1
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McNeil MB, Cook GM, Krause KL. Dual transcriptional inhibition of glutamate and alanine racemase is synergistic in Mycobacterium tuberculosis. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001484. [PMID: 39115544 PMCID: PMC11309781 DOI: 10.1099/mic.0.001484] [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: 01/30/2024] [Accepted: 07/16/2024] [Indexed: 08/10/2024]
Abstract
Synergistic interactions between chemical inhibitors, whilst informative, can be difficult to interpret, as chemical inhibitors can often have multiple targets, many of which can be unknown. Here, using multiplexed transcriptional repression, we have validated that the simultaneous repression of glutamate racemase and alanine racemase has a synergistic interaction in