1
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Son JE, Park SH, Choi U, Lee CR. Lytic transglycosylase repertoire diversity enables intrinsic antibiotic resistance and daughter cell separation in Escherichia coli under acidic stress. Antimicrob Agents Chemother 2024:e0037224. [PMID: 38884456 DOI: 10.1128/aac.00372-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/21/2024] [Indexed: 06/18/2024] Open
Abstract
Peptidoglycan (PG) is an important architectural element that imparts physical toughness and rigidity to the bacterial envelope. It is also a dynamic structure that undergoes continuous turnover or autolysis. Escherichia coli possesses redundant PG degradation enzymes responsible for PG turnover; however, the advantage afforded by the existence of numerous PG degradation enzymes remains incompletely understood. In this study, we elucidated the physiological roles of MltE and MltC, members of the lytic transglycosylase (LTG) family that catalyze the cleavage of glycosidic bonds between disaccharide subunits within PG strands. MltE and MltC are acidic LTGs that exhibit increased enzymatic activity and protein levels under acidic pH conditions, respectively, and deletion of these two LTGs results in a pronounced growth defect at acidic pH. Furthermore, inactivation of these two LTGs induces increased susceptibility at acidic pH against various antibiotics, particularly vancomycin, which seems to be partially caused by elevated membrane permeability. Intriguingly, inactivation of these LTGs induces a chaining morphology, indicative of daughter cell separation defects, only under acidic pH conditions. Simultaneous deletion of PG amidases, known contributors to daughter cell separation, exacerbates the chaining phenotype at acidic pH. This suggests that the two LTGs may participate in the cleavage of glycan strands between daughter cells under acidic pH conditions. Collectively, our findings highlight the role of LTG repertoire diversity in facilitating bacterial survival and antibiotic resistance under stressful conditions.
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Affiliation(s)
- Ji Eun Son
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
| | - Si Hyoung Park
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
| | - Umji Choi
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
| | - Chang-Ro Lee
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
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2
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Dierksheide KJ, Li GW. A historical sequence deletion in a commonly used Bacillus subtilis chromosome integration vector generates undetected loss-of-function mutations. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001455. [PMID: 38602388 PMCID: PMC11084560 DOI: 10.1099/mic.0.001455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 04/03/2024] [Indexed: 04/12/2024]
Abstract
Since the 1980s, chromosome-integration vectors have been used as a core method of engineering Bacillus subtilis. One of the most frequently used vector backbones contains chromosomally derived regions that direct homologous recombination into the amyE locus. Here, we report a gap in the homology region inherited from the original amyE integration vector, leading to erroneous recombination in a subset of transformants and a loss-of-function mutation in the downstream gene. Internal to the homology arm that spans the 3' portion of amyE and the downstream gene ldh, an unintentional 227 bp deletion generates two crossover events. The major event yields the intended genotype, but the minor event, occurring in ~10 % of colonies, results in a truncation of ldh, which encodes lactate dehydrogenase. Although both types of colonies test positive for amyE disruption by starch plating, the potential defect in fermentative metabolism may be left undetected and confound the results of subsequent experiments.
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Affiliation(s)
- K. Julia Dierksheide
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Gene-Wei Li
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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3
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Yan D, Xue J, Xiao J, Lyu Z, Yang X. Protocol for single-molecule labeling and tracking of bacterial cell division proteins. STAR Protoc 2024; 5:102766. [PMID: 38085639 PMCID: PMC10733747 DOI: 10.1016/j.xpro.2023.102766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/11/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
Here, we present a protocol for labeling and tracking individual molecules, particularly cell division proteins in live bacterial cells. The protocol encompasses strain construction, single-molecule imaging, trajectory segmentation, and motion property analysis. The protocol enables the identification of distinctive motion states associated with different cell division proteins. Subsequent assessments of the dynamic behaviors of these proteins provide insights into their activities and interactions at the septum during cell division. For complete details on the use and execution of this protocol, please refer to Yang et al. (2021),1 Lyu et al. (2022),2 and Mahone et al. (2024).3.
