Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Timeless’ gene found to play key role as timekeeper in mammals

17.10.2003


In 1998, scientists found the mammalian version of a gene, known as timeless, which in flies is crucial for the biological clock. However, all but one of the research groups involved determined that timeless did not have such a role in mammals. Now that research group says timeless is indeed a key timekeeper in mammals.



In a new complex molecular study of rats, published in the Oct. 17 issue of Science, researchers at the University of Illinois at Urbana-Champaign blocked the functional ability of timeless, leaving the circadian clock in disarray.

The key difference between the previous studies and this new one was the identification of two timeless proteins -- one a full-length protein and the other a shorter, incomplete version.


"There has been a lot of dispute about the role of timeless, and timeless has been generally excluded in research done since 1998," said Martha U. Gillette, the head of the department of cell and structural biology at Illinois. In the initial studies, her lab had seen differences in timeless RNA expression. The other labs had not.

The research in Gillette’s lab, led by Jessica W. Barnes and Jeffrey A. Barnes, both doctoral students, and Shelley A. Tischkau, a professor of veterinary biosciences, continued with the goal to decipher the previously conflicting findings.

"This paper has substantial supportive data that provides definitive evidence that timeless needs to be back in the loop," Gillette said. Much of the supporting data, in fact, is presented online to complement the material appearing in the Science paper.

The "loop" is the 24-hour circadian rhythm in the brain and cells. It consists of an automatically regulated loop of transcription and translation of gene products important for many diverse physiological functions such as sleep, metabolism and reproduction.

The earlier findings had led to the conclusion that timeless was vital only to cellular development in mammals but not to the clock. "The other labs had targeted their reagents at the end of the gene where changes in only full-length timeless are difficult to isolate due to the over-abundance of the short isoform," Jessica Barnes said. "So their results were being confounded."

Working with the whole molecule, the interaction of timeless with the five other mammalian clock genes (three forms of mPER, mClk and bmal) became clear.

In normal and control-treated brain slices from the rats’ suprachiasmatic nucleus, the site of the circadian clock, normal activity occurred in the presence of timeless. When specially designed antisense molecules were added to block it, electrical rhythms were disrupted. "When you have really low levels of timeless, you also disrupt the other clock genes," Barnes said. "You get an uncoupling. The clock is very much in disarray."

Some clock genes send positive signals, triggering mRNA production. The Illinois team theorizes that timeless and another clock gene (mPER2) work in tandem as negative signals to shut down mRNA production during the 24-hour cycle. With timeless back in the mammalian equation, it means that the clock genes of Drosophila and mammals correspond and function similarly.

"This conservation of timeless is very important, that what is happening in Drosophila is holding true in the mammal," Gillette said. "Without timeless, you are missing a whole set of gears in an intricate mechanism."

Other contributors to the paper were postdoctoral researchers Jennifer W. Mitchell and Penny W. Burgoon, both in cell and structural biology, and Jason R. Hickok, a doctoral student in cell and structural biology.


The U.S. Department of Health and Human Services, the University of Illinois Scholars Program and the Illinois Governor’s Venture Technology Fund/Molecular & Endrocrine Pharmacology Program supported the research.

Jim Barlow | EurekAlert!
Further information:
http://www.uiuc.edu/

More articles from Life Sciences:

nachricht Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine

nachricht New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>