title: The many faces of small nucleolar RNAs.
abstract: Small nucleolar RNAs (snoRNAs) are a class of evolutionally conserved non-coding RNAs traditionally associated with nucleotide modifications in other RNA species. Acting as guides pairing with ribosomal (rRNA) and small nuclear RNAs (snRNAs), snoRNAs direct partner enzymes to specific sites for uridine isomerization or ribose methylation, thereby influencing stability, folding and protein-interacting properties of target RNAs. In recent years, however, numerous non-canonical functions have also been ascribed to certain members of the snoRNA group, ranging from regulation of mRNA editing and/or alternative splicing to posttranscriptional gene silencing by a yet poorly understood pathway that may involve microRNA-like mechanisms. While some of these intriguing snoRNAs (the so-called orphan snoRNAs) have no sequence complementarity to rRNA or snRNA, others apparently display dual functionality, performing both traditional and newly elucidated functions. Here, we review the effects elicited by non-canonical snoRNA activities.
authors.affiliation: University of Ljubljana, Faculty of Pharmacy, Department of Pharmaceutical Biology, Aškerčeva 7, SI-1000 Ljubljana, Slovenia. Electronic address: tomaz.bratkovic@ffa.uni-lj.si.
authors.forename: Tomaž
authors.initials: T
authors.lastname: Bratkovič
authors.affiliation: Jozef Stefan Institute, Department of Biotechnology, Jamova 39, SI-1000 Ljubljana, Slovenia. Electronic address: boris.rogelj@ijs.si.
authors.forename: Boris
authors.initials: B
authors.lastname: Rogelj
mesh_terms: D002466:Cell Nucleolus / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional; D020537:RNA, Small Nucleolar / Q000235:genetics*
chemical_list: D020537:RNA, Small Nucleolar
keywords: Alternative splicing; Bifunctional snoRNA; Orphan snoRNA; Posttranscriptional modification; miRNA