Recently, Nobel Prize in Physiology or Medicine 2017 was jointly awarded to Jeffrey C. Hall, Michael Rosbash and Michael W. Young “for their discoveries of molecular mechanisms controlling the circadian rhythm”.
Here I am going to discuss about circadian rhythm and what is it actually mean??
Circadian rhythm was originated from the latin words circa meaning “around” and diem meaning “day”. It is basically a 24 hour internal clock that is running in the background of the brain and help living organisms to anticipate and adapt to the regular rhythm of the day. This clock is present in all plants, animals and humans so that they all can synchronize themselves with the earth’s revolutions.
These Nobel laureates worked on fruit fly that is Drosophila melanogaster. Here is how the whole molecular machinery works to maintain our daily clock:
This mechanism has two main genes that control the process: period gene and timeless gene.
period gene encodes the period protein, PER that accumulates during night and degrade during the day. PER protein levels oscillate over a 24 hour cycle.
PER protein synthesis occurs in cytoplasm and then it is being transported to the nucleus by TIM protein (encoded by timeless gene).
In the nucleus PER protein block the activity of period gene and block its own synthesis by inhibitory feedback loop.
This year’s laureates identified additional proteins that are essential for period gene’s activation.
Circadian rhythm regulates our functions such as sleep, body temperature, metabolism, hormonal levels etc. When there is an imbalance between our external environment and our clock then we experience uneasiness like we experience jet lag, when we travel from one time zone to another.
Discovery of this whole mechanism and it’s molecular aspects was a great job that this year’s Nobel laureates did.
Stay tuned for more research updates.