Binding-driven forward tearing protospacer activated CRISPR-Cas12a system and applications for microRNA detection

作者：Lina Zhao, Xiangyu Deng, Yuqing Li, Qing Zhao, Lizhu Xiao, Jianjiang Xue, Anyi Chen, Wei Cheng, Min Zhao · 发表于：Journal of Nanobiotechnology · 年份：2024 · DOI：10.1186/s12951-024-02915-5 · 被引用次数：5 · 研究领域：CRISPR and Genetic Engineering、Advanced biosensing and bioanalysis techniques、RNA Interference and Gene Delivery

CRISPR-Cas12a system, characterized by its precise sequence recognition and cleavage activity, has emerged as a powerful and programmable tool for molecular diagnostics. However, current CRISPR-Cas12a-based nucleic acid detection methods, particularly microRNA (miRNA) detection, necessitate additional bio-engineering strategies to exert control over Cas12a activity. Herein, we propose an engineered target-responsive hairpin DNA activator (TRHDA) to mediate forward tearing protospacer activated CRISPR-Cas12a system, which enables direct miRNA detection with high specificity and sensitivity. Target miRNA specifically binding to hairpin DNA can drive forward tearing protospacer in the stem sequence of hairpin structure, facilitating the complementarity between crRNA spacer and protospacer to activate Cas12a. Upon the hairpin DNA as input-responsive activator of Cas12a, a universal biosensing method enables the multiple miRNAs (miR-21, let-7a, miR-30a) detection and also has exceptional capability in identifying single-base mismatches and distinguishing homologous let-7/miR-30 family members. Besides, TRHDA-mediated Cas12a-powered biosensing has realized the evaluation of miR-21 expression levels in diverse cellular contexts by intracellular imaging. Considering the easy programmability of hairpin DNA in responsive region, this strategy could expand for the other target molecules detection (e.g., proteins, micromolecules, peptides, exosomes), which offers significant implications...