Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1151843 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:C-to-T base editing mediated by CRISPR/Cas9 base editors (BEs) needs a G/C-rich PAM and the editing fidelity is compromised by unwanted indels and non-C-to-T substitutions. We developed CRISPR/Cpf1-based BEs to recognize a T-rich PAM and induce efficient C-to-T editing with few indels and/or non-C-to-T substitutions. The requirement of editing fidelity in therapeutic-related trials necessitates the development of CRISPR/Cpf1-based BEs, which also facilitates base editing in A/T-rich regions.
2018-10-16 | GSE105002 | GEO
Project description:The targeting range of CRISPR-Cas9 base editors (BEs) is limited by their G/C-rich PAM sequences. To overcome this limitation, we developed a CRISPR/Cpf1-based BE by fusing the rat cytosine deaminase APOBEC1 to a catalytically inactive version of Lachnospiraceae bacterium Cpf1. The base editor recognizes a T-rich PAM sequence and converts C to T in human cells with low levels of indels, non-C-to-T substitutions and off-target editing.
2018-03-18 | GSE110136 | GEO
Project description:Adenine and cytosine base editors (ABEs and CBEs) represent a new genome editing technology that allows the programmable installation of A-to-G or C-to-T alterations on DNA. We engineered Streptococcus pyogenes Cas9-based adenine and cytosine base editor (SpACE) that enables efficient simultaneous introduction of A-to-G and C-to-T substitutions in the same base editing window on DNA.
2020-07-02 | GSE137411 | GEO
Project description:CRISPR-guided DNA base editors enable the efficient installation of targeted single-nucleotide changes. Cytosine or adenine base editors (CBEs or ABEs), which are fusions of cytidine or adenosine deaminases to CRISPR-Cas nickases, can efficiently induce DNA C-to-T or A-to-G alterations in DNA, respectively. We recently demonstrated that both the widely used CBE BE3 (harboring a rat APOBEC1 cytidine deaminase) and the optimized ABEmax editor can induce tens of thousands of guide RNA-independent, transcriptome-wide RNA base edits in human cells with high efficiencies. In addition, we showed the feasibility of creating SElective Curbing of Unwanted RNA Editing (SECURE)-BE3 variants that exhibit substantially reduced unwanted RNA editing activities while retaining robust and more precise on-target DNA editing. Here we describe structure-guided engineering of SECURE-ABE variants that not only possess reduced off-target RNA editing with comparable on-target DNA activities but are also the smallest Streptococcus pyogenes Cas9 (SpCas9) base editors described to date. In addition, we tested CBEs composed of cytidine deaminases other than APOBEC1 and found that human APOBEC3A (hA3A) cytidine deaminase CBE induces substantial transcriptome-wide RNA base edits with high efficiencies. By contrast, a previously described “enhanced” A3A (eA3A) cytidine deaminase CBE or a human activation-induced cytidine deaminase (hAID) CBE induce substantially reduced or near background levels of RNA edits. In sum, our work describes broadly useful SECURE-ABE and -CBE base editors and reinforces the importance of minimizing RNA editing activities of DNA base editors for research and therapeutic applications.
