And now, while studying the mechanism behind RNAi researchers at Oxford and Helsinki University have discovered that the functional core of a key enzyme (enzymes are proteins which promote biochemical reactions in the body) involved in the formation of RNAi molecules is striking similar to an enzyme involved in gene expression.
The research, published in the journal "Public Library of Science Biology", supports the idea that the two enzymes have a common ancestor and gives weight to the theory that life started as self-replicating RNA molecules in a RNA world (as opposed to the present world where molecules of DNA are the basis of life).
In fact, we live in a DNA world, as genes are segments of DNA, and it is the information contained in the genes of an organism that, when translated into proteins, makes up the blueprint for the body structure and function. This process, the expression of genes into proteins, is comprised of two steps: the first by which genetic information in DNA is converted into RNA and the second which is the synthesis of proteins based on the information/instructions contained in the newly made RNA (DNA ? RNA ? protein).
But there is a dent in this apparently perfect process. In fact, for a long time scientists have been puzzled why approximately 32% of the human genome/DNA, although transformed into RNA, does not lead to protein production (DNA ? RNA ? no protein)? So why would this huge amount of “junk” RNA keep being formed instead of being eliminated during evolution? After all, a basic rule of life is that any reaction that costs energy and is not advantageous for the individual must be eliminated. What recent research unveiled is that RNA is a much more multifaceted molecule than previously thought, and some of that “junk” RNA actually plays an important role in gene regulation. One such example is RNAi, a RNA that is capable of blocking the activity of specific genes.
And it was while studying the mechanisms behind RNAi, that Paula S. Salgado, Jonathan M. Grimes and colleagues discovered that the functional core of an enzyme involved in the formation of short RNAi molecules from other RNA molecules (RNA? RNA), was remarkably similar to the one that mediates the formation of RNA from DNA (DNA ? RNA) during the first step of gene expression. This striking similarity suggested a common ancestor and further analysis seemed to indicate that the enzyme involved in the RNAi process had appeared before and so would probably be more similar structurally to the common ancestor.
These results support the idea of life starting in a (RNA) world where self-replicating (RNA?RNA) multifunctional RNA molecules evolved (as well as the enzymes mediating the process) into the present situation where genetic information is contained instead on DNA. In fact, although RNA is chemically similar to DNA it has, as the “originater” of life, two major advantages over the latter molecule: 1- it is easily synthesised from non-complex blocks so it had higher possibility of occurring spontaneously and 2 - it is easy to imagine that it could evolve into DNA, which by being a much more stable molecule would then take over. Furthermore, the idea of a primitive RNA world, if proved, could solve one of biggest conundrums on the origin of life: if life needs both DNA as a source of genetic information and proteins to drive life’s chemical reactions how could have one appeared first without the other? Some scientists believe that the answer lies in this ancient RNA molecule which was capable of supporting life reactions and also contained life’s genetic blueprint and whose existence seems to be consistent with the findings of Salgado, Grimes and colleagues.
In this way, Salgado’s work sheds light not only on the mechanism behind this extremely interesting and important process that is RNAi, but can also help to understand better how life began on earth.Piece researched and written by:
Catarina Amorim | alfa
Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
22.05.2018 | Life Sciences
22.05.2018 | Earth Sciences
22.05.2018 | Trade Fair News