Optimized bisulfite sequencing reveals the lack of 5-methylcytosine in mammalian mitochondrial DNA [TAPS]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE217114 | GEO | 2023/06/12
REPOSITORIES: GEO
Similar Datasets
Project description:Whether 5mC exists in mitochondrial DNA is controversial, as data ranging from lack of 5mC to very extensive 5mC have been reported. By comprehensive bioinformatic analyses of published and our own data, we reveal that the observation of extensive and strand-biased mtDNA-5mC is artifact due to combinatorial effects of inefficient bisulfite conversion, extremely low sequencing reads in the L strand and interfering signals from nuclear mitochondrial DNA sequences (NUMTs).
2023-06-12 | GSE217116 | GEO
Project description:Whilst 5-methylcytosine (5mC) is a major epigenetic mark in the nuclear DNA in mammals, whether or not mitochondrial DNA (mtDNA) receives 5mC modification remains controversial. Herein, we exhaustively analysed mouse mtDNA using three methods that are based upon different principles for detecting 5mC. Next-generation bisulfite sequencing did not give any significant signatures of methylation in mtDNAs of liver, brain and embryonic stem cells (ESCs). Also, treatment with methylated cytosine-sensitive endonuclease McrBC resulted in no substantial decrease of mtDNA band intensities in Southern hybridisation. Furthermore, mass spectrometric nucleoside analyses of highly purified liver mtDNA preparations did not detect 5-methyldeoxycytidine at the levels found in the nuclear DNA but at a range of only 0.3–0.5% of deoxycytidine. Taken together, we propose that 5mC is not present at any specific region(s) of mtDNA and that levels of the methylated cytosine are fairly low, provided the modification occurs. It is thus unlikely that 5mC plays a universal role in mtDNA gene expression or mitochondrial metabolism.
2018-04-11 | GSE104104 | GEO
Project description:How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in human and other animals were strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages, but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene body and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand specific non-CpG methylation, its dynamic regulation and its impact on the polycistronic mitochondrial transcript processing.
2019-08-22 | GSE133962 | GEO
Project description:How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in human and other animals were strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages, but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene body and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand specific non-CpG methylation, its dynamic regulation and its impact on the polycistronic mitochondrial transcript processing.
2019-08-22 | GSE133964 | GEO
Project description:How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in human and other animals were strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages, but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene body and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand specific non-CpG methylation, its dynamic regulation and its impact on the polycistronic mitochondrial transcript processing.
2019-08-22 | GSE133963 | GEO
Project description:How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in human and other animals were strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages, but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene body and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand specific non-CpG methylation, its dynamic regulation and its impact on the polycistronic mitochondrial transcript processing.
2019-08-22 | GSE133961 | GEO
Project description:How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in human and other animals were strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages, but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene body and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand specific non-CpG methylation, its dynamic regulation and its impact on the polycistronic mitochondrial transcript processing.
2019-08-22 | GSE133960 | GEO
Project description:How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in human and other animals were strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages, but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene body and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand specific non-CpG methylation, its dynamic regulation and its impact on the polycistronic mitochondrial transcript processing.
2019-08-22 | GSE133959 | GEO
Project description:Human mitochondria contain multiple copies of a circular, double-stranded DNA genome which encode for unique protein components required for the synthesis of ATP. On each strand of mitochondrial DNA (mtDNA), polycistronic transcription is initiated from a dedicated promoter. Transcription from the light strand promoter can produce both near-genome length transcripts and short RNA primers for mtDNA replication. In this way, light strand gene expression and mitochondrial DNA replication are seen as coupled events, although there is no consensus as to how this is regulated. Here we report the discovery of a second light strand promoter (LSP2) in human mtDNA, located immediately upstream of the first gene on the light strand. LSP2 possesses nearly identical characteristics to canonical mitochondrial promoters. Our results challenge the prevailing model in mammals wherein regulation of transcription from the light strand promoter is a prerequisite for the synthesis of light strand genes, and suggests that light strand transcription can be decoupled from replication primer formation.
2022-08-29 | GSE176046 | GEO
Project description:In many mammalian tissues and cells, two classes of mitochondrial DNA (mtDNA) replication intermediates have been observed. One involves leading-strand synthesis in the absence of synchronous lagging-strand synthesis (strand-asynchronous replication), and the other has properties of coupled leading- and lagging-strand synthesis (strand-coupled replication). While strand-asynchronous replication is primed by long RNA synthesized from a defined transcription initiation site, little is known about the commencement of strand-coupled replication. To investigate it, we attempted to abolish strand-asynchronous replication in cultured human cybrid cells by knocking out the components of the transcription initiation complexes, mitochondrial transcription factor B2 (TFB2M/mtTFB2) and mitochondrial RNA polymerase (POLRMT/mtRNAP). Surprisingly, removal of either protein resulted in the complete mtDNA loss, demonstrating for the first time that TFB2M and POLRMT are indispensable for human mtDNA maintenance. Moreover, the lack of TFB2M could not be compensated for by mitochondrial transcription factor B1 (TFB1M/mtTFB1). These findings indicate that TFB2M and POLRMT are crucial for the priming of not only strand-asynchronous but also strand-coupled replication, providing deeper insights into the molecular basis of strand-coupled replication initiation.
2021-11-21 | GSE161542 | GEO