Double duty

When the Herpes virus attacks, its mi rnas undertake double duty, found scientists. When a cell has to produce a protein, the dna unzips, a messenger rna (mrna) mirrors one of its strands for protein codes. Micro rnas (mirnas) sometimes attach to portions of mrnas, not allowing those parts to code for the protein. This is a regulatory mechanism which the virus takes advantage of. Viral mirnas regulate viral genes and also latch on to the immune cell's mrnas disallowing formation of anti-viral proteins.

Source

Down to Earth, June 2010