Newly discovered molecule essential to resetting 'body clocks'

Jul 13, 2011
Scientists explored the impact of light on fruit flies (pictured)

(PhysOrg.com) -- Research has shown that light is the key to getting our 'body clocks' back in sync and now a new study exploring the resynchronisation mechanism in insects has discovered a molecule essential to the process.

Researchers from Queen Mary, University of London looked at the impact of light on the circadian clocks (commonly known as 'body clocks') of . They identified a novel molecule, QUASIMODO (QSM), which was intrinsically involved in relaying light-information to the flies' inner clocks.

Ralf Stanewsky, Professor of Neurobiology at Queen Mary's School of Biological and who led the research, explained: "Circadian clocks regulate rhythmic in many organisms. A famous example is our sleep/wake cycle.

"It is regulated by our , which tells us when to go to bed and when to wake up. If you bring your clock out of sync with the external time, for example when you fly from London to New York, your internal clock still sends you to sleep according to London time.

"This shows that we indeed have a timer in us and that this timer needs to be reset like a normal wrist watch when you move to a different time zone or if you're a shift worker and need to adjust your sleep/ accordingly."

Professor Stanewsky had previously isolated a specialised circadian photoreceptor named CRYPTOCHROME (CRY) which is active directly within the clock neurones of flies' brains.

"Both insects and mammals use visual photoreceptors [i.e. those responsible for the ability to see] and specialised circadian photoreceptors, to synchronise the inner ," he said.

"In analysing the CRY receptor we realised there must be additional ways how light is transmitted to the . When we investigated further we found that the novel molecule QSM is involved.

"We isolated the quasimodo gene in a genetic screen for novel timing genes, and found that the amount of QSM protein drastically increased in response to light. This results in a decrease of an important timing protein (named TIMELESS, or TIM) within the circadian clock and when QSM levels were decreased, the TIM protein was stabilised, even when the flies were continuously exposed to light."

The daily fluctuating levels of TIM protein are indicative of the 'time of day' and tell the fly when to be active or not. Since TIM levels are regulated by QSM, and QSM is regulated by light, this is an elegant and novel way to reset the clock according to the daily changes of light and darkness.

"QSM appears to be integral to the synchronisation of the circadian clock in flies and it will be interesting to see if a similar mechanism or molecule helps to synchronise our human circadian clock to light," Professor Stanewsky said.

The research was published in the journal Current Biology.

Explore further: Researchers identify new mechanism to aid cells under stress

Related Stories

Recommended for you

Researchers identify new mechanism to aid cells under stress

4 hours ago

A team of biologists from NYU and Harvard has identified new details in a cellular mechanism that serves as a defense against stress. The findings potentially offer insights into tumor progression and neurodegenerative diseases, ...

Researchers image and measure tubulin transport in cilia

5 hours ago

Defective cilia can lead to a host of diseases and conditions in the human body—from rare, inherited bone malformations to blindness, male infertility, kidney disease and obesity. Scientists knew that somehow ...

Researchers find unusually elastic protein

8 hours ago

Scientists at Heidelberg University have discovered an unusually elastic protein in one of the most ancient groups of animals, the over 600-million-year-old cnidarians. The protein is a part of the "weapons system" that the ...

How malaria-spreading mosquitoes can tell you're home

Jan 22, 2015

Females of the malaria-spreading mosquito tend to obtain their blood meals within human dwellings. Indeed, this mosquito, Anopheles gambiae, spends much of its adult life indoors where it is constantly expose ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.