"The genes that control the production of various proteins in the body represent a smaller proportion of our DNA than endogenous retroviruses. They account for approximately 2 per cent, while retroviruses account for 8-10 per cent of the total genome. If it turns out that they are able to influence the production of proteins, this will provide us with a huge new source of information about the human brain," says Johan Jakobsson.
And this is precisely what the researchers discovered. They have determined that several thousands of the retroviruses that have established themselves in our genome may serve as "docking platforms" for a protein called TRIM28. This protein has the ability to "switch off" not only viruses but also the standard genes adjacent to them in the DNA helix, allowing the presence of ERV to affect gene expression.
This switching-off mechanism may behave differently in different people, since retroviruses are a type of genetic material that may end up in different places in the genome. This makes it a possible tool for evolution, and even a possible underlying cause of neurological diseases. In fact, there are studies that indicate a deviating regulation of ERV in several neurological diseases such as ALS, schizophrenia and bipolar disorder.