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:4/28/2016)... and BANGALORE, India , April 28, 2016 ... a product subsidiary of Infosys (NYSE: INFY ), ... a global partnership that will provide end customers ... mobile banking and payment services.      (Logo: ... innovation area for financial services, but it also plays a ...
(Date:4/19/2016)... April 20, 2016 The new ... a compact web-based "all-in-one" system solution for all door ... reader or the door interface with integration authorization management ... control systems. The minimal dimensions of the access control ... the building installations offer considerable freedom of design with ...
(Date:4/13/2016)... April 13, 2016  IMPOWER physicians supporting Medicaid patients ... a new clinical standard in telehealth thanks to a ... the higi platform, IMPOWER patients can routinely track key ... body mass index, and, when they opt in, share ... visit to a local retail location at no cost. ...
Breaking Biology News(10 mins):
(Date:5/23/2016)... , May 23, 2016 Zimmer Biomet Holdings, Inc. ... today announced that its Board of Directors has approved the ... second quarter of 2016. The cash dividend ... July 29, 2016 to stockholders of record as of the ... dividends are subject to approval of the Board of Directors ...
(Date:5/23/2016)... , May 23, 2016 - Leading CRO,s ... - Frontage Implement a Single Platform to Manage End-to-end ... Traceability Within the Bioanalytical lab Frontage Laboratories, a full-service ... States and China , has selected ... facilities. In addition to serving as the global electronic lab notebook ...
(Date:5/23/2016)... ... May 23, 2016 , ... Foresight ... nanotechnology, announced the winners for the 2015 Foresight Institute Feynman Prizes. , ... in two categories, one for experiment and the other for theory in nanotechnology. ...
(Date:5/20/2016)... Diego, CA (PRWEB) , ... May 20, 2016 , ... ... that 10 of its most experienced veterinary clients have treated over 100 of their ... cutting edge technology to provide the highest level of care for their patients. ...
Breaking Biology Technology: