Release date: 2015-02-06 Most of the human genome is located in the nucleus. However, a small but important piece of DNA is located in the mitochondria. In the past few years, this mitochondrial DNA (mtDNA) has received much attention for its traceable ancestors, mitochondrial diseases, and three-parent test tube babies. The unique nature of mitochondrial DNA means that it has different regulatory mechanisms. Recently, a new study by Dmitry Temiakov of Rowan University in the United States provided evidence for the first time that mtDNA transcription and replication are regulated by a molecular switch, providing insights into embryonic development and spermatogenesis. Related research results were published in the recent issue of Science. Mitochondrial DNA, unlike nuclear DNA, is transcribed and replicated at the same location. The transcriptional protein used to read the mitochondrial RNA (mtRNA) strand, which is made of mtDNA, is different from the transcriptional proteins used in the replication process, but occurs at the same time and space, which may lead to conflicts during gene expression and Subsequent questions. Temiakov's team wants to know whether TEFM, a mitochondrial transcription elongation factor, has been shown to gradually enhance the transcriptional activity of promoter-free DNA, and whether it also plays a role in mitochondrial transcription and replication. Mitochondrial transcription occurs in two locations, the light chain promoter and the heavy chain promoter. Previous studies have shown that about 120 base pairs before the light chain promoter, transcription is terminated early, in one region of most vertebrate mtDNA, called CSBII, or conserved sequence block II. Together with the nascent RNA and DNA non-template strands form a mixed complex. This complex is formed near the origin of the heavy chain replication primer and will replicate two-thirds of the mtDNA on the heavy chain. It can stop near the origin of the light chain. A single light chain forms a hairpin structure that is recognized by mitochondrial RNA polymerase as a signal to initiate replication of the light chain. Temiakov's team noted that when TEFM is present, mitochondrial DNA polymerase does not stop at CSBII, as it usually does in human mtDNA transcription, but continues to transcribe through the CSBII portion. Since TEFM prevents transcription termination, it also prevents the synthesis of mtDNA polymerase primers for replication. This finding provides one of several clues that TEFM regulates human mitochondrial DNA replication and transcription. Although the study was conducted, the team unintentionally found that their reference genomes were rarely polymorphic in the CSBII region, and their observed mechanism of transcription termination was reduced. They believe that polymorphism disrupts the formation of G-quadruplex, which is involved in the CSBII mechanism. Further studies of how the G-quadruplex participates in the TEFM mechanism suggest that TEFM interacts with specific portions of the nascent RNA transcript. The Temiakov team believes that TEFM can interfere with the formation of G-quadruplexes, resulting in the inability to form hairpin structures. This, in turn, does not signal mtRNA polymerase to begin replication. Further studies have shown that TEFM can affect how long transcripts can be produced by mtRNA polymerase. Without TEFM, a shorter transcript is formed, terminating in the CSBII region. TEFM increases the ability of mtRNA polymerase to continue synthesis. Temiakov believes that TEFM acts as a switch that can "turn on" the transcription, making it more efficient, or it "opens" the copy. This study suggests that in the human mitochondrial genome, replication and transcription are likely to be mutually exclusive processes, thus preventing the possibility that "transcription and replication processes will clash". In addition, the switch may be an important factor in the developmental process during which mtDNA transcription occurs but does not replicate. Source: Biological help Oat Powder is produced by the specific enzymatic hydrolysis and spray drying technology, so it is called Hydrolyzed oat powder or Enzymolysis Oat Powder. It has a pleasant oat fragrance with creamy mouthfeel and smooth texture. It retains all the soluble nutrients of oats, such as high-quality plant protein, fat, soluble dietary fiber(3-glucan>3%). It is high-viscosity and slightly sweet, easy to digest and absorb. It is stable and good resistance to acid and heat treatment after dissolution in water. Oat Powder,Oat Milk Powder,Hydrolyzed Oat Flour,Hydrolyzed Oat Powder,Enzymolysis Oat Powder Xi'an Gawen Biotechnology Co., Ltd , https://www.amulyn-bio.com