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 'Y' a protein unicorn might matter in glaucoma
23.10.2017 | Georgia Institute of Technology

nachricht Microfluidics probe 'cholesterol' of the oil industry
23.10.2017 | Rice 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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>