees of their degradation, we highlight here the hallmarks of mammalian NMD and point out open questions. We review the links between NMD and disease by summarizing the role of NMD in cancer, neurodegeneration, and viral infections. Finally, we describe strategies to modulate NMD activity and specificity as potential therapeutic approaches for various diseases.
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Affiliation(s)
- Evangelos D Karousis
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
| | - Oliver Mühlemann
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
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Gao Y, Pang AP, Ma L, Wang H, Durrani S, Li B, Wu FG, Lin F. Intron retention coupled with nonsense-mediated decay is involved in cellulase biosynthesis in cellulolytic fungi. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:53. [PMID: 35590374 PMCID: PMC9118705 DOI: 10.1186/s13068-022-02141-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/14/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Knowledge on regulatory networks associated with cellulase biosynthesis is prerequisite for exploitation of such regulatory systems in enhancing cellulase production with low cost. The biological functions of intron retention (IR) and nonsense-mediated mRNA decay (NMD) in filamentous fungi is lack of study, let alone their roles in cellulase biosynthesis. RESULTS We found that major cellulase genes (cel7a, cel7b, and cel3a) exhibited concomitant decrease in IR rates and increase in their gene expression in T. reesei under cellulase-producing condition (cellulose and lactose) that was accompanied with a more active NMD pathway, as compared to cellulase non-producing condition (glucose). In the presence of the NMD pathway inhibitor that successfully repressed the NMD pathway, the mRNA levels of cellulase genes were sharply down-regulated, but the rates of IR in these genes were significantly up-regulated. Consistently, the cellulase activities were severely inhibited. In addition, the NMD pathway inhibitor caused the downregulated mRNA levels of two important genes of the target of rapamycin (TOR) pathway, trfkbp12 and trTOR1. The absence of gene trfkbp12 made the cellulase production in T. reesei more sensitive to the NMD pathway inhibitor. CONCLUSIONS All these findings suggest that the IR of cellulase genes regulates their own gene expression by coupling with the NMD pathway, which might involve the TOR pathway. Our results provide better understanding on intron retention, the NMD pathway, and cellulase production mechanism in filamentous fungi.
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Affiliation(s)
- Yichen Gao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Leyao Ma
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Samran Durrani
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
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No-nonsense: insights into the functional interplay of nonsense-mediated mRNA decay factors. Biochem J 2022; 479:973-993. [PMID: 35551602 PMCID: PMC9162471 DOI: 10.1042/bcj20210556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/10/2022] [Accepted: 04/12/2022] [Indexed: 11/22/2022]
Abstract
Nonsense-mediated messenger RNA decay (NMD) represents one of the main surveillance pathways used by eukaryotic cells to control the quality and abundance of mRNAs and to degrade viral RNA. NMD recognises mRNAs with a premature termination codon (PTC) and targets them to decay. Markers for a mRNA with a PTC, and thus NMD, are a long a 3′-untranslated region and the presence of an exon-junction complex (EJC) downstream of the stop codon. Here, we review our structural understanding of mammalian NMD factors and their functional interplay leading to a branched network of different interconnected but specialised mRNA decay pathways. We discuss recent insights into the potential impact of EJC composition on NMD pathway choice. We highlight the coexistence and function of different isoforms of up-frameshift protein 1 (UPF1) with an emphasis of their role at the endoplasmic reticulum and during stress, and the role of the paralogs UPF3B and UPF3A, underscoring that gene regulation by mammalian NMD is tightly controlled and context-dependent being conditional on developmental stage, tissue and cell types.