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Affiliation(s)
- Di Yan
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Jinchan Xue
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
| | - Zhixin Lyu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
| | - Xinxing Yang
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China.
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4
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Santiago-Collazo G, Brown PJB, Randich AM. The divergent early divisome: is there a functional core? Trends Microbiol 2024; 32:231-240. [PMID: 37741788 DOI: 10.1016/j.tim.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/25/2023]
Abstract
The bacterial divisome is a complex nanomachine that drives cell division and separation. The essentiality of these processes leads to the assumption that proteins with core roles will be strictly conserved across all bacterial genomes. However, recent studies in diverse proteobacteria have revealed considerable variation in the early divisome compared with Escherichia coli. While some proteins are highly conserved, their specific functions and interacting partners vary. Meanwhile, different subphyla use clade-specific proteins with analogous functions. Thus, instead of focusing on gene conservation, we must also explore how key functions are maintained during early division by diverging protein networks. An enhanced awareness of these complex genetic networks will clarify the physical and evolutionary constraints of bacterial division.
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Affiliation(s)
- Gustavo Santiago-Collazo
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri-Columbia, Columbia, MO, USA
| | - Pamela J B Brown
- Division of Biological Sciences, College of Arts and Sciences, University of Missouri-Columbia, Columbia, MO, USA
| | - Amelia M Randich
- Department of Biology, College of Arts and Sciences, University of Scranton, Scranton, PA, USA.
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5
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Zhou P, G. C. B, Stolte F, Wu C. Use of CRISPR interference for efficient and rapid gene inactivation in Fusobacterium nucleatum. Appl Environ Microbiol 2024; 90:e0166523. [PMID: 38185820 PMCID: PMC10880640 DOI: 10.1128/aem.01665-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/27/2023] [Indexed: 01/09/2024] Open
Abstract
Gene inactivation by creating in-frame deletion mutations in Fusobacterium nucleatum is time consuming, and most fusobacterial strains are genetically intractable. Addressing these problems, we introduced a riboswitch-based inducible CRISPR interference (CRISPRi) system. This system employs the nuclease-inactive Streptococcus pyogenes Cas9 protein (dCas9), specifically guided to the gene of interest by a constantly expressed single-guide RNA (sgRNA). Mechanistically, this dCas9-sgRNA complex serves as an insurmountable roadblock for RNA polymerase, thus repressing the target gene transcription. Leveraging this system, we first examined two non-essential genes, ftsX and radD, which are pivotal for fusobacterial cytokinesis and coaggregation. Upon adding the inducer, theophylline, ftsX suppression caused filamentous cell formation akin to chromosomal ftsX deletion, while targeting radD significantly reduced RadD protein levels, abolishing RadD-mediated coaggregation. The system was then extended to probe essential genes bamA and ftsZ, which are vital for outer membrane biogenesis and cell division. Impressively, bamA suppression disrupted membrane integrity and bacterial separation, stalling growth, while ftsZ targeting yielded elongated cells in broth with compromised agar growth. Further studies on F. nucleatum clinical strain CTI-2 and Fusobacterium periodonticum revealed reduced indole synthesis when targeting tnaA. Moreover, silencing clpB in F. periodonticum decreased ClpB, increasing thermal sensitivity. In summary, our CRISPRi system streamlines gene inactivation across various fusobacterial strains.IMPORTANCEHow can we effectively investigate the gene functions in Fusobacterium nucleatum, given the dual challenges of gene inactivation and the inherent genetic resistance of many strains? Traditional methods have been cumbersome and often inadequate. Addressing this, our work introduces a novel inducible CRISPR interference (CRISPRi) system in which dCas9 expression is controlled at the translation level by a theophylline-responsive riboswitch unit, and single-guide RNA expression is driven by the robust, constitutive rpsJ promoter. This approach simplifies gene inactivation in the model organism (ATCC 23726) and extends its application to previously considered genetically intractable strains like CTI-2 and Fusobacterium periodonticum. With CRISPRi's potential, it is a pivotal tool for in-depth genetic studies into fusobacterial pathogenesis, potentially unlocking targeted therapeutic strategies.
