For the first time, scientists have discovered that a poorly understood class of RNA produced in a mammal's cells during a respiratory virus attack may affect the outcome of the infection. Their findings are reported today in mBio, a journal of the American Society for Microbiology.
RNA (ribonucleic acid) contains information transcribed from the cell's instruction manual, its DNA. The best known of these RNAs translate sections of DNA code into building blocks for proteins.
Most studies of how animals' cells respond to virus infection typically look at protein-coding genes, which produce germ-fighting or inflammation-producing substances. However, mammalian cells also transcribe thousands of other RNAs that don't code for proteins.
"The role of most of these non-protein
-coding RNAs remains an enigma," noted lead author of the study Dr. Xinxia Peng. computational research scientist, UW Department of Microbiology. Dr. Michael Katze, professor of microbiology at the University of Washington (UW) in Seattle, directed the project. Katze heads the Center for Systems and Translational Research on Infectious Disease (STRIDE).
"Some attention," Katze said, "has been given to small RNAs, like microRNAs, in host-virus interactions, but now it's becoming apparent that many long -non-protein coding RNAs -- bigger than 200 nucleotides -- are also biologically important."
Researchers are learning that long non-protein-coding RNAs have a wide variety of functions. A few examples are modifying chromosomes, regulating genes, influencing cell structure, and serving as precursors for small RNAs and microRNAs, which are involved in virus-host interactions.