Bratkovič Tomaž, Rogelj Boris
University of Ljubljana, Faculty of Pharmacy, Department of Pharmaceutical Biology, Aškerčeva 7, SI-1000 Ljubljana, Slovenia.
Jozef Stefan Institute, Department of Biotechnology, Jamova 39, SI-1000 Ljubljana, Slovenia.
Biochim Biophys Acta. 2014 Jun;1839(6):438-43. doi: 10.1016/j.bbagrm.2014.04.009. Epub 2014 Apr 13.
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.
小核仁RNA（snoRNA）是一类进化上保守的非编码RNA，传统上与其他RNA种类中的核苷酸修饰相关。作为与核糖体RNA（rRNA）和小核RNA（snRNA）配对的向导，snoRNA将伴侣酶引导至特定位点进行尿苷异构化或核糖甲基化，从而影响靶RNA的稳定性、折叠和蛋白质相互作用特性。然而，近年来，snoRNA家族的某些成员也被赋予了许多非经典功能，从mRNA编辑和/或可变剪接的调控到通过一种尚未完全理解的途径进行转录后基因沉默，该途径可能涉及类似微小RNA的机制。虽然这些有趣的snoRNA中的一些（所谓的孤儿snoRNA）与rRNA或snRNA没有序列互补性，但其他一些显然具有双重功能，既执行传统功能，也执行新发现的功能。在这里，我们综述了非经典snoRNA活性所引发的效应。