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36
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De S, Mühlemann O. A comprehensive coverage insurance for cells: revealing links between ribosome collisions, stress responses and mRNA surveillance. RNA Biol 2022; 19:609-621. [PMID: 35491909 PMCID: PMC9067528 DOI: 10.1080/15476286.2022.2065116] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Cells of metazoans respond to internal and external stressors by activating stress response pathways that aim for re-establishing cellular homoeostasis or, if this cannot be achieved, triggering programmed cell death. Problems during translation, arising from defective mRNAs, tRNAs, ribosomes or protein misfolding, can activate stress response pathways as well as mRNA surveillance and ribosome quality control programs. Recently, ribosome collisions have emerged as a central signal for translational stress and shown to elicit different stress responses. Here, we review our current knowledge about the intricate mutual connections between ribosome collisions, stress response pathways and mRNA surveillance. A central factor connecting the sensing of collided ribosomes with degradation of the nascent polypeptides, dissociation of the stalled ribosomes and degradation of the mRNA by no-go or non-stop decay is the E3-ligase ZNF598. We tested whether ZNF598 also plays a role in nonsense-mediated mRNA decay (NMD) but found that it is dispensable for this translation termination-associated mRNA surveillance pathway, which in combination with other recent data argues against stable ribosome stalling at termination codons being the NMD-triggering signal.
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Affiliation(s)
- Soumasree De
- University of Bern, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, Bern, Switzerland
| | - Oliver Mühlemann
- University of Bern, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, Bern, Switzerland
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Unique and Repeated Stwintrons (Spliceosomal Twin Introns) in the Hypoxylaceae. J Fungi (Basel) 2022; 8:jof8040397. [PMID: 35448628 PMCID: PMC9024468 DOI: 10.3390/jof8040397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/06/2022] [Accepted: 04/09/2022] [Indexed: 12/04/2022] Open
Abstract
Introns are usually non-coding sequences interrupting open reading frames in pre-mRNAs [D1,2]. Stwintrons are nested spliceosomal introns, where an internal intron splits a second donor sequence into two consecutive splicing reactions leading to mature mRNA. In Hypoxylon sp. CO27-5, 36 highly sequence-similar [D1,2] stwintrons are extant (sister stwintrons). An additional 81 [D1,2] sequence-unrelated stwintrons are described here. Most of them are located at conserved gene positions rooted deep in the Hypoxylaceae. Absence of exonic sequence bias at the exon–stwintron junctions and a very similar phase distribution were noted for both groups. The presence of an underlying sequence symmetry in all 117 stwintrons was striking. This symmetry, more pronounced near the termini of most of the full-length sister stwintrons, may lead to a secondary structure that brings into close proximity the most distal splice sites, the donor of the internal and the acceptor of the external intron. The Hypoxylon stwintrons were overwhelmingly excised by consecutive splicing reactions precisely removing the whole intervening sequence, whereas one excision involving the distal splice sites led to a frameshift. Alternative (mis)splicing took place for both sister and uniquely occurring stwintrons. The extraordinary symmetry of the sister stwintrons thus seems dispensable for the infrequent, direct utilisation of the distal splice sites.
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Lee HC, Hsieh CC, Tsai HJ. KEPI plays a negative role in the repression that accompanies translational inhibition guided by the uORF element of human CHOP transcript during stress response. Gene X 2022; 817:146160. [PMID: 35031423 DOI: 10.1016/j.gene.2021.146160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/28/2021] [Accepted: 12/10/2021] [Indexed: 11/04/2022] Open
Abstract
Translation of the downstream coding sequence of some mRNAs may be repressed by the upstream open reading frame (uORF) at their 5'-end. The mechanism underlying this uORF-mediated translational inhibition (uORF-MTI) is not fully understood in vivo. Recently, it was found that zebrafish Endouc or its human orthologue ENDOU (Endouc/ENDOU) plays a positive role in repressing the uORF-MTI of human CHOP (uORFchop-MTI) during stress by blocking its activity However, the repression of uORFchop-MTI assisted by an as-yet unidentified negative effector remains to be elucidated. Compared to the upregulated CHOP transcript, we herein report that the kepi (kinase-enhanced PP1 inhibitor) transcript was downregulated in the zebrafish embryos treated with both heat shock and hypoxia. Quantitative RT-PCR also revealed that the level of kepi mRNA was noticeably decreased in both heat-shock-treated and hypoxia-exposed embryos. When kepi mRNA was microinjected into the one-celled embryos from transgenic line huORFZ, the translation of downstream GFP reporter controlled by the uORFchop-MTI was reduced in the hypoxia-exposed embryos. In contrast, when kepi was knocked down by injection of antisense Morpholino oligonucleotide, the translation of downstream GFP reporter was induced and expressed in the brain and spinal cord of injected embryos in the absence of stress. During normal condition, overexpression of KEPI increased eIF2α phosphorylation, resulting in inducing the translation of uORF-tag mRNA, such as ATF4 and CHOP mRNAs. However, during stress condition, overexpression of KEPI decreased eIF2α phosphorylation, resulting in reducing the GFP reporter and CHOP proteins. This is the first report to demonstrate that KEPI plays a negative role in uORFchop - mediated translation during ER stress.
