Project description:To investigate if the truncated PE can be dilivered by dual AAV8 vectors for in vivo prime editing. We injected the dual AAV8 into 10-week-old C57BL/6J mice . Livers were isolated 4 weeks after injection and next generation sequencing showed an average of 1.4% and 5.4% precise prime editing with the low and high AAV doses, respectively (Figure 4D ). This demonstrates that PECO-Mini can be efficiently delivered by dual AAVs for in vivo prime editing.
2022-06-09 | GSE205532 | GEO
Project description:Programmable large DNA deletion, replacement, integration, and inversion with twin prime editing and site-specific recombinases
| PRJNA770428 | ENA
Project description:Precise genomic deletions using paired prime editing
Project description:Prime editor (PE) is a precise genome-editing tool capable of all possible base conversions, as well as insertions and deletions without DSBs or donor DNA. The efficient delivery of PE in vivo is critical for realizing its full potential in disease modeling and therapeutic correction. Although PE has been divided into two halves and delivered using dual adeno-associated viruses (AAVs), editing efficiency at different gene loci varies among split sites, and efficient split sites within Cas9 nickase are limited. In this study, by screening multiple split sites, we demonstrated a series of efficient split site when delivering PE by dual-AAV. Additionally, we utilized a feature reported by others recently that RNase could be detached from the Cas9n and designed split sites in the first half of Cas9n. To test the editing efficiency in vivo, a novel dual-AAV split-ePE3 was packaged in AAV9 and delivered via tail vein injection in mice, achieving 24.4% precise genome editing 3 weeks post-injection. Our findings establish an alternative split-PE architecture that could achieve robust gene editing efficiency, facilitating the potential utility both in model organisms and as a therapeutic modality.
Project description:Prime editor (PE) is a precise genome-editing tool capable of all possible base conversions, as well as insertions and deletions without DSBs or donor DNA. The efficient delivery of PE in vivo is critical for realizing its full potential in disease modeling and therapeutic correction. Although PE has been divided into two halves and delivered using dual adeno-associated viruses (AAVs), editing efficiency at different gene loci varies among split sites, and efficient split sites within Cas9 nickase are limited. In this study, by screening multiple split sites, we demonstrated a series of efficient split site when delivering PE by dual-AAV. Additionally, we utilized a feature reported by others recently that RNase could be detached from the Cas9n and designed split sites in the first half of Cas9n. To test the editing efficiency in vivo, a novel dual-AAV split-ePE3 was packaged in AAV9 and delivered via tail vein injection in mice, achieving 24.4% precise genome editing 3 weeks post-injection. Our findings establish an alternative split-PE architecture that could achieve robust gene editing efficiency, facilitating the potential utility both in model organisms and as a therapeutic modality.
2024-12-01 | GSE270813 | GEO
Project description:Precise genome engineering in Drosophila using prime editing
| PRJNA655492 | ENA
Project description:Prime editing enables precise genome editing in mouse liver and retina
Project description:Prime editing allows precise modification of genomes. To identify cellular determinants of prime editing, we developed scalable prime editing reporters and performed genome-scale CRISPR-interference screens. From these screens, a single factor emerged as the strongest mediator of prime editing: the small RNA-binding exonuclease protection factor La (SSB). Further investigation revealed that La promotes prime editing across approaches (PE2, PE3, PE4, PE5), edit types (substitutions, insertions, deletions), guide RNA designs (pegRNAs, epegRNAs), endogenous loci, and cell types, but has no consistent effect on genome editing approaches that rely on standard, unextended guide RNAs. La binds polyuridine tracts at the 3' ends of RNA polymerase III transcripts and protects those transcripts from cellular exonucleases. We found that La stabilizes (e)pegRNAs, with particular effect on their 3' extensions, where edits are encoded. Guided by these insights, we developed a prime editing protein (PE7) fused to the RNA-binding, N-terminal domain of La. This editor improved prime editing with expressed (e)pegRNAs and synthetic pegRNAs optimized for La binding. Our results provide key insights into how prime editing components interact with the cellular environment and suggest general strategies for stabilizing exogenous small RNAs therein.
Project description:Prime editing enables the precise modification of genomes through reverse transcription of template sequences appended to the 3′ ends of CRISPR–Cas guide RNAs. To identify cellular determinants of prime editing, we developed scalable prime editing reporters and performed genome-scale CRISPR-interference screens. From these screens, a single factor emerged as the strongest mediator of prime editing: the small RNA-binding exonuclease protection factor La. Further investigation revealed that La promotes prime editing across approaches (PE2, PE3, PE4 and PE5), edit types (substitutions, insertions and deletions), endogenous loci and cell types but has no consistent effect on genome-editing approaches that rely on standard, unextended guide RNAs. Previous work has shown that La binds polyuridine tracts at the 3′ ends of RNA polymerase III transcripts. We found that La functionally interacts with the 3′ ends of polyuridylated prime editing guide RNAs (pegRNAs). Guided by these results, we developed a prime editor protein (PE7) fused to the RNA-binding, N-terminal domain of La. This editor improved prime editing with expressed pegRNAs and engineered pegRNAs (epegRNAs), as well as with synthetic pegRNAs optimized for La binding. Together, our results provide key insights into how prime editing components interact with the cellular environment and suggest general strategies for stabilizing exogenous small RNAs therein.
Project description:Prime editing is a powerful means of introducing precise changes to specific locations in mammalian genomes. However, the widely varying efficiency of prime editing across target sites of interest has limited its adoption in the context of both basic research and clinical settings. Here, we set out to exhaustively characterize the impact of the cis-chromatin environment on prime editing efficiency. Utilizing a newly developed and highly sensitive method for mapping the genomic locations of a randomly integrated “sensor”, we identify specific epigenetic features that strongly correlate with the highly variable efficiency of prime editing across different genomic locations. Next, to assess the interaction of trans-acting factors with the cis-chromatin environment, we develop and apply a pooled genetic screening approach with which the impact of knocking down various DNA repair factors on prime editing efficiency can be stratified by cis-chromatin context. Finally, we demonstrate that we can dramatically modulate the efficiency of prime editing through epigenome editing, i.e. enhancing (or restricting) local chromatin accessibility in order to increase (or decrease) the efficiency of prime editing at a target site. Looking forward, we envision that the insights and tools described here will broaden the range of both basic research and therapeutic contexts in which prime editing is useful.