Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Features of replication suggest viruses have common themes, vulnerabilities

14.08.2007
A study of the reproductive apparatus of a model virus is bolstering the idea that broad classes of viruses - including those that cause important human diseases such as AIDS, SARS and hepatitis C - have features in common that could eventually make them vulnerable to broad-spectrum antiviral agents.

In a study published today (Aug. 14) in the online, open-access journal Public Library of Science Biology, a team of researchers from the Howard Hughes Medical Institute (HHMI) at the University of Wisconsin-Madison describes in fine detail how an RNA virus known as flock house virus co-opts a cell's membranes to create an intracellular lair where it can safely replicate its genes.

The results provide strong evidence that at least some of the machinery four of the seven distinct classes of known viruses use to reproduce have common attributes. Such a discovery is important because it reveals a common viral theme that may be vulnerable to disruption and could lead to the development of drugs to treat many different kinds of viral infections, much like antibiotics are used to attack different kinds of bacterial pathogens.

"It turns out that viruses previously thought of as distinct share common features," says Paul Ahlquist, an HHMI investigator and virologist at UW-Madison. "We've found some features of replication that appear to cross over among many viruses."

Using powerful electron microscopy techniques, Ahlquist's group and their collaborators made the first three-dimensional maps of a viral replication complex using flock house virus, which, like all viruses, requires a host cell to make new genetic material and maintain the chain of infection.

In the case of flock house virus, the Wisconsin group found, the virus co-opts intracellular membranes of mitochondria, critical energy-regulating structures found in most eukaryotic cells.

Squeezing into the space between the inner and outer membrane of the double-lined mitochondria, the virus creates tens of thousands of protein-lined, balloon-like pockets where it can make new copies of the viral genome while safe from surveillance and defense mechanisms of the host.

" The virus has developed a very elegant strategy," says Ahlquist. "It creates for itself a new compartment for RNA synthesis, where it can collect its (constituent) components, organize successive steps of replication, and sequester these steps from other processes in the cell, most importantly, host defense responses."

In essence, the virus is reorganizing the cell to make a new intracellular architecture for its own purposes, according to Ahlquist. "The virus is reorganizing the cell to make a new organelle. It is a way to keep out competing processes and alarm-ringers and have a place where it can carry out its processes efficiently and for long periods of time."

The balloon-like sacs or spherules observed by Ahlquist and his colleagues all had narrow necks that transcended the membrane of the organelle to the cytoplasm, the medium inside the cell and in which the organelle is suspended. The neck is a gateway that appears to permit substrates needed for replication to enter and newly made viral genomes to exit.

The virus begins to co-opt the cell as a critical viral protein and viral RNA localize to the budding organelles, Ahlquist explains. "The virus takes over most of the available membrane. The protein creates a shell inside the spherule" to provide stability, and it is this use of a protein shell in replicating viral genes, the Wisconsin virologist suggests, that could be one of several common themes among different groups of viruses.

"Multiple features in the structure and function of these replication compartments appear similar across several virus classes," says Ahlquist. "This includes ways in which cell membranes are used to organize virus replication."

The shared features extend to most RNA viruses and a group known as reverse transcribing viruses, which include retroviruses such as HIV, suggesting a possible evolutionary link from a common ancestor.

Paul Ahlquist | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>