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Affiliation(s)
- Hung-Chieh Lee
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan
| | - Chi-Cheng Hsieh
- The Liver Disease Prevention and Treatment Research Foundation, Taipei, Taiwan
| | - Huai-Jen Tsai
- Department of Life Science, Fu-Jen Catholic University, New Taipei City, Taiwan; School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan.
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39
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Morita T, Hayashi K. Actin-related protein 5 functions as a novel modulator of MyoD and MyoG in skeletal muscle and in rhabdomyosarcoma. eLife 2022; 11:77746. [PMID: 35348112 PMCID: PMC8983046 DOI: 10.7554/elife.77746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Myogenic regulatory factors (MRFs) are pivotal transcription factors in myogenic differentiation. MyoD commits cells to the skeletal muscle lineage by inducing myogenic genes through recruitment of chromatin remodelers to its target loci. This study showed that Actin-related protein 5 (Arp5) acts as an inhibitory regulator of MyoD and MyoG by binding to their cysteine-rich (CR) region, which overlaps with the region essential for their epigenetic functions. Arp5 expression was faint in skeletal muscle tissues. Excessive Arp5 in mouse hind limbs caused skeletal muscle fiber atrophy. Further, Arp5 overexpression in myoblasts inhibited myotube formation by diminishing myogenic gene expression, whereas Arp5 depletion augmented myogenic gene expression. Arp5 disturbed MyoD-mediated chromatin remodeling through competition with the three-amino-acid-loop-extension-class homeodomain transcription factors the Pbx1–Meis1 heterodimer for binding to the CR region. This antimyogenic function was independent of the INO80 chromatin remodeling complex, although Arp5 is an important component of that. In rhabdomyosarcoma (RMS) cells, Arp5 expression was significantly higher than in normal myoblasts and skeletal muscle tissue, probably contributing to MyoD and MyoG activity dysregulation. Arp5 depletion in RMS partially restored myogenic properties while inhibiting tumorigenic properties. Thus, Arp5 is a novel modulator of MRFs in skeletal muscle differentiation.
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40
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Yang Q, Qin Z, Zhang Q, Yi S, Yi S, Luo J. Identification of a novel compound heterozygous SMG9 variants in a Chinese family with heart and brain malformation syndrome using whole exome sequencing. BMC Med Genomics 2022; 15:67. [PMID: 35321723 PMCID: PMC8943999 DOI: 10.1186/s12920-022-01217-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/17/2022] [Indexed: 11/13/2022] Open
Abstract
SMG9-deficiency syndrome, also known as heart and brain malformation syndrome, is a very rare congenital genetic disorder mainly characterized by brain, heart, and growth and developmental abnormalities. This syndrome is an autosomal recessive disease resulting from mutations in the SMG9 gene, which encodes a critical component of nonsense-mediated mRNA decay. Thus far, only twelve SMG9 deficiency patients have been reported with five novel homozygous SMG9 mutations. The most frequent characteristic features of these patients are facial dysmorphism, severe global developmental delay, intellectual disability, congenital heart disease, growth restriction, microcephaly, and brain abnormalities. Herein, whole exome sequencing was performed to identify novel compound heterozygous SMG9 variants (NM_019108.3: c.1318_1319delAG (p.Ser440*) and c.947A>G (p.His316Arg)) in the proband, who exhibited syndromic intellectual disability. Mutations were confirmed as segregating in his affected sister and other unaffected family members by Sanger sequencing. The patients we describe here have a similar dysmorphology profile associated with SMG9-deficiency syndrome. Comparing the phenotype with that of patients in published reports, our patients can walk independently and their growth parameters are normal. In addition, short stature, failure to thrive, and microcephaly were not observed. Possible residual function of the H316R SMG9 variant could explain the milder phenotype observed in our patients. Our report is the first description of a non-consanguineous Chinese pedigree with novel compound heterozygous variants in the SMG9 gene. The molecular confirmation of the patient expands the genetic spectrum of SMG9-deficiency syndrome, and the manifestation of SMG9-deficiency syndrome in the patient provides additional clinical information regarding this syndrome.
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Affiliation(s)
- Qi Yang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, No. 59, Xiangzhu Road, Nanning, China.,Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Zailong Qin
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, No. 59, Xiangzhu Road, Nanning, China.,Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qinle Zhang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, No. 59, Xiangzhu Road, Nanning, China.,Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Shang Yi
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, No. 59, Xiangzhu Road, Nanning, China.,Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Sheng Yi
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, No. 59, Xiangzhu Road, Nanning, China.,Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jingsi Luo
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, No. 59, Xiangzhu Road, Nanning, China. .,Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
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41
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Kim YJ, Sivetz N, Layne J, Voss DM, Yang L, Zhang Q, Krainer AR. Exon-skipping antisense oligonucleotides for cystic fibrosis therapy. Proc Natl Acad Sci U S A 2022; 119:e2114858118. [PMID: 35017301 PMCID: PMC8784140 DOI: 10.1073/pnas.2114858118] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 11/16/2021] [Indexed: 11/25/2022] Open
Abstract
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF), and the CFTR-W1282X nonsense mutation causes a severe form of CF. Although Trikafta and other CFTR-modulation therapies benefit most CF patients, targeted therapy for patients with the W1282X mutation is lacking. The CFTR-W1282X protein has residual activity but is expressed at a very low level due to nonsense-mediated messenger RNA (mRNA) decay (NMD). NMD-suppression therapy and read-through therapy are actively being researched for CFTR nonsense mutants. NMD suppression could increase the mutant CFTR mRNA, and read-through therapies may increase the levels of full-length CFTR protein. However, these approaches have limitations and potential side effects: because the NMD machinery also regulates the expression of many normal mRNAs, broad inhibition of the pathway is not desirable, and read-through drugs are inefficient partly because the mutant mRNA template is subject to NMD. To bypass these issues, we pursued an exon-skipping antisense oligonucleotide (ASO) strategy to achieve gene-specific NMD evasion. A cocktail of two splice-site-targeting ASOs induced the expression of CFTR mRNA without the premature-termination-codon-containing exon 23 (CFTR-Δex23), which is an in-frame exon. Treatment of human bronchial epithelial cells with this cocktail of ASOs that target the splice sites flanking exon 23 results in efficient skipping of exon 23 and an increase in CFTR-Δex23 protein. The splice-switching ASO cocktail increases the CFTR-mediated chloride current in human bronchial epithelial cells. Our results set the stage for developing an allele-specific therapy for CF caused by the W1282X mutation.
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Affiliation(s)
- Young Jin Kim
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794
- Medical Scientist Training Program, Stony Brook University School of Medicine, Stony Brook, NY 11794
| | - Nicole Sivetz
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Jessica Layne
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Dillon M Voss
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794
- Medical Scientist Training Program, Stony Brook University School of Medicine, Stony Brook, NY 11794
| | - Lucia Yang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794
- Medical Scientist Training Program, Stony Brook University School of Medicine, Stony Brook, NY 11794
| | - Qian Zhang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
- Graduate Program in Molecular and Cell Biology, Stony Brook University, Stony Brook, NY 11794
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Gamper H, Masuda I, Hou YM. Genome Expansion by tRNA +1 Frameshifting at Quadruplet Codons. J Mol Biol 2022; 434:167440. [PMID: 34995554 PMCID: PMC9643101 DOI: 10.1016/j.jmb.2021.167440] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/27/2021] [Accepted: 12/30/2021] [Indexed: 11/29/2022]
Abstract
Inducing tRNA +1 frameshifting to read a quadruplet codon has the potential to incorporate a non-canonical amino acid (ncAA) into the polypeptide chain. While this strategy is attractive for genome expansion in biotechnology and bioengineering endeavors, improving the yield is hampered by a lack of understanding of where the shift can occur in an elongation cycle of protein synthesis. Lacking a clear answer to this question, current efforts have focused on designing +1-frameshifting tRNAs with an extra nucleotide inserted to the anticodon loop for pairing with a quadruplet codon in the aminoacyl-tRNA binding (A) site of the ribosome. However, the designed and evolved +1-frameshifting tRNAs vary broadly in achieving successful genome expansion. Here we summarize recent work on +1-frameshifting tRNAs. We suggest that, rather than engineering the quadruplet anticodon-codon pairing scheme at the ribosome A site, efforts should be made to engineer the pairing scheme at steps after the A site, including the step of the subsequent translocation and the step that stabilizes the pairing scheme in the +1-frame in the peptidyl-tRNA binding (P) site.
