How is mitochondrial DNA transcribed?
Almost the entire mitochondrial genome is transcribed as long polycistronic transcripts. Maturation of the transcripts requires endonucleolytic cleavage, but not all mRNAs are produced through RNase P and RNase Z function. Mitochondrial mRNA steady-state levels are mainly controlled post-transcriptionally.
What is mitochondrial transcription?
Mitochondrial transcription is central to gene expression and is also intimately associated with replication and mitochondrial DNA maintenance. Mitochondrial gene expression is therefore subject to regulation in the nucleus, but local regulation also takes place in the mitochondria.
Does transcription occur in the mitochondria?
In bacteria, ribosomes are directly associated with RNA polymerase, thus regulating the rate of gene expression (Kohler et al., 2017; Demo et al., 2017). In mitochondria, such coupling does not occur because transcription and translation are most likely compartmented.
Do mitochondria transcribe own DNA?
Mitochondria are structures within cells that convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA. This genetic material is known as mitochondrial DNA or mtDNA.
What are the main differences between nuclear DNA and mitochondrial DNA?
The main difference between mitochondrial DNA and nuclear DNA is that mitochondrial DNA is encoded for the genetic information required by mitochondria whereas nuclear DNA is encoded for the genetic information required by the entire cell.
Does mitochondrial DNA get translated?
Their independent genetic system includes mitochondrial DNA (mtDNA), messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and ribosomes. Mitochondrial DNA replication, mRNA transcription, and protein translation occur independently, including the synthesis of polypeptides encoded by mtDNA.
How do you separate mitochondrial DNA from nuclear DNA?
If you have access to an ultracentrifuge, the gold standard of mtDNA enrichment is through density gradient centrifugation. In this method, total DNA is loaded onto a caesium chloride density gradient and centrifuged for 10 hours at 450,000 x g to separate the DNA by size.
What is the function of mitochondrial DNA?
They play an important role in the regulation of cellular metabolism, apoptosis and oxydative stress control. Mitochondrial DNA (mtDNA) has many special features such as a high copy number in cell, maternal inheritance, and a high mutation rate which have made it attractive to scientists from many fields.
Which transcription factors are involved in mitochondrial DNA (mtDNA) transcription?
The transcription machinery of the mtDNA is regulated by several transcription factors TFAM, TEFM and TFB2M and mitochondrial RNA polymerase POLRMT [ 7 ]. The 13 mtDNA encoded components of the OXPHOS machinery using the mitochondrial translation mechanism are synthesized within the mitochondria, with the participation of the mitoribosome [ 8, 9 ].
How is mitochondrial DNA (mtDNA) expressed?
Expression of the mitochondrial genome is initiated by transcription of the mtDNA from bidirectional heavy and light strand promoters to produce two polycistronic transcripts [ 3 ].
What is the mechanism of translation in mitochondria?
Mitochondrial translation requires that each tRNA is charged with the cognate amino acid. This process is mediated by the mitochondrial aminoacyl-tRNA synthetases (ARS2s), which are encoded by nuclear genes.
How are mRNAs transcribed in mitochondria?
Almost the entire mitochondrial genome is transcribed as long polycistronic transcripts. Maturation of the transcripts requires endonucleolytic cleavage, but not all mRNAs are produced through RNase P and RNase Z function.