Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Designer molecule shines a spotlight on mysterious 4-stranded DNA

09.09.2015

A small fluorescent molecule has shed new light on knots of DNA thought to play a role in regulating how genes are switched on and off.

DNA is typically arranged in a double helix, where two strands are intertwined like a coiled ladder, but previous research has shown the existence of unusual DNA structures called quadruplexes, where four strands are arranged in the form of little knots.


Structure of a G-quadruplex DNA highlighting one of the guanine tetrads.

Credit: Imperial College London

Now researchers at Imperial College London led by Dr Marina Kuimova and Professor Ramon Vilar are unravelling the mysteries of these four-stranded DNA structures. They have created a fluorescent molecule that can reveal the presence of these structures in living cells.

The team used the glowing molecule to target quadruplex DNA inside human bone cancer cells grown in the laboratory. Together with colleagues from Kings College London, they studied the interactions between the two in real time, using powerful microscopes.

Quadruplexes can form when a strand of DNA rich in guanines - one of the four building blocks in DNA - folds over onto itself. Several distinct quadruplex structures have been found in the human genome but their exact role remains unclear. Recent studies have shown they are particularly prevalent in regions nearby oncogenes - genes that have the potential to cause cancer.

"There is mounting evidence that quadruplexes are involved in switching genes on and off because of where they are usually positioned within the genome," says Professor Vilar, from Imperial's Department of Chemistry.

"If this can be proved, it would make quadruplexes an extremely important target for treating diseases such as cancer. But to understand what role they play, we need to be able to study them in living cells. Our new fluorescent molecule allows us to do this by directly monitoring the behaviour of quadruplexes inside living cells in real time."

The team designed the fluorescent molecule to glow more intensely when attached to DNA. Using powerful microscopes they discovered that they could distinguish between the molecules binding to the more common double helical DNA and quadruplex DNA because it glowed for much longer when bound to quadruplexes.

The researchers were also able to visualise the fluorescent molecule being displaced from quadruplex DNA by another molecule known to be a very good quadruplex binder. This suggests that the Imperial molecule could be used to hunt for new compounds that can bind to quadruplexes.

Co-author Arun Shivalingam, who worked on the study during his PhD at Imperial, says: "Until now, to image quadruplexes in cells researchers have had to hold the cells in place using chemical fixation. However, this kills them and brings into question whether the molecule really interacts with quadruplexes in a dynamic environment."

Professor Vilar adds: "We've shown that our molecule could be potentially used to verify in live cells and in real time whether potential quadruplex DNA binders are hitting their target. This could be a game changer to accelerate research into these DNA structures."

The study is published in Nature Communications.

Media Contact

Hayley Dunning
h.dunning@imperial.ac.uk
44-020-759-42412

 @imperialspark

http://www.imperial.ac.uk/press 

Hayley Dunning | EurekAlert!

More articles from Life Sciences:

nachricht Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>