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Affiliation(s)
- Howard Gamper
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, USA
| | - Isao Masuda
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, USA.
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43
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Bongiorno R, Colombo MP, Lecis D. Deciphering the nonsense-mediated mRNA decay pathway to identify cancer cell vulnerabilities for effective cancer therapy. J Exp Clin Cancer Res 2021; 40:376. [PMID: 34852841 PMCID: PMC8638473 DOI: 10.1186/s13046-021-02192-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/22/2021] [Indexed: 12/22/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a highly conserved cellular surveillance mechanism, commonly studied for its role in mRNA quality control because of its capacity of degrading mutated mRNAs that would produce truncated proteins. However, recent studies have proven that NMD hides more complex tasks involved in a plethora of cellular activities. Indeed, it can control the stability of mutated as well as non-mutated transcripts, tuning transcriptome regulation. NMD not only displays a pivotal role in cell physiology but also in a number of genetic diseases. In cancer, the activity of this pathway is extremely complex and it is endowed with both pro-tumor and tumor suppressor functions, likely depending on the genetic context and tumor microenvironment. NMD inhibition has been tested in pre-clinical studies showing favored production of neoantigens by cancer cells, which can stimulate the triggering of an anti-tumor immune response. At the same time, NMD inhibition could result in a pro-tumor effect, increasing cancer cell adaptation to stress. Since several NMD inhibitors are already available in the clinic to treat genetic diseases, these compounds could be redirected to treat cancer patients, pending the comprehension of these variegated NMD regulation mechanisms. Ideally, an effective strategy should exploit the anti-tumor advantages of NMD inhibition and simultaneously preserve its intrinsic tumor suppressor functions. The targeting of NMD could provide a new therapeutic opportunity, increasing the immunogenicity of tumors and potentially boosting the efficacy of the immunotherapy agents now available for cancer treatment.
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Affiliation(s)
- Roberta Bongiorno
- Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Amadeo 42, 20133, Milan, Italy
| | - Mario Paolo Colombo
- Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Amadeo 42, 20133, Milan, Italy
| | - Daniele Lecis
- Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Amadeo 42, 20133, Milan, Italy.
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44
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Chu V, Feng Q, Lim Y, Shao S. Selective destabilization of polypeptides synthesized from NMD-targeted transcripts. Mol Biol Cell 2021; 32:ar38. [PMID: 34586879 PMCID: PMC8694075 DOI: 10.1091/mbc.e21-08-0382] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The translation of mRNAs that contain a premature termination codon (PTC) generates truncated proteins that may have toxic dominant negative effects. Nonsense-mediated decay (NMD) is an mRNA surveillance pathway that degrades PTC-containing mRNAs to limit the production of truncated proteins. NMD activation requires a ribosome terminating translation at a PTC, but what happens to the polypeptides synthesized during the translation cycle needed to activate NMD is incompletely understood. Here, by establishing reporter systems that encode the same polypeptide sequence before a normal termination codon or PTC, we show that termination of protein synthesis at a PTC is sufficient to selectively destabilize polypeptides in mammalian cells. Proteasome inhibition specifically rescues the levels of nascent polypeptides produced from PTC-containing mRNAs within an hour, but also disrupts mRNA homeostasis within a few hours. PTC-terminated polypeptide destabilization is also alleviated by depleting the central NMD factor UPF1 or SMG1, the kinase that phosphorylates UPF1 to activate NMD, but not by inhibiting SMG1 kinase activity. Our results suggest that polypeptide degradation is linked to PTC recognition in mammalian cells and clarify a framework to investigate these mechanisms.
