Schematic diagram of the molecular mechanism of circMEF2As regulating myogenesis.

MEF2A protein promotes linear MEF2A and circMEF2As biogenesis through a transcription manner. CircMEF2A1 activates PPP3CA/NFATC1 signaling by targets miR-30a-3p, and circMEF2A2 activates SLIT3/ROBO2/β-Catenin signaling by targets miR-148a-5p. circMEF2As also regulate the expression of linear MEF2A via target miR-30a-3p and miR-148a-5p. MEF2A, NFATC1, and β-catenin proteins transfer to the nucleus to activate the transcription of myogenic genes.