Nobel Prize winners in Medicine (2017)

In all living organisms, there is an internal biological clock, which is synchronized with the earth’s 24- hour day-night cycle, and is called the Circadian clock. A circadian rhythm is any biological process that displays an inborn, environment-matching oscillation of about 24 hours. This year’s (2017) Nobel Prize for Medicine went to Jeffrey C. Hall, Michael Rosbash and Michael W. Young, who worked out the molecular mechanism of the functioning of this body clock. Using fruit flies as a model organism, they isolated a gene that controls the normal daily biological rhythm. They showed that this gene encodes a protein “PER”, that accumulates in the cell during the night, and is then degraded during the day.

Subsequently, they identified additional protein components of this machinery, exposing the mechanism governing the self-sustaining clockwork inside the cell. Another protein, TIM, binds to the PER protein and takes it inside the cell nucleus. When the PER protein reaches a certain concentration, its production is stopped. Another protein, called DBT, controls the frequency of these oscillations, helping cells to adjust to the 24-hour cycle. Our inner clock adapts our physiology to the dramatically different phases of the day. The clock regulates critical functions such as behavior, hormone levels, sleep, body temperature and metabolism. Our wellbeing is affected when there is a temporary mismatch between our external environment and this internal biological clock.