2019-07-11 | GSE129893 | GEO
Project description:CRISPR-guided DNA base editors enable the efficient installation of targeted single-nucleotide changes. Cytosine or adenine base editors (CBEs or ABEs), which are fusions of cytidine or adenosine deaminases to CRISPR-Cas nickases, can efficiently induce DNA C-to-T or A-to-G alterations in DNA, respectively. We recently demonstrated that both the widely used CBE BE3 (harboring a rat APOBEC1 cytidine deaminase) and the optimized ABEmax editor can induce tens of thousands of guide RNA-independent, transcriptome-wide RNA base edits in human cells with high efficiencies. In addition, we showed the feasibility of creating SElective Curbing of Unwanted RNA Editing (SECURE)-BE3 variants that exhibit substantially reduced unwanted RNA editing activities while retaining robust and more precise on-target DNA editing. Here we describe structure-guided engineering of SECURE-ABE variants that not only possess reduced off-target RNA editing with comparable on-target DNA activities but are also the smallest Streptococcus pyogenes Cas9 (SpCas9) base editors described to date. In addition, we tested CBEs composed of cytidine deaminases other than APOBEC1 and found that human APOBEC3A (hA3A) cytidine deaminase CBE induces substantial transcriptome-wide RNA base edits with high efficiencies. By contrast, a previously described “enhanced” A3A (eA3A) cytidine deaminase CBE or a human activation-induced cytidine deaminase (hAID) CBE induce substantially reduced or near background levels of RNA edits. In sum, our work describes broadly useful SECURE-ABE and -CBE base editors and reinforces the importance of minimizing RNA editing activities of DNA base editors for research and therapeutic applications.
2019-07-11 | GSE129889 | GEO
Project description:Exon skipping technologies enable exclusion of targeted exons from mature mRNA transcripts, which has broad applications in molecular and cellular biology, medicine and biotechnology. Existing exon skipping techniques include antisense oligonucleotides, targetable nucleases and base editors, which, while effective for specific applications at some target exons, remain hindered by shortcomings preventing their broader implementation including transient effects in the case of oligonucleotides or limiting PAM motifs, sequence context preferences for deaminases, and undesirable cryptic splicing in the case of gene editing tools. To overcome these limitations, we created SPLICER, a toolbox of next-generation base editors consisting of near-PAMless Cas9 nickase variants fused with different deaminases for simultaneous editing of splice acceptor (SA) and splice donor (SD) sequences. Synchronized SA and SD editing not only improves exon skipping rates but also reduces aberrant outcomes such as cryptic splicing and intron retention. SPLICER enables editing of exon splice sites with high efficiency, including many exons refractory to splicing reprogramming by the native SpCas9 BEs. To demonstrate the therapeutic potential of SPLICER, we targeted APP exon 17, which contains the amino acid residues responsible for the formation of Aβ plaques in Alzheimer’s disease. SPLICER enabled precise and highly efficient exon skipping, which reduced the formation of Aβ42 peptides in vitro while inducing DNA editing and exon skipping in vivo within a humanized mouse model of Alzheimer’s disease. Overall, SPLICER is a widely applicable and highly efficient toolbox for exon skipping with broad therapeutic applications.
2023-12-10 | GSE246587 | GEO
Project description:Exon skipping technologies enable exclusion of targeted exons from mature mRNA transcripts, which has broad applications in molecular and cellular biology, medicine and biotechnology. Existing exon skipping techniques include antisense oligonucleotides, targetable nucleases and base editors, which, while effective for specific applications at some target exons, remain hindered by shortcomings preventing their broader implementation including transient effects in the case of oligonucleotides or limiting PAM motifs, sequence context preferences for deaminases, and undesirable cryptic splicing in the case of gene editing tools. To overcome these limitations, we created SPLICER, a toolbox of next-generation base editors consisting of near-PAMless Cas9 nickase variants fused with different deaminases for simultaneous editing of splice acceptor (SA) and splice donor (SD) sequences. Synchronized SA and SD editing not only improves exon skipping rates but also reduces aberrant outcomes such as cryptic splicing and intron retention. SPLICER enables editing of exon splice sites with high efficiency, including many exons refractory to splicing reprogramming by the native SpCas9 BEs. To demonstrate the therapeutic potential of SPLICER, we targeted APP exon 17, which contains the amino acid residues responsible for the formation of Aβ plaques in Alzheimer’s disease. SPLICER enabled precise and highly efficient exon skipping, which reduced the formation of Aβ42 peptides in vitro while inducing DNA editing and exon skipping in vivo within a humanized mouse model of Alzheimer’s disease. Overall, SPLICER is a widely applicable and highly efficient toolbox for exon skipping with broad therapeutic applications.
2023-12-10 | GSE246586 | GEO