Nobel 2012, chemistry. Intercellular communication networks

The 2012 Nobel Prize in Chemistry was won by Americans Robert Lefkowitz and Brian Kobilka, who studied a large family of receptor proteins that provide communication and interaction between the body's cells.

Indeed, our mortal body is a system that has no equal in complexity. All his cells live in perfect harmony, working clearly and strictly in coordination with others, always on command and according to circumstances. In response to the command from the “center”, adrenaline is released into the blood – and a variety of systems instantly respond to this signal. Blood pressure rises, the heart speeds up, the pupils dilate, the lung muscles relax, and so on.

How do cells receive such signals? Almost 150 years ago it became clear that without a nervous system: blocking the nerves has no effect on the perception of adrenaline. There is another possibility - with the help of receptor proteins. Sitting on the cell membrane, they instantly catch various chemical signals and, changing their configuration, trigger the appropriate response.

In principle, this was assumed quite a long time ago. However, for decades, no one really knew what exactly these receptors were, what they were made of, or how they worked. One thing was clear: for the colossal network of interactions connecting billions of cells in the body, these proteins must be a very sophisticated and numerous ensemble.

Robert Lefkowitz addressed this topic back in the late 1960s. He used radioactive atoms as tags for molecules of various hormones. With their help, he was able to identify several long-awaited receptor proteins, including β-adrenergic receptors, which in some cells provide a response to adrenaline. The authors were able to isolate adrenergic receptors in their pure form and conduct the first studies of the mechanism of their work.

The next significant step came in the 1980s, when Brian Kobilka joined Lefkowitz's team to rummage through human chromosomes and find the single gene that encodes the synthesis of the β-adrenergic receptor. Having examined this gene in detail, scientists discovered that it is surprisingly similar to another known gene, which is responsible for the synthesis of light-sensitive proteins in the eye. It became clear that we are talking about a whole family of proteins that perform receptor functions.

Today they are known by the long name G-protein-coupled receptors, because, perceiving a signal from outside the cell, they transmit it to G-proteins working inside - the next link in the chain of reactions that is triggered in response to a specific signal. And these proteins are also called seven-helical (serpentines), because of the structural detail common to all of them, seven helices, which, like threads of fabric, pierce the cell membrane several times in both directions.

Such receptors are not found in bacteria; they are known only in higher eukaryotic organisms. But in our country they participate in a huge number of physiological processes, regulating the functioning of the nervous and immune systems, the perception of light and the sense of smell. They provide a response to such important hormones as dopamine, GABA, adrenaline, histamine, serotonin. In general, more than 40% of all medicines sold in pharmacies (minus homeopathy) somehow affect serpentine proteins. And the appearance of many of them was a direct consequence of the work of the newly minted Nobel laureates.