Pub Date : 2024-07-19DOI: 10.1038/s41589-024-01680-8
Di Zhang, Jinjun Gao, Zhijun Zhu, Qianying Mao, Zhiqiang Xu, Pankaj K. Singh, Cornelius C. Rimayi, Carlos Moreno-Yruela, Shuling Xu, Gongyu Li, Yi-Cheng Sin, Yue Chen, Christian A. Olsen, Nathaniel W. Snyder, Lunzhi Dai, Lingjun Li, Yingming Zhao
Lysine l-lactylation (Kl-la) is a novel protein posttranslational modification (PTM) driven by l-lactate. This PTM has three isomers: Kl-la, N-ε-(carboxyethyl)-lysine (Kce) and d-lactyl-lysine (Kd-la), which are often confused in the context of the Warburg effect and nuclear presence. Here we introduce two methods to differentiate these isomers: a chemical derivatization and high-performance liquid chromatography analysis for efficient separation, and isomer-specific antibodies for high-selectivity identification. We demonstrated that Kl-la is the primary lactylation isomer on histones and dynamically regulated by glycolysis, not Kd-la or Kce, which are observed when the glyoxalase system was incomplete. The study also reveals that lactyl-coenzyme A, a precursor in l-lactylation, correlates positively with Kl-la levels. This work not only provides a methodology for distinguishing other PTM isomers, but also highlights Kl-la as the primary responder to glycolysis and the Warburg effect.
{"title":"Lysine l-lactylation is the dominant lactylation isomer induced by glycolysis","authors":"Di Zhang, Jinjun Gao, Zhijun Zhu, Qianying Mao, Zhiqiang Xu, Pankaj K. Singh, Cornelius C. Rimayi, Carlos Moreno-Yruela, Shuling Xu, Gongyu Li, Yi-Cheng Sin, Yue Chen, Christian A. Olsen, Nathaniel W. Snyder, Lunzhi Dai, Lingjun Li, Yingming Zhao","doi":"10.1038/s41589-024-01680-8","DOIUrl":"https://doi.org/10.1038/s41589-024-01680-8","url":null,"abstract":"<p>Lysine <span>l</span>-lactylation (K<sub><span>l</span>-la</sub>) is a novel protein posttranslational modification (PTM) driven by <span>l</span>-lactate. This PTM has three isomers: K<sub><span>l</span>-la</sub>, <i>N</i>-ε-(carboxyethyl)-lysine (K<sub>ce</sub>) and <span>d</span>-lactyl-lysine (K<sub><span>d</span>-la</sub>), which are often confused in the context of the Warburg effect and nuclear presence. Here we introduce two methods to differentiate these isomers: a chemical derivatization and high-performance liquid chromatography analysis for efficient separation, and isomer-specific antibodies for high-selectivity identification. We demonstrated that K<sub><span>l</span>-la</sub> is the primary lactylation isomer on histones and dynamically regulated by glycolysis, not K<sub><span>d</span>-la</sub> or K<sub>ce</sub>, which are observed when the glyoxalase system was incomplete. The study also reveals that lactyl-coenzyme A, a precursor in <span>l</span>-lactylation, correlates positively with <span>K</span><sub><span>l</span></sub><sub>-la</sub> levels. This work not only provides a methodology for distinguishing other PTM isomers, but also highlights K<sub><span>l</span>-la</sub> as the primary responder to glycolysis and the Warburg effect.</p><figure></figure>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141726002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-15DOI: 10.1038/s41589-024-01672-8
Krishna Neupane, Abhishek Narayan, Supratik Sen Mojumdar, Gaurav Adhikari, Craig R. Garen, Michael T. Woodside
Many neurodegenerative diseases feature misfolded proteins that propagate via templated conversion of natively folded molecules. However, crucial questions about how such prion-like conversion occurs and what drives it remain unsolved, partly because technical challenges have prevented direct observation of conversion for any protein. We observed prion-like conversion in single molecules of superoxide dismutase-1 (SOD1), whose misfolding is linked to amyotrophic lateral sclerosis. Tethering pathogenic misfolded SOD1 mutants to wild-type molecules held in optical tweezers, we found that the mutants vastly increased misfolding of the wild-type molecule, inducing multiple misfolded isoforms. Crucially, the pattern of misfolding was the same in the mutant and converted wild-type domains and varied when the misfolded mutant was changed, reflecting the templating effect expected for prion-like conversion. Ensemble measurements showed decreased enzymatic activity in tethered heterodimers as conversion progressed, mirroring the single-molecule results. Antibodies sensitive to disease-specific epitopes bound to the converted protein, implying that conversion produced disease-relevant misfolded conformers. Protein misfolding can spread from one molecule to another in infectious prion diseases. The propagation of protein misfolding has been directly observed in single protein molecules. These results showed that pathogenic mutants of the protein superoxide dismutase-1 (SOD1), which causes familial amyotrophic lateral sclerosis, imprint their misfolding onto native wild-type molecules.
