Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Powerful tool for genetic engineering

22.11.2013
Researchers from Braunschweig describe new possibilities of the CRISPR-Cas-system

Viruses cannot only cause illnesses in humans, they also infect bacteria. Those protect themselves with a kind of ‘immune system’ which – simply put – consists of specific sequences in the genetic material of the bacteria and a suitable enzyme.


Streptococcus pyogenes is one of the bacteria in which the HZI scientists have studied the CRISPR-Cas system. © HZI / Rohde

It detects foreign DNA, which may originate from a virus, cuts it up and thus makes the invaders harmless. Scientists from the Helmholtz Centre for Infection Research (HZI) in Braunschweig have now shown that the dual-RNA guided enzyme Cas9 which is involved in the process has developed independently in various strains of bacteria.

This enhances the potential of exploiting the bacterial immune system for genome engineering.

Even though it has only been discovered in recent years the immune system with the cryptic name ‘CRISPR-Cas’ has been attracting attention of geneticists and biotechnologists as it is a promising tool for genetic engineering. CRISPR is short for Clustered Regularly Interspaced Palindromic Repeats, whereas Cas simply stands for the CRISPR-associated protein. Throughout evolution, this molecule has developed independently in numerous strains of bacteria. This is now shown by Prof Emmanuelle Charpentier and her colleagues at the Helmholtz Centre for Infection Research (HZI) who published their finding in the international open access journal Nucleic Acids Research.

The CRISPR-Cas-system is not only valuable for bacteria but also for working in the laboratory. It detects a specific sequence of letters in the genetic code and cuts the DNA at this point. Thus, scientists can either remove or add genes at the interface. By this, for instance, plants can be cultivated which are resistant against vermins or fungi. Existing technologies doing the same thing are often expensive, time consuming or less accurate. In contrast to them the new method is faster, more precise and cheaper, as fewer components are needed and it can target longer gene sequences.

Additionally, this makes the system more flexible, as small changes allow the technology to adapt to different applications. “The CRISPR-Cas-system is a very powerful tool for genetic engineering,“ says Emmanuelle Charpentier, who came to the HZI from Umeå and was awarded with the renowned Humboldt Professorship in 2013. “We have analysed and compared the enzyme Cas9 and the dual-tracrRNAs-crRNAs that guide this enzyme site-specifically to the DNA in various strains of bacteria.” Their findings allow them to classify the Cas9 proteins originating from different bacteria into groups. Within those the CRISPR-Cas systems are exchangeable which is not possible between different groups.

This allows for new ways of using the technology in the laboratory: The enzymes can be combined and thereby a variety of changes in the target-DNA can be made at once. Thus, a new therapy for genetic disorders caused by different mutations in the DNA of the patient could be on the horizon. Furthermore, the method could be used to fight the AIDS virus HIV which uses a receptor of the human immune cells to infect them. Using CRISPR-Cas, the gene for the receptor could be removed and the patients could become immune to the virus. However, it is still a long way until this aim will be reached.

Still those examples show the huge potential of the CRISPR-Cas technology. “Some of my colleagues already compare it to the PCR,” says Charpentier. This method, developed in the 1980s, allows scientists to ‘copy’ nucleic acids and therefore to manifold small amounts of DNA to such an extent that they can be analysed biochemically. Without this ground-breaking technology a lot of experiments we consider to be routine would have never been possible.

Charpentier was not looking for new molecular methods in the first place. “Originally, we were looking for new targets for antibiotics. But we found something completely different,” says Charpentier. This is not rare in science. In fact some of the most significant scientific discoveries have been made incidentally or accidentally.

Original publication:
Ines Fonfara, Anaïs Le Rhun, Krzysztof Chylinski, Kira Makarova, Anne-Laure Lécrivain, Janek Bzdrenga, Eugene V. Koonin, Emmanuelle Charpentier
Phylogeny of Cas9 determines functional exchangeability of dual-RNA and Cas9 among orthologous type II CRISPR-Cas systems

Nucleic Acids Research, 2013, DOI: 10.1093/nar/gkt1074

The department “Regulation in Infection Biology” studies how the expression of bacterial RNA and bacterial proteins is controlled. Both factors contribute to the establishment and the course of an infection.

The Helmholtz Centre for Infection Research (HZI)
Scientists at the Helmholtz Centre for Infection Research in Braunschweig, Germany, are engaged in the study of different mechanisms of infection and of the body’s response to infection. Helping to improve the scientific community’s understanding of a given bacterium’s or virus’ pathogenicity is key to developing effective new treatments and vaccines.

http://www.helmholtz-hzi.de

Dr. Jan Grabowski | Helmholtz-Zentrum
Further information:
http://www.helmholtz-hzi.de/en/news_events/news/view/article/complete/powerful_tool_for_genetic_engineering/

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>