The Nobel prize in physiology or medicine has been awarded to a trio of American scientists for their discoveries on the molecular mechanisms controlling circadian rhythms – in other words, the 24-hour body clock.
According to the Nobel committee’s citation, Jeffrey C Hall, Michael Rosbash and Michael W Young were recognised for their discoveries explaining “how plants, animals and humans adapt their biological rhythm so that it is synchronised with the Earth’s revolutions.”
The team identified a gene within fruit flies that controls the creatures’ daily rhythm, known as the “period” gene. This gene encodes a protein within the cell during the night which then degrades during the day.
When there is a mismatch between this internal “clock” and the external surroundings, it can affect the organism’s wellbeing – for example, in humans, when we experience jet lag.
All three winners are from the US. Hall, 72, has retired but spent the majority of his career at Brandeis University in Waltham, Massachussetts, where fellow laureate Rosbash, 73, is still a faculty member. Young, 68, works at Rockefeller University in New York.
Hall and Rosbash went on to unpick how the body clock actually works, revealing that the levels of protein encoded by the period gene rise and fall throughout the day in a negative feedback loop. Young, meanwhile, discovered a second gene involved in the system, dubbed “timeless”, that was critical to this process. Only when the proteins produced from the period gene combined with those from the timeless gene could they enter the cell’s nucleus and halt further activity of the period gene. Young also discovered the gene that controlled the frequency of this cycle.
The team’s discoveries also helped to explain the mechanism by which light can synchronise the clock.
Sir Paul Nurse, director of the Francis Crick Institute, who shared the Nobel prize in 2001 for research on the cell cycle, said the work was important for the basic understanding of life. “Every living organism on this planet responds to the sun,” he said. “All plant and animal behaviour is determined by the light-dark cycle. We on this planet are slaves to the sun. The circadian clock is embedded in our mechanisms of working, our metabolism, it’s embedded everywhere, it’s a real core feature for understanding life.
“We are increasingly becoming aware that there are implications for human disease,” Nurse added. “There is some evidence that treatment of disease can be influenced by circadian rhythms too. People have reported that when you have surgery or when you have a drug can actually influence things. It’s still not clear, but there will almost certainly be some implications for the treatment of disease too.”
The impact of the team’s work on medicine is becoming ever more apparent, said Ralf Stanewsky, ?a professor of molecular behavioural biology at the University of Münster and a former colleague of Hall. “You can see that more and more health issues, human health issues, are boiled down to either genetic defects in the circadian clock or self-imposed problems, by work and jet lag for example,” he said. “This [internal] timer is constantly struggling to reset to what environment people are exposed to. If you shift your clock every week by six hours or three hours, that puts an enormous pressure on your body.”
Source: The Guardian