MOSCOW, December 9 - RIA Novosti . Biologists from the US and Canada have opened an unusual family of proteins that viruses use to protect yourself from cell "anti-virus" and that can be used to protect cells and whole organisms from editing their DNA, according to an article published in the Cell .
"We have not even tried to find protection from the CRISPR, we were just trying to understand how the phage viruses insert themselves into the genomes of bacteria. As a result, we came across something that I think will be very important for the further development of biotechnology. A similar" switch "CRISPR will allow us to control where, how and when we will edit DNA" - said Alan Davidson (Alan Davidson) from the University of Toronto (Canada).
Genomic editor CRISPR / Cas9, called main scientific breakthrough of 2015, was created by the American scientist Fenem Zhang (Feng Zhang) and a number of other molecular biologists about three years ago, and since then it has gone through several upgrades that allow scientists to use it to edit the genome with absolute precision.
In fact, CRISPR / Cas9, like many other things, invented not a man, and nature - initially, the system has evolved in bacteria hundreds of millions of years ago to protect against retroviruses, and only in 2012, Feng Zhang (Feng Zhang) and his colleagues adapted it to modify the genome of multicellular creatures. It consists of two components - a "library" of genetic code of the virus sample (CRISPR), and the enzyme Cas9, searching for similar sequences in the DNA of the bacteria and remove them if necessary.
Davidson and his colleagues have found that viruses are not left out of this "race of bio-weapons" and created their own response to the CRISPR / Cas9 - a set of three proteins that cling to the different parts of cas9 protein and neutralize it before it time to cut the DNA of the virus from the genome of a microbe.
These proteins were discovered as Davidson says, quite by accident. His research team watched as the various versions of bacteriophages viruses penetrate cells meningococcus (Neisseria meningitidis) - causes of meningitis, actively using the CRISPR / Cas9 to protect yourself from viruses.
It turned out that some bacteriophages contain three previously unknown protein - acrIIC1, acrIIC2 and acrIIC3. These proteins, as shown by further experiments, can be attached to molecules Cas9 and neutralize them, preventing them from recognizing the viral DNA or RNA and destroy it.
When scientists identified the genes responsible for the production of these proteins, and insert them into human cells, it made DNA of these cells, "protected" from being overwritten - all further attempts to modify the genetic code using the CRISPR / Cas9 stayed bacteriophage proteins.
What is interesting is the opening? It means that scientists finally have a way to flexibly control how and where will be genome editing using CRISPR / Cas9 system. This will create a safe kind of gene therapy for the treatment of congenital diseases, to make a "clean" GMO genetics point of view and implement many other things that were not possible to make due to the fact that scientists do not know how to control the operation of the genome editor.
In addition, from an evolutionary point of view, the opening of "antiredaktora" DNA explains the next puzzle - if the CRISPR / Cas9 system is so effective, why viruses are not extinct? As it turned out, coped with the challenge viruses bacteria, answering to create biological 'anti-virus' discovery of molecules that inhibit its operation.
No comments:
Post a Comment