Evolutionary divergent spliceosomal snRNAs and a conserved non-coding RNA processing motif in Giardia lamblia
Loading...
Date
2012
Authors
Hudson, Andrew J.
Moore, Ashley N.
Elniski, David
Joseph, Joella
Yee, Janet
Russell, Anthony G.
Journal Title
Journal ISSN
Volume Title
Publisher
Oxford University Press
Abstract
Non-coding RNAs (ncRNAs) have diverse essential
biological functions in all organisms, and in eukaryotes,
two such classes of ncRNAs are the small
nucleolar (sno) and small nuclear (sn) RNAs. In this
study, we have identified and characterized a collection
of sno and snRNAs in Giardia lamblia, by exploiting
our discovery of a conserved 12 nt RNA
processing sequence motif found in the 30 end
regions of a large number of G. lamblia ncRNA
genes. RNA end mapping and other experiments
indicate the motif serves to mediate ncRNA 30 end
formation from mono- and di-cistronic RNA precursor
transcripts. Remarkably, we find the motif is
also utilized in the processing pathway of all four
previously identified trans-spliced G. lamblia
introns, revealing a common RNA processing pathway
for ncRNAs and trans-spliced introns in this
organism. Motif sequence conservation then
allowed for the bioinformatic and experimental identification
of additional G. lamblia ncRNAs, including
new U1 and U6 spliceosomal snRNA candidates.
The U6 snRNA candidate was then used as a tool
to identity novel U2 and U4 snRNAs, based on predicted
phylogenetically conserved snRNA–snRNA
base-pairing interactions, from a set of previously
identified G. lamblia ncRNAs without assigned
function. The Giardia snRNAs retain the core
features of spliceosomal snRNAs but are sufficiently
evolutionarily divergent to explain the difficulties
in their identification. Most intriguingly, all of
these snRNAs show structural features diagnostic of U2-dependent/major and U12-dependent/minor
spliceosomal snRNAs.
Description
Sherpa Romeo green journal
Keywords
Non-coding RNAs , ncRNAs , snRNAs , Spliceosomal
Citation
Hudson, A.J., Moore, A.N., Elniski, D., Joseph, J., Yee, J., & Russell, A.G. (2012). Evolutionary divergent spliceosomal snRNAs and a conserved non-coding RNA processing motif in Giardia lamblia. Nucleic Acids Research, 40(2), 10995-11008. doi:10.1093/nar/gks887