{"title":"Direct observation of prion-like propagation of protein misfolding templated by pathogenic mutants","authors":"Krishna Neupane, Abhishek Narayan, Supratik Sen Mojumdar, Gaurav Adhikari, Craig R. Garen, Michael T. Woodside","doi":"10.1038/s41589-024-01672-8","DOIUrl":"10.1038/s41589-024-01672-8","url":null,"abstract":"Many neurodegenerative diseases feature misfolded proteins that propagate via templated conversion of natively folded molecules. However, crucial questions about how such prion-like conversion occurs and what drives it remain unsolved, partly because technical challenges have prevented direct observation of conversion for any protein. We observed prion-like conversion in single molecules of superoxide dismutase-1 (SOD1), whose misfolding is linked to amyotrophic lateral sclerosis. Tethering pathogenic misfolded SOD1 mutants to wild-type molecules held in optical tweezers, we found that the mutants vastly increased misfolding of the wild-type molecule, inducing multiple misfolded isoforms. Crucially, the pattern of misfolding was the same in the mutant and converted wild-type domains and varied when the misfolded mutant was changed, reflecting the templating effect expected for prion-like conversion. Ensemble measurements showed decreased enzymatic activity in tethered heterodimers as conversion progressed, mirroring the single-molecule results. Antibodies sensitive to disease-specific epitopes bound to the converted protein, implying that conversion produced disease-relevant misfolded conformers. Protein misfolding can spread from one molecule to another in infectious prion diseases. The propagation of protein misfolding has been directly observed in single protein molecules. These results showed that pathogenic mutants of the protein superoxide dismutase-1 (SOD1), which causes familial amyotrophic lateral sclerosis, imprint their misfolding onto native wild-type molecules.","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141618270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-10DOI: 10.1038/s41589-024-01663-9
Günter Fritz, Peter M. H. Kroneck, Julia Steuber
Biological reduction of dinitrogen by nitrogenase requires high-energy electrons to form ammonium ion. A new study reveals the structure and function of a molecular machine that exploits the proton-motive force to provide a powerful reductant used by the nitrogen-reducing system of the soil bacterium Azotobacter vinelandii.
{"title":"The power supply for biological nitrogen fixation","authors":"Günter Fritz, Peter M. H. Kroneck, Julia Steuber","doi":"10.1038/s41589-024-01663-9","DOIUrl":"10.1038/s41589-024-01663-9","url":null,"abstract":"Biological reduction of dinitrogen by nitrogenase requires high-energy electrons to form ammonium ion. A new study reveals the structure and function of a molecular machine that exploits the proton-motive force to provide a powerful reductant used by the nitrogen-reducing system of the soil bacterium Azotobacter vinelandii.","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141573277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-09DOI: 10.1038/s41589-024-01665-7
Alejandro González-Delgado, Santiago C. Lopez, Matías Rojas-Montero, Chloe B. Fishman, Seth L. Shipman
During recent years, the use of libraries-scale genomic manipulations scaffolded on CRISPR guide RNAs have been transformative. However, these existing approaches are typically multiplexed across genomes. Unfortunately, building cells with multiple, nonadjacent precise mutations remains a laborious cycle of editing, isolating an edited cell and editing again. The use of bacterial retrons can overcome this limitation. Retrons are genetic systems composed of a reverse transcriptase and a noncoding RNA that contains an multicopy single-stranded DNA, which is reverse transcribed to produce multiple copies of single-stranded DNA. Here we describe a technology—termed a multitron—for precisely modifying multiple sites on a single genome simultaneously using retron arrays, in which multiple donor-encoding DNAs are produced from a single transcript. The multitron architecture is compatible with both recombineering in prokaryotic cells and CRISPR editing in eukaryotic cells. We demonstrate applications for this approach in molecular recording, genetic element minimization and metabolic engineering.
