1
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Mittal N, Ataman M, Tintignac L, Ham DJ, Jörin L, Schmidt A, Sinnreich M, Ruegg MA, Zavolan M. Calorie restriction and rapamycin distinctly restore non-canonical ORF translation in the muscles of aging mice. NPJ Regen Med 2024; 9:23. [PMID: 39300171 DOI: 10.1038/s41536-024-00369-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 09/10/2024] [Indexed: 09/22/2024] Open
Abstract
Loss of protein homeostasis is one of the hallmarks of aging. As such, interventions that restore proteostasis should slow down the aging process and improve healthspan. Two of the most broadly used anti-aging interventions that are effective in organisms from yeast to mammals are calorie restriction (CR) and rapamycin (RM) treatment. To identify the regulatory mechanisms by which these interventions improve the protein homeostasis, we carried out ribosome footprinting in the muscle of mice aged under standard conditions, or under long-term treatment with CR or RM. We found that the treatments distinctly impact the non-canonical translation, RM primarily remodeling the translation of upstream open reading frames (uORFs), while CR restores stop codon readthrough and the translation of downstream ORFs. Proteomics analysis revealed the expression of numerous non-canonical ORFs at the protein level. The corresponding peptides may provide entry points for therapies aiming to maintain muscle function and extend health span.
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Affiliation(s)
- Nitish Mittal
- Biozentrum, University of Basel, Basel, Switzerland.
| | - Meric Ataman
- Biozentrum, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Lionel Tintignac
- Biozentrum, University of Basel, Basel, Switzerland
- Departments of Neurology and Biomedicine, University of Basel, Basel, Switzerland
- University Hospital Basel, Basel, Switzerland
| | - Daniel J Ham
- Biozentrum, University of Basel, Basel, Switzerland
| | - Lena Jörin
- Biozentrum, University of Basel, Basel, Switzerland
| | | | - Michael Sinnreich
- Departments of Neurology and Biomedicine, University of Basel, Basel, Switzerland
- University Hospital Basel, Basel, Switzerland
| | | | - Mihaela Zavolan
- Biozentrum, University of Basel, Basel, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Switzerland.
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2
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Evans MM, Liu S, Krautner JS, Seguin CG, Leung R, Ronald JA. Evaluation of DNA minicircles for delivery of adenine and cytosine base editors using activatable gene on "GO" reporter imaging systems. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102248. [PMID: 39040503 PMCID: PMC11260848 DOI: 10.1016/j.omtn.2024.102248] [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: 12/11/2023] [Accepted: 06/07/2024] [Indexed: 07/24/2024]
Abstract
Over 30,000 point mutations are associated with debilitating diseases, including many cancer types, underscoring a critical need for targeted genomic solutions. CRISPR base editors, like adenine base editors (ABEs) and cytosine base editors (CBEs), enable precise modifications by converting adenine to guanine and cytosine to thymine, respectively. Challenges in efficiency and safety concerns regarding viral vectors used in delivery limit the scope of base editing. This study introduces non-viral minicircles, bacterial-backbone-free plasmids, as a delivery vehicle for ABEs and CBEs. The research uses cells engineered with the "Gene On" (GO) reporter gene systems for tracking minicircle-delivered ABEs, CBEs, or Cas9 nickase (control), using green fluorescent protein (GFPGO), bioluminescence reporter firefly luciferase (LUCGO), or a highly sensitive Akaluciferase (AkalucGO) designed in this study. The results show that transfection of minicircles expressing CBE or ABE resulted in significantly higher GFP expression and luminescence signals over controls, with minicircles demonstrating the most substantial editing. This study presents minicircles as a new strategy for base editor delivery and develops an enhanced bioluminescence imaging reporter system for tracking ABE activity. Future studies aim to evaluate the use of minicircles in preclinical cancer models, facilitating potential clinical applications.
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Affiliation(s)
- Melissa M. Evans
- Robarts Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Shirley Liu
- Robarts Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Joshua S. Krautner
- Robarts Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Caroline G. Seguin
- Robarts Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Rajan Leung
- Robarts Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5C1, Canada
| | - John A. Ronald
- Robarts Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5C1, Canada
- Lawson Health Research Institute, London, ON N6C 2R5, Canada
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3
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Akhtar MN, Singh A, Manjunath LE, Dey D, Kumar SD, Vasu K, Das A, Eswarappa SM. Hominini-specific regulation of the cell cycle by stop codon readthrough of FEM1B. J Cell Sci 2024; 137:jcs261921. [PMID: 39140134 PMCID: PMC11385324 DOI: 10.1242/jcs.261921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 07/25/2024] [Indexed: 08/15/2024] Open
Abstract
FEM1B is a substrate-recognition component of the CRL2 E3 ubiquitin-protein ligase. This multi-protein complex targets specific proteins for ubiquitylation, which leads to their degradation. Here, we demonstrate the regulation of FEM1B expression by stop codon readthrough (SCR). In this process, translating ribosomes readthrough the stop codon of FEM1B to generate a C-terminally extended isoform that is highly unstable. A total of 81 nucleotides in the proximal 3'UTR of FEM1B constitute the necessary and sufficient cis-signal for SCR. Also, they encode the amino acid sequence responsible for the degradation of the SCR product. CRISPR-edited cells lacking this region, and therefore SCR of FEM1B, showed increased FEM1B expression. This in turn resulted in reduced expression of SLBP (a target of FEM1B-mediated degradation) and replication-dependent histones (target of SLBP for mRNA stability), causing cell cycle delay. Evolutionary analysis revealed that this phenomenon is specific to the genus Pan and Homo (Hominini). Overall, we show a relatively recently evolved SCR process that relieves the cell cycle from the negative regulation by FEM1B.
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Affiliation(s)
- Md Noor Akhtar
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Dhruba Dey
- Undergraduate Program, Indian Institute of Science, Bengaluru 560012, India
| | - Sangeetha Devi Kumar
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Kirtana Vasu
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Arpan Das
- Undergraduate Program, Indian Institute of Science, Bengaluru 560012, India
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
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4
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Romero Romero ML, Poehls J, Kirilenko A, Richter D, Jumel T, Shevchenko A, Toth-Petroczy A. Environment modulates protein heterogeneity through transcriptional and translational stop codon readthrough. Nat Commun 2024; 15:4446. [PMID: 38789441 PMCID: PMC11126739 DOI: 10.1038/s41467-024-48387-x] [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: 02/22/2023] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
Stop codon readthrough events give rise to longer proteins, which may alter the protein's function, thereby generating short-lasting phenotypic variability from a single gene. In order to systematically assess the frequency and origin of stop codon readthrough events, we designed a library of reporters. We introduced premature stop codons into mScarlet, which enabled high-throughput quantification of protein synthesis termination errors in E. coli using fluorescent microscopy. We found that under stress conditions, stop codon readthrough may occur at rates as high as 80%, depending on the nucleotide context, suggesting that evolution frequently samples stop codon readthrough events. The analysis of selected reporters by mass spectrometry and RNA-seq showed that not only translation but also transcription errors contribute to stop codon readthrough. The RNA polymerase was more likely to misincorporate a nucleotide at premature stop codons. Proteome-wide detection of stop codon readthrough by mass spectrometry revealed that temperature regulated the expression of cryptic sequences generated by stop codon readthrough in E. coli. Overall, our findings suggest that the environment affects the accuracy of protein production, which increases protein heterogeneity when the organisms need to adapt to new conditions.
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Affiliation(s)
- Maria Luisa Romero Romero
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany.
- Center for Systems Biology Dresden, 01307, Dresden, Germany.
| | - Jonas Poehls
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
- Center for Systems Biology Dresden, 01307, Dresden, Germany
| | - Anastasiia Kirilenko
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
- Center for Systems Biology Dresden, 01307, Dresden, Germany
| | - Doris Richter
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
- Center for Systems Biology Dresden, 01307, Dresden, Germany
| | - Tobias Jumel
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Anna Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Agnes Toth-Petroczy
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany.
- Center for Systems Biology Dresden, 01307, Dresden, Germany.
- Cluster of Excellence Physics of Life, TU Dresden, 01062, Dresden, Germany.
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5
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Lebeda D, Fierenz A, Werfel L, Rosin-Arbesfeld R, Hofhuis J, Thoms S. Systematic and quantitative analysis of stop codon readthrough in Rett syndrome nonsense mutations. J Mol Med (Berl) 2024; 102:641-653. [PMID: 38430393 PMCID: PMC11055764 DOI: 10.1007/s00109-024-02436-6] [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: 10/13/2023] [Revised: 01/16/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder resulting from genetic mutations in the methyl CpG binding protein 2 (MeCP2) gene. Specifically, around 35% of RTT patients harbor premature termination codons (PTCs) within the MeCP2 gene due to nonsense mutations. A promising therapeutic avenue for these individuals involves the use of aminoglycosides, which stimulate translational readthrough (TR) by causing stop codons to be interpreted as sense codons. However, the effectiveness of this treatment depends on several factors, including the type of stop codon and the surrounding nucleotides, collectively referred to as the stop codon context (SCC). Here, we develop a high-content reporter system to precisely measure TR efficiency at different SCCs, assess the recovery of the full-length MeCP2 protein, and evaluate its subcellular localization. We have conducted a comprehensive investigation into the intricate relationship between SCC characteristics and TR induction, examining a total of 14 pathogenic MeCP2 nonsense mutations with the aim to advance the prospects of personalized therapy for individuals with RTT. Our results demonstrate that TR induction can successfully restore full-length MeCP2 protein, albeit to varying degrees, contingent upon the SCC and the specific position of the PTC within the MeCP2 mRNA. TR induction can lead to the re-establishment of nuclear localization of MeCP2, indicating the potential restoration of protein functionality. In summary, our findings underscore the significance of SCC-specific approaches in the development of tailored therapies for RTT. By unraveling the relationship between SCC and TR therapy, we pave the way for personalized, individualized treatment strategies that hold promise for improving the lives of individuals affected by this debilitating neurodevelopmental disorder. KEY MESSAGES: The efficiency of readthrough induction at MeCP2 premature termination codons strongly depends on the stop codon context. The position of the premature termination codon on the transcript influences the readthrough inducibility. A new high-content dual reporter assay facilitates the measurement and prediction of readthrough efficiency of specific nucleotide stop contexts. Readthrough induction results in the recovery of full-length MeCP2 and its re-localization to the nucleus. MeCP2 requires only one of its annotated nuclear localization signals.
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Affiliation(s)
- Dennis Lebeda
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Adrian Fierenz
- Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany
| | - Lina Werfel
- Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany
- Present Address: Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Julia Hofhuis
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Sven Thoms
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany.
- Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany.
