Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1300410 | ENA |
REPOSITORIES: ENA
Similar Datasets
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:Even the latest generation of base editor (BE3) causes unwanted indels and non-C-to-T substitutions, compromising the fidelity of base editing outcome. Here we report a enhanced base editing system. The enhanced base edting system decreased the formation of unintended indels and C-to-A/C-to-G substitutions, and increased the frequency of desired C-to-T substitution, thereby improving both the accuracy and efficiency of base editing.
2017-08-29 | GSE98685 | GEO
Project description:Current base editors use DNA deaminases, including cytidine deaminase in cytidine base editor (CBE) or adenine deaminase in adenine base editor (ABE), to facilitate transition nucleotide substitutions. Combining CBE or ABE with glycosylase enzymes can induce limited transversion mutations. Nonetheless, a critical demand remains for base editors capable of generating alternative mutation types, such as T>G corrections. In this study, we leveraged pre-trained protein language models to optimize a uracil-N-glycosylase (UNG) variant with altered specificity for thymines (eTDG). Notably, after two rounds of testing fewer than 50 top-ranking variants, more than 50% exhibited over 1.5-fold enhancement in enzymatic activities. When eTDG was fused with nCas9, it induced programmable T-to-S (G/C) substitutions and corrected db/db diabetic mutation in mice (up to 55%). Our findings not only establish orthogonal strategies for developing novel base editors, but also demonstrate the capacities of protein language models for optimizing enzymes without extensive task-specific training data.
2024-01-23 | GSE253655 | 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: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 mitochondrial serine catabolism to formate induces a metabolic switch to a hypermetabolic state with high rates of glycolysis, purine synthesis and pyrimidine synthesis. While formate is a purine precursor it is not obvious link between formate and pyrimidine synthesis. Methods Here we combine phospho-proteome and metabolic profiling to determine how formate induces pyrimidine synthesis. We discover that formate induces CAD phosphorylation. Mechanistically formate induces mTORC1 activity as quantified by S6K1 phosphorylation, which is known to phosphorylate CAD and increase its enzymatic activity. Treatment with the allosteric mTORC1 inhibitor rapamycin abrogates CAD phosphorylation and pyrimidine synthesis induced by formate. We conclude that formate activates mTORC1 and induces pyrimidine synthesis via increasing CAD activity.
2020-09-28 | PXD019347 | Pride
Project description:Mutagenic purine-pyrimidine repeats can adopt the left-handed Z-DNA conformation. DNA breaks at potential Z-DNA sites can lead to somatic mutations in cancer or to germ line mutations which are transmitted to the next generation. It is not known whether any mechanism exists in the germ line to control Z-DNA structure and DNA breaks at purine-pyrimidine repeats. Here, we provide genetic, epigenomic, and biochemical evidence for the existence of a biological process that erases Z-DNA specifically in germ cells of the mouse male fetus. We show that a previously uncharacterized zinc finger protein, ZBTB43, binds to and removes Z-DNA, preventing the formation of DNA double-strand breaks. By removing Z-DNA, ZBTB43 also promotes de novo DNA methylation at CG-containing purine-pyrimidine repeats in prospermatogonia. Therefore, the genomic and epigenomic integrity of the species is safeguarded by remodeling DNA structure in the mammalian germ line during a critical window of germline epigenome reprogramming.
2022-04-14 | GSE200728 | GEO
Project description:Mutagenic purine-pyrimidine repeats can adopt the left-handed Z-DNA conformation. DNA breaks at potential Z-DNA sites can lead to somatic mutations in cancer or to germ line mutations which are transmitted to the next generation. It is not known whether any mechanism exists in the germ line to control Z-DNA structure and DNA breaks at purine-pyrimidine repeats. Here, we provide genetic, epigenomic, and biochemical evidence for the existence of a biological process that erases Z-DNA specifically in germ cells of the mouse male fetus. We show that a previously uncharacterized zinc finger protein, ZBTB43, binds to and removes Z-DNA, preventing the formation of DNA double-strand breaks. By removing Z-DNA, ZBTB43 also promotes de novo DNA methylation at CG-containing purine-pyrimidine repeats in prospermatogonia. Therefore, the genomic and epigenomic integrity of the species is safeguarded by remodeling DNA structure in the mammalian germ line during a critical window of germline epigenome reprogramming.
2022-04-14 | GSE200722 | GEO
Project description:Optimization of CRISPR/Cas9-mediated genome engineering has resulted in base editors that hold promise for mutation repair and disease modeling. Here, we demonstrate the application of base editors for the generation of complex tumor models in human ASC-derived organoids. First we show Efficacy of cytosine and adenine base editors in modelingCTNNB1hot-spot mutations in hepatocyte organoids. Next, we use C>T base editors to insert nonsense mutations inPTENin endometrial organoids and demonstrate tumorigenicity even in the heterozygous state. Moreover, drug screening assays on organoids harboring eitherPTENorPTENandPIK3CAmutations reveal the mechanism underlying the initial stages of endometrial tumorigenesis. To further increase the scope of base editing we combine SpCas9 and SaCas9 for simultaneous C>T and A>G editing at individual target sites. Finally, we show that base editor multiplexing allow modeling of colorectal tumorigenesis in a single step by simultaneously transfecting sgRNAs targeting five cancer genes.
2023-07-30 | GSE236490 | GEO
Project description:Mutagenic purine-pyrimidine repeats can adopt the left-handed Z-DNA conformation. DNA breaks at potential Z-DNA sites can lead to somatic mutations in cancer or to germ line mutations which are transmitted to the next generation. It is not known whether any mechanism exists in the germ line to control Z-DNA structure and DNA breaks at purine-pyrimidine repeats. Here, we provide genetic, epigenomic, and biochemical evidence for the existence of a biological process that erases Z-DNA specifically in germ cells of the mouse male fetus. We show that a previously uncharacterized zinc finger protein, ZBTB43, binds to and removes Z-DNA, preventing the formation of DNA double-strand breaks. By removing Z-DNA, ZBTB43 also promotes de novo DNA methylation at CG-containing purine-pyrimidine repeats in prospermatogonia. Therefore, the genomic and epigenomic integrity of the species is safeguarded by remodeling DNA structure in the mammalian germ line during a critical window of germline epigenome reprogramming.
2022-04-14 | GSE200719 | GEO