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.
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. 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.
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.
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.
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.
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.
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.
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.