A compact, versatile drug-induced splicing switch system with minimal background expression.

Gene-switch techniques hold promising applications in contemporary genetics research, particularly in disease treatment and genetic engineering. Here, we developed a compact drug-induced splicing system that maintains low background using a human ubiquitin C (hUBC) promoter and optimized drug (LMI070) binding sequences based on the Xon switch system. To ensure precise subcellular localization of the protein of interest (POI), we inserted a 2A self-cleaving peptide between the extra N-terminal peptide and POI. This streamlined and optimized switch system, named miniXon2G, effectively regulated POIs in different subcellular localizations both in vitro and in vivo. Furthermore, miniXon2G could be integrated into endogenous gene loci, resulting in precise, reversible regulation of target genes by both endogenous regulators and drugs. Overall, these findings highlight the performance of miniXon2G in controlling protein expression with great potential for general applicability to diverse biological scenarios requiring precise and delicate regulation.