Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Keeping to time counter-intuitively

28.03.2011
For more than 20 years, theoretical mathematical models have predicted that a delay built into a negative feedback system is at the heart of the molecular mechanism that governs circadian clocks in mammalian cells.

Now, the first experimental proof of this theory has been provided by an international research team led by molecular biologists and information scientists from the RIKEN Center for Developmental Biology in Kobe[1].

The demonstration of the feedback delay should lead to a better understanding of how cellular clocks function, and therefore how mammals adjust to the regular daily and seasonal changes in their environment. The work could also open the way to the development of treatments for circadian disorders, such as seasonal affective disorder, jet lag and even bipolar disorder.

Mammals not only show daily rhythms of waking and sleeping, but also body temperature, hormone secretion, and many other biological activities. The master cellular clocks that act as timers for these patterns are found in the suprachiasmatic nucleus of the brain. The molecular mechanism is built around a negative feedback system involving cryptochrome (Cry) genes, which code for proteins that repress their own activation by binding with the products of two other genes Bmal1 and Clock. The whole clock system is orchestrated by the interaction of these proteins with a complex array of promoters and enhancers, genetic sequences that regulate gene activity.

Within these clock-gene regulators are short sequences often known as clock-controlled elements. Different clock-controlled elements bind with the different proteins likely to be prevalent at different times of the day or night. The researchers carefully modified these sequences, and observed the impact on circadian rhythms of cells. They focused their studies in particular on the gene Cry1, and observed how the rhythm of its activity was affected by the modifications of clock-controlled elements within promoters and enhancers.

In addition to revealing a previously unknown clock-controlled element in the Cry1 promoter, the researchers also found that different combinations of clock-controlled elements led to different lengths of delay in the activation of Cry1. They demonstrated that this delay of Cry1 was required for the circadian clock to function (Fig. 1).

Based on these findings, they proposed a simple model of the mammalian circadian clock and now want to construct it using artificial components. “We think further experimental and theoretical analyses of this minimal circuit will lead to a deeper understanding of the mammalian circadian clock,” say team members Rikuhiro Yamada and Maki Ukai-Tadenuma.

The corresponding author for this highlight is based at the Laboratory for System Biology, RIKEN Center for Developmental Biology

Journal information

[1] Ukai-Tadenuma, M., Yamada, R.G., Xu, H., Ripperger, J.A., Liu, A.C. & Ueda, H.R. Delay in feedback repression by Cryptochrome 1 is required for circadian clock function. Cell 144, 268–281(2011).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6555
http://www.researchsea.com

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>