{"title":"Simultaneous multi-site editing of individual genomes using retron arrays","authors":"Alejandro González-Delgado, Santiago C. Lopez, Matías Rojas-Montero, Chloe B. Fishman, Seth L. Shipman","doi":"10.1038/s41589-024-01665-7","DOIUrl":"https://doi.org/10.1038/s41589-024-01665-7","url":null,"abstract":"<p>During recent years, the use of libraries-scale genomic manipulations scaffolded on CRISPR guide RNAs have been transformative. However, these existing approaches are typically multiplexed across genomes. Unfortunately, building cells with multiple, nonadjacent precise mutations remains a laborious cycle of editing, isolating an edited cell and editing again. The use of bacterial retrons can overcome this limitation. Retrons are genetic systems composed of a reverse transcriptase and a noncoding RNA that contains an multicopy single-stranded DNA, which is reverse transcribed to produce multiple copies of single-stranded DNA. Here we describe a technology—termed a multitron—for precisely modifying multiple sites on a single genome simultaneously using retron arrays, in which multiple donor-encoding DNAs are produced from a single transcript. The multitron architecture is compatible with both recombineering in prokaryotic cells and CRISPR editing in eukaryotic cells. We demonstrate applications for this approach in molecular recording, genetic element minimization and metabolic engineering.</p><figure></figure>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141561555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-08DOI: 10.1038/s41589-024-01677-3
Gihoon Lee, Tom W. Muir
The post-translational regulation of protein function is involved in most cellular processes. As such, synthetic biology tools that operate at this level provide opportunities for manipulating cellular states. Here we deploy proximity-triggered protein trans-splicing technology to enable the time-resolved synthesis of target proteins from premade parts. The modularity of the strategy allows for the addition or removal of various control elements as a function of the splicing reaction, in the process permitting the cellular location and/or activity state of starting materials and products to be differentiated. The approach is applied to a diverse set of proteins, including the kinase oncofusions breakpoint cluster region–Abelson (BCR–ABL) and DNAJ–PKAc where dynamic cellular phosphorylation events are dissected, revealing distinct phases of signaling and identifying molecular players connecting the oncofusion to cancer transformation as new therapeutic targets of cancer cells. We envision that the tools and control strategies developed herein will allow the activity of both naturally occurring and designer proteins to be harnessed for basic and applied research.
{"title":"Distinct phases of cellular signaling revealed by time-resolved protein synthesis","authors":"Gihoon Lee, Tom W. Muir","doi":"10.1038/s41589-024-01677-3","DOIUrl":"https://doi.org/10.1038/s41589-024-01677-3","url":null,"abstract":"<p>The post-translational regulation of protein function is involved in most cellular processes. As such, synthetic biology tools that operate at this level provide opportunities for manipulating cellular states. Here we deploy proximity-triggered protein <i>trans</i>-splicing technology to enable the time-resolved synthesis of target proteins from premade parts. The modularity of the strategy allows for the addition or removal of various control elements as a function of the splicing reaction, in the process permitting the cellular location and/or activity state of starting materials and products to be differentiated. The approach is applied to a diverse set of proteins, including the kinase oncofusions breakpoint cluster region–Abelson (BCR–ABL) and DNAJ–PKAc where dynamic cellular phosphorylation events are dissected, revealing distinct phases of signaling and identifying molecular players connecting the oncofusion to cancer transformation as new therapeutic targets of cancer cells. We envision that the tools and control strategies developed herein will allow the activity of both naturally occurring and designer proteins to be harnessed for basic and applied research.</p><figure></figure>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IscB has a similar domain organization to Cas9, but the small size of IscB is better suited for delivery by adeno-associated virus. To improve the low editing efficiency of OgeuIscB (IscB from human gut metagenome) in mammalian cells, we developed high-efficiency miniature base editors by engineering OgeuIscB nickase and its cognate ωRNA, termed IminiBEs. We demonstrated the robust editing efficiency of IminiCBE (67% on average) or IminiABE (52% on average). Fusing non-specific DNA-binding protein Sso7d to IminiBEs increased the editing efficiency of low-efficiency sites by around two- to threefold, and we termed it SIminiBEs. In addition, IminiCBE and SIminiCBE recognize NNRR, NNRY and NNYR target-adjacent motifs, which broaden the canonical NWRRNA target-adjacent motif sites for the wild-type IscB nickase. Overall, IminiBEs and SIminiBEs are efficient miniature base editors for site-specific genomic mutations.
