Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Breakthrough shows how DNA is 'edited' to correct genetic diseases

27.05.2014

An international team of scientists has made a major step forward in our understanding of how enzymes 'edit' genes, paving the way for correcting genetic diseases in patients.

Researchers at the Universities of Bristol, Münster and the Lithuanian Institute of Biotechnology have observed the process by which a class of enzymes called CRISPR – pronounced 'crisper' – bind and alter the structure of DNA.

The results, published in the Proceedings of the National Academy of Sciences (PNAS) today, provide a vital piece of the puzzle if these genome editing tools are ultimately going to be used to correct genetic diseases in humans.

CRISPR enzymes were first discovered in bacteria in the 1980s as an immune defence used by bacteria against invading viruses. Scientists have more recently shown that one type of CRISPR enzyme – Cas9 – can be used to edit the human genome - the complete set of genetic information for humans.

These enzymes have been tailored to accurately target a single combination of letters within the three billion base pairs of the DNA molecule. This is the equivalent of correcting a single misspelt word in a 23-volume encyclopaedia.

To find this needle in a haystack, CRISPR enzymes use a molecule of RNA - a nucleic acid similar in structure to DNA. The targeting process requires the CRISPR enzymes to pull apart the DNA strands and insert the RNA to form a sequence-specific structure called an 'R-loop'.

The global team tested the R-loop model using specially modified microscopes in which single DNA molecules are stretched in a magnetic field. By altering the twisting force on the DNA, the researchers could directly monitor R-loop formation events by individual CRISPR enzymes.

This allowed them to reveal previously hidden steps in the process and to probe the influence of the sequence of DNA bases.

Professor Mark Szczelkun, from Bristol University's School of Biochemistry, said: "An important challenge in exploiting these exciting genome editing tools is ensuring that only one specific location in a genome is targeted.

"Our single molecule assays have led to a greater understanding of the influence of DNA sequence on R-loop formation. In the future this will help in the rational re-engineering of CRISPR enzymes to increase their accuracy and minimise off-target effects. This will be vital if we are to ultimately apply these tools to correct genetic diseases in patients. "

###

The work was funded at the University of Bristol by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Wellcome Trust.

Paper

'Direct observation of R-loop formation by single RNA-guided Cas9 and Cascade effector complexes' by Mark D. Szczelkuna, Maria S. Tikhomirovab, Tomas Sinkunasd, Giedrius Gasiunasd, Tautvydas Karvelisd, Patrizia Pscherac, Virginijus Siksnysd and Ralf Seidel in PNAS.

About the Biotechnology and Biological Sciences Research Council

The Biotechnology and Biological Sciences Research Council (BBSRC) invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.

Funded by Government, and with an annual budget of around £467m (2012-2013), we support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.

About the Wellcome Trust

The Wellcome Trust is a global charitable foundation dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust's breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests.

Philippa Walker | Eurek Alert!
Further information:
http://www.bristol.ac.uk/

Further reports about: BBSRC Biotechnology Breakthrough CRISPR DNA PNAS RNA bacteria diseases enzymes humans sequence structure

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>