For many years, so called 'junk RNA' was thought to be nothing more than cellular trash. Recent research, however, has called this view into question as scientists have discovered the importance of some small RNAs that generally contain more than 20 molecular units called nucleotides.

Now, a new study released last week may put the idea of 'junk RNA' to rest forever. Researchers at the University of Pittsburgh School of Medicine and the University of Pittsburgh Cancer Institute have discovered that RNAs as small as 15 nucleotides are actually very stable molecules that may play significant roles in cellular processes. The team is also optimistic about the possibility of these RNA strands serving as useful tools for diagnosing disease and developing new drugs. The researchers have dubbed them 'usRNAs.'

Published in the Journal of Virology, team's research began with the observation that the Kaposi sarcoma-associated herpesvirus produces a usRNA that can control the production of a human protein. Detailed studies using both computational and experimental tools revealed a surprisingly large world of approximately 15 nucleotide-long usRNAs with intriguing characteristics. Many usRNAs interact with proteins already known to be involved in small RNA regulatory pathways. Some also share highly specific nucleotide patterns at one end. The researchers wrote that the existence of several different patterns in usRNAs reflects the diverse pathways in which the RNAs participate.

In addition to exploring biomarker potential, senior author Bino John, Ph.D. and his colleagues
plan to better characterize the various subclasses of usRNAs, identify their protein partners and study how they are made in the cell.