Fig. (1).

RNA circularization mechanisms. (A) Introns complement. Complementary pairing elements such as RCMS/ICSS/AIU promote flanking intron pairing and cyclization; (B) RNA binding protein drives cyclization. RNA binding proteins promote cyclization by binding to flanking introns of circularized exons; (C) Lasso driven cyclization. The exon skipping event that occurs during the splicing of mRNA precursor results in the formation of intermediate containing intron and exon, thus forming circular RNA. (A higher resolution / colour version of this figure is available in the electronic copy of the article).