Fig. 3.

Roles of m6A modification in circRNAs. A m6A controls biogenesis of circRNAs. Pre-mRNAs with m6A sites recruits spliceosome or enzymes associated with methylation to promote back splicing of pre-mRNAs, while pre-mRNAs without m6A sites go through linear splicing to become linear mRNAs. B YTHDC1 binds to m6A sites in circRNAs to help circRNA nuclear export. C Different from translation initiation complex (IC) that binds to 5′ cap to initiate translation of mRNAs, IC binds directly to m6A sites that function as an IRES to initiate translation of circRNAs in a cap-independent way. D CircRNAs can be degraded through endoribonucleolytic cleavage way, where HRSP12 bridges between RNase/MRP and YTHDF2