Figure 2.

Schematic representation of circRNA- and/or miRNA-mediated functional inhibition of mRNA translation. The AGO2 protein interacts with GW182 constructing the miRNA-loaded RNA-induced silencing complex (miRISC), which may facilitate the deadenylation and/or mRNA degradation process by CAF1/CCR4/NOT1 with the PABP and APRO protein complex. Consequently, the circRNA and/or miRNA could play an active role in regulating post-transcriptional gene expression via the decapping, translational inhibition, deadenylation, and degradation of mRNA. The CAF1/CCR4/NOT1 complex is recruited to the 3′ UTR of specific mRNAs through an interaction with the PABP protein. APRO family proteins might also interact with PABP to recruit the CAF1/CCR4/NOT1 complex. The arrowhead means stimulation, and the hammerhead represents inhibition. Note that some critical pathways have been omitted for clarity. Abbreviations: ORF, open reading frame; miRISC, microRNA-induced silencing complex, “?” means for our speculation.