The Nobel Prize in Medicine 2017 is given to US scientists Jeffrey Hall, Michael Rosbash and Michael Young for exploring the body’s inner clock. Their discoveries of molecular mechanisms explain how plants, animals and humans adapt their biological rhythm so that they are optimally adapted to the various challenges throughout the day.

Our metabolism follows a regular day-night cycle. The internal clock ensures that the many processes in the body are synchronized with itself and the environment. This is true for humans and all other multicellular organisms. For a long time, the functioning of the internal clock was a mystery, but in the 1970s for the first-time researchers could show the genetic basis of the biological time measurement.

In 1984, a gene was isolated that decisively controls the biological rhythm, called “period gene (PER)”. They demonstrated that this gene produces the protein PER. PER accumulates during the night and is then dismantled during the day. Thus, the PER protein levels swing over a 24-hour cycle – synchronized with the circadian rhythm (Hall, Rosbash, Young 1990).

It was unclear, however, how these vibrations could be generated and maintained. Researchers assumed that the PER protein inhibits its own synthesis by an inhibitory feedback loop and thus regulates its own level in a cyclic rhythm. Hall and Rosbash showed in this context that the PER protein accumulates during the night in the cell nucleus (Hall, Rosbash, Young 1990).

Young finally produced an explanation for mechanism of PER gene, protein, and circadian cycle functions. in 1994, he discovered another clock gene, the so-called TIM, which is necessary for a normal circadian rhythm. Finally, he demonstrated that when TIM is bound to PER, the two proteins can reach the cell nucleus. There, they block the activity of the period gene to close the inhibitory feedback loop (Young, 1998).

Since the discoveries of the three award winners, the circadian biology has developed into a highly dynamic field of research, with an impact on our health and well-being, according to the reasons for awarding the prize.

COPYRIGHT: This article is property of We Speak Science, a nonprofit institution co-founded by Dr. Detina Zalli (Harvard University) and Dr. Argita Zalli (Imperial College London). The article is written by Dardan Beqaj ( M.Sc. Microbiology, Ebehard-Karls Uniersity of Tübingen)





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