Unexpected links found between many R...( March 25 2002 -- Howard Hughes Medi...)

March 25, 2002 -- Howard Hughes Medical Institute researchers have discovered surprising parallels in the way that three different classes of RNA viruses replicate. The discovery suggests that there might one day be a common strategy to kill many different RNA viruses, a group that includes HIV, rotavirus, hepatitis C and polio viruses.

In an article published in the March 2002 issue of the journal Molecular Cell, HHMI investigator Paul Ahlquist and colleagues at the University of Wisconsin at Madison described the parallels among positive-strand RNA viruses ([+]RNA), retroviruses and double-stranded RNA viruses. Since these viruses cause a broad range of diseases, the scientists believe that finding a common link between the viruses may be the first step to devising more general virus control or treatment strategies. Positive-strand RNA viruses are those that first copy their RNA genome into a negative-strand intermediate RNA before replicating their RNA. These viruses cause hepatitis C, encephalitis, hemorrhagic fevers, polio, foot and mouth disease and the common cold, and many other illnesses.

Retroviruses and other reverse-transcribing viruses, which include HIV and hepatitis B, first copy their RNA into DNA before replicating their genome back into RNA. Double-stranded RNA viruses -- which include the rotavirus that kills about one million children a year in developing countries -- separates its strands and copies one to replicate itself.

Ahlquist and his colleagues discovered that, although the viruses seem to take distinct routes to replication, all three types use related pathways and structures to replicate their genes. By linking three of the six major classes of viruses, the results offer a significant unification within the field of virology.

The multiple functional parallels we have found in replication mechanisms reveal unexpe
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Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute
25-Mar-2002