Uncovering the Details of a Viral Secret Weapon

Recent years have seen a sharp growth in awareness of the importance of microRNAs (miRNAs); small RNA molecules that, rather than coding for proteins, instead triggers the silencing of specific target genes. Numerous miRNAs have been identified in plants, invertebrates, and vertebrates. However, it was only recently - in the laboratory of Thomas Tuschl - that these molecules were also found in viruses, suggesting that this regulatory tactic could also be exploited to assist in the process of infection and replication.

Tuschl and his colleagues, including the group of Swiss researcher Mihaela Zavolan, announce their latest advance in this research front: a combined computational and experimental strategy for the identification of viral miRNAs. The first phase of this strategy involved identifying likely characteristics of viral miRNAs, and then developing an algorithm to apply these guidelines to locate appropriate genomic sequences. They analyzed a wide variety of human pathogenic viruses using this computational approach, and then experimentally confirmed their findings by cloning the small RNA molecules produced by cells infected with these viruses.

They identified and confirmed a number of novel miRNAs expressed by various DNA viruses, particularly among members of the herpesvirus family; at the same time, the RNA viruses that they investigated, including HIV-1 and hepatitis C virus, did not appear to produce miRNAs at all. Tuschl and Zavolan conclude that although a number of viral miRNAs may remain to be discovered, the new sequences identified by this strategy could lend powerful new insights into the process and prevention of viral pathogenesis.

Author contact:

Thomas Tuschl
The Rockefeller University
Tel: +1 212 327 7696
E-mail: ttuschl@rockefeller.edu

Mihaela Zavolan
Biozentrum der Universität Basel
Tel: +41 61 267 15 84
E-mail: mihaela.zavolan@unibas.ch

Also available online.

(C) Nature Methods press release.

Message posted by: Trevor M. D'Souza