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6
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Manjunath LE, Singh A, Devi Kumar S, Vasu K, Kar D, Sellamuthu K, Eswarappa SM. Transcript-specific induction of stop codon readthrough using a CRISPR-dCas13 system. EMBO Rep 2024; 25:2118-2143. [PMID: 38499809 PMCID: PMC11015002 DOI: 10.1038/s44319-024-00115-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 02/23/2024] [Accepted: 02/28/2024] [Indexed: 03/20/2024] Open
Abstract
Stop codon readthrough (SCR) is the process where translation continues beyond a stop codon on an mRNA. Here, we describe a strategy to enhance or induce SCR in a transcript-selective manner using a CRISPR-dCas13 system. Using specific guide RNAs, we target dCas13 to the region downstream of canonical stop codons of mammalian AGO1 and VEGFA mRNAs, known to exhibit natural SCR. Readthrough assays reveal enhanced SCR of these mRNAs (both exogenous and endogenous) caused by the dCas13-gRNA complexes. This effect is associated with ribosomal pausing, which has been reported for several SCR events. Our data show that CRISPR-dCas13 can also induce SCR across premature termination codons (PTCs) in the mRNAs of green fluorescent protein and TP53. We demonstrate the utility of this strategy in the induction of readthrough across the thalassemia-causing PTC in HBB mRNA and hereditary spherocytosis-causing PTC in SPTA1 mRNA. Thus, CRISPR-dCas13 can be programmed to enhance or induce SCR in a transcript-selective and stop codon-specific manner.
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Affiliation(s)
- Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Sangeetha Devi Kumar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Kirtana Vasu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Debaleena Kar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Karthi Sellamuthu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
- University of Texas Medical Branch, Galveston, TX, USA
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India.
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7
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Mangkalaphiban K, Fu L, Du M, Thrasher K, Keeling KM, Bedwell DM, Jacobson A. Extended stop codon context predicts nonsense codon readthrough efficiency in human cells. Nat Commun 2024; 15:2486. [PMID: 38509072 PMCID: PMC10954755 DOI: 10.1038/s41467-024-46703-z] [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: 08/01/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Protein synthesis terminates when a stop codon enters the ribosome's A-site. Although termination is efficient, stop codon readthrough can occur when a near-cognate tRNA outcompetes release factors during decoding. Seeking to understand readthrough regulation we used a machine learning approach to analyze readthrough efficiency data from published HEK293T ribosome profiling experiments and compared it to comparable yeast experiments. We obtained evidence for the conservation of identities of the stop codon, its context, and 3'-UTR length (when termination is compromised), but not the P-site codon, suggesting a P-site tRNA role in readthrough regulation. Models trained on data from cells treated with the readthrough-promoting drug, G418, accurately predicted readthrough of premature termination codons arising from CFTR nonsense alleles that cause cystic fibrosis. This predictive ability has the potential to aid development of nonsense suppression therapies by predicting a patient's likelihood of improvement in response to drugs given their nonsense mutation sequence context.
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Affiliation(s)
- Kotchaphorn Mangkalaphiban
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA
- Department of Genomics and Computational Biology, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA
| | - Lianwu Fu
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Ming Du
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Kari Thrasher
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Kim M Keeling
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - David M Bedwell
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA.
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8
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Garrelfs SF, Chornyi S, Te Brinke H, Ruiter J, Groothoff J, Wanders RJA. Glyoxylate reductase: Definitive identification in human liver mitochondria, its importance for the compartment-specific detoxification of glyoxylate. J Inherit Metab Dis 2024; 47:280-288. [PMID: 38200664 DOI: 10.1002/jimd.12711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 11/13/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024]
Abstract
Glyoxylate is a key metabolite generated from various precursor substrates in different subcellular compartments including mitochondria, peroxisomes, and the cytosol. The fact that glyoxylate is a good substrate for the ubiquitously expressed enzyme lactate dehydrogenase (LDH) requires the presence of efficient glyoxylate detoxification systems to avoid the formation of oxalate. Furthermore, this detoxification needs to be compartment-specific since LDH is actively present in multiple subcellular compartments including peroxisomes, mitochondria, and the cytosol. Whereas the identity of these protection systems has been established for both peroxisomes and the cytosol as concluded from the deficiency of alanine glyoxylate aminotransferase (AGT) in primary hyperoxaluria type 1 (PH1) and glyoxylate reductase (GR) in PH2, the glyoxylate protection system in mitochondria has remained less well defined. In this manuscript, we show that the enzyme glyoxylate reductase has a bimodal distribution in human embryonic kidney (HEK293), hepatocellular carcinoma (HepG2), and cervical carcinoma (HeLa) cells and more importantly, in human liver, and is actively present in both the mitochondrial and cytosolic compartments. We conclude that the metabolism of glyoxylate in humans requires the complicated interaction between different subcellular compartments within the cell and discuss the implications for the different primary hyperoxalurias.
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Affiliation(s)
- Sander F Garrelfs
- Departments of Pediatrics, Emma Children's Hospital, Section Pediatric Nephrology & Laboratory Division, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Serhii Chornyi
- Departments of Pediatrics, Emma Children's Hospital, Section Pediatric Nephrology & Laboratory Division, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Heleen Te Brinke
- Departments of Pediatrics, Emma Children's Hospital, Section Pediatric Nephrology & Laboratory Division, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Jos Ruiter
- Departments of Pediatrics, Emma Children's Hospital, Section Pediatric Nephrology & Laboratory Division, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Jaap Groothoff
- Departments of Pediatrics, Emma Children's Hospital, Section Pediatric Nephrology & Laboratory Division, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Ronald J A Wanders
- Departments of Pediatrics, Emma Children's Hospital, Section Pediatric Nephrology & Laboratory Division, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
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9
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Zhang Y, Li H, Shen Y, Wang S, Tian L, Yin H, Shi J, Xing A, Zhang J, Ali U, Sami A, Chen X, Gao C, Zhao Y, Lyu Y, Wang X, Chen Y, Tian Z, Wu SB, Wu L. Readthrough events in plants reveal plasticity of stop codons. Cell Rep 2024; 43:113723. [PMID: 38300801 DOI: 10.1016/j.celrep.2024.113723] [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: 05/20/2023] [Revised: 10/02/2023] [Accepted: 01/15/2024] [Indexed: 02/03/2024] Open
Abstract
Stop codon readthrough (SCR) has important biological implications but remains largely uncharacterized. Here, we identify 1,009 SCR events in plants using a proteogenomic strategy. Plant SCR candidates tend to have shorter transcript lengths and fewer exons and splice variants than non-SCR transcripts. Mass spectrometry evidence shows that stop codons involved in SCR events can be recoded as 20 standard amino acids, some of which are also supported by suppressor tRNA analysis. We also observe multiple functional signals in 34 maize extended proteins and characterize the structural and subcellular localization changes in the extended protein of basic transcription factor 3. Furthermore, the SCR events exhibit non-conserved signature, and the extensions likely undergo protein-coding selection. Overall, our study not only characterizes that SCR events are commonly present in plants but also identifies the recoding plasticity of stop codons, which provides important insights into the flexibility of genetic decoding.
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Affiliation(s)
- Yuqian Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China; School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Hehuan Li
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yanting Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shunxi Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Lei Tian
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Haoqiang Yin
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Jiawei Shi
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Anqi Xing
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA
| | - Jinghua Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Usman Ali
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Abdul Sami
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Xueyan Chen
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Chenxuan Gao
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yangtao Zhao
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yajing Lyu
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Xiaoxu Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yanhui Chen
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Advanced Agriculture Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Shu-Biao Wu
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
| | - Liuji Wu
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China; School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
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10
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Plessner M, Thiele L, Hofhuis J, Thoms S. Tissue-specific roles of peroxisomes revealed by expression meta-analysis. Biol Direct 2024; 19:14. [PMID: 38365851 PMCID: PMC10873952 DOI: 10.1186/s13062-024-00458-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 01/30/2024] [Indexed: 02/18/2024] Open
Abstract
Peroxisomes are primarily studied in the brain, kidney, and liver due to the conspicuous tissue-specific pathology of peroxisomal biogenesis disorders. In contrast, little is known about the role of peroxisomes in other tissues such as the heart. In this meta-analysis, we explore mitochondrial and peroxisomal gene expression on RNA and protein levels in the brain, heart, kidney, and liver, focusing on lipid metabolism. Further, we evaluate a potential developmental and heart region-dependent specificity of our gene set. We find marginal expression of the enzymes for peroxisomal fatty acid oxidation in cardiac tissue in comparison to the liver or cardiac mitochondrial β-oxidation. However, the expression of peroxisome biogenesis proteins in the heart is similar to other tissues despite low levels of peroxisomal fatty acid oxidation. Strikingly, peroxisomal targeting signal type 2-containing factors and plasmalogen biosynthesis appear to play a fundamental role in explaining the essential protective and supporting functions of cardiac peroxisomes.
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Affiliation(s)
- Matthias Plessner
- Department of Biochemistry and Molecular Medicine, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Leonie Thiele
- Department of Biochemistry and Molecular Medicine, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Julia Hofhuis
- Department of Biochemistry and Molecular Medicine, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Sven Thoms
- Department of Biochemistry and Molecular Medicine, Medical School OWL, Bielefeld University, Bielefeld, Germany.
- Department of Child and Adolescent Health, University Medical Center, Göttingen, Germany.
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11
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Kumar R, Islinger M, Worthy H, Carmichael R, Schrader M. The peroxisome: an update on mysteries 3.0. Histochem Cell Biol 2024; 161:99-132. [PMID: 38244103 PMCID: PMC10822820 DOI: 10.1007/s00418-023-02259-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2023] [Indexed: 01/22/2024]
Abstract
Peroxisomes are highly dynamic, oxidative organelles with key metabolic functions in cellular lipid metabolism, such as the β-oxidation of fatty acids and the synthesis of myelin sheath lipids, as well as the regulation of cellular redox balance. Loss of peroxisomal functions causes severe metabolic disorders in humans. Furthermore, peroxisomes also fulfil protective roles in pathogen and viral defence and immunity, highlighting their wider significance in human health and disease. This has sparked increasing interest in peroxisome biology and their physiological functions. This review presents an update and a continuation of three previous review articles addressing the unsolved mysteries of this remarkable organelle. We continue to highlight recent discoveries, advancements, and trends in peroxisome research, and address novel findings on the metabolic functions of peroxisomes, their biogenesis, protein import, membrane dynamics and division, as well as on peroxisome-organelle membrane contact sites and organelle cooperation. Furthermore, recent insights into peroxisome organisation through super-resolution microscopy are discussed. Finally, we address new roles for peroxisomes in immune and defence mechanisms and in human disorders, and for peroxisomal functions in different cell/tissue types, in particular their contribution to organ-specific pathologies.
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Grants
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- European Union’s Horizon 2020 research and innovation programme
- Deutsches Zentrum für Herz-Kreislaufforschung
- German Research Foundation
- Medical Faculty Mannheim, University of Heidelberg
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Affiliation(s)
- Rechal Kumar
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Markus Islinger
- Institute of Neuroanatomy, Medical Faculty Mannheim, Mannheim Centre for Translational Neuroscience, University of Heidelberg, 68167, Mannheim, Germany
| | - Harley Worthy
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Ruth Carmichael
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - Michael Schrader
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
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12
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Kar D, Manna D, Manjunath LE, Singh A, Som S, Vasu K, Eswarappa SM. Kinetics of Translating Ribosomes Determine the Efficiency of Programmed Stop Codon Readthrough. J Mol Biol 2023; 435:168274. [PMID: 37714299 DOI: 10.1016/j.jmb.2023.168274] [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: 03/05/2023] [Revised: 08/15/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
During translation, a stop codon on the mRNA signals the ribosomes to terminate the process. In certain mRNAs, the termination fails due to the recoding of the canonical stop codon, and ribosomes continue translation to generate C-terminally extended protein. This process, termed stop codon readthrough (SCR), regulates several cellular functions. SCR is driven by elements/factors that act immediately downstream of the stop codon. Here, we have analysed the process of SCR using a simple mathematical model to investigate how the kinetics of translating ribosomes influences the efficiency of SCR. Surprisingly, the analysis revealed that the rate of translation inversely regulates the efficiency of SCR. We tested this prediction experimentally in mammalian AGO1 and MTCH2 mRNAs. Reduction in translation either globally by harringtonine or locally by rare codons caused an increase in the efficiency of SCR. Thus, our study has revealed a hitherto unknown mode of regulation of SCR.
