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 Hot vibrating gases under the electron spotlight
12.12.2017 | Institute of Industrial Science, The University of Tokyo

nachricht Plankton swim against the current
12.12.2017 | Schweizerischer Nationalfonds SNF

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>