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Affiliation(s)
- Vincent Chu
- Department of Cell Biology, Harvard Medical School, Blavatnik Institute, Boston, MA 02115.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - Qing Feng
- Department of Cell Biology, Harvard Medical School, Blavatnik Institute, Boston, MA 02115
| | - Yang Lim
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Blavatnik Institute, Boston, MA 02115
| | - Sichen Shao
- Department of Cell Biology, Harvard Medical School, Blavatnik Institute, Boston, MA 02115
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Lamandé SR. Collagen VI Muscle Disorders: Mutation Types, Pathogenic Mechanisms and Approaches to Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1348:311-323. [PMID: 34807426 DOI: 10.1007/978-3-030-80614-9_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mutations in the genes encoding the major collagen VI isoform, COL6A1, COL6A2 and COL6A3, are responsible for the muscle disorders Bethlem myopathy and Ullrich congenital muscular dystrophy. These disorders form a disease spectrum from mild to severe. Dominant and recessive mutations are found along the entire spectrum and the clinical phenotype is strongly influenced by the way mutations impede collagen VI protein assembly. Most mutations are in the triple helical domain, towards the N-terminus and they compromise microfibril assembly. Some mutations are found outside the helix in the C- and N-terminal globular domains, but because these regions are highly polymorphic it is difficult to discriminate mutations from rare benign changes without detailed structural and functional studies. Collagen VI deficiency leads to mitochondrial dysfunction, deficient autophagy and increased apoptosis. Therapies that target these consequences have been tested in mouse models and some have shown modest efficacy in small human trials. Antisense therapies for a common mutation that introduces a pseudoexon show promise in cell culture but haven't yet been tested in an animal model. Future therapeutic approaches await new research into how collagen VI deficiency signals downstream consequences.
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Affiliation(s)
- Shireen R Lamandé
- Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC, Australia.
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46
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Yin BK, Wang ZQ. Beyond HAT Adaptor: TRRAP Liaisons with Sp1-Mediated Transcription. Int J Mol Sci 2021; 22:12445. [PMID: 34830324 PMCID: PMC8625110 DOI: 10.3390/ijms222212445] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/09/2021] [Accepted: 11/15/2021] [Indexed: 12/19/2022] Open
Abstract
The members of the phosphatidylinositol 3-kinase-related kinase (PIKK) family play vital roles in multiple biological processes, including DNA damage response, metabolism, cell growth, mRNA decay, and transcription. TRRAP, as the only member lacking the enzymatic activity in this family, is an adaptor protein for several histone acetyltransferase (HAT) complexes and a scaffold protein for multiple transcription factors. TRRAP has been demonstrated to regulate various cellular functions in cell cycle progression, cell stemness maintenance and differentiation, as well as neural homeostasis. TRRAP is known to be an important orchestrator of many molecular machineries in gene transcription by modulating the activity of some key transcription factors, including E2F1, c-Myc, p53, and recently, Sp1. This review summarizes the biological and biochemical studies on the action mode of TRRAP together with the transcription factors, focusing on how TRRAP-HAT mediates the transactivation of Sp1-governing biological processes, including neurodegeneration.
