Site-Specific m A Erasing via Conditionally Stabilized CRISPR-Cas13b Editor.

N6-methyladenosine (m A) on RNAs plays an important role in regulating various biological processes and CRIPSR technology has been employed for programmable m A editing. However, the bulky size of CRISPR protein and constitutively expressed CRISPR/RNA editing enzymes can interfere with the native function of target RNAs and cells. Herein, we reported a conditional m A editing platform (FKBP*-dCas13b-ALK) based on a ligand stabilized dCas13 editor. The inducible expression of this m A editing system was achieved by adding or removing the Shield-1 molecule. We further demonstrated that the targeted recruitment of dCas13b-m A eraser fusion protein and site-specific m A erasing were achieved under the control of Shield-1. Moreover, the release and degradation of dCas13b fusion protein occurred faster than the restoration of m A on the target RNAs after Shield-1 removal, which provides an ideal opportunity to study the m A function with minimal steric interference from bulky dCas13b fusion protein.