Navigation Links
Watching the cogwheels of the biological clock in living cells
Date:10/26/2012

Our master circadian clock resides in a small group of about 10'000 neurons in the brain, called the suprachiasmatic nucleus. However, similar clocks are ticking in nearly all cells of the body, as demonstrated by the group of Ueli Schibler, professor at the Department of Molecular Biology of the University of Geneva, Switzerland. The molecular mechanisms of circadian clocks can thus be studied outside of the animals, in cultured cells.

A system to study gene regulation live in single cells

"Given the important role of the DBP protein in the regulation of detoxifying enzymes, we were interested in studying the molecular mechanisms underlying the rhythmic transcription of the DBP gene", points out the biologist, who is member of the NCCR Frontiers in Genetics. To do so, his team devised an elegant method to watch directly under the microscope how the clock's molecular "cogwheels" govern the activity rhythms of this gene in individual living cells. To this end, the scientists engineered a cell line with a piece of a chromosome exclusively composed of repeated DBP gene copies. They showed that the daily transcription of DBP is due to the rhythmic association of an essential clock component, the transcription factor BMAL1. "This is the first time a transcription factor binding to a circadian gene could be visualized in real time in single cells" explains Markus Stratmann, first author of the article.

The clock transcription factor must be sacrificed

To their surprise, the scientists found that the clock protein BMAL1 is destroyed while stimulating the expression of the DBP gene. By applying a variety of sophisticated imaging and biochemical techniques, they showed that the BMAL1 molecules bound to the DBP gene are degraded by an intracellular protein destruction machine, termed the proteasome.

Curiously, the chopping of the triggering protein BMAL1 is absolutely required for the efficient activation of the DBP gene. In other words, BMAL1 must die while embracing that gene in order to do its job. "In a sense, these transcription factors have the same cruel fate as males of the carnivorous insect Mantis. Sadly, Mantis females decapitate and then start eating their partners before the act of love is even completed" says Markus Stratmann.

At the moment, the biologists can only speculate about the broader impact of their findings. "We do not yet understand why the destruction of the BMAL1 protein is mandatory for the optimal functioning of the DBP gene" remarks Ueli Schibler. In fact, BMAL1 molecules regulate the daily activity of many other genes without getting killed while doing their work. The researchers noticed, however, that genes whose activity is not associated with the destruction of BMAL1 are expressed many hours later than the DBP gene. Their work thus offers a plausible explanation to the enigma of how one and the same transcription factor, BMAL1, can impose dramatically different daily cycles of gene expression.


'/>"/>
Contact: Ueli Schibler
ueli.schibler@unige.ch
41-223-796-175
Universit de Genve
Source:Eurekalert  

Related biology news :

1. Self-forming biological scaffolding
2. Merging the biological and the electronic
3. Boston subway system to be used to test new sensors for biological agents
4. Making sense out of the biological matrix of bipolar disorder
5. Understanding the biological and ecological implications of safe nanotechnology
6. Iowa State, Ames Lab researchers invent new tool to study single biological molecules
7. Mathematicians find solution to biological building block puzzle
8. Allergies? Your sneeze is a biological response to the noses blue screen of death
9. Johns Hopkins researchers link 2 biological risk factors for schizophrenia
10. Golden West Biologicals, Inc. Exhibiting at AACC Clinical Lab Expo 2012
11. Biological and Pharmaceutical Complex Fluids Conference
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Watching the cogwheels of the biological clock in living cells
(Date:4/15/2016)...  A new partnership announced today will help ... in a fraction of the time it takes ... life insurance policies to consumers without requiring inconvenient ... Diagnostics, rapid testing (A1C, Cotinine and HIV) and ... weight, pulse, BMI, and activity data) available at ...
(Date:4/13/2016)...  IMPOWER physicians supporting Medicaid patients in ... standard in telehealth thanks to a new partnership with ... IMPOWER patients can routinely track key health measurements, such ... and, when they opt in, share them with IMPOWER ... local retail location at no cost. By leveraging this ...
(Date:3/29/2016)... RATON, Florida , March 29, 2016 ... or the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are ... DNA in ink used in a variety of writing ... theft. Buyers of originally created collectibles from athletes on ... through forensic analysis of the DNA. ...
Breaking Biology News(10 mins):
(Date:5/26/2016)... ... 26, 2016 , ... FireflySci has been manufacturing quartz and ... over the globe. Their cute firefly logo has been spreading to more and ... spectrophotometer calibration standards that never require recalibration. These revolutionary standards have changed ...
(Date:5/25/2016)... ... May 25, 2016 , ... The American Medical Informatics ... of the National Coordinator for Health IT (ONC) outlining a measurement approach to ... were available when and where it was needed. The organization of health informatics ...
(Date:5/24/2016)... ... May 24, 2016 , ... Cell ... injuries, will be accelerated by research at Worcester Polytechnic Institute (WPI) that yielded ... healing and tissue regeneration. , The novel method, developed by WPI faculty members ...
(Date:5/23/2016)... Ohio (PRWEB) , ... May 23, 2016 , ... ... Trends That Will Drive Precision Farming in 2017 and Beyond. The paper outlines ... practitioners in the precision ag industry. , “We’ve witnessed a lot of highs ...
Breaking Biology Technology: