Let’s all do the ncRNA limbo! They may not be as festive as the dance at the office holiday party, but non-coding RNAs are really getting down…in size anyway! It seems every few months, we’re learning about a new class of RNAs that’s even shorter than before.
Recent work from Bino John’s group at the University of Pittsburgh has uncovered a novel class of small regulatory RNAs which they refer to as ‘unusually small’ RNAs, or usRNAs.
The paper walks us through their discovery:
- Initially studying the K12-1 miRNA of Kaposi sarcoma-associated herpes virus, the authors observed a persistent smaller RNA which associated with K12-1, which they named us-K12-1.
- To determine the nature of this new RNA, they split small RNA into two pools, from 8-18 bases and from 19-30 bases, and sequenced both.
- In their deep sequencing results, they obtained extensive evidence for the presence of numerous small RNA, both viral and mammalian, below the sizes often studied, with varying potential molecular origins and structural motifs.
- To further characterize these usRNAs, they focused their follow-up work on us-K12-1, ultimately demonstrating its ability to regulate RAD21 expression in the absence of K12-1 miRNA.
To see just how many nucleotides is enough and learn more about this novel class of epigenetically active RNAs, you can check out the article at Journal of Virology, October 2009.