Features of replication suggest viruses have common themes, vulnerabilities
Date: 14.8.2007
**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." ....
"Source":[ http://www.physorg.com/news106317179.html]