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Affiliation(s)
- Peng Zhou
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Bibek G. C.
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Flynn Stolte
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
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6
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Howard CB, Rabinovitch A, Yehezkel G, Zaritsky A. Tight coupling of cell width to nucleoid structure in Escherichia coli. Biophys J 2024; 123:502-508. [PMID: 38243596 PMCID: PMC10912912 DOI: 10.1016/j.bpj.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 10/24/2023] [Accepted: 01/16/2024] [Indexed: 01/21/2024] Open
Abstract
Cell dimensions of rod-shaped bacteria such as Escherichia coli are connected to mass growth and chromosome replication. During their interdivision cycle (τ min), cells enlarge by elongation only, but at faster growth in richer media, they are also wider. Changes in width W upon nutritional shift-up (shortening τ) occur during the division process. The elusive signal directing the mechanism for W determination is likely related to the tightly linked duplications of the nucleoid (DNA) and the sacculus (peptidoglycan), the only two structures (macromolecules) existing in a single copy that are coupled, temporally and spatially. Six known parameters related to the nucleoid structure and replication are reasonable candidates to convey such a signal, all simple functions of the key number of replication positions n(=C/τ), the ratio between the rates of growth (τ-1) and of replication (C-1). The current analysis of available literature-recorded data discovered that, of these, nucleoid complexity NC[=(2n-1)/(n×ln2)] is by far the most likely parameter affecting cell width W. The exceedingly high correlations found between these two seemingly unrelated measures (NC and W) indicate that coupling between them is of major importance to the species' survival. As an exciting corollary, to the best of our knowledge, a new, indirect approach to estimate DNA replication rate is revealed. Potential involvement of DNA topoisomerases in W determination is also proposed and discussed.
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Affiliation(s)
- Charles B Howard
- Department of Life Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Avinoam Rabinovitch
- Department of Physics, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Galit Yehezkel
- Department of Life Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | - Arieh Zaritsky
- Department of Life Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel.
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7
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Wang H, Mi Q, Mao Y, Tan Y, Yang M, Liu W, Wang N, Tian X, Huang L. Streptothricin-F Inhibition of FtsZ Function: A Promising Approach for Controlling Pseudomonas syringae pv. actinidiae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:2624-2633. [PMID: 38277222 DOI: 10.1021/acs.jafc.3c08474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2024]
Abstract
Pseudomonas syringae pv. actinidiae (Psa) is a significant pathogenic bacterium affecting the kiwifruit industry. This study investigated the target sites of streptothricin-F (ST-F), produced by Streptomyces lavendulae gCLA4. The inhibition of ST-F on Psa was examined by the microscopic structural differences of Psa before and after treatment with ST-F, as well as the interaction between ST-F and cell division-related proteins. The results revealed filamentation of Psa after ST-F treatment, and fluorescence microscopy showed that ST-F inhibited the formation of the Z-ring composed of FtsZ protein. In vitro experiments and molecular docking demonstrated that ST-F can bind to FtsZ with a binding energy of 0.4 μM and inhibit FtsZ's GTP-dependent polymerization reaction. In addition, ST-F does not exert inhibitory effects on cell division in Psa strains overexpressing ftsZ. In conclusion, FtsZ is one of the target sites for ST-F inhibition of Psa, highlighting its potential as a therapeutic target for controlling Psa-induced kiwifruit bacterial canker.
