Circular exonic RNAs: when RNA structure meets topology

Publication date: Available online 15 May 2019Source: Biochimica et Biophysica Acta (BBA) - Gene Regulatory MechanismsAuthor(s): Dmitri D. PervouchineAbstractAlthough RNA circularization was first documented in the 1990s, the extent to which it occurs was not known until recent advances in high-throughput sequencing enabled the widespread identification of circular RNAs (circRNAs). Despite this, many aspects of circRNA biogenesis, structure, and function yet remain obscure. This review focuses on circular exonic RNAs, a subclass of circRNAs that are generated through backsplicing. Here, I hypothesize that RNA secondary structure can be the common factor that promotes both exon skipping and spliceosomal RNA circularization, and that backsplicing of double-stranded regions could generate topologically linked circRNA molecules. CircRNAs manifest themselves by the presence of tail-to-head exon junctions, which were previously attributed to post-transcriptional exon permutation and repetition. I revisit these observations and argue that backsplicing does not automatically imply RNA circularization because tail-to-head exon junctions give only local information about transcript architecture and, therefore, they are in principle insufficient to determine globally circular topology.

Source: Biochimica et Biophysica Acta (BBA) Gene Regulatory Mechanisms - May 15, 2019 Category: Genetics & Stem Cells Source Type: research