Abstract

Precise activation of endogenous genes is a powerful strategy for functional genomics and therapeutic development, but current CRISPR-based transcriptional activation (CRISPRa) systems are limited by the large size of Cas proteins for adeno-associated virus (AAV) delivery. Here, we present a h igh- e fficiency dC a s12f-based transcriptiona l activation system (HEAL), which recruits transactivators through MS2 coat protein binding to MS2 aptamers embedded within the sgRNA scaffold. Engineered to enhance DNA binding, nuclear localization, and transactivator recruitment, HEAL induces over 100,000-fold activation of endogenous genes and outperforms existing CRISPRa systems in vitro and in vivo. We further develop red-light-inducible OptoHEAL and small-molecule-inducible ChemHEAL for remote and precise transcriptional control. AAV-delivered HEAL targeting interleukin 10 alleviates acute kidney injury in mice, while ChemHEAL-mediated activation of thymic stromal lymphopoietin reduces body weight in obese mice. HEAL provides a modular, compact, and controllable platform for endogenous gene activation with strong potential for fundamental research and gene therapy.