{"title":"Engineering miniature IscB nickase for robust base editing with broad targeting range","authors":"Linxiao Han, Yueer Hu, Qiqin Mo, Hao Yang, Feng Gu, Fang Bai, Yadong Sun, Hanhui Ma","doi":"10.1038/s41589-024-01670-w","DOIUrl":"https://doi.org/10.1038/s41589-024-01670-w","url":null,"abstract":"<p>IscB has a similar domain organization to Cas9, but the small size of IscB is better suited for delivery by adeno-associated virus. To improve the low editing efficiency of OgeuIscB (IscB from human gut metagenome) in mammalian cells, we developed high-efficiency miniature base editors by engineering OgeuIscB nickase and its cognate ωRNA, termed IminiBEs. We demonstrated the robust editing efficiency of IminiCBE (67% on average) or IminiABE (52% on average). Fusing non-specific DNA-binding protein Sso7d to IminiBEs increased the editing efficiency of low-efficiency sites by around two- to threefold, and we termed it SIminiBEs. In addition, IminiCBE and SIminiCBE recognize NNRR, NNRY and NNYR target-adjacent motifs, which broaden the canonical NWRRNA target-adjacent motif sites for the wild-type IscB nickase. Overall, IminiBEs and SIminiBEs are efficient miniature base editors for site-specific genomic mutations.</p><figure></figure>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Clustered regularly interspaced short palindromic repeats (CRISPR)–Cas systems are prokaryotic adaptive immune systems against invading phages and other mobile genetic elements. Notably, some phages, including the Vibrio cholerae-infecting ICP1 (International Center for Diarrheal Disease Research, Bangladesh cholera phage 1), harbor CRISPR–Cas systems to counteract host defenses. Nevertheless, ICP1 Cas8f lacks the helical bundle domain essential for recruitment of helicase-nuclease Cas2/3 during target DNA cleavage and how this system accomplishes the interference stage remains unknown. Here, we found that Cas1, a highly conserved component known to exclusively work in the adaptation stage, also mediates the interference stage through connecting Cas2/3 to the DNA-bound CRISPR-associated complex for antiviral defense (Cascade; CRISPR system yersinia, Csy) of the ICP1 CRISPR–Cas system. A series of structures of Csy, Csy–dsDNA (double-stranded DNA), Cas1–Cas2/3 and Csy–dsDNA–Cas1–Cas2/3 complexes reveal the whole process of Cas1-mediated target DNA cleavage by the ICP1 CRISPR–Cas system. Together, these data support an unprecedented model in which Cas1 mediates the interference stage in a phage-encoded CRISPR–Cas system and the study also sheds light on a unique model of primed adaptation.