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Affiliation(s)
- Hua Wang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Qianqian Mi
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Yiru Mao
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Yunxiao Tan
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Mingming Yang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Wei Liu
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Nana Wang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Life Science, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Xiangrong Tian
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Forestry, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
| | - Lili Huang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100 Shaanxi Province, P. R. China
- College of Plant Protection, Northwest A&F University, Yangling Shaanxi Province 712100, P. R. China
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8
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Dierksheide KJ, Li GW. A historical sequence deletion in a commonly used Bacillus subtilis chromosome integration vector generates undetected loss-of-function mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.04.574214. [PMID: 38260694 PMCID: PMC10802373 DOI: 10.1101/2024.01.04.574214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Since the 1980s, chromosome-integration vectors have been used as a core method of engineering Bacillus subtilis. One of the most frequently used vector backbones contains chromosomally derived regions that direct homologous recombination into the amyE locus. Here, we report a gap in the homology region inherited from the original amyE integration vector, leading to erroneous recombination in a subset of transformants and a loss-of-function mutation in the downstream gene. Internal to the homology arm that spans the 3' portion of amyE and the downstream gene ldh, an unintentional 227-bp deletion generates two crossover events. The major event yields the intended genotype, but the minor event, occurring in ~10% of colonies, results in a truncation of ldh, which encodes lactate dehydrogenase. Although both types of colonies test positive for amyE disruption by starch plating, the potential defect in fermentative metabolism may be left undetected and confound the results of subsequent experiments.
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Affiliation(s)
- K. Julia Dierksheide
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Gene-Wei Li
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
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9
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Kaufmann A, Vigogne M, Neuendorf TA, Reverte-López M, Rivas G, Thiele J. Studying Nucleoid-Associated Protein-DNA Interactions Using Polymer Microgels as Synthetic Mimics. ACS Synth Biol 2023; 12:3695-3703. [PMID: 37965889 DOI: 10.1021/acssynbio.3c00488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
Microfluidically fabricated polymer microgels are used as an experimental platform to analyze protein-DNA interactions regulating bacterial cell division. In particular, we focused on the nucleoid-associated protein SlmA, which forms a nucleoprotein complex with short DNA binding sequences (SBS) that acts as a negative regulator of the division ring stability in Escherichia coli. To mimic the bacterial nucleoid as a dense DNA region of a bacterial cell and investigate the influence of charge and permeability on protein binding and diffusion in there, we have chosen nonionic polyethylene glycol and anionic hyaluronic acid as precursor materials for hydrogel formation, previously functionalized with SBS. SlmA binds specifically to the coupled SBS for both types of microgels while preferentially accumulating at the microgels' surface. We could control the binding specificity by adjusting the buffer composition of the DNA-functionalized microgels. The microgel charge did not impact protein binding; however, hyaluronic acid-based microgels exhibit a higher permeability, promoting protein diffusion; thus, they were the preferred choice for preparing nucleoid mimics. The approaches described here provide attractive tools for bottom-up reconstitution of essential cellular processes in media that more faithfully reproduce intracellular environments.
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Affiliation(s)
- Anika Kaufmann
- Institute of Physical Chemistry and Polymer Physics, Leibniz Institute of Polymer Research Dresden, 01069 Dresden, Germany
| | - Michelle Vigogne
- Institute of Physical Chemistry and Polymer Physics, Leibniz Institute of Polymer Research Dresden, 01069 Dresden, Germany
| | - Talika A Neuendorf
- Institute of Physical Chemistry and Polymer Physics, Leibniz Institute of Polymer Research Dresden, 01069 Dresden, Germany
| | - María Reverte-López
- Department of Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Julian Thiele
- Institute of Physical Chemistry and Polymer Physics, Leibniz Institute of Polymer Research Dresden, 01069 Dresden, Germany
- Institute of Chemistry, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
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10
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Suigo L, Margolin W, Ulzurrun E, Hrast Rambaher M, Zanotto C, Sebastián-Pérez V, Campillo NE, Straniero V, Valoti E. Benzodioxane-Benzamides as FtsZ Inhibitors: Effects of Linker's Functionalization on Gram-Positive Antimicrobial Activity. Antibiotics (Basel) 2023; 12:1712. [PMID: 38136746 PMCID: PMC10740499 DOI: 10.3390/antibiotics12121712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/23/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
FtsZ is an essential bacterial protein abundantly studied as a novel and promising target for antimicrobials. FtsZ is highly conserved among bacteria and mycobacteria, and it is crucial for the correct outcome of the cell division process, as it is responsible for the division of the parent bacterial cell into two daughter cells. In recent years, the benzodioxane-benzamide class has emerged as very promising and capable of targeting both Gram-positive and Gram-negative FtsZs. In this study, we explored the effect of including a substituent on the ethylenic linker between the two main moieties on the antimicrobial activity and pharmacokinetic properties. This substitution, in turn, led to the generation of a second stereogenic center, with both erythro and threo isomers isolated, characterized, and evaluated. With this work, we discovered how the hydroxy group slightly affects the antimicrobial activity, while being an important anchor for the exploitation and development of prodrugs, probes, and further derivatives.
