Navigation Links
A mystery solved: How genes are selectively silenced
Date:10/18/2010

Our genetic material is often compared to a book. However, it is not so much like a novel to be read in one piece, but rather like a cookbook. The cell reads only those recipes which are to be cooked at the moment. The recipes are the genes; 'reading' in the book of the cell means creating RNA copies of individual genes, which will then be translated into proteins.

The cell uses highly complex, sophisticated regulatory mechanisms to make sure that not all genes are read at the same time. Particular gene switches need to be activated and, in addition, there are particular chemical labels in the DNA determining which genes are transcribed into RNA and which others will be inaccessible, i.e. where the book literally remains closed. The biological term for this is epigenetic gene regulation.

Among the epigenetic mechanisms which are well studied is the silencing of genes by methyl groups. This is done by specialized enzymes called methyltransferases which attach methyl labels to particular 'letters' of a gene whereby access to the whole gene is blocked. "One of the great mysteries of modern molecular biology is: How do methyltransferases know where to attach their labels in order to selectively inactivate an individual gene?" says Professor Ingrid Grummt of the German Cancer Research Center (DKFZ).

Grummt has now come much closer towards unraveling this mystery. She has focused on studying those text passages in the genetic material which do not contain any recipes. Nevertheless, these texts are transcribed into RNA molecules in a controlled manner. "These so-called noncoding RNAs do not contain recipes for proteins. They are important regulators in the cell which we are just beginning to understand," says Ingrid Grummt.

In her most recent work, Grummt and her co-workers have shown for the first time that epigenetic regulation and regulation by noncoding RNAs interact. The scientists artificially introduced a noncoding RNA molecule called pRNA into cells. As a result, methyl labels are attached to a particular gene switch so that the genes behind it are not read. The trick is that pRNA exactly matches (is complementary to) the DNA sequence of this gene switch. The investigators found out that pRNA forms a kind of plait, or triple helix, with the two DNA strands in the area of this gene switch. Methyltransferases, in turn, are able to specifically dock to this 'plait' and are thus directed exactly to the place where a gene is to be blocked.

More than half of our genetic material is transcribed into noncoding RNA. This prompts Ingrid Grummt to speculate: "It is very well possible that there are exactly matching noncoding RNA molecules for all genes that are temporarily silenced. This would explain how such a large number of genes can be selectively turned on and off."


'/>"/>

Contact: Dr. Sibylle Kohlstdt
s.kohlstaedt@dkfz.de
Helmholtz Association of German Research Centres
Source:Eurekalert

Related biology news :

1. Scientists solve mystery of arsenic compound
2. Marine scientists unveil the mystery of life on undersea mountains
3. Toward resolving Darwins abominable mystery
4. Interdisciplinary research looks at Charlottes green mystery
5. Mystery unraveled: How asbestos causes cancer
6. Answer to saliva mystery has practical impact
7. Solution to beading-saliva mystery has practical purposes
8. Uncovering the mystery of a major threat to wheat
9. A Dicty mystery solved
10. Scripps Research scientists solve mystery of fragile stem cells
11. Experts gather to solve mystery of largest recorded die-off of great whales
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/24/2017)... -- EyeLock LLC, a leader of iris-based identity authentication ... solution on the latest Qualcomm® Snapdragon™ 835 mobile ... Congress 2017 (February 27 – March 2, ... Stand 3E10. The Snapdragon 835 ... combination of hardware, software and biometrics technologies ...
(Date:2/21/2017)... , February 21, 2017 ... 70 Millionen US-Dollar wachsen. Nach einem Gespräch mit mehr als ... einige Hindernisse zu überwinden gilt, um diese Prognose zu ... ... anderem die Mobilisierung der finanziellen Mittel für die Biobank, ...
(Date:2/13/2017)... FRANCISCO , Feb. 13, 2017  RSA ... centralized platform that is designed to enhance fraud ... latest release in the RSA Fraud & Risk ... enable organizations to leverage additional insights from internal ... tools to better protect their customers from targeted ...
Breaking Biology News(10 mins):
(Date:3/24/2017)... , March 24, 2017  Infectex Ltd., a ... today announced positive results of a Phase 2b-3 clinical ... regimen in patients with multidrug-resistant pulmonary tuberculosis (MDR-TB). SQ109 ... at Sequella, Inc. ( USA ) and ... A total of 140 patients were enrolled in a ...
(Date:3/24/2017)... March 24, 2017 Agenus Inc. (NASDAQ: AGEN), ... antibodies and cancer vaccines, today announced participation at the ...  Annual William Blair and Maidstone Life Sciences conference "Cancer ... in New York, NY . Agenus ... 29 at 9:40 am: Robert B. Stein , ...
(Date:3/23/2017)... , March 23, 2017  SeraCare ... to global in vitro diagnostics manufacturers and ... the industry,s first multiplexed Inherited Cancer ... testing by next-generation sequencing (NGS). The Seraseq™ ... developed with input from industry experts to ...
(Date:3/23/2017)... NetworkNewsWire Editorial Coverage  ... Cancer remains one of the world,s ... systems, in terms of costs and resources. However, as the ... of innovative and efficient therapies that demonstrate higher chances of ... cancer treatments, a growing number of patients receiving immuno-oncology therapies ...
Breaking Biology Technology: