Genomic DNA at the intended CRISPR cut site (Target DNA)

Genomic DNA at the intended CRISPR cut site refers to the specific nucleotide sequence within the host genome targeted for modification by a CRISPR-Cas system. This target is defined by a protospacer sequence complementary to a synthetic guide RNA (gRNA) and must be adjacent to a protospacer adjacent motif (PAM) (Jinek et al., Science, 2012). In therapeutic applications, this site is strategically selected to disrupt a disease-causing gene, correct a pathogenic mutation, or insert a functional genetic element (Hsu et al., Cell, 2014). Upon binding, the Cas nuclease induces a double-strand break or performs single-base editing at this precise locus. The subsequent cellular repair mechanisms, such as non-homologous end joining (NHEJ) or homology-directed repair (HDR), result in the desired therapeutic genetic change (Komor et al., Nature, 2016). This target is central to the mechanism of exagamglogene autotemcel, the first FDA-approved CRISPR therapy, which targets the BCL11A erythroid-specific enhancer to treat sickle cell disease (FDA, 2023). Ensuring high specificity for this target is critical to minimize off-target effects and potential genotoxicity (Fu et al., Nature Biotechnology, 2013).

Other names

ProtospacerCRISPR target sequenceGenomic target locusTarget DNA sequencegRNA target site

Site-specific DNA binding and cleavage (or chemical modification) mediated by a guide RNA-nuclease complex, followed by endogenous cellular DNA repair processes such as non-homologous end joining (NHEJ) or homology-directed repair (HDR).