101
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Lin CS, Wei YH, Yeh YC, Pan SC, Lu SY, Chen YJ, Chueh WY. Role of mitochondrial DNA copy number alteration in non-small cell lung cancer. FORMOSAN JOURNAL OF SURGERY 2020. [DOI: 10.4103/fjs.fjs_15_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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102
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Thairu MW, Hansen AK. It's a small, small world: unravelling the role and evolution of small RNAs in organelle and endosymbiont genomes. FEMS Microbiol Lett 2019; 366:5371121. [PMID: 30844054 DOI: 10.1093/femsle/fnz049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 03/05/2019] [Indexed: 12/19/2022] Open
Abstract
Organelles and host-restricted bacterial symbionts are characterized by having highly reduced genomes that lack many key regulatory genes and elements. Thus, it has been hypothesized that the eukaryotic nuclear genome is primarily responsible for regulating these symbioses. However, with the discovery of organelle- and symbiont-expressed small RNAs (sRNAs) there is emerging evidence that these sRNAs may play a role in gene regulation as well. Here, we compare the diversity of organelle and bacterial symbiont sRNAs recently identified using genome-enabled '-omic' technologies and discuss their potential role in gene regulation. We also discuss how the genome architecture of small genomes may influence the evolution of these sRNAs and their potential function. Additionally, these new studies suggest that some sRNAs are conserved within organelle and symbiont taxa and respond to changes in the environment and/or their hosts. In summary, these results suggest that organelle and symbiont sRNAs may play a role in gene regulation in addition to nuclear-encoded host mechanisms.
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Affiliation(s)
- Margaret W Thairu
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
| | - Allison K Hansen
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
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103
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Mishmar D, Levin R, Naeem MM, Sondheimer N. Higher Order Organization of the mtDNA: Beyond Mitochondrial Transcription Factor A. Front Genet 2019; 10:1285. [PMID: 31998357 PMCID: PMC6961661 DOI: 10.3389/fgene.2019.01285] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/21/2019] [Indexed: 01/09/2023] Open
Abstract
The higher order organization of eukaryotic and prokaryotic genomes is pivotal in the regulation of gene expression. Specifically, chromatin accessibility in eukaryotes and nucleoid accessibility in bacteria are regulated by a cohort of proteins to alter gene expression in response to diverse physiological conditions. By contrast, prior studies have suggested that the mitochondrial genome (mtDNA) is coated solely by mitochondrial transcription factor A (TFAM), whose increased cellular concentration was proposed to be the major determinant of mtDNA packaging in the mitochondrial nucleoid. Nevertheless, recent analysis of DNase-seq and ATAC-seq experiments from multiple human and mouse samples suggest gradual increase in mtDNA occupancy during the course of embryonic development to generate a conserved footprinting pattern which correlate with sites that have low TFAM occupancy in vivo (ChIP-seq) and tend to adopt G-quadruplex structures. These findings, along with recent identification of mtDNA binding by known modulators of chromatin accessibility such as MOF, suggest that mtDNA higher order organization is generated by cross talk with the nuclear regulatory system, may have a role in mtDNA regulation, and is more complex than once thought.
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Affiliation(s)
- Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Rotem Levin
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Mansur M Naeem
- Institute of Medical Sciences and the Department of Paediatrics, The University of Toronto, Toronto, ON, Canada
| | - Neal Sondheimer
- Institute of Medical Sciences and the Department of Paediatrics, The University of Toronto, Toronto, ON, Canada
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104
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Ion torrent high throughput mitochondrial genome sequencing (HTMGS). PLoS One 2019; 14:e0224847. [PMID: 31730669 PMCID: PMC6857855 DOI: 10.1371/journal.pone.0224847] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
The implementation and popularity of next generation sequencing (NGS) has led to the development of various rapid whole mitochondrial genome sequencing techniques. We summarise an efficient and cost-effective NGS approach for mitochondrial genomic DNA in humans using the Ion Torrent platform, and further discuss our bioinformatics pipeline for streamlined variant calling. Ion 316 chips were utilised with the Ion Torrent semi-conductor platform Personal Genome Machine (PGM) to perform tandem sequencing of mitochondrial genomes from the core pedigree (n = 315) of the Norfolk Island Health Study. Key improvements from commercial methods focus on the initial PCR step, which currently requires extensive optimisation to ensure the accurate and reproducible elongation of each section of the complete mitochondrial genome. Dual-platform barcodes were incorporated into our protocol thereby extending its potential application onto Illumina-based systems. Our bioinformatics pipeline consists of a modified version of GATK best practices tailored for mitochondrial genomic data. When compared with current commercial methods, our method, termed high throughput mitochondrial genome sequencing (HTMGS), allows high multiplexing of samples and the use of alternate library preparation reagents at a lower cost per sample (~1.7 times) when compared to current commercial methodologies. Our HTMGS methodology also provides robust mitochondrial sequencing data (>450X average coverage) that can be applied and modified to suit various study designs. On average, we were able to identify ~30 variants per sample with 572 variants observed across 315 samples. We have developed a high throughput sequencing and analysis method targeting complete mitochondrial genomes; with the potential to be platform agnostic with analysis options that adhere to current best practices.
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105
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Albensi BC. What Is Nuclear Factor Kappa B (NF-κB) Doing in and to the Mitochondrion? Front Cell Dev Biol 2019; 7:154. [PMID: 31448275 PMCID: PMC6692429 DOI: 10.3389/fcell.2019.00154] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/23/2019] [Indexed: 12/20/2022] Open
Abstract
A large body of literature supports the idea that nuclear factor kappa B (NF-κB) signaling contributes to not only immunity, but also inflammation, cancer, and nervous system function. However, studies on NF-κB activity in mitochondrial function are much more limited and scattered throughout the literature. For example, in 2001 it was first published that NF-κB subunits were found in the mitochondria, including not only IkBα and NF-κB p65 subunits, but also NF-κB pathway proteins such as IKKα, IKKβ, and IKKγ, but not much follow-up work has been done to date. Upon further thought the lack of studies on NF-κB activity in mitochondrial function is surprising given the importance and the evolutionary history of both NF-κB and the mitochondrion. Both are ancient in their appearance in our biological record where both contribute substantially to cell survival, cell death, and the regulation of function and/or disease. Studies also show NF-κB can influence mitochondrial function from outside the mitochondria. Therefore, it is essential to understand the complexity of these roles both inside and out of this organelle. In this review, an attempt is made to understand how NF-κB activity contributes to overall mitochondrial function – both inside and out. The discussion at times is speculative and perhaps even provocative to some, since NF-κB does not yet have defined mitochondrial targeting sequences for some nuclear-encoded mitochondrial genes and mechanisms of mitochondrial import for NF-κB are not yet entirely understood. Also, the data associated with the mitochondrial localization of proteins must be yet further proved with additional experiments.
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Affiliation(s)
- Benedict C Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
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106
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Niazi AK, Delannoy E, Iqbal RK, Mileshina D, Val R, Gabryelska M, Wyszko E, Soubigou-Taconnat L, Szymanski M, Barciszewski J, Weber-Lotfi F, Gualberto JM, Dietrich A. Mitochondrial Transcriptome Control and Intercompartment Cross-Talk During Plant Development. Cells 2019; 8:E583. [PMID: 31200566 PMCID: PMC6627697 DOI: 10.3390/cells8060583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/03/2019] [Accepted: 06/11/2019] [Indexed: 01/17/2023] Open
Abstract
We address here organellar genetic regulation and intercompartment genome coordination. We developed earlier a strategy relying on a tRNA-like shuttle to mediate import of nuclear transgene-encoded custom RNAs into mitochondria in plants. In the present work, we used this strategy to drive trans-cleaving hammerhead ribozymes into the organelles, to knock down specific mitochondrial RNAs and analyze the regulatory impact. In a similar approach, the tRNA mimic was used to import into mitochondria in Arabidopsis thaliana the orf77, an RNA associated with cytoplasmic male sterility in maize and possessing sequence identities with the atp9 mitochondrial RNA. In both cases, inducible expression of the transgenes allowed to characterise early regulation and signaling responses triggered by these respective manipulations of the organellar transcriptome. The results imply that the mitochondrial transcriptome is tightly controlled by a "buffering" mechanism at the early and intermediate stages of plant development, a control that is released at later stages. On the other hand, high throughput analyses showed that knocking down a specific mitochondrial mRNA triggered a retrograde signaling and an anterograde nuclear transcriptome response involving a series of transcription factor genes and small RNAs. Our results strongly support transcriptome coordination mechanisms within the organelles and between the organelles and the nucleus.
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Affiliation(s)
- Adnan Khan Niazi
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
- Centre of Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture, Faisalabad 38000, Pakistan.
| | - Etienne Delannoy
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France.
| | - Rana Khalid Iqbal
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
| | - Daria Mileshina
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
| | - Romain Val
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
| | - Marta Gabryelska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Ul. Z. Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Eliza Wyszko
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Ul. Z. Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Ludivine Soubigou-Taconnat
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France.
| | - Maciej Szymanski
- Department of Computational Biology, Institute of Molecular Biology and Biotechnology, A. Mickiewicz University Poznan, Ul. Umultowska 89, 61-614 Poznan, Poland.
| | - Jan Barciszewski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Ul. Z. Noskowskiego 12/14, 61-704 Poznan, Poland.
- NanoBioMedical Centre of the Adam Mickiewicz University, Umultowska 85, 61614 Poznan, Poland.
| | - Frédérique Weber-Lotfi
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
| | - José Manuel Gualberto
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
| | - André Dietrich
- Institute of Plant Molecular Biology (IBMP), CNRS and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
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107
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Barkhash AV, Kozlova IV, Pozdnyakova LL, Yudin NS, Voevoda MI, Romaschenko AG. New Genetic Marker of Human Predisposition to Severe Forms of Tick-Borne Encephalitis. Mol Biol 2019. [DOI: 10.1134/s0026893319020031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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108
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Dostal V, Churchill MEA. Cytosine methylation of mitochondrial DNA at CpG sequences impacts transcription factor A DNA binding and transcription. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2019; 1862:598-607. [PMID: 30807854 PMCID: PMC7806247 DOI: 10.1016/j.bbagrm.2019.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/21/2019] [Accepted: 01/23/2019] [Indexed: 12/22/2022]
Abstract
In eukaryotes, cytosine methylation of nuclear DNA at CpG sequences (5mCpG) regulates epigenetic inheritance through alterations in chromatin structure. However, mitochondria lack nucleosomal chromatin, therefore the molecular mechanisms by which 5mCpG influences mitochondria must be different and are as yet unknown. Mitochondrial Transcription Factor A (TFAM) is both the primary DNA-compacting protein in the mitochondrial DNA (mtDNA) nucleoid and a transcription-initiation factor. TFAM must encounter hundreds of CpGs in mtDNA, so the occurrence of 5mCpG has the potential to impact TFAM-DNA recognition. We used biophysical approaches to determine whether 5mCpG alters any TFAM-dependent activities. 5mCpG in the heavy strand promoter (HSP1) increased the binding affinity of TFAM and induced TFAM multimerization with increased cooperativity compared to nonmethylated DNA. However, 5mCpG had no apparent effect on TFAM-dependent DNA compaction. Additionally, 5mCpG had a clear and context-dependent effect on transcription initiating from the three mitochondrial promoters. Taken together, our findings demonstrate that 5mCpG in the mitochondrial promoter region does impact TFAM-dependent activities in vitro.
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Affiliation(s)
- Vishantie Dostal
- Program in Structural Biology and Biochemistry, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mair E A Churchill
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Program in Structural Biology and Biochemistry, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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109
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Mitochondrial DNA Integrity: Role in Health and Disease. Cells 2019; 8:cells8020100. [PMID: 30700008 PMCID: PMC6406942 DOI: 10.3390/cells8020100] [Citation(s) in RCA: 131] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 01/06/2023] Open
Abstract
As the primary cellular location for respiration and energy production, mitochondria serve in a critical capacity to the cell. Yet, by virtue of this very function of respiration, mitochondria are subject to constant oxidative stress that can damage one of the unique features of this organelle, its distinct genome. Damage to mitochondrial DNA (mtDNA) and loss of mitochondrial genome integrity is increasingly understood to play a role in the development of both severe early-onset maladies and chronic age-related diseases. In this article, we review the processes by which mtDNA integrity is maintained, with an emphasis on the repair of oxidative DNA lesions, and the cellular consequences of diminished mitochondrial genome stability.
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110
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Marom S, Blumberg A, Kundaje A, Mishmar D. mtDNA Chromatin-like Organization Is Gradually Established during Mammalian Embryogenesis. iScience 2019; 12:141-151. [PMID: 30684873 PMCID: PMC6352746 DOI: 10.1016/j.isci.2018.12.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/08/2018] [Accepted: 12/27/2018] [Indexed: 02/06/2023] Open
Abstract
Unlike the nuclear genome, the mammalian mitochondrial genome (mtDNA) is thought to be coated solely by mitochondrial transcription factor A (TFAM), whose binding sequence preferences are debated. Therefore, higher-order mtDNA organization is considered much less regulated than both the bacterial nucleoid and the nuclear chromatin. However, our recently identified conserved DNase footprinting pattern in human mtDNA, which co-localizes with regulatory elements and responds to physiological conditions, likely reflects a structured higher-order mtDNA organization. We hypothesized that this pattern emerges during embryogenesis. To test this hypothesis, we analyzed assay for transposase-accessible chromatin sequencing (ATAC-seq) results collected during the course of mouse and human early embryogenesis. Our results reveal, for the first time, a gradual and dynamic emergence of the adult mtDNA footprinting pattern during embryogenesis of both mammals. Taken together, our findings suggest that the structured adult chromatin-like mtDNA organization is gradually formed during mammalian embryogenesis. Mouse and human mtDNA ATAC-seq footprinting patterns are formed during embryogenesis mtDNA footprinting sites were either occupied in preimplantation or appeared later mtDNA footprinting associates with regulatory elements and protein-binding sites The mtDNA footprinting sites tend to harbor secondary structures
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Affiliation(s)
- Shani Marom
- Department of Life Sciences, Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Amit Blumberg
- Department of Life Sciences, Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA, USA; Department of Computer Science, Stanford University, Stanford, CA, USA
| | - Dan Mishmar
- Department of Life Sciences, Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
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111
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Hahn A, Zuryn S. The Cellular Mitochondrial Genome Landscape in Disease. Trends Cell Biol 2018; 29:227-240. [PMID: 30509558 DOI: 10.1016/j.tcb.2018.11.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/06/2018] [Accepted: 11/09/2018] [Indexed: 12/18/2022]
Abstract
Mitochondrial genome (mitochondrial DNA, mtDNA) lesions that unbalance bioenergetic and oxidative outputs are an important cause of human disease. A major impediment in our understanding of the pathophysiology of mitochondrial disorders is the complexity with which mtDNA mutations are spatiotemporally distributed and managed within individual cells, tissues, and organs. Unlike the comparatively static nuclear genome, accumulating evidence highlights the variability, dynamism, and modifiability of the mtDNA nucleotide sequence between individual cells over time. In this review, we summarize and discuss the impact of mtDNA defects on disease within the context of a mosaic and shifting mutational landscape.
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Affiliation(s)
- Anne Hahn
- The University of Queensland, Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, Brisbane, Australia
| | - Steven Zuryn
- The University of Queensland, Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, Brisbane, Australia.
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112
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Liu J, Jiang H, Zan J, Bao Y, Dong J, Xiong L, Nie L. Single-molecule long-read transcriptome profiling of Platysternon megacephalum mitochondrial genome with gene rearrangement and control region duplication. RNA Biol 2018; 15:1244-1249. [PMID: 30200821 DOI: 10.1080/15476286.2018.1521212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Platysternon megacephalum is the sole living representative of the poorly studied turtle lineage Platysternidae. Their mitochondrial genome has been subject to gene rearrangement and control region duplication, resulting in a unique mitochondrial gene order in vertebrates. In this study, we sequenced the first full-length turtle (P. megacephalum) liver transcriptome using single-molecule real-time sequencing to study the transcriptional mechanisms of its mitochondrial genome. ND5 and ND6 anti-sense (ND6AS) forms a single transcript with the same expression in the human mitochondrial genome, but here we demonstrated differential expression of the rearranged ND5 and ND6AS genes in P. megacephalum. And some polycistronic transcripts were also reported in this study. Notably, we detected some novel long non-coding RNAs with alternative polyadenylation from the duplicated control region, and a novel ND6AS transcript composed of a long non-coding sequence, ND6AS, and tRNA-GluAS. These results provide the first description of a mtDNA transcriptome with gene rearrangement and control region duplication. These findings further our understanding of the fundamental concepts of mitochondrial gene transcription and RNA processing, and provide a new insight into the mechanism of transcription regulation of the mitochondrial genome.
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Affiliation(s)
- Jianjun Liu
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
| | - Hui Jiang
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
| | - Jiawei Zan
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
| | - Yuantian Bao
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
| | - Jinxiu Dong
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
| | - Lei Xiong
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
| | - Liuwang Nie
- a Provincial Key Laboratory of the Conservation and Exploitation Research of Biological Resources in Anhui , Life Science College of Anhui Normal University , Wuhu , Anhui , P.R. China
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113
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Blumberg A, Danko CG, Kundaje A, Mishmar D. A common pattern of DNase I footprinting throughout the human mtDNA unveils clues for a chromatin-like organization. Genome Res 2018; 28:1158-1168. [PMID: 30002158 PMCID: PMC6071632 DOI: 10.1101/gr.230409.117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 06/13/2018] [Indexed: 12/16/2022]
Abstract
Human mitochondrial DNA (mtDNA) is believed to lack chromatin and histones. Instead, it is coated solely by the transcription factor TFAM. We asked whether mtDNA packaging is more regulated than once thought. To address this, we analyzed DNase-seq experiments in 324 human cell types and found, for the first time, a pattern of 29 mtDNA Genomic footprinting (mt-DGF) sites shared by ∼90% of the samples. Their syntenic conservation in mouse DNase-seq experiments reflect selective constraints. Colocalization with known mtDNA regulatory elements, with G-quadruplex structures, in TFAM-poor sites (in HeLa cells) and with transcription pausing sites, suggest a functional regulatory role for such mt-DGFs. Altered mt-DGF pattern in interleukin 3-treated CD34+ cells, certain tissue differences, and significant prevalence change in fetal versus nonfetal samples, offer first clues to their physiological importance. Taken together, human mtDNA has a conserved protein-DNA organization, which is likely involved in mtDNA regulation.
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Affiliation(s)
- Amit Blumberg
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105 Israel
| | - Charles G Danko
- Baker Institute for Animal Health, Cornell University, Ithaca, New York 14853, USA
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, California 94305-5120, USA
| | - Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105 Israel
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