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Affiliation(s)
- Debaleena Kar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/debaleenak8
| | - Debraj Manna
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/DebrajManna27
| | - Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/emlekha
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/Anumehasingh25
| | - Saubhik Som
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/SaubhikSom
| | - Kirtana Vasu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India.
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13
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Sankaranarayanan S, Kwon S, Heimel K, Feldbrügge M. The RNA world of fungal pathogens. PLoS Pathog 2023; 19:e1011762. [PMID: 38032970 PMCID: PMC10688622 DOI: 10.1371/journal.ppat.1011762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Affiliation(s)
- Srimeenakshi Sankaranarayanan
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Seomun Kwon
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Kai Heimel
- Georg-August University Göttingen, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Göttingen, Germany
| | - Michael Feldbrügge
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
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14
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Chornyi S, Costa CF, IJlst L, Fransen M, Wanders RJA, van Roermund CWT, Waterham HR. Human peroxisomal NAD +/NADH homeostasis is regulated by two independent NAD(H) shuttle systems. Free Radic Biol Med 2023; 206:22-32. [PMID: 37355054 DOI: 10.1016/j.freeradbiomed.2023.06.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 06/26/2023]
Abstract
Reduced (NADH) and oxidized (NAD+) nicotinamide adenine dinucleotides are ubiquitous hydride-donating/accepting cofactors that are essential for cellular bioenergetics. Peroxisomes are single-membrane-bounded organelles that are involved in multiple lipid metabolism pathways, including beta-oxidation of fatty acids, and which contain several NAD(H)-dependent enzymes. Although maintenance of NAD(H) homeostasis in peroxisomes is considered essential for peroxisomal beta-oxidation, little is known about the regulation thereof. To resolve this issue, we have developed methods to specifically measure intraperoxisomal NADH levels in human cells using peroxisome-targeted NADH biosensors. By targeted CRISPR-Cas9-mediated genome editing of human cells, we showed with these sensors that the NAD+/NADH ratio in cytosol and peroxisomes are closely connected and that this crosstalk is mediated by intraperoxisomal lactate and malate dehydrogenases, generated via translational stop codon readthrough of the LDHB and MDH1 mRNAs. Our study provides evidence for the existence of two independent redox shuttle systems in human peroxisomes that regulate peroxisomal NAD+/NADH homeostasis. This is the first study that shows a specific metabolic function of protein isoforms generated by translational stop codon readthrough in humans.
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Affiliation(s)
- Serhii Chornyi
- Amsterdam UMC - University of Amsterdam, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands
| | - Cláudio F Costa
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Lodewijk IJlst
- Amsterdam UMC - University of Amsterdam, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - Marc Fransen
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Ronald J A Wanders
- Amsterdam UMC - University of Amsterdam, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands; Amsterdam Reproduction & Development, Amsterdam, the Netherlands
| | - Carlo W T van Roermund
- Amsterdam UMC - University of Amsterdam, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - Hans R Waterham
- Amsterdam UMC - University of Amsterdam, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands; Amsterdam Reproduction & Development, Amsterdam, the Netherlands.
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15
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Valášek LS, Kučerová M, Zeman J, Beznosková P. Cysteine tRNA acts as a stop codon readthrough-inducing tRNA in the human HEK293T cell line. RNA (NEW YORK, N.Y.) 2023; 29:1379-1387. [PMID: 37221013 PMCID: PMC10573299 DOI: 10.1261/rna.079688.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/12/2023] [Indexed: 05/25/2023]
Abstract
Under certain circumstances, any of the three termination codons can be read through by a near-cognate tRNA; i.e., a tRNA whose two out of three anticodon nucleotides base pair with those of the stop codon. Unless programed to synthetize C-terminally extended protein variants with expanded physiological roles, readthrough represents an undesirable translational error. On the other side of a coin, a significant number of human genetic diseases is associated with the introduction of nonsense mutations (premature termination codons [PTCs]) into coding sequences, where stopping is not desirable. Here, the tRNA's ability to induce readthrough opens up the intriguing possibility of mitigating the deleterious effects of PTCs on human health. In yeast, the UGA and UAR stop codons were described to be read through by four readthrough-inducing rti-tRNAs-tRNATrp and tRNACys, and tRNATyr and tRNAGln, respectively. The readthrough-inducing potential of tRNATrp and tRNATyr was also observed in human cell lines. Here, we investigated the readthrough-inducing potential of human tRNACys in the HEK293T cell line. The tRNACys family consists of two isoacceptors, one with ACA and the other with GCA anticodons. We selected nine representative tRNACys isodecoders (differing in primary sequence and expression level) and tested them using dual luciferase reporter assays. We found that at least two tRNACys can significantly elevate UGA readthrough when overexpressed. This indicates a mechanistically conserved nature of rti-tRNAs between yeast and human, supporting the idea that they could be used in the PTC-associated RNA therapies.
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MESH Headings
- Humans
- Codon, Terminator/genetics
- Cysteine/genetics
- Cysteine/metabolism
- HEK293 Cells
- Saccharomyces cerevisiae/genetics
- RNA, Transfer, Cys/metabolism
- RNA, Transfer, Trp/metabolism
- RNA, Transfer, Tyr
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Anticodon
- Codon, Nonsense/genetics
- Protein Biosynthesis
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Affiliation(s)
- Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Michaela Kučerová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Jakub Zeman
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
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16
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Hasenjäger S, Bologna A, Essen LO, Spadaccini R, Taxis C. C-terminal sequence stability profiling in Saccharomyces cerevisiae reveals protective protein quality control pathways. J Biol Chem 2023; 299:105166. [PMID: 37595870 PMCID: PMC10493509 DOI: 10.1016/j.jbc.2023.105166] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/22/2023] [Accepted: 08/09/2023] [Indexed: 08/20/2023] Open
Abstract
Protein quality control (PQC) mechanisms are essential for degradation of misfolded or dysfunctional proteins. An essential part of protein homeostasis is recognition of defective proteins by PQC components and their elimination by the ubiquitin-proteasome system, often concentrating on protein termini as indicators of protein integrity. Changes in amino acid composition of C-terminal ends arise through protein disintegration, alternative splicing, or during the translation step of protein synthesis from premature termination or translational stop-codon read-through. We characterized reporter protein stability using light-controlled exposure of the random C-terminal peptide collection (CtPC) in budding yeast revealing stabilizing and destabilizing features of amino acids at positions -5 to -1 of the C terminus. The (de)stabilization properties of CtPC-degrons depend on amino acid identity, position, as well as composition of the C-terminal sequence and are transferable. Evolutionary pressure toward stable proteins in yeast is evidenced by amino acid residues under-represented in cytosolic and nuclear proteins at corresponding C-terminal positions, but over-represented in unstable CtPC-degrons, and vice versa. Furthermore, analysis of translational stop-codon read-through peptides suggested that such extended proteins have destabilizing C termini. PQC pathways targeting CtPC-degrons involved the ubiquitin-protein ligase Doa10 and the cullin-RING E3 ligase SCFDas1 (Skp1-Cullin-F-box protein). Overall, our data suggest a proteome protection mechanism that targets proteins with unnatural C termini by recognizing a surprisingly large number of C-terminal sequence variants.
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Affiliation(s)
- Sophia Hasenjäger
- Department of Biology/Genetics, Philipps-University Marburg, Marburg, Germany
| | - Andrea Bologna
- Department of Science and Technology, Universita' Degli Studi Del Sannio, Benevento, Italy
| | - Lars-Oliver Essen
- Department of Chemistry/Biochemistry, Philipps-University Marburg, Marburg, Germany
| | - Roberta Spadaccini
- Department of Science and Technology, Universita' Degli Studi Del Sannio, Benevento, Italy; Department of Chemistry/Biochemistry, Philipps-University Marburg, Marburg, Germany
| | - Christof Taxis
- Department of Medicine, Health and Medical University, Erfurt, Germany.
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17
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Trexler M, Bányai L, Kerekes K, Patthy L. Evolution of termination codons of proteins and the TAG-TGA paradox. Sci Rep 2023; 13:14294. [PMID: 37653005 PMCID: PMC10471768 DOI: 10.1038/s41598-023-41410-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023] Open
Abstract
In most eukaryotes and prokaryotes TGA is used at a significantly higher frequency than TAG as termination codon of protein-coding genes. Although this phenomenon has been recognized several years ago, there is no generally accepted explanation for the TAG-TGA paradox. Our analyses of human mutation data revealed that out of the eighteen sense codons that can give rise to a nonsense codon by single base substitution, the CGA codon is exceptional: it gives rise to the TGA stop codon at an order of magnitude higher rate than the other codons. Here we propose that the TAG-TGA paradox is due to methylation and hypermutabilty of CpG dinucleotides. In harmony with this explanation, we show that the coding genomes of organisms with strong CpG methylation have a significant bias for TGA whereas those from organisms that lack CpG methylation use TGA and TAG termination codons with similar probability.
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Affiliation(s)
- Mária Trexler
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - László Bányai
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - Krisztina Kerekes
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - László Patthy
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary.
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18
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Wagner RN, Wießner M, Friedrich A, Zandanell J, Breitenbach-Koller H, Bauer JW. Emerging Personalized Opportunities for Enhancing Translational Readthrough in Rare Genetic Diseases and Beyond. Int J Mol Sci 2023; 24:6101. [PMID: 37047074 PMCID: PMC10093890 DOI: 10.3390/ijms24076101] [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: 02/16/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Nonsense mutations trigger premature translation termination and often give rise to prevalent and rare genetic diseases. Consequently, the pharmacological suppression of an unscheduled stop codon represents an attractive treatment option and is of high clinical relevance. At the molecular level, the ability of the ribosome to continue translation past a stop codon is designated stop codon readthrough (SCR). SCR of disease-causing premature termination codons (PTCs) is minimal but small molecule interventions, such as treatment with aminoglycoside antibiotics, can enhance its frequency. In this review, we summarize the current understanding of translation termination (both at PTCs and at cognate stop codons) and highlight recently discovered pathways that influence its fidelity. We describe the mechanisms involved in the recognition and readthrough of PTCs and report on SCR-inducing compounds currently explored in preclinical research and clinical trials. We conclude by reviewing the ongoing attempts of personalized nonsense suppression therapy in different disease contexts, including the genetic skin condition epidermolysis bullosa.