簇状有规律间隔短回文重复序列(CRISPR)-Cas系统是原核生物对抗入侵噬菌体和其他移动遗传因子的适应性免疫系统。值得注意的是,一些噬菌体,包括感染霍乱弧菌的ICP1(国际腹泻病研究中心,孟加拉霍乱噬菌体1),都携带CRISPR-Cas系统,以对抗宿主的防御。然而,ICP1的Cas8f缺乏在靶DNA裂解过程中招募螺旋酶-核酸酶Cas2/3所必需的螺旋束结构域,该系统如何完成干扰阶段仍是未知数。在这里,我们发现,已知只在适应阶段发挥作用的高度保守成分Cas1也通过连接Cas2/3和ICP1 CRISPR-Cas系统中与DNA结合的抗病毒防御CRISPR相关复合物(Cascade; CRISPR system yersinia, Csy)来介导干扰阶段。Csy、Csy-dsDNA(双链DNA)、Cas1-Cas2/3和Csy-dsDNA-Cas1-Cas2/3复合物的一系列结构揭示了ICP1 CRISPR-Cas系统介导的Cas1裂解靶DNA的全过程。这些数据共同支持了一个前所未有的模型,在该模型中,Cas1介导了噬菌体编码的CRISPR-Cas系统中的干扰阶段,该研究还揭示了一个独特的引物适应模型。
{"title":"Cas1 mediates the interference stage in a phage-encoded CRISPR–Cas system","authors":"Laixing Zhang, Hao Wang, Jianwei Zeng, Xueli Cao, Zhengyu Gao, Zihe Liu, Feixue Li, Jiawei Wang, Yi Zhang, Maojun Yang, Yue Feng","doi":"10.1038/s41589-024-01659-5","DOIUrl":"https://doi.org/10.1038/s41589-024-01659-5","url":null,"abstract":"<p>Clustered regularly interspaced short palindromic repeats (CRISPR)–Cas systems are prokaryotic adaptive immune systems against invading phages and other mobile genetic elements. Notably, some phages, including the <i>Vibrio cholerae</i>-infecting ICP1 (International Center for Diarrheal Disease Research, Bangladesh cholera phage 1), harbor CRISPR–Cas systems to counteract host defenses. Nevertheless, ICP1 Cas8f lacks the helical bundle domain essential for recruitment of helicase-nuclease Cas2/3 during target DNA cleavage and how this system accomplishes the interference stage remains unknown. Here, we found that Cas1, a highly conserved component known to exclusively work in the adaptation stage, also mediates the interference stage through connecting Cas2/3 to the DNA-bound CRISPR-associated complex for antiviral defense (Cascade; CRISPR system yersinia, Csy) of the ICP1 CRISPR–Cas system. A series of structures of Csy, Csy–dsDNA (double-stranded DNA), Cas1–Cas2/3 and Csy–dsDNA–Cas1–Cas2/3 complexes reveal the whole process of Cas1-mediated target DNA cleavage by the ICP1 CRISPR–Cas system. Together, these data support an unprecedented model in which Cas1 mediates the interference stage in a phage-encoded CRISPR–Cas system and the study also sheds light on a unique model of primed adaptation.</p><figure></figure>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OMEGA RNA (ωRNA)-guided endonuclease IscB, the evolutionary ancestor of Cas9, is an attractive system for in vivo genome editing because of its compact size and mechanistic resemblance to Cas9. However, wild-type IscB–ωRNA systems show limited activity in human cells. Here we report enhanced OgeuIscB, which, with eight amino acid substitutions, displayed a fourfold increase in in vitro DNA-binding affinity and a 30.4-fold improvement in insertion–deletion (indel) formation efficiency in human cells. Paired with structure-guided ωRNA engineering, the enhanced OgeuIscB–ωRNA systems efficiently edited the human genome across 26 target sites, attaining up to 87.3% indel and 62.2% base-editing frequencies. Both wild-type and engineered OgeuIscB–ωRNA showed moderate fidelity in editing the human genome, with off-target profiles revealing key determinants of target selection including an NARR target-adjacent motif (TAM) and the TAM-proximal 14 nucleotides in the R-loop. Collectively, our engineered OgeuIscB–ωRNA systems are programmable, potent and sufficiently specific for human genome editing.
