Compact RNA editors with small Cas13 proteins

CRISPR-Cas13 systems have been developed for precise RNA editing, and can potentially be used therapeutically when temporary changes are desirable or when DNA editing is challenging. We have identified and characterized an ultrasmall family of Cas13b proteins-Cas13bt-that can mediate mammalian transcript knockdown. We have engineered compact variants of REPAIR and RESCUE RNA editors by functionalizing Cas13bt with adenosine and cytosine deaminase domains, and demonstrated packaging of the editors within a single adeno-associated virus.

Automated summary

CRISPR-Cas13 systems have been developed for precise RNA editing, and a new ultrasmall family of Cas13b proteins called Cas13bt has been identified, which can facilitate mammalian transcript knockdown. By engineering compact variants of RNA editors using Cas13bt, researchers have demonstrated successful packaging within a single adeno-associated virus, with potential therapeutic applications.