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Affiliation(s)
- Roland N. Wagner
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | - Michael Wießner
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | - Andreas Friedrich
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria
| | - Johanna Zandanell
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | | | - Johann W. Bauer
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
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19
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Manjunath LE, Singh A, Som S, Eswarappa SM. Mammalian proteome expansion by stop codon readthrough. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1739. [PMID: 35570338 DOI: 10.1002/wrna.1739] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 04/11/2022] [Accepted: 04/16/2022] [Indexed: 12/20/2022]
Abstract
Recognition of a stop codon by translation machinery as a sense codon results in translational readthrough instead of termination. This recoding process, termed stop codon readthrough (SCR) or translational readthrough, is found in all domains of life including mammals. The context of the stop codon, local mRNA topology, and molecules that interact with the mRNA region downstream of the stop codon determine SCR. The products of SCR can have localization, stability, and function different from those of the canonical isoforms. In this review, we discuss how recent technological and computational advances have increased our understanding of the SCR process in the mammalian system. Based on the known molecular events that occur during SCR of multiple mRNAs, we propose transient molecular roadblocks on an mRNA downstream of the stop codon as a possible mechanism for the induction of SCR. We argue, with examples, that the insights gained from the natural SCR events can guide us to develop novel strategies for the treatment of diseases caused by premature stop codons. This article is categorized under: Translation > Regulation.
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Affiliation(s)
- Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Saubhik Som
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
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20
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Katsioudi G, Dreos R, Arpa ES, Gaspari S, Liechti A, Sato M, Gabriel CH, Kramer A, Brown SA, Gatfield D. A conditional Smg6 mutant mouse model reveals circadian clock regulation through the nonsense-mediated mRNA decay pathway. SCIENCE ADVANCES 2023; 9:eade2828. [PMID: 36638184 PMCID: PMC9839329 DOI: 10.1126/sciadv.ade2828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Nonsense-mediated messenger RNA (mRNA) decay (NMD) has been intensively studied as a surveillance pathway that degrades erroneous transcripts arising from mutations or RNA processing errors. While additional roles in physiological control of mRNA stability have emerged, possible functions in mammalian physiology in vivo remain unclear. Here, we created a conditional mouse allele that allows converting the NMD effector nuclease SMG6 from wild-type to nuclease domain-mutant protein. We find that NMD down-regulation affects the function of the circadian clock, a system known to require rapid mRNA turnover. Specifically, we uncover strong lengthening of free-running circadian periods for liver and fibroblast clocks and direct NMD regulation of Cry2 mRNA, encoding a key transcriptional repressor within the rhythm-generating feedback loop. Transcriptome-wide changes in daily mRNA accumulation patterns in the entrained liver, as well as an altered response to food entrainment, expand the known scope of NMD regulation in mammalian gene expression and physiology.
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Affiliation(s)
- Georgia Katsioudi
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - René Dreos
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Enes S. Arpa
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Sevasti Gaspari
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Angelica Liechti
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Miho Sato
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Christian H. Gabriel
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Laboratory of Chronobiology, Berlin, Germany
| | - Achim Kramer
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Laboratory of Chronobiology, Berlin, Germany
| | - Steven A. Brown
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - David Gatfield
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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21
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Wanders RJA, Baes M, Ribeiro D, Ferdinandusse S, Waterham HR. The physiological functions of human peroxisomes. Physiol Rev 2023; 103:957-1024. [PMID: 35951481 DOI: 10.1152/physrev.00051.2021] [Citation(s) in RCA: 52] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peroxisomes are subcellular organelles that play a central role in human physiology by catalyzing a range of unique metabolic functions. The importance of peroxisomes for human health is exemplified by the existence of a group of usually severe diseases caused by an impairment in one or more peroxisomal functions. Among others these include the Zellweger spectrum disorders, X-linked adrenoleukodystrophy, and Refsum disease. To fulfill their role in metabolism, peroxisomes require continued interaction with other subcellular organelles including lipid droplets, lysosomes, the endoplasmic reticulum, and mitochondria. In recent years it has become clear that the metabolic alliance between peroxisomes and other organelles requires the active participation of tethering proteins to bring the organelles physically closer together, thereby achieving efficient transfer of metabolites. This review intends to describe the current state of knowledge about the metabolic role of peroxisomes in humans, with particular emphasis on the metabolic partnership between peroxisomes and other organelles and the consequences of genetic defects in these processes. We also describe the biogenesis of peroxisomes and the consequences of the multiple genetic defects therein. In addition, we discuss the functional role of peroxisomes in different organs and tissues and include relevant information derived from model systems, notably peroxisomal mouse models. Finally, we pay particular attention to a hitherto underrated role of peroxisomes in viral infections.
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Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniela Ribeiro
- Institute of Biomedicine (iBiMED) and Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
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22
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Loughran G, Li X, O’Loughlin S, Atkins JF, Baranov P. Monitoring translation in all reading frames downstream of weak stop codons provides mechanistic insights into the impact of nucleotide and cellular contexts. Nucleic Acids Res 2022; 51:304-314. [PMID: 36533511 PMCID: PMC9841425 DOI: 10.1093/nar/gkac1180] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/08/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
A stop codon entering the ribosome A-site is normally decoded by release factors that induce release of the polypeptide. Certain factors influence the efficiency of the termination which is in competition with elongation in either the same (readthrough) or an alternative (frameshifting) reading frame. To gain insight into the competition between these processes, we monitored translation in parallel from all three reading frames downstream of stop codons while changing the nucleotide context of termination sites or altering cellular conditions (polyamine levels). We found that P-site codon identity can have a major impact on the termination efficiency of the OPRL1 stop signal, whereas for the OAZ1 ORF1 stop signal, the P-site codon mainly influences the reading frame of non-terminating ribosomes. Changes to polyamine levels predominantly influence the termination efficiency of the OAZ1 ORF1 stop signal. In contrast, increasing polyamine levels stimulate readthrough of the OPRL1 stop signal by enhancing near-cognate decoding rather than by decreasing termination efficiency. Thus, by monitoring the four competing processes occurring at stop codons we were able to determine which is the most significantly affected upon perturbation. This approach may be useful for the interrogation of other recoding phenomena where alternative decoding processes compete with standard decoding.
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Affiliation(s)
- Gary Loughran
- Correspondence may also be addressed to Gary Loughran.
| | - Xiang Li
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Sinead O’Loughlin
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland,Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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23
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Zhang J, Xu C. Gene product diversity: adaptive or not? Trends Genet 2022; 38:1112-1122. [PMID: 35641344 PMCID: PMC9560964 DOI: 10.1016/j.tig.2022.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/30/2022] [Accepted: 05/03/2022] [Indexed: 01/24/2023]
Abstract
One gene does not equal one RNA or protein. The genomic revolution has revealed numerous different RNA and protein molecules that can be produced from one gene, such as circular RNAs generated by back-splicing, proteins with residues mismatching the genomic encoding because of RNA editing, and proteins extended in the C terminus via stop codon readthrough in translation. Are these diverse products results of exquisite gene regulations or imprecise biological processes? While there are cases where the gene product diversity appears beneficial, genome-scale patterns suggest that much of this diversity arises from nonadaptive, molecular errors. This finding has important implications for studying the functions of diverse gene products and for understanding the fundamental properties and evolution of cellular life.
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Affiliation(s)
- Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Chuan Xu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
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24
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Yao H, Yang F, Li Y. Natural products targeting human lactate dehydrogenases for cancer therapy: A mini review. Front Chem 2022; 10:1013670. [PMID: 36247675 PMCID: PMC9556992 DOI: 10.3389/fchem.2022.1013670] [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: 08/07/2022] [Accepted: 08/31/2022] [Indexed: 12/04/2022] Open
Abstract
Reprogramming cancer metabolism has become the hallmark of cancer progression. As the key enzyme catalyzing the conversion of pyruvate to lactate in aerobic glycolysis of cancer cells, human lactate dehydrogenase (LDH) has been a promising target in the discovery of anticancer agents. Natural products are important sources of new drugs. Up to now, some natural compounds have been reported with the activity to target LDH. To give more information on the development of LDH inhibitors and application of natural products, herein, we reviewed the natural compounds with inhibition of LDH from diverse structures and discussed the future direction of the discovery of natural LDH inhibitors for cancer therapy.
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Affiliation(s)
- Huankai Yao
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
- *Correspondence: Huankai Yao,
| | - Feng Yang
- School of Stomatology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yan Li
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
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25
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Bittner E, Stehlik T, Freitag J. Sharing the wealth: The versatility of proteins targeted to peroxisomes and other organelles. Front Cell Dev Biol 2022; 10:934331. [PMID: 36225313 PMCID: PMC9549241 DOI: 10.3389/fcell.2022.934331] [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: 05/02/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Peroxisomes are eukaryotic organelles with critical functions in cellular energy and lipid metabolism. Depending on the organism, cell type, and developmental stage, they are involved in numerous other metabolic and regulatory pathways. Many peroxisomal functions require factors also relevant to other cellular compartments. Here, we review proteins shared by peroxisomes and at least one different site within the cell. We discuss the mechanisms to achieve dual targeting, their regulation, and functional consequences. Characterization of dual targeting is fundamental to understand how peroxisomes are integrated into the metabolic and regulatory circuits of eukaryotic cells.
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Affiliation(s)
| | | | - Johannes Freitag
- Department of Biology, Philipps-University Marburg, Marburg, Germany
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26
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Sapkota D, Florian C, Doherty BM, White KM, Reardon KM, Ge X, Garbow JR, Yuede CM, Cirrito JR, Dougherty JD. Aqp4 stop codon readthrough facilitates amyloid-β clearance from the brain. Brain 2022; 145:2982-2990. [PMID: 36001414 PMCID: PMC10233234 DOI: 10.1093/brain/awac199] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 05/08/2022] [Accepted: 05/15/2022] [Indexed: 01/07/2023] Open
Abstract
Alzheimer's disease is initiated by the toxic aggregation of amyloid-β. Immunotherapeutics aimed at reducing amyloid beta are in clinical trials but with very limited success to date. Identification of orthogonal approaches for clearing amyloid beta may complement these approaches for treating Alzheimer's disease. In the brain, the astrocytic water channel Aquaporin 4 is involved in clearance of amyloid beta, and the fraction of Aquaporin 4 found perivascularly is decreased in Alzheimer's disease. Further, an unusual stop codon readthrough event generates a conserved C-terminally elongated variant of Aquaporin 4 (AQP4X), which is exclusively perivascular. However, it is unclear whether the AQP4X variant specifically mediates amyloid beta clearance. Here, using Aquaporin 4 readthrough-specific knockout mice that still express normal Aquaporin 4, we determine that this isoform indeed mediates amyloid beta clearance. Further, with high-throughput screening and counterscreening, we identify small molecule compounds that enhance readthrough of the Aquaporin 4 sequence and validate a subset on endogenous astrocyte Aquaporin 4. Finally, we demonstrate these compounds enhance brain amyloid-β clearance in vivo, which depends on AQP4X. This suggests derivatives of these compounds may provide a viable pharmaceutical approach to enhance clearance of amyloid beta and potentially other aggregating proteins in neurodegenerative disease.
