Now, Thomas Jefferson University researchers provide evidence that RNA segments can be written back into DNA via a polymerase called theta, which could have wide implications affecting many fields of biology. This prevents RNA messages from being rewritten back into the master recipe book of genomic DNA. But polymerases were thought to only work in one direction DNA into DNA or RNA. That same class of machines, called polymerases, also build RNA messages, which are like notes copied from the central DNA repository of recipes, so they can be read more efficiently into proteins. Thanks to the results that have now been published, it is now clear that by no means all RNA polymerases that start the transcription process actually make it to the end of the gene and that the protein SPT6 is essential for this arrival.Cells contain machinery that duplicates DNA into a new set that goes into a newly formed cell. With these findings, the researchers are helping to shed more light on the process of transcription: "Until now, scientists had assumed that the only thing that mattered for mRNA production was how many RNA polymerases started transcription," Wolf says. Thus, it is clear that the SPT6 protein is a central element in the production of mRNA in cells. "Without SPT6, the polymerase destroys the obstacles and the racetrack, which is why functional RNA polymerases are then unable to find their way," says Wolf. On the other hand, however, the gene itself is also affected. This failure has two consequences that have a negative impact on cell function: On one hand, hardly any RNA polymerase makes it to the destination, which is why hardly any mRNA is produced. But then it regularly gets stuck in difficult places-you could say that it falls over an obstacle. The result was quite clear: "Interestingly, RNA polymerase starts making mRNA even in the absence of SPT6," Wolf described. That's exactly what Wolf and his team did. What do the scientists do when they want to learn about the function of a protein: they remove it from the cells and see what happens. The question they explored is: "Is SPT6 important for the process of transcription and-if so-in what way?"
"We studied an important component of the RNA polymerase: the protein SPT6," explains Wolf. In order to better understand what happens at the molecular level during the race, Wolf and his team took a close look at the process of transcription. After all, many genes are a long 'race track' with plenty of obstacles. Scientists have long known that a lot can go wrong in this process. If the polymerase makes it through to the end, the mRNA has been produced. The RNA polymerase starts the reading process at the beginning of the gene, then moves through the entire gene and, finally reach the finish line," Wolf explains. The transcription process from DNA to mRNA sounds relatively simple: "You can think of transcription as an obstacle race. "The mRNA composition thus decides how the cells of our body look and how they function," Wolf says.
Only the mRNA is capable of transmitting the information from the genetic material of the DNA in the nucleus of the cell to the sites of protein biosynthesis outside the nucleus. Transcription: If one can still remember their biology lessons, then they know that it is the process by which the genetic information in the DNA is translated into messenger RNA-or as how scientists like to call it: mRNA. The team presents the results of their research in the current issue of Molecular Cell. With his research team, he has now deciphered new details about the formation of mRNA which provide novel insights into how a fundamental process inside cells works: the transcription. Wolf is a professor of tumor system biology at the Department of Biochemistry and Molecular Biology at the University of Würzburg.
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