Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Waking up is hard to do

17.02.2011
Scientists identify a gene important for the daily rhythms of the sleep-wake cycle

Northwestern University scientists have discovered a new mechanism in the core gears of the circadian clock. They found the loss of a certain gene, dubbed "twenty-four," messes up the rhythm of the common fruit fly's sleep-wake cycle, making it harder for the flies to awaken.

The circadian clock drives, among other things, when an organism wakes up and when it sleeps. While the Northwestern study was done using the fly Drosophila melanogaster, the findings have implications for humans.

The research will be published Feb. 17 in the journal Nature.

"The function of a clock is to tell your system to be prepared, that the sun is rising, and it's time to get up," said Ravi Allada, M.D., who led the research at Northwestern. "The flies without the twenty-four gene did not become much more active before dawn. The equivalent in humans would be someone who has trouble getting out of bed in the morning."

Allada is professor of neurobiology and physiology in the Weinberg College of Arts and Sciences and associate director for the Center for Sleep and Circadian Biology.

Period (per) is a gene in fruit flies that encodes a protein, called PER, which regulates circadian rhythm. Allada and his colleagues found that twenty-four is critically important to producing this key clock protein. When twenty-four is not present very little PER protein is found in the neurons of the brain, and the fly's sleep-wake rhythm is disturbed.

It seems it was fate that the gene Allada and his team pinpointed would be important in regulating the 24-hour sleep-wake cycle. The gene's generic name is CG4857, and the numbers add up to 24, earning it the twenty-four nickname. (The fruit fly's genome was sequenced in 2000, but until now the function of this gene was unknown.)

The known core mechanisms of the circadian clock, both in flies and humans, involve the process of transcription, where RNA is produced from DNA. A portion of the control system called a transcriptional feedback loop also is important. (The word circadian comes from the Latin phrase "circa diem," meaning "about a day.")

In trying to identify new clock components, the researchers identified a new player in the system, the gene twenty-four. Instead of operating in the process of transcription, they found twenty-four operates in the process of translation: translating proteins from RNA.

Twenty-four appears to be a protein that promotes translation of period RNA to protein. "This really defines a new mechanism by which circadian clocks are functioning," Allada said. "We found that twenty-four has a really strong and critical role in translating a key clock protein. Translation really wasn't appreciated before as having such an important role in the process."

The researchers believe it is likely that a mechanism similar to that described for the fly gene twenty-four will be evolutionarily conserved and found in humans.

Allada and his Northwestern team worked with scientists at the Korea Advanced Institute of Science and Technology (KAIST). Using a Drosophila library at KAIST, the researchers first screened the behavior of 4,000 different flies looking for flies whose sleep-wake cycles were awry. (Each fly had a different overexpressed gene and thus different behavior.) The fly with the most dramatic change was one with a longer cycle than normal, 26 hours instead of 24.

The overexpressed gene in this fly was CG4857. The researchers next removed, or knocked out, this gene in the flies. These flies had very poor sleep-wake rhythm and would sleep and wake at all times of day. The researchers found very little of the critical PER protein in the brain neurons despite the fact that per RNA is likely produced in the neurons. Without twenty-four the RNA was not translated into the PER protein, leading to dysfunction.

The paper is titled "The Novel Gene Twenty-four Defines a Critical Translational Step in the Drosophila Clock." In addition to Allada, other authors of the paper Chunghun Lim and Valerie L. Kilman, from Northwestern; Jongbin Lee, Changtaek Choi, Juwon Kim and Joonho Choe, from Korea Advanced Institute of Science and Technology, Korea; and Sung Mi Park and Sung Key Jang, from Pohang University of Science and Technology, Korea.

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>