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Affiliation(s)
- Darshan Sapkota
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Colin Florian
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brookelyn M Doherty
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kelli M White
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kate M Reardon
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xia Ge
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joel R Garbow
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
- Alvin J Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carla M Yuede
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John R Cirrito
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joseph D Dougherty
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
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27
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Yifrach E, Holbrook‐Smith D, Bürgi J, Othman A, Eisenstein M, van Roermund CWT, Visser W, Tirosh A, Rudowitz M, Bibi C, Galor S, Weill U, Fadel A, Peleg Y, Erdmann R, Waterham HR, Wanders RJA, Wilmanns M, Zamboni N, Schuldiner M, Zalckvar E. Systematic multi-level analysis of an organelle proteome reveals new peroxisomal functions. Mol Syst Biol 2022; 18:e11186. [PMID: 36164978 PMCID: PMC9513677 DOI: 10.15252/msb.202211186] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/29/2022] [Accepted: 09/05/2022] [Indexed: 11/18/2022] Open
Abstract
Seventy years following the discovery of peroxisomes, their complete proteome, the peroxi-ome, remains undefined. Uncovering the peroxi-ome is crucial for understanding peroxisomal activities and cellular metabolism. We used high-content microscopy to uncover peroxisomal proteins in the model eukaryote - Saccharomyces cerevisiae. This strategy enabled us to expand the known peroxi-ome by ~40% and paved the way for performing systematic, whole-organellar proteome assays. By characterizing the sub-organellar localization and protein targeting dependencies into the organelle, we unveiled non-canonical targeting routes. Metabolomic analysis of the peroxi-ome revealed the role of several newly identified resident enzymes. Importantly, we found a regulatory role of peroxisomes during gluconeogenesis, which is fundamental for understanding cellular metabolism. With the current recognition that peroxisomes play a crucial part in organismal physiology, our approach lays the foundation for deep characterization of peroxisome function in health and disease.
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Affiliation(s)
- Eden Yifrach
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | | | - Jérôme Bürgi
- Hamburg Unit c/o DESYEuropean Molecular Biology Laboratory (EMBL)HamburgGermany
| | - Alaa Othman
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Miriam Eisenstein
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | - Carlo WT van Roermund
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Gastroenterology, Endocrinology & MetabolismAmsterdam University Medical Centers – Location AMCAmsterdamThe Netherlands
| | - Wouter Visser
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Gastroenterology, Endocrinology & MetabolismAmsterdam University Medical Centers – Location AMCAmsterdamThe Netherlands
| | - Asa Tirosh
- Life Sciences Core Facilities (LSCF)The Weizmann Institute of ScienceRehovotIsrael
| | - Markus Rudowitz
- Department of Systems Biochemistry, Institute of Biochemistry and PathobiochemistryRuhr‐University BochumBochumGermany
| | - Chen Bibi
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | - Shahar Galor
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | - Uri Weill
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | - Amir Fadel
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | - Yoav Peleg
- Life Sciences Core Facilities (LSCF)The Weizmann Institute of ScienceRehovotIsrael
| | - Ralf Erdmann
- Department of Systems Biochemistry, Institute of Biochemistry and PathobiochemistryRuhr‐University BochumBochumGermany
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Gastroenterology, Endocrinology & MetabolismAmsterdam University Medical Centers – Location AMCAmsterdamThe Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Gastroenterology, Endocrinology & MetabolismAmsterdam University Medical Centers – Location AMCAmsterdamThe Netherlands
| | - Matthias Wilmanns
- Hamburg Unit c/o DESYEuropean Molecular Biology Laboratory (EMBL)HamburgGermany
- University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Nicola Zamboni
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Maya Schuldiner
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
| | - Einat Zalckvar
- Department of Molecular GeneticsThe Weizmann Institute of ScienceRehovotIsrael
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28
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Sargsyan Y, Kalinowski J, Thoms S. Calcium in peroxisomes: An essential messenger in an essential cell organelle. Front Cell Dev Biol 2022; 10:992235. [PMID: 36111338 PMCID: PMC9468670 DOI: 10.3389/fcell.2022.992235] [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: 07/12/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
Calcium is a central signal transduction element in biology. Peroxisomes are essential cellular organelles, yet calcium handling in peroxisomes has been contentious. Recent advances show that peroxisomes are part of calcium homeostasis in cardiac myocytes and therefore may contribute to or even shape their calcium-dependent functionality. However, the mechanisms of calcium movement between peroxisomes and other cellular sites and their mediators remain elusive. Here, we review calcium handling in peroxisomes in concert with other organelles and summarize the most recent knowledge on peroxisomal involvement in calcium dynamics with a focus on mammalian cells.
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Affiliation(s)
- Yelena Sargsyan
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
- Department of Child and Adolescent Health, University Medical Center, Göttingen, Germany
| | - Julia Kalinowski
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Sven Thoms
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
- Department of Child and Adolescent Health, University Medical Center, Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
- *Correspondence: Sven Thoms,
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29
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2-Guanidino-quinazoline promotes the readthrough of nonsense mutations underlying human genetic diseases. Proc Natl Acad Sci U S A 2022; 119:e2122004119. [PMID: 35994666 PMCID: PMC9436315 DOI: 10.1073/pnas.2122004119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Nonsense mutations account for approximately 11% of all described gene lesions causing human inherited diseases. This premature termination codon (PTC) leads to the premature arrest of translation that generates a truncated peptide and the degradation of the corresponding mRNA through the nonsense-mediated mRNA decay (NMD) pathway. The possibility of restoring the protein expression by promoting PTC readthrough using drugs appears to be an important therapeutic strategy. Unfortunately, this strategy is limited by the small number of molecules known to promote PTC readthrough without affecting normal translation termination. In this work, we identify a new molecule, TLN468, that promotes a high level of PTC readthrough without a detectable effect on normal stop codons. Premature termination codons (PTCs) account for 10 to 20% of genetic diseases in humans. The gene inactivation resulting from PTCs can be counteracted by the use of drugs stimulating PTC readthrough, thereby restoring production of the full-length protein. However, a greater chemical variety of readthrough inducers is required to broaden the medical applications of this therapeutic strategy. In this study, we developed a reporter cell line and performed high-throughput screening (HTS) to identify potential readthrough inducers. After three successive assays, we isolated 2-guanidino-quinazoline (TLN468). We assessed the clinical potential of this drug as a potent readthrough inducer on the 40 PTCs most frequently responsible for Duchenne muscular dystrophy (DMD). We found that TLN468 was more efficient than gentamicin, and acted on a broader range of sequences, without inducing the readthrough of normal stop codons (TC).
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30
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Baba H. [Introduction to Myelin Research]. YAKUGAKU ZASSHI 2022; 142:837-853. [PMID: 35908945 DOI: 10.1248/yakushi.21-00224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myelin is a multilamellar membrane structure formed by oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS). It has been recognized as an insulator that is essential for the rapid and efficient propagation of action potentials by saltatory conduction. However, recently many studies have shown that myelin and myelin-forming cells interact with axons and regulate the nervous system far more actively than previously thought. For example, myelination changes axons dynamically and divides them into four distinct functional domains: node of Ranvier, paranode, juxtaparanode, and internode. Voltage-gated Na+ channels are clustered at the node, while K+ channels are at the juxtaparanode, and segregation of these channels by paranodal axoglial junction is necessary for proper axonal function. My research experience began at the neurology ward of the Niigata University Medical Hospital, where I saw a patient with peripheral neuropathy of unknown etiology more than 37 years ago. In the patient's serum, we found an autoantibody against a glycolipid enriched in the PNS. Since then, I have been interested in myelin because of its beautiful structure and unique roles in the nervous system. In this review, our recent studies related to CNS and PNS myelin are presented.
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Affiliation(s)
- Hiroko Baba
- Department of Molecular Neurobiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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31
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Ho AT, Hurst LD. Stop codon usage as a window into genome evolution: mutation, selection, biased gene conversion and the TAG paradox. Genome Biol Evol 2022; 14:6648529. [PMID: 35867377 PMCID: PMC9348620 DOI: 10.1093/gbe/evac115] [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] [Accepted: 07/17/2022] [Indexed: 11/16/2022] Open
Abstract
Protein coding genes terminate with one of three stop codons (TAA, TGA, or TAG) that, like synonymous codons, are not employed equally. With TGA and TAG having identical nucleotide content, analysis of their differential usage provides an unusual window into the forces operating on what are ostensibly functionally identical residues. Across genomes and between isochores within the human genome, TGA usage increases with G + C content but, with a common G + C → A + T mutation bias, this cannot be explained by mutation bias-drift equilibrium. Increased usage of TGA in G + C-rich genomes or genomic regions is also unlikely to reflect selection for the optimal stop codon, as TAA appears to be universally optimal, probably because it has the lowest read-through rate. Despite TAA being favored by selection and mutation bias, as with codon usage bias G + C pressure is the prime determinant of between-species TGA usage trends. In species with strong G + C-biased gene conversion (gBGC), such as mammals and birds, the high usage and conservation of TGA is best explained by an A + T → G + C repair bias. How to explain TGA enrichment in other G + C-rich genomes is less clear. Enigmatically, across bacterial and archaeal species and between human isochores TAG usage is mostly unresponsive to G + C pressure. This unresponsiveness we dub the TAG paradox as currently no mutational, selective, or gBGC model provides a well-supported explanation. That TAG does increase with G + C usage across eukaryotes makes the usage elsewhere yet more enigmatic. We suggest resolution of the TAG paradox may provide insights into either an unknown but common selective preference (probably at the DNA/RNA level) or an unrecognized complexity to the action of gBGC.
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Affiliation(s)
- Alexander T Ho
- Milner Centre for Evolution, University of Bath, Bath, UK
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32
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Sahoo S, Singh D, Singh A, Pandit M, Vasu K, Som S, Pullagurla NJ, Laha D, Eswarappa SM. Identification and functional characterization of mRNAs that exhibit stop codon readthrough in Arabidopsis thaliana. J Biol Chem 2022; 298:102173. [PMID: 35752360 PMCID: PMC9293766 DOI: 10.1016/j.jbc.2022.102173] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 06/16/2022] [Accepted: 06/18/2022] [Indexed: 11/29/2022] Open
Abstract
Stop codon readthrough (SCR) is the process of continuation of translation beyond the stop codon, generating protein isoforms with C-terminal extensions. SCR has been observed in viruses, fungi, and multicellular organisms, including mammals. However, SCR is largely unexplored in plants. In this study, we have analyzed ribosome profiling datasets to identify mRNAs that exhibit SCR in Arabidopsis thaliana. Analyses of the ribosome density, ribosome coverage, and three-nucleotide periodicity of the ribosome profiling reads in the mRNA region downstream of the stop codon provided strong evidence for SCR in mRNAs of 144 genes. We show that SCR generated putative evolutionarily conserved nuclear localization signals, transmembrane helices, and intrinsically disordered regions in the C-terminal extensions of several of these proteins. Furthermore, gene ontology (GO) functional enrichment analysis revealed that these 144 genes belong to three major functional groups - translation, photosynthesis, and abiotic stress tolerance. Using a luminescence-based readthrough assay, we experimentally demonstrated SCR in representative mRNAs belonging to each of these functional classes. Finally, using microscopy, we show that the SCR product of one gene that contains a nuclear localization signal at the C-terminal extension, CURT1B, localizes to the nucleus as predicted. Based on these observations, we propose that SCR plays an important role in plant physiology by regulating protein localization and function.
