Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cracking a virus protection shield

16.06.2006
Ebola, measles and rabies are serious threats to public health in developing countries. Despite different symptoms all of the diseases are caused by the same class of viruses that unlike most other living beings carry their genetic information on a single RNA molecule instead of a double strand of DNA.

Now researchers from the Institut de Virologie Moléculaire et Structurale (IVMS) and the Outstation of the European Molecular Biology Laboratory (EMBL) in Grenoble have obtained a detailed structural picture of a protein that allows the rabies virus to withstand the human immune response and survive and replicate in our cells. The study that is published in this week’s online edition of Science suggests new potential drug targets in rabies and sheds light on how similar approaches can help fighting other viral diseases.

When the rabies virus enters a human cell through the membrane, the RNA molecule that carries its genes is transported into the centre of the cell. Here it redirects the cellular machinery of the host to produce many new copies of the virus that go on to infect more cells. One molecule that is crucial in this process is a viral protein called nucleoprotein. The protein ensures that on its way through the cell the virus RNA is not destroyed by the immune response of the host.

“Nucleoprotein is vital for the rabies virus,” says Rob Ruigrok, Head of the IVMS. “It is one of the few proteins that the virus brings into the host cell and it wraps around the RNA like a protection shield. Without this shield the RNA would be degraded by the enzymes of the human immune system that try to eliminate the invader.”

To investigate how exactly this protection shield works, Aurélie Albertini from Ruigrok’s team obtained crystals of nucleoprotein bound to RNA. Examining the crystals with high-intensity X-ray sources at the European Synchrotron Radiation Facility (ESRF), Amy Wernimont from Winfried Weissenhorn’s group at EMBL Grenoble produced a high-resolution image of the protein.

“Nucleoprotein acts like a clamp,” says Weissenhorn. “It consists of two domains that like two jaws clasp around the RNA strand. Many nucleoproteins bind side-by-side along the length of an RNA molecule and make it inaccessible for degrading enzymes but also for the machinery needed to replicate the virus. This means that the protection shield must be flexible and able to distinguish between different types of enzymes trying to gain access.”

The detailed structural picture suggests that upon a signal a part of the protein located between the two main domains might act as a hinge that moves the upper jaw out of the way when time for replication has come.

“This dynamic mechanism makes nucleoproteins an excellent drug target,” says Ruigrok, “Small agents that bind to the protein in such a way to block its flexibility and keep it in the closed state, would prevent replication of the virus and would stop it from spreading.”

Rabies virus shares this protection strategy with other viruses of its class; in Ebola, measles and Borna virus similar complexes of RNA and nucleoproteins have been found.

“This means that our results do not only have implications for the design of new drugs against rabies, but they suggest new therapeutic approaches in a variety of diseases, some of which are much more threatening than rabies. On a different note, the conservation of the nucleoprotein system also leaves room for evolutionary speculations about common ancestors and primordial infectious units of RNA viruses,” Weissenhorn concludes.

Anna-Lynn Wegener | alfa
Further information:
http://www.embl.org/aboutus/news/press/2006/16jun06/index.html

More articles from Life Sciences:

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

nachricht Snap, Digest, Respire
20.01.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Bodyguards in the gut have a chemical weapon

20.01.2017 | Life Sciences

SF State astronomer searches for signs of life on Wolf 1061 exoplanet

20.01.2017 | Physics and Astronomy

Treated carbon pulls radioactive elements from water

20.01.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>