Controlling an E3 ligase and its substrate: A function for MARCHF6 circRNA

⁎Circular RNAs (circRNAs) are stable RNA molecules that can perform a variety of rapidly emerging functions.⁎A circRNA formed by the back-splicing of two exons of MARCHF6 (hsa_circ_0001467) is highly expressed in human brains.⁎The E3 ubiquitin ligase MARCHF6 is a critical regulator of cholesterol homeostasis.⁎We found the abundant MARCHF6 circRNA regulates protein levels of MARCHF6 and its canonical substrate, squalene monooxygenase, a key rate-controlling step in cholesterol synthesis.⁎Our work highlights a newly discovered function of a circRNA, with important implications for cholesterol homeostasis.