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Affiliation(s)
- Sarthak Sahoo
- Undergraduate Program, Indian Institute of Science, Bengaluru, India; Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Divyoj Singh
- Undergraduate Program, Indian Institute of Science, Bengaluru, India
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Madhuparna Pandit
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Kirtana Vasu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Saubhik Som
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | | | - Debabrata Laha
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
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33
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Biziaev N, Sokolova E, Yanvarev DV, Toropygin IY, Shuvalov A, Egorova T, Alkalaeva E. Recognition of 3' nucleotide context and stop codon readthrough are determined during mRNA translation elongation. J Biol Chem 2022; 298:102133. [PMID: 35700825 PMCID: PMC9272376 DOI: 10.1016/j.jbc.2022.102133] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/16/2022] Open
Abstract
The nucleotide context surrounding stop codons significantly affects the efficiency of translation termination. In eukaryotes, various 3′ contexts that are unfavorable for translation termination have been described; however, the exact molecular mechanism that mediates their effects remains unknown. In this study, we used a reconstituted mammalian translation system to examine the efficiency of stop codons in different contexts, including several previously described weak 3′ stop codon contexts. We developed an approach to estimate the level of stop codon readthrough in the absence of eukaryotic release factors (eRFs). In this system, the stop codon is recognized by the suppressor or near-cognate tRNAs. We observed that in the absence of eRFs, readthrough occurs in a 3′ nucleotide context-dependent manner, and the main factors determining readthrough efficiency were the type of stop codon and the sequence of the 3′ nucleotides. Moreover, the efficiency of translation termination in weak 3′ contexts was almost equal to that in the tested standard context. Therefore, the ability of eRFs to recognize stop codons and induce peptide release is not affected by mRNA context. We propose that ribosomes or other participants of the elongation cycle can independently recognize certain contexts and increase the readthrough of stop codons. Thus, the efficiency of translation termination is regulated by the 3′ nucleotide context following the stop codon and depends on the concentrations of eRFs and suppressor/near-cognate tRNAs.
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Affiliation(s)
- Nikita Biziaev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Elizaveta Sokolova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Dmitry V Yanvarev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Ilya Yu Toropygin
- Orekhovich Research Institute of Biomedical Chemistry, Moscow, 119992, Russia.
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Tatiana Egorova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, 117997, Russia.
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
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34
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Lismont C, Revenco I, Li H, Costa CF, Lenaerts L, Hussein MAF, De Bie J, Knoops B, Van Veldhoven PP, Derua R, Fransen M. Peroxisome-Derived Hydrogen Peroxide Modulates the Sulfenylation Profiles of Key Redox Signaling Proteins in Flp-In T-REx 293 Cells. Front Cell Dev Biol 2022; 10:888873. [PMID: 35557958 PMCID: PMC9086853 DOI: 10.3389/fcell.2022.888873] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 03/31/2022] [Indexed: 12/12/2022] Open
Abstract
The involvement of peroxisomes in cellular hydrogen peroxide (H2O2) metabolism has been a central theme since their first biochemical characterization by Christian de Duve in 1965. While the role of H2O2 substantially changed from an exclusively toxic molecule to a signaling messenger, the regulatory role of peroxisomes in these signaling events is still largely underappreciated. This is mainly because the number of known protein targets of peroxisome-derived H2O2 is rather limited and testing of specific targets is predominantly based on knowledge previously gathered in related fields of research. To gain a broader and more systematic insight into the role of peroxisomes in redox signaling, new approaches are urgently needed. In this study, we have combined a previously developed Flp-In T-REx 293 cell system in which peroxisomal H2O2 production can be modulated with a yeast AP-1-like-based sulfenome mining strategy to inventory protein thiol targets of peroxisome-derived H2O2 in different subcellular compartments. By using this approach, we identified more than 400 targets of peroxisome-derived H2O2 in peroxisomes, the cytosol, and mitochondria. We also observed that the sulfenylation kinetics profiles of key targets belonging to different protein families (e.g., peroxiredoxins, annexins, and tubulins) can vary considerably. In addition, we obtained compelling but indirect evidence that peroxisome-derived H2O2 may oxidize at least some of its targets (e.g., transcription factors) through a redox relay mechanism. In conclusion, given that sulfenic acids function as key intermediates in H2O2 signaling, the findings presented in this study provide valuable insight into how peroxisomes may be integrated into the cellular H2O2 signaling network.
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Affiliation(s)
- Celien Lismont
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Iulia Revenco
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Hongli Li
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Cláudio F Costa
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Lisa Lenaerts
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Mohamed A F Hussein
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Jonas De Bie
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Bernard Knoops
- Group of Animal Molecular and Cellular Biology, Institute of Biomolecular Science and Technology (LIBST), Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Rita Derua
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.,SyBioMa, KU Leuven, Leuven, Belgium
| | - Marc Fransen
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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35
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Ast J, Bäcker N, Bittner E, Martorana D, Ahmad H, Bölker M, Freitag J. Two Pex5 Proteins With Different Cargo Specificity Are Critical for Peroxisome Function in Ustilago maydis. Front Cell Dev Biol 2022; 10:858084. [PMID: 35646929 PMCID: PMC9133605 DOI: 10.3389/fcell.2022.858084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
Peroxisomes are dynamic multipurpose organelles with a major function in fatty acid oxidation and breakdown of hydrogen peroxide. Many proteins destined for the peroxisomal matrix contain a C-terminal peroxisomal targeting signal type 1 (PTS1), which is recognized by tetratricopeptide repeat (TPR) proteins of the Pex5 family. Various species express at least two different Pex5 proteins, but how this contributes to protein import and organelle function is not fully understood. Here, we analyzed truncated and chimeric variants of two Pex5 proteins, Pex5a and Pex5b, from the fungus Ustilago maydis. Both proteins are required for optimal growth on oleic acid-containing medium. The N-terminal domain (NTD) of Pex5b is critical for import of all investigated peroxisomal matrix proteins including PTS2 proteins and at least one protein without a canonical PTS. In contrast, the NTD of Pex5a is not sufficient for translocation of peroxisomal matrix proteins. In the presence of Pex5b, however, specific cargo can be imported via this domain of Pex5a. The TPR domains of Pex5a and Pex5b differ in their affinity to variations of the PTS1 motif and thus can mediate import of different subsets of matrix proteins. Together, our data reveal that U. maydis employs versatile targeting modules to control peroxisome function. These findings will promote our understanding of peroxisomal protein import also in other biological systems.
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Affiliation(s)
- Julia Ast
- Department of Biology, Philipps-University Marburg, Marburg, Germany
- Institute of Metabolism and Systems Research (IMSR), and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Nils Bäcker
- Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Elena Bittner
- Department of Biology, Philipps-University Marburg, Marburg, Germany
| | | | - Humda Ahmad
- Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Michael Bölker
- Department of Biology, Philipps-University Marburg, Marburg, Germany
- Center for Synthetic Microbiology, Philipps-University Marburg, Marburg, Germany
| | - Johannes Freitag
- Department of Biology, Philipps-University Marburg, Marburg, Germany
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36
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Jiang H, Jing Q, Yang Q, Qiao C, Liao Y, Liu W, Xing Y. Efficient Simultaneous Introduction of Premature Stop Codons in Three Tumor Suppressor Genes in PFFs via a Cytosine Base Editor. Genes (Basel) 2022; 13:genes13050835. [PMID: 35627220 PMCID: PMC9140995 DOI: 10.3390/genes13050835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 12/04/2022] Open
Abstract
Base editing is an efficient and precise gene-editing technique, by which a single base can be changed without introducing double-strand breaks, and it is currently widely used in studies of various species. In this study, we used hA3A-BE3-Y130F to simultaneously introduce premature stop codons (TAG, TGA, and TAA) into three tumor suppressor genes, TP53, PTEN, and APC, in large white porcine fetal fibroblasts (PFFs). Among the isolated 290 single-cell colonies, 232 (80%) had premature stop codons in all the three genes. C−to−T conversion was found in 98.6%, 92.8%, and 87.2% of these cell colonies for TP53, PTEN, and APC, respectively. High frequencies of bystander C−to−T edits were observed within the editing window (positions 3−8), and there were nine (3.01%) clones with the designed simultaneous three-gene C−to−T conversion without bystander conversion. C−to−T conversion outside the editing window was found in 9.0%, 14.1%, and 26.2% of the 290 cell colonies for TP53, PTEN, and APC, respectively. Low-frequency C−to−G or C−to−A transversion occurred in APC. The mRNA levels of the three genes showed significant declines in triple-gene-mutant (Tri-Mut) cells as expected. No PTEN and a significantly lower (p < 0.05) APC protein expression were detected in Tri-Mut cells. Interestingly, the premature stop codon introduced into the TP53 gene did not eliminate the expression of its full-length protein in the Tri-Mut cells, suggesting that stop codon read-through occurred. Tri-Mut cells showed a significantly higher (p < 0.05) proliferation rate than WT cells. Furthermore, we identified 1418 differentially expressed genes (DEGs) between the Tri-Mut and WT groups, which were mainly involved in functions such as tumor progression, cell cycle, and DNA repair. This study indicates that hA3A-BE3-Y130F can be a powerful tool to create diverse knockout cell models without double-strand breaks (DSBs), with further possibilities to produce porcine models with various purposes.
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37
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Influence of novel readthrough agents on myelin protein zero translation in the peripheral nervous system. Neuropharmacology 2022; 211:109059. [DOI: 10.1016/j.neuropharm.2022.109059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 02/24/2022] [Accepted: 04/06/2022] [Indexed: 12/22/2022]
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38
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A compact and simple method of achieving differential transgene expression by exploiting translational readthrough. Biotechniques 2022; 72:143-154. [PMID: 35234525 DOI: 10.2144/btn-2021-0079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The development of multicistronic vectors enabling differential transgene expression is a goal of gene therapy and poses a significant engineering challenge. Current approaches rely on the insertion of long regulatory sequences that occupy valuable space in vectors, which have a finite and limited packaging capacity. Here we describe a simple method of achieving differential transgene expression by inserting stop codons and translational readthrough motifs (TRMs) to suppress stop codon termination. TRMs reduced downstream transgene expression ∼sixfold to ∼140-fold, depending on the combination of stop codon and TRM used. We show that a TRM can facilitate the controlled secretion of the highly potent cytokine IL-12 at therapeutically beneficial levels in an aggressive immunocompetent mouse melanoma model to prevent tumor growth. Given their compact size (6 bp) and ease of introduction, we envisage that TRMs will be widely adopted in recombinant DNA engineering to facilitate differential transgene expression.