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Affiliation(s)
- Lorenzo Suigo
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy; (L.S.); (E.V.)
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston, TX 77030, USA;
| | - Eugenia Ulzurrun
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (E.U.); (V.S.-P.); (N.E.C.)
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Darwin 3, 28049 Madrid, Spain
| | - Martina Hrast Rambaher
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta, 7, 1000 Ljubljana, Slovenia;
| | - Carlo Zanotto
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Via Vanvitelli, 32, 20129 Milano, Italy;
| | - Victor Sebastián-Pérez
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (E.U.); (V.S.-P.); (N.E.C.)
- Exscientia, The Schrödinger Building, Oxford Science Park, Oxford OX4 4GE, UK
| | - Nuria E. Campillo
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (E.U.); (V.S.-P.); (N.E.C.)
- Instituto de Ciencias Matemáticas, Consejo Superior de Investigaciones Científicas (CSIC), C. Nicolás Cabrera, 13-15, 28049 Madrid, Italy
| | - Valentina Straniero
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy; (L.S.); (E.V.)
| | - Ermanno Valoti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy; (L.S.); (E.V.)
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11
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Zhou P, G C B, Stolte F, Wu C. Use of CRISPR interference for efficient and rapid gene inactivation in Fusobacterium nucleatum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.19.558491. [PMID: 37781593 PMCID: PMC10541141 DOI: 10.1101/2023.09.19.558491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Gene inactivation via creating in-frame deletion mutations in Fusobacterium nucleatum is time-consuming, and most fusobacterial strains are genetically intractable. Addressing these problems, we introduced a riboswitch-based inducible CRISPRi system. This system employs the nuclease-inactive Streptococcus pyogenes Cas9 protein (dCas9), specifically guided to the gene of interest by a constantly expressed single guide RNA (sgRNA). Mechanistically, this dCas9-sgRNA complex serves as an insurmountable roadblock for RNA polymerase, thus repressing the target gene transcription. Leveraging this system, we first examined two non-essential genes, ftsX, and radD , pivotal for fusobacterial cytokinesis and coaggregation. Upon adding the inducer, theophylline, ftsX suppression caused filamentous cell formation akin to chromosomal ftsX deletion, while targeting radD significantly reduced RadD protein levels, abolishing coaggregation. The system was then extended to probe essential genes bamA and ftsZ , vital for outer membrane biogenesis and cell division. Impressively, bamA suppression disrupted membrane integrity and bacterial separation, stalling growth, while ftsZ- targeting yielded elongated cells in broth with compromised agar growth. Further studies on F. nucleatum clinical strain CTI-2 and Fusobacterium periodonticum revealed reduced indole synthesis when targeting tnaA . Moreover, silencing clpB in F. periodonticum decreased ClpB, increasing thermal sensitivity. In summary, our CRISPRi system streamlines gene inactivation across various fusobacterial strains. IMPORTANCE How can we effectively investigate the gene functions in Fusobacterium nucleatum , given the dual challenges of gene inactivation and the inherent genetic resistance of many strains? Traditional methods have been cumbersome and often inadequate. Addressing this, our work introduces a novel inducible CRISPRi system in which dCas9 expression is controlled at the translation level by a theophylline-responsive riboswitch unit, and sgRNA expression is driven by the robust, constitutive rpsJ promoter. This approach simplifies gene inactivation in the model organism (ATCC 23726) and extends its application to previously considered resistant strains like CTI-2 and Fusobacterium periodontium . With CRISPRi's potential, it is a pivotal tool for in-depth genetic studies into fusobacterial pathogenesis, potentially unlocking targeted therapeutic strategies.
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