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Affiliation(s)
- Bo-Kun Yin
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), 07745 Jena, Germany;
| | - Zhao-Qi Wang
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), 07745 Jena, Germany;
- Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
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Morris C, Cluet D, Ricci EP. Ribosome dynamics and mRNA turnover, a complex relationship under constant cellular scrutiny. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021; 12:e1658. [PMID: 33949788 PMCID: PMC8519046 DOI: 10.1002/wrna.1658] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/26/2021] [Accepted: 03/26/2021] [Indexed: 12/01/2022]
Abstract
Eukaryotic gene expression is closely regulated by translation and turnover of mRNAs. Recent advances highlight the importance of translation in the control of mRNA degradation, both for aberrant and apparently normal mRNAs. During translation, the information contained in mRNAs is decoded by ribosomes, one codon at a time, and tRNAs, by specifically recognizing codons, translate the nucleotide code into amino acids. Such a decoding step does not process regularly, with various obstacles that can hinder ribosome progression, then leading to ribosome stalling or collisions. The progression of ribosomes is constantly monitored by the cell which has evolved several translation-dependent mRNA surveillance pathways, including nonsense-mediated decay (NMD), no-go decay (NGD), and non-stop decay (NSD), to degrade certain problematic mRNAs and the incomplete protein products. Recent progress in sequencing and ribosome profiling has made it possible to discover new mechanisms controlling ribosome dynamics, with numerous crosstalks between translation and mRNA decay. We discuss here various translation features critical for mRNA decay, with particular focus on current insights from the complexity of the genetic code and also the emerging role for the ribosome as a regulatory hub orchestrating mRNA decay, quality control, and stress signaling. Even if the interplay between mRNA translation and degradation is no longer to be demonstrated, a better understanding of their precise coordination is worthy of further investigation. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability Translation > Translation Regulation RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Christelle Morris
- Laboratory of Biology and Modeling of the CellUniversité de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, Inserm U1293LyonFrance
| | - David Cluet
- Laboratory of Biology and Modeling of the CellUniversité de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, Inserm U1293LyonFrance
| | - Emiliano P. Ricci
- Laboratory of Biology and Modeling of the CellUniversité de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, Inserm U1293LyonFrance
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48
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Lu YY, Krebber H. Nuclear mRNA Quality Control and Cytoplasmic NMD Are Linked by the Guard Proteins Gbp2 and Hrb1. Int J Mol Sci 2021; 22:ijms222011275. [PMID: 34681934 PMCID: PMC8541090 DOI: 10.3390/ijms222011275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/13/2021] [Accepted: 10/17/2021] [Indexed: 12/23/2022] Open
Abstract
Pre-mRNA splicing is critical for cells, as defects in this process can lead to altered open reading frames and defective proteins, potentially causing neurodegenerative diseases and cancer. Introns are removed in the nucleus and splicing is documented by the addition of exon-junction-complexes (EJCs) at exon-exon boundaries. This “memory” of splicing events is important for the ribosome, which translates the RNAs in the cytoplasm. In case a stop codon was detected before an EJC, translation is blocked and the RNA is eliminated by the nonsense-mediated decay (NMD). In the model organism Saccharomyces cerevisiae, two guard proteins, Gbp2 and Hrb1, have been identified as nuclear quality control factors for splicing. In their absence, intron-containing mRNAs leak into the cytoplasm. Their presence retains transcripts until the process is completed and they release the mRNAs by recruitment of the export factor Mex67. On transcripts that experience splicing problems, these guard proteins recruit the nuclear RNA degradation machinery. Interestingly, they continue their quality control function on exported transcripts. They support NMD by inhibiting translation and recruiting the cytoplasmic degradation factors. In this way, they link the nuclear and cytoplasmic quality control systems. These discoveries are also intriguing for humans, as homologues of these guard proteins are present also in multicellular organisms. Here, we provide an overview of the quality control mechanisms of pre-mRNA splicing, and present Gbp2 and Hrb1, as well as their human counterparts, as important players in these pathways.
