Figure 1.

Biogenesis and functions of circRNAs. A. The biogenesis of circRNAs: CircRNAs are formed by a noncanonical back-splicing process that competes with linear premRNA splicing. B. Biological functions of circRNAs: a. CircRNAs can function as miRNA sponges to regulate the expression of relevant target genes. b. CircRNAs containing RNA binding protein (RBP) binding motifs can interact with proteins. c. CircRNAs can function as protein scaffolds to facilitate the colocalization of enzymes and their substrates. d. CircRNAs can enhance gene transcription by interacting with RNA pol II or U1 small nuclear snRNP. e. CircRNAs can be translated into proteins