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39
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Kamoshita M, Kumar R, Anteghini M, Kunze M, Islinger M, Martins dos Santos V, Schrader M. Insights Into the Peroxisomal Protein Inventory of Zebrafish. Front Physiol 2022; 13:822509. [PMID: 35295584 PMCID: PMC8919083 DOI: 10.3389/fphys.2022.822509] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/07/2022] [Indexed: 12/19/2022] Open
Abstract
Peroxisomes are ubiquitous, oxidative subcellular organelles with important functions in cellular lipid metabolism and redox homeostasis. Loss of peroxisomal functions causes severe disorders with developmental and neurological abnormalities. Zebrafish are emerging as an attractive vertebrate model to study peroxisomal disorders as well as cellular lipid metabolism. Here, we combined bioinformatics analyses with molecular cell biology and reveal the first comprehensive inventory of Danio rerio peroxisomal proteins, which we systematically compared with those of human peroxisomes. Through bioinformatics analysis of all PTS1-carrying proteins, we demonstrate that D. rerio lacks two well-known mammalian peroxisomal proteins (BAAT and ZADH2/PTGR3), but possesses a putative peroxisomal malate synthase (Mlsl) and verified differences in the presence of purine degrading enzymes. Furthermore, we revealed novel candidate peroxisomal proteins in D. rerio, whose function and localisation is discussed. Our findings confirm the suitability of zebrafish as a vertebrate model for peroxisome research and open possibilities for the study of novel peroxisomal candidate proteins in zebrafish and humans.
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Affiliation(s)
- Maki Kamoshita
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, United Kingdom
| | - Rechal Kumar
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, United Kingdom
| | - Marco Anteghini
- LifeGlimmer GmbH, Berlin, Germany
- Systems and Synthetic Biology, Wageningen University & Research, Wageningen, Netherlands
| | - Markus Kunze
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Markus Islinger
- Institute of Neuroanatomy, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Vítor Martins dos Santos
- LifeGlimmer GmbH, Berlin, Germany
- Systems and Synthetic Biology, Wageningen University & Research, Wageningen, Netherlands
| | - Michael Schrader
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, United Kingdom
- *Correspondence: Michael Schrader,
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40
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Del Toro N, Lessard F, Bouchard J, Mobasheri N, Guillon J, Igelmann S, Tardif S, Buffard T, Bourdeau V, Brakier-Gingras L, Ferbeyre G. Cellular Senescence limits Translational Readthrough. Biol Open 2021; 10:272574. [PMID: 34676390 PMCID: PMC8649927 DOI: 10.1242/bio.058688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 10/14/2021] [Indexed: 11/20/2022] Open
Abstract
The origin and evolution of cancer cells is considered to be mainly fueled by DNA mutations. Although translation errors could also expand the cellular proteome, their role in cancer biology remains poorly understood. Tumor suppressors called caretakers block cancer initiation and progression by preventing DNA mutations and/or stimulating DNA repair. If translational errors contribute to tumorigenesis, then caretaker genes should prevent such errors in normal cells in response to oncogenic stimuli. Here, we show that the process of cellular senescence induced by oncogenes, tumor suppressors or chemotherapeutic drugs is associated with a reduction in translational readthrough (TR) measured using reporters containing termination codons withing the context of both normal translation termination or programmed TR. Senescence reduced both basal TR and TR stimulated by aminoglycosides. Mechanistically, the reduction of TR during senescence is controlled by the RB tumor suppressor pathway. Cells that escape from cellular senescence either induced by oncogenes or chemotherapy have an increased TR. Also, breast cancer cells that escape from therapy-induced senescence express high levels of AGO1x, a TR isoform of AGO1 linked to breast cancer progression. We propose that senescence and the RB pathway reduce TR limiting proteome diversity and the expression of TR proteins required for cancer cell proliferation. Summary: We report that senescence and the RB pathway reduce translational readthrough (TR) limiting proteome diversity and the expression of TR proteins such as Ago1X required for cancer cell proliferation.
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Affiliation(s)
- Neylen Del Toro
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Frédéric Lessard
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Jacob Bouchard
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Nasrin Mobasheri
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Jordan Guillon
- CRCHUM, 900 Saint-Denis, bureau R10.432, Montréal, Québec, H2X 0A9, Canada
| | - Sebastian Igelmann
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada.,CRCHUM, 900 Saint-Denis, bureau R10.432, Montréal, Québec, H2X 0A9, Canada
| | - Sarah Tardif
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Tony Buffard
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Véronique Bourdeau
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Léa Brakier-Gingras
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada
| | - Gerardo Ferbeyre
- Département de Biochimie et Médecine Moléculaire, Université de Montréal C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada.,CRCHUM, 900 Saint-Denis, bureau R10.432, Montréal, Québec, H2X 0A9, Canada
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41
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Bartoschek MD, Ugur E, Nguyen TA, Rodschinka G, Wierer M, Lang K, Bultmann S. Identification of permissive amber suppression sites for efficient non-canonical amino acid incorporation in mammalian cells. Nucleic Acids Res 2021; 49:e62. [PMID: 33684219 PMCID: PMC8216290 DOI: 10.1093/nar/gkab132] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/20/2022] Open
Abstract
The genetic code of mammalian cells can be expanded to allow the incorporation of non-canonical amino acids (ncAAs) by suppressing in-frame amber stop codons (UAG) with an orthogonal pyrrolysyl-tRNA synthetase (PylRS)/tRNAPylCUA (PylT) pair. However, the feasibility of this approach is substantially hampered by unpredictable variations in incorporation efficiencies at different stop codon positions within target proteins. Here, we apply a proteomics-based approach to quantify ncAA incorporation rates at hundreds of endogenous amber stop codons in mammalian cells. With these data, we compute iPASS (Identification of Permissive Amber Sites for Suppression; available at www.bultmannlab.eu/tools/iPASS), a linear regression model to predict relative ncAA incorporation efficiencies depending on the surrounding sequence context. To verify iPASS, we develop a dual-fluorescence reporter for high-throughput flow-cytometry analysis that reproducibly yields context-specific ncAA incorporation efficiencies. We show that nucleotides up- and downstream of UAG synergistically influence ncAA incorporation efficiency independent of cell line and ncAA identity. Additionally, we demonstrate iPASS-guided optimization of ncAA incorporation rates by synonymous exchange of codons flanking the amber stop codon. This combination of in silico analysis followed by validation in living mammalian cells substantially simplifies identification as well as adaptation of sites within a target protein to confer high ncAA incorporation rates.
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Affiliation(s)
- Michael D Bartoschek
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Enes Ugur
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany.,Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Tuan-Anh Nguyen
- Department of Chemistry, Synthetic Biochemistry, Technical University of Munich, Garching 85748, Germany
| | - Geraldine Rodschinka
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Michael Wierer
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Kathrin Lang
- Department of Chemistry, Synthetic Biochemistry, Technical University of Munich, Garching 85748, Germany
| | - Sebastian Bultmann
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany
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42
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Schilff M, Sargsyan Y, Hofhuis J, Thoms S. Stop Codon Context-Specific Induction of Translational Readthrough. Biomolecules 2021; 11:biom11071006. [PMID: 34356630 PMCID: PMC8301745 DOI: 10.3390/biom11071006] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Premature termination codon (PTC) mutations account for approximately 10% of pathogenic variants in monogenic diseases. Stimulation of translational readthrough, also known as stop codon suppression, using translational readthrough-inducing drugs (TRIDs) may serve as a possible therapeutic strategy for the treatment of genetic PTC diseases. One important parameter governing readthrough is the stop codon context (SCC)-the stop codon itself and the nucleotides in the vicinity of the stop codon on the mRNA. However, the quantitative influence of the SCC on treatment outcome and on appropriate drug concentrations are largely unknown. Here, we analyze the readthrough-stimulatory effect of various readthrough-inducing drugs on the SCCs of five common premature termination codon mutations of PEX5 in a sensitive dual reporter system. Mutations in PEX5, encoding the peroxisomal targeting signal 1 receptor, can cause peroxisomal biogenesis disorders of the Zellweger spectrum. We show that the stop context has a strong influence on the levels of readthrough stimulation and impacts the choice of the most effective drug and its concentration. These results highlight potential advantages and the personalized medicine nature of an SCC-based strategy in the therapy of rare diseases.
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Affiliation(s)
- Mirco Schilff
- Department of Child and Adolescent Health, University Medical Center, 37075 Göttingen, Germany; (M.S.); (Y.S.); (J.H.)
| | - Yelena Sargsyan
- Department of Child and Adolescent Health, University Medical Center, 37075 Göttingen, Germany; (M.S.); (Y.S.); (J.H.)
| | - Julia Hofhuis
- Department of Child and Adolescent Health, University Medical Center, 37075 Göttingen, Germany; (M.S.); (Y.S.); (J.H.)
- Department of Biochemistry and Molecular Medicine, Medical School, Bielefeld University, 33615 Bielefeld, Germany
| | - Sven Thoms
- Department of Child and Adolescent Health, University Medical Center, 37075 Göttingen, Germany; (M.S.); (Y.S.); (J.H.)
- Department of Biochemistry and Molecular Medicine, Medical School, Bielefeld University, 33615 Bielefeld, Germany
- Correspondence: ; Tel.: +49-521-106-86502
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43
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Beznosková P, Bidou L, Namy O, Valášek LS. Increased expression of tryptophan and tyrosine tRNAs elevates stop codon readthrough of reporter systems in human cell lines. Nucleic Acids Res 2021; 49:5202-5215. [PMID: 34009360 PMCID: PMC8136774 DOI: 10.1093/nar/gkab315] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 11/25/2022] Open
Abstract
Regulation of translation via stop codon readthrough (SC-RT) expands not only tissue-specific but also viral proteomes in humans and, therefore, represents an important subject of study. Understanding this mechanism and all involved players is critical also from a point of view of prospective medical therapies of hereditary diseases caused by a premature termination codon. tRNAs were considered for a long time to be just passive players delivering amino acid residues according to the genetic code to ribosomes without any active regulatory roles. In contrast, our recent yeast work identified several endogenous tRNAs implicated in the regulation of SC-RT. Swiftly emerging studies of human tRNA-ome also advocate that tRNAs have unprecedented regulatory potential. Here, we developed a universal U6 promotor-based system expressing various human endogenous tRNA iso-decoders to study consequences of their increased dosage on SC-RT employing various reporter systems in vivo. This system combined with siRNA-mediated downregulations of selected aminoacyl-tRNA synthetases demonstrated that changing levels of human tryptophan and tyrosine tRNAs do modulate efficiency of SC-RT. Overall, our results suggest that tissue-to-tissue specific levels of selected near-cognate tRNAs may have a vital potential to fine-tune the final landscape of the human proteome, as well as that of its viral pathogens.
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Affiliation(s)
- Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska 1083, 142 20 Prague, the Czech Republic
| | - Laure Bidou
- Sorbonne Universités, Paris, France.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Olivier Namy
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska 1083, 142 20 Prague, the Czech Republic
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44
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Detailed Dissection and Critical Evaluation of the Pfizer/BioNTech and Moderna mRNA Vaccines. Vaccines (Basel) 2021; 9:vaccines9070734. [PMID: 34358150 PMCID: PMC8310186 DOI: 10.3390/vaccines9070734] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 06/25/2021] [Accepted: 06/30/2021] [Indexed: 01/19/2023] Open
Abstract
The design of Pfizer/BioNTech and Moderna mRNA vaccines involves many different types of optimizations. Proper optimization of vaccine mRNA can reduce dosage required for each injection leading to more efficient immunization programs. The mRNA components of the vaccine need to have a 5′-UTR to load ribosomes efficiently onto the mRNA for translation initiation, optimized codon usage for efficient translation elongation, and optimal stop codon for efficient translation termination. Both 5′-UTR and the downstream 3′-UTR should be optimized for mRNA stability. The replacement of uridine by N1-methylpseudourinine (Ψ) complicates some of these optimization processes because Ψ is more versatile in wobbling than U. Different optimizations can conflict with each other, and compromises would need to be made. I highlight the similarities and differences between Pfizer/BioNTech and Moderna mRNA vaccines and discuss the advantage and disadvantage of each to facilitate future vaccine improvement. In particular, I point out a few optimizations in the design of the two mRNA vaccines that have not been performed properly.