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49
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Zeng Y, Qian H, Campos MM, Li Y, Vijayasarathy C, Sieving PA. Rs1h -/y exon 3-del rat model of X-linked retinoschisis with early onset and rapid phenotype is rescued by RS1 supplementation. Gene Ther 2021; 29:431-440. [PMID: 34548657 PMCID: PMC8938309 DOI: 10.1038/s41434-021-00290-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/03/2021] [Accepted: 08/18/2021] [Indexed: 12/27/2022]
Abstract
Animal models of X-linked juvenile retinoschisis (XLRS) are valuable tools for understanding basic biochemical function of retinoschisin (RS1) protein and to investigate outcomes of preclinical efficacy and toxicity studies. In order to work with an eye larger than mouse, we generated and characterized an Rs1h−/y knockout rat model created by removing exon 3. This rat model expresses no normal RS1 protein. The model shares features of an early onset and more severe phenotype of human XLRS. The morphologic pathology includes schisis cavities at postnatal day 15 (p15), photoreceptors that are misplaced into the subretinal space and OPL, and a reduction of photoreceptor cell numbers by p21. By 6 mo age only 1–3 rows of photoreceptors nuclei remain, and the inner/outer segment layers and the OPL shows major changes. Electroretinogram recordings show functional loss with considerable reduction of both the a-wave and b-wave by p28, indicating early age loss and dysfunction of photoreceptors. The ratio of b-/a-wave amplitudes indicates impaired synaptic transmission to bipolar cells in addition. Supplementing the Rs1h−/y exon3-del retina with normal human RS1 protein using AAV8-RS1 delivery improved the retinal structure. This Rs1h−/y rat model provides a further tool to explore underlying mechanisms of XLRS pathology and to evaluate therapeutic intervention for the XLRS condition.
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Affiliation(s)
- Yong Zeng
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Haohua Qian
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Yichao Li
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA. .,Department of Ophthalmology, University of California Davis, Sacramento, CA, USA. .,Center for Ocular Regenerative Therapy, Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA, USA.
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50
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Jin X, Yin J, Zhu H, Li W, Yu K, Liu M, Zhang X, Lu M, Wan Z, Huang X. SMG9 Serves as an Oncogene to Promote the Tumor Progression via EMT and Wnt/β-Catenin Signaling Pathway in Hepatocellular Carcinoma. Front Pharmacol 2021; 12:701454. [PMID: 34456727 PMCID: PMC8397484 DOI: 10.3389/fphar.2021.701454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 08/03/2021] [Indexed: 01/02/2023] Open
Abstract
Background/Aims: SMG9 participates in the nonsense-mediated mRNA decay process that degrades mRNA harboring nonsense mutations introduced either at the level of transcription or RNA processing. However, little is known about the role of SMG9 in hepatocellular carcinoma (HCC). The objective of this research was to clarify the effects of SMG9 expression on HCC progression. Methods: Microarray data were acquired from NCBI Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database to bioinformatically analyze the differential expression of SMG9 between HCC patients and normal controls. SMG9 mRNA level was measured in sixteen sets of fresh tumor tissues and adjacent non-cancerous liver tissues (ANLTs) via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). SMG9 protein expression was analyzed in ninety-five sets of paired formalin-fixed and paraffin-embedded tissue specimens by immunohistochemistry (IHC). In addition, clinicopathological features of SMG9 in HCC were checked. For in vitro studies, small interfering RNA (siRNA) was used to silence SMG9 expression for exploring biological functions and underlying mechanisms of SMG9 in SMMC-7721 and HepG2. Results: We found that SMG9 was upregulated in HCC tissues and SMG9 levels were closely related to TNM stage, tumor number and tumor size. Cox regression and Kaplan–Meier proportional hazards analyses showed that high expression of SMG9 was associated with poor patient survival. Furthermore, proliferation, apoptosis resistance, migration and invasion of both SMMC-7721 and HepG2 cells were suppressed by SMG9 inhibition. In addition, EMT and the Wnt/β-catenin signaling pathway were involved in SMG9-mediated HCC progression. Conclusions: SMG9 may serve as a potential novel prognostic biomarker and therapeutic target in HCC patients.
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Affiliation(s)
- Xing Jin
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jie Yin
- Department of Nuclear Medicine, The Affiliated Hospital of Yangzhou University, Yangzhou, China
| | - Hongling Zhu
- Department of Gynecology, Shanghai Armed Police Corps Hospital, Shanghai, China
| | - Weikang Li
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Kewei Yu
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Miao Liu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiujuan Zhang
- Department of Liver Disease, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Miaolian Lu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zemin Wan
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xianzhang Huang
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
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