Emerging Functions for snoRNAs and snoRNA-Derived Fragments

Abstract

The widespread implementation of mass sequencing has revealed a diverse landscape of small RNAs derived from larger precursors. Whilst many of these are likely to be byproducts of degradation, there are nevertheless metabolically stable fragments derived from tRNAs, rRNAs, snoRNAs, and other non-coding RNA, with a number of examples of the production of such fragments being conserved across species. Coupled with specific interactions to RNA-binding proteins and a growing number of experimentally reported examples suggesting function, a case is emerging whereby the biological significance of small non-coding RNAs extends far beyond miRNAs and piRNAs. Related to this, a similarly complex picture is emerging of non-canonical roles for the non-coding precursors, such as for snoRNAs that are also implicated in such areas as the silencing of gene expression and the regulation of alternative splicing. This is in addition to a body of literature describing snoRNAs as an additional source of miRNA-like regulators. This review seeks to highlight emerging roles for such non-coding RNA, focusing specifically on “new” roles for snoRNAs and the small fragments derived from them.

Benefits of aerobic exercise in myotonic dystrophy type 1

“…RNA-Seq of DM1 muscle also showed a huge upregulation of small nucleolar RNAs (snoRNAs), which are noncoding RNAs involved in ribosome biogenesis and other aspects of RNA metabolism ( 19 , 20 ). This programmatic shift of an entire class of small RNAs was unexpected, and the functional importance is unclear.…”

A Non-Canonical Link between Non-Coding RNAs and Cardiovascular Diseases

“…Certain snoRNA-derived miRNAs have been reported to share similar targets with miRNAs and to regulate several biological processes, such as cell proliferation and inflammation [ 88 ]. As an example, sdRNA-93 and sno-miR-28 regulate cell proliferation by repressing the p53-stabilizing transcription initiation factor TFIID subunit 9b (TAF9B) [ 88 , 89 , 90 ]. MiR-320 is dysregulated in ischemic hearts, where its inhibition using anti-miR-320 reduces cardiac infarction size [ 91 ].…”

Context-Dependent Regulation of Gene Expression by Non-Canonical Small RNAs

“…snoRNA-derived RNAs larger than 22 nt are also referred to as processed snoRNAs (psnoRNAs). The term sdRNAs describes both psnoRNAs and snoRNA-derived miRNAs [ 140 , 141 , 142 , 143 ].…”

“…Interestingly, sdRNAs produced under stress conditions were found to be associated with ribosomes, suggesting yet unidentified roles of sdRNAs in translation. Considering that translation typically decreases under stress conditions, sdRNAs could potentially participate in the downregulation of protein synthesis [ 143 , 157 ].…”