People differ more than we thought
Scientists have revealed an unexpectedly strong role of mutations in the work of the human body
Small differences in the structure of DNA in different people unexpectedly strongly affect the structure of proteins and their work, the consequences of which were previously extremely underestimated, biologists say in an article published in the journal Scientific Reports (Mahlich et al., Common sequence variations affect molecular function more than rare variations?).
"Until now, almost all of us believed that these variations do not significantly affect the functioning of proteins. These variations can change our perception of odors or predisposition to react to different pathogens. None of these changes can be noticed in everyday life, but in some situations they can become critically important, for example, when drugs or psychoactive substances enter the body," says Burkhard Rost from the Technological University of Munich (in a press release We are much more unique than assumed).
The effect of frequent, moderate and rare variants of amino acid substitutions
on the functions of the corresponding proteins. Figure from an article in Scientific Reports – VM.
Genetic studies of the last two decades show that no one, even identical twins, is a complete DNA copy of someone else. The genetic material of children contains, as a rule, two new mutations compared to the structure of the genome of their parents, and on average unrelated people differ by 10-20 thousand unique "typos" in the structure of their genes.
Moreover, five years ago, American geneticists discovered, by examining the genomes of "reprogrammed" skin cells, that the genomes of virtually all of them differ from each other and contain many mutations, repeats and other changes in the structure of DNA.
Most of these changes, despite their large number, are extremely rare and they do not change the structure and working principles of proteins that are encoded by similar "mutated" genes. Therefore, scientists paid almost no attention to how they change the work of individual proteins and related cellular systems.
Rost and his colleagues filled this gap in molecular biology by analyzing approximately 60 thousand blood samples taken from people from different countries, social and racial groups. In total, the scientists analyzed several tens of thousands of single-letter "typos" (snips, from single nucleotide polymorphisms) in their genes. Biologists used these data to create an artificial intelligence system that can predict how the work of proteins changes after the appearance of such small mutations.
These calculations led to extremely unexpected results – more than half of the small mutations in almost all human proteins led to the appearance of quite noticeable changes in their three-dimensional structure and in the principles of operation.
Each such change in itself will have little effect on the work of the body and will not be unambiguously bad or good. At the same time, their cumulative effect, a combination of all such "typos" in the genes, will make each person's body, in fact, a unique thing.
According to scientists, this should be taken into account when developing personal medicine techniques and conducting research on the role and function of different proteins and genes in the work of our body and cells, the structure and nature of which can vary greatly for different individuals.
Portal "Eternal youth" http://vechnayamolodost.ru
20.06.2017