Skip to main content
Fig. 1 | ExRNA

Fig. 1

From: Circular RNA: functions, applications and prospects

Fig. 1

Overview of the Biogenesis and Functionality of Circular RNA. Explanation and Footnotes: a A messenger RNA in its mature form, in which interaction between both the exons and introns are absent. b Lariat-Driven Circularisation. The upstream exon (exon 1) and downstream exon (exon 4) are covalently bonded due to the mRNA being spliced. This facilitates the production of a RNA lariat alongside paired-up exons that remain, which are Exons 2 and 3. c RNA-Binding Protein Driven and Intron-pairing Driven Circularisations. In both cases, the upstream and downstream introns (introns 1 and 3) are paired up to provide opportunity for the sandwiched Exons (exons 2 and 3) to interact, the only difference is that with the former case, an external RBP molecule joins the equation to actively facilitate the reaction, whereas with Intron-pairing Driven Circularisation, the hydroxyl group and the phosphate group of the upstream and downstream introns respectively pair up independently. d ecircRNA or ElcircRNA is produced regardless of Circularisation route. In some cases, intronic segments resides in the loop, hence giving rise to ElcircRNAs as opposed to ecircRNA which contains purely exonic segments. e Functionalities of mature circRNAs include miRNA sponging, acting as a double inhibitor for some chemical reactions; Protein Translation is possible, albeit quite rare and research is being carried to understand how it differs from linear RNA translations; RBP-Protein Complex formations help regulate and moderate pathways and indirectly impact the production of other circRNAs; mRNA Interactions, be it facilitative or inhibitory

Back to article page