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The 11 th International Workshop on KSHV & Related Agents, Birmingham, UK
Poster Session Abstract P13
IDENTIFICATION OF NOVEL CONSERVED GAMMAHERPESVIRUS MICRORNAS
Nicole Walz , Thomas Christalla and Adam Grundhoff
Heinrich-Pette Institute for Experimental Virology and Immunology, D-20251 Hamburg,
Germany
Abstract
microRNAs (miRNAs) are small (~22 nt.), non-coding RNA molecules which posttranscriptionally
regulate mRNA expression and play important roles in the regulation of
diverse cellular processes. The current release of the miRNA database (miRBase) lists a
total of 132 known viral miRNAs, the vast majority of which are encoded by members of
the herpesvirus family. While the propensity to encode miRNAs appears to be a
conserved feature of many herpesviruses, the miRNAs themselves show little
conservation: with the exception of 7 miRNAs known to be shared between Epstein-Barr
Virus (EBV) and its close relative Rhesus Lymphocryptovirus (rLCV), all other herpesvirus
miRNAs appear unrelated in sequence. We have recently developped VMir, a
computational ab initio prediction method to identify viral miRNAs, and have employed
the program to identify miRNAs in SV40, KSHV and EBV. We have modified the algorithm
to allow consideration of evolutionary conservation and conducted an extended analysis
of the herpesvirus family. We were able to identify and experimentally verify 2 novel
EBV- and 17 novel rLCV-encoded miRNAs; with a total of 33 miRNAs rLCV is now the
virus with the highest number of known miRNAs. In contrast, we have found little
evidence for the existence of hitherto unknown conserved miRNAs shared by other
herpesviruses, including KSHV and the closely related Rhesus Rhadinovirus (RRV). While
EBV and rLCV thus share even more miRNAs than previously thought, our results
underline the notion that, in contrast to their cellular counterparts, viral miRNAs show an
almost total lack of sequence conservation.
Presenting author Email: Adam.Grundhoff@hpi.uni-hamburg.de
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