The flash of a new "star"
Biologists have learned to turn on arbitrary genes using RNA
"RNA can be called a kind of molecular "puzzle", a maddening Rubik's cube that needs to be disassembled in order to learn how to do a variety of things in cells. We have figured out how to create an RNA molecule that opens up a piece of this puzzle to us. The STAR system has become the key to this lock," says Julius Lucks from Cornell University in Ithaca (USA).
The STAR system, which Lux talks about, is a set of several short RNA molecules that are able to recognize special "stop marks" on the surface of genes in DNA strands and force the cell to ignore them.
Diagram from The Lucks Lab press release: STARs are born in Nature Chemical Biology! – VM
As scientists explain, RNA plays the role of the main information carrier in living cells – it "conducts" the activity of genes and how actively they are read. Molecular biologists are actively trying to take advantage of this property of RNA today, using short RNA molecules to create living "biocomputers" based on microbes and drugs that suppress the work of some genes.
Such short RNAs have one big limitation. They cannot be used to "turn on" genes, since they do not interact directly with DNA, but with the so-called matrix RNA. It is a "cast" of a gene in a form understandable for ribosomes, cellular "assembly factories".
Lux and his colleagues were able to solve this problem by paying attention to how the system of "blocking" genes in the DNA of living beings works and how chemically arranged. Using these data, scientists have collected four types of RNA molecules, which modifies the structure of the gene in such a way that the cell ceases to recognize stop marks located at the beginning of DNA or matrix RNA.
Such an action is not something irreversible, and the gene can be activated or deactivated almost an unlimited number of times. Biologists have successfully tested the work of these molecules, which they call STAR-RNA, on the culture of E. coli, one of the genes of which they tried to first turn off and then turn on.
According to the researchers, STAR can be used not only for genetic experiments, but also as a base for biological computing systems. As Lux notes, his team has already managed to assemble and "insert" into the E. coli the simplest logical chains, analogs of expressions AND, AND + NOT and other primitive operations. In the future, scientists believe, STAR will become the basis for intracellular computers.
Portal "Eternal youth" http://vechnayamolodost.ru03.02.2015