Fig. 5: Chemically inducible exon activation by iCASFx.

a Schematic of the two-peptide CRISPR artificial splicing factors inducible by rapamycin. The RNA binding module (FKBP- dCasRx or dCasRx-FKBP) and effector module (RBFOX1N-FRB-C) containing the splicing activator domains are expressed separately as two peptides, fused to FKBP or FRB, respectively. FKBP and FRB can be induced to interact by rapamycin, bringing together the RNA binding module and the splicing activator module, and when guided by gRNAs, assemble at the target to activate exon inclusion. b Upper panel shows inclusion/exclusion (inc/exc) ratio fold-changes assayed by qRT-PCR on SMN2 minigene transcripts in cells co-transfected with the indicated constructs, and cultured with (“+”) or without (“−”) rapamycin. Fold-changes are relative to GFP-transfected sample. Data are represented as mean ± SD (n = 3). Lower panel shows a gel image of semi-quantitative splicing RT-PCR of SMN2 minigene transcripts in cells co-transfected with the indicated constructs, and cultured with (“+”) or without (“−”) rapamycin. Uncropped gel images and qRT-PCR values are included in the Source Data file.