Linking microRNA to hepatitis C

There is a surprising new role for a microRNA in the accumulation of hepatitis C virus in the liver, a study in Science suggests. A team led by Peter Sarnow at Stanford University School of Medicine found that the liver-specific microRNA-122 (miR-122) interacts with the 5' noncoding region of the viral mRNA to enhance its replication.

While previous work has shown that microRNAs can cleave mRNA or repress its translation by binding with mRNA's 3' noncoding region, this is the first time such a molecule has been found to interact with the 5' region in an animal cell, or to positively regulate gene expression. "In the last couple of years, many people have found new and varied forms in which miRNAs can interact with the replication of animal viruses. This is a new and quite different example," said John Taylor, of the Fox Chase Cancer Center, who did not participate ...