Genomic DNA at prime editing guide RNA (pegRNA)-specified loci (pegRNA-DNA locus)

Genomic DNA at prime editing guide RNA (pegRNA)-specified loci refers to the precise chromosomal locations targeted for modification by prime editing technology [Anzalone et al., Nature 2019]. Prime editing is a versatile "search-and-replace" genome editing method that employs a fusion protein consisting of a catalytically impaired Cas9 nickase and an engineered reverse transcriptase enzyme [Anzalone et al., Nature 2019; Chen & Liu, Nat Rev Genet 2023]. The pegRNA serves a dual purpose: it guides the fusion protein to the specific genomic coordinates via its spacer sequence and provides the template for the desired genetic change through its 3' extension, which includes a primer binding site (PBS) and a reverse transcriptase template (RTT) [Anzalone et al., Nature 2019]. This target is central to the treatment of various genetic diseases, as it allows for the correction of point mutations, small insertions, or deletions without requiring double-strand breaks or exogenous donor DNA [Kantor et al., Mol Ther 2020]. By directly rewriting the genetic code at these loci, prime editing offers a high degree of precision and reduced off-target effects compared to traditional CRISPR-Cas9 systems [Anzalone et al., Nature 2019]. Therapeutic applications targeting these loci are currently being explored for conditions such as sickle cell disease, cystic fibrosis, and various metabolic disorders [Chen & Liu, Nat Rev Genet 2023].

Other names

Prime editing target sitepegRNA target locusGenomic DNA (Prime Editing)Target DNA sequence for prime editing

Prime editing involves a search-and-replace mechanism where a Cas9 nickase-reverse transcriptase fusion protein uses a pegRNA to identify a target DNA site, nick one strand, and synthesize a new DNA sequence directly into the target locus using the pegRNA's 3' extension as a template [Anzalone et al., Nature 2019].