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45
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Tissue-specific dynamic codon redefinition in Drosophila. Proc Natl Acad Sci U S A 2021; 118:2012793118. [PMID: 33500350 DOI: 10.1073/pnas.2012793118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Translational stop codon readthrough occurs in organisms ranging from viruses to mammals and is especially prevalent in decoding Drosophila and viral mRNAs. Recoding of UGA, UAG, or UAA to specify an amino acid allows a proportion of the protein encoded by a single gene to be C-terminally extended. The extended product from Drosophila kelch mRNA is 160 kDa, whereas unextended Kelch protein, a subunit of a Cullin3-RING ubiquitin ligase, is 76 kDa. Previously we reported tissue-specific regulation of readthrough of the first kelch stop codon. Here, we characterize major efficiency differences in a variety of cell types. Immunoblotting revealed low levels of readthrough in malpighian tubules, ovary, and testis but abundant readthrough product in lysates of larval and adult central nervous system (CNS) tissue. Reporters of readthrough demonstrated greater than 30% readthrough in adult brains, and imaging in larval and adult brains showed that readthrough occurred in neurons but not glia. The extent of readthrough stimulatory sequences flanking the readthrough stop codon was assessed in transgenic Drosophila and in human tissue culture cells where inefficient readthrough occurs. A 99-nucleotide sequence with potential to form an mRNA stem-loop 3' of the readthrough stop codon stimulated readthrough efficiency. However, even with just six nucleotides of kelch mRNA sequence 3' of the stop codon, readthrough efficiency only dropped to 6% in adult neurons. Finally, we show that high-efficiency readthrough in the Drosophila CNS is common; for many neuronal proteins, C-terminal extended forms of individual proteins are likely relatively abundant.
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The Trypanosome UDP-Glucose Pyrophosphorylase Is Imported by Piggybacking into Glycosomes, Where Unconventional Sugar Nucleotide Synthesis Takes Place. mBio 2021; 12:e0037521. [PMID: 34044588 PMCID: PMC8262884 DOI: 10.1128/mbio.00375-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Glycosomes are peroxisome-related organelles of trypanosomatid parasites containing metabolic pathways, such as glycolysis and biosynthesis of sugar nucleotides, usually present in the cytosol of other eukaryotes. UDP-glucose pyrophosphorylase (UGP), the enzyme responsible for the synthesis of the sugar nucleotide UDP-glucose, is localized in the cytosol and glycosomes of the bloodstream and procyclic trypanosomes, despite the absence of any known peroxisome-targeting signal (PTS1 and PTS2). The questions that we address here are (i) is the unusual glycosomal biosynthetic pathway of sugar nucleotides functional and (ii) how is the PTS-free UGP imported into glycosomes? We showed that UGP is imported into glycosomes by piggybacking on the glycosomal PTS1-containing phosphoenolpyruvate carboxykinase (PEPCK) and identified the domains involved in the UGP/PEPCK interaction. Proximity ligation assays revealed that this interaction occurs in 3 to 10% of glycosomes, suggesting that these correspond to organelles competent for protein import. We also showed that UGP is essential for the growth of trypanosomes and that both the glycosomal and cytosolic metabolic pathways involving UGP are functional, since the lethality of the knockdown UGP mutant cell line (RNAiUGP, where RNAi indicates RNA interference) was rescued by expressing a recoded UGP (rUGP) in the organelle (RNAiUGP/EXPrUGP-GPDH, where GPDH is glycerol-3-phosphate dehydrogenase). Our conclusion was supported by targeted metabolomic analyses (ion chromatography–high-resolution mass spectrometry [IC-HRMS]) showing that UDP-glucose is no longer detectable in the RNAiUGP mutant, while it is still produced in cells expressing UGP exclusively in the cytosol (PEPCK null mutant) or glycosomes (RNAiUGP/EXPrUGP-GPDH). Trypanosomatids are the only known organisms to have selected functional peroxisomal (glycosomal) sugar nucleotide biosynthetic pathways in addition to the canonical cytosolic ones.
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Mangkalaphiban K, He F, Ganesan R, Wu C, Baker R, Jacobson A. Transcriptome-wide investigation of stop codon readthrough in Saccharomyces cerevisiae. PLoS Genet 2021; 17:e1009538. [PMID: 33878104 PMCID: PMC8087045 DOI: 10.1371/journal.pgen.1009538] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/30/2021] [Accepted: 04/06/2021] [Indexed: 11/18/2022] Open
Abstract
Translation of mRNA into a polypeptide is terminated when the release factor eRF1 recognizes a UAA, UAG, or UGA stop codon in the ribosomal A site and stimulates nascent peptide release. However, stop codon readthrough can occur when a near-cognate tRNA outcompetes eRF1 in decoding the stop codon, resulting in the continuation of the elongation phase of protein synthesis. At the end of a conventional mRNA coding region, readthrough allows translation into the mRNA 3'-UTR. Previous studies with reporter systems have shown that the efficiency of termination or readthrough is modulated by cis-acting elements other than stop codon identity, including two nucleotides 5' of the stop codon, six nucleotides 3' of the stop codon in the ribosomal mRNA channel, and stem-loop structures in the mRNA 3'-UTR. It is unknown whether these elements are important at a genome-wide level and whether other mRNA features proximal to the stop codon significantly affect termination and readthrough efficiencies in vivo. Accordingly, we carried out ribosome profiling analyses of yeast cells expressing wild-type or temperature-sensitive eRF1 and developed bioinformatics strategies to calculate readthrough efficiency, and to identify mRNA and peptide features which influence that efficiency. We found that the stop codon (nt +1 to +3), the nucleotide after it (nt +4), the codon in the P site (nt -3 to -1), and 3'-UTR length are the most influential features in the control of readthrough efficiency, while nts +5 to +9 had milder effects. Additionally, we found low readthrough genes to have shorter 3'-UTRs compared to high readthrough genes in cells with thermally inactivated eRF1, while this trend was reversed in wild-type cells. Together, our results demonstrated the general roles of known regulatory elements in genome-wide regulation and identified several new mRNA or peptide features affecting the efficiency of translation termination and readthrough.
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Affiliation(s)
- Kotchaphorn Mangkalaphiban
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Feng He
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Robin Ganesan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Chan Wu
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Richard Baker
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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Abramov D, Guiberson NGL, Burré J. STXBP1 encephalopathies: Clinical spectrum, disease mechanisms, and therapeutic strategies. J Neurochem 2021; 157:165-178. [PMID: 32643187 PMCID: PMC7812771 DOI: 10.1111/jnc.15120] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
Mutations in Munc18-1/STXBP1 (syntaxin-binding protein 1) are linked to various severe early epileptic encephalopathies and neurodevelopmental disorders. Heterozygous mutations in the STXBP1 gene include missense, nonsense, frameshift, and splice site mutations, as well as intragenic deletions and duplications and whole-gene deletions. No genotype-phenotype correlation has been identified so far, and patients are treated by anti-epileptic drugs because of the lack of a specific disease-modifying therapy. The molecular disease mechanisms underlying STXBP1-linked disorders are yet to be fully understood, but both haploinsufficiency and dominant-negative mechanisms have been proposed. This review focuses on the current understanding of the phenotypic spectrum of STXBP1-linked disorders, as well as discusses disease mechanisms in the context of the numerous pathways in which STXBP1 functions in the brain. We additionally evaluate the available animal models to study these disorders and highlight potential therapeutic approaches for treating these devastating diseases.
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Affiliation(s)
- Debra Abramov
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Noah Guy Lewis Guiberson
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Jacqueline Burré
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
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Chornyi S, IJlst L, van Roermund CWT, Wanders RJA, Waterham HR. Peroxisomal Metabolite and Cofactor Transport in Humans. Front Cell Dev Biol 2021; 8:613892. [PMID: 33505966 PMCID: PMC7829553 DOI: 10.3389/fcell.2020.613892] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 12/10/2020] [Indexed: 12/20/2022] Open
Abstract
Peroxisomes are membrane-bound organelles involved in many metabolic pathways and essential for human health. They harbor a large number of enzymes involved in the different pathways, thus requiring transport of substrates, products and cofactors involved across the peroxisomal membrane. Although much progress has been made in understanding the permeability properties of peroxisomes, there are still important gaps in our knowledge about the peroxisomal transport of metabolites and cofactors. In this review, we discuss the different modes of transport of metabolites and essential cofactors, including CoA, NAD+, NADP+, FAD, FMN, ATP, heme, pyridoxal phosphate, and thiamine pyrophosphate across the peroxisomal membrane. This transport can be mediated by non-selective pore-forming proteins, selective transport proteins, membrane contact sites between organelles, and co-import of cofactors with proteins. We also discuss modes of transport mediated by shuttle systems described for NAD+/NADH and NADP+/NADPH. We mainly focus on current knowledge on human peroxisomal metabolite and cofactor transport, but also include knowledge from studies in plants, yeast, fruit fly, zebrafish, and mice, which has been exemplary in understanding peroxisomal transport mechanisms in general.
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Affiliation(s)
- Serhii Chornyi
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Lodewijk IJlst
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Carlo W T van Roermund
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
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Gabay-Maskit S, Cruz-Zaragoza LD, Shai N, Eisenstein M, Bibi C, Cohen N, Hansen T, Yifrach E, Harpaz N, Belostotsky R, Schliebs W, Schuldiner M, Erdmann R, Zalckvar E. A piggybacking mechanism enables peroxisomal localization of the glyoxylate cycle enzyme Mdh2 in yeast. J Cell Sci 2020; 133:jcs244376. [PMID: 33177075 PMCID: PMC7758625 DOI: 10.1242/jcs.244376] [Citation(s) in RCA: 18] [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: 01/22/2020] [Accepted: 10/26/2020] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic cells have evolved organelles that allow the compartmentalization and regulation of metabolic processes. Knowledge of molecular mechanisms that allow temporal and spatial organization of enzymes within organelles is therefore crucial for understanding eukaryotic metabolism. Here, we show that the yeast malate dehydrogenase 2 (Mdh2) is dually localized to the cytosol and to peroxisomes and is targeted to peroxisomes via association with Mdh3 and a Pex5-dependent piggybacking mechanism. This dual localization of Mdh2 contributes to our understanding of the glyoxylate cycle and provides a new perspective on compartmentalization of cellular metabolism, which is critical for the perception of metabolic disorders and aging.
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Affiliation(s)
- Shiran Gabay-Maskit
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Luis Daniel Cruz-Zaragoza
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Nadav Shai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Miriam Eisenstein
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Chen Bibi
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nir Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tobias Hansen
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Eden Yifrach
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nofar Harpaz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ruth Belostotsky
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Wolfgang Schliebs
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ralf Erdmann
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Einat Zalckvar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
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