{"title":"Assessing and engineering the IscB–ωRNA system for programmed genome editing","authors":"Hao Yan, Xiaoqing Tan, Siyuan Zou, Yihong Sun, Ailong Ke, Weixin Tang","doi":"10.1038/s41589-024-01669-3","DOIUrl":"https://doi.org/10.1038/s41589-024-01669-3","url":null,"abstract":"<p>OMEGA RNA (ωRNA)-guided endonuclease IscB, the evolutionary ancestor of Cas9, is an attractive system for in vivo genome editing because of its compact size and mechanistic resemblance to Cas9. However, wild-type IscB–ωRNA systems show limited activity in human cells. Here we report enhanced OgeuIscB, which, with eight amino acid substitutions, displayed a fourfold increase in in vitro DNA-binding affinity and a 30.4-fold improvement in insertion–deletion (indel) formation efficiency in human cells. Paired with structure-guided ωRNA engineering, the enhanced OgeuIscB–ωRNA systems efficiently edited the human genome across 26 target sites, attaining up to 87.3% indel and 62.2% base-editing frequencies. Both wild-type and engineered OgeuIscB–ωRNA showed moderate fidelity in editing the human genome, with off-target profiles revealing key determinants of target selection including an NARR target-adjacent motif (TAM) and the TAM-proximal 14 nucleotides in the R-loop. Collectively, our engineered OgeuIscB–ωRNA systems are programmable, potent and sufficiently specific for human genome editing.</p><figure></figure>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-08DOI: 10.1038/s41589-024-01667-5
In type I-F CRISPR–Cas systems, Cas2/3 is typically recruited to the interference complex Cascade by Cas8f. We resolved the structures of the phage ICP1 CRISPR–Cas complexes and discovered a Cas2/3 recruitment mechanism distinct from that in other type I-F systems — recruitment by Cas1.
{"title":"An alternative mechanism for recruiting Cas2/3 in a phage-encoded CRISPR–Cas system","authors":"","doi":"10.1038/s41589-024-01667-5","DOIUrl":"https://doi.org/10.1038/s41589-024-01667-5","url":null,"abstract":"In type I-F CRISPR–Cas systems, Cas2/3 is typically recruited to the interference complex Cascade by Cas8f. We resolved the structures of the phage ICP1 CRISPR–Cas complexes and discovered a Cas2/3 recruitment mechanism distinct from that in other type I-F systems — recruitment by Cas1.","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":14.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-05DOI: 10.1038/s41589-024-01673-7
Carolina Monck, Yuval Elani, Francesca Ceroni
Synthetic cells containing genetic programs and protein expression machinery are increasingly recognized as powerful counterparts to engineered living cells in the context of biotechnology, therapeutics and cellular modelling. So far, genetic regulation of synthetic cell activity has been largely confined to chemical stimuli; to unlock their potential in applied settings, engineering stimuli-responsive synthetic cells under genetic regulation is imperative. Here we report the development of temperature-sensitive synthetic cells that control protein production by exploiting heat-responsive mRNA elements. This is achieved by combining RNA thermometer technology, cell-free protein expression and vesicle-based synthetic cell design to create cell-sized capsules able to initiate synthesis of both soluble proteins and membrane proteins at defined temperatures. We show that the latter allows for temperature-controlled cargo release phenomena with potential implications for biomedicine. Platforms like the one presented here can pave the way for customizable, genetically programmed synthetic cells under thermal control to be used in biotechnology.
{"title":"Genetically programmed synthetic cells for thermo-responsive protein synthesis and cargo release.","authors":"Carolina Monck, Yuval Elani, Francesca Ceroni","doi":"10.1038/s41589-024-01673-7","DOIUrl":"10.1038/s41589-024-01673-7","url":null,"abstract":"<p><p>Synthetic cells containing genetic programs and protein expression machinery are increasingly recognized as powerful counterparts to engineered living cells in the context of biotechnology, therapeutics and cellular modelling. So far, genetic regulation of synthetic cell activity has been largely confined to chemical stimuli; to unlock their potential in applied settings, engineering stimuli-responsive synthetic cells under genetic regulation is imperative. Here we report the development of temperature-sensitive synthetic cells that control protein production by exploiting heat-responsive mRNA elements. This is achieved by combining RNA thermometer technology, cell-free protein expression and vesicle-based synthetic cell design to create cell-sized capsules able to initiate synthesis of both soluble proteins and membrane proteins at defined temperatures. We show that the latter allows for temperature-controlled cargo release phenomena with potential implications for biomedicine. Platforms like the one presented here can pave the way for customizable, genetically programmed synthetic cells under thermal control to be used in biotechnology.</p>","PeriodicalId":18832,"journal":{"name":"Nature chemical biology","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141538193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}