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:6/2/2016)... LONDON , June 2, 2016 ... Systems, Manned Platforms, Unmanned Systems, Physical Infrastructure, Support & ... intelligence provider visiongain offers comprehensive analysis of ... that this market will generate revenues of $17.98 billion ... Systems acquired DVTEL Inc, a leader in software and ...
(Date:5/16/2016)... --  EyeLock LLC , a market leader of iris-based ... IoT Center of Excellence in Austin, Texas ... embedded iris biometric applications. EyeLock,s iris authentication ... with unmatched biometric accuracy, making it the most proven ... platform uses video technology to deliver a fast and ...
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 ... subsidiary of Infosys (NYSE: INFY ), and Samsung ... global partnership that will provide end customers with a ... and payment services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ... for financial services, but it also plays a fundamental part ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... , June 27, 2016  Global demand ... 4.6 percent through 2020 to $7.2 billion.  This ... and beverages, cleaning products, biofuel production, animal feed, ... biotechnology, diagnostics, and biocatalysts). Food and beverages will ... driven by increasing consumption of products containing enzymes ...
(Date:6/27/2016)... ... June 27, 2016 , ... Cancer experts from ... believe could be a new and helpful biomarker for malignant pleural mesothelioma. Surviving ... to read it now. , Biomarkers are components in the blood, tissue ...
(Date:6/27/2016)... ... 27, 2016 , ... Rolf K. Hoffmann, former senior vice ... University of North Carolina Kenan-Flagler Business School effective June 27. , ... with a focus on the school’s international efforts, leading classes and participating in ...
(Date:6/24/2016)... TOKYO , June 24, 2016  Regular discussions on ... to take place between the two entities said Poloz. ... in Ottawa , he pointed to the ... and the federal government. ... Poloz said, "Both institutions have common economic goals, why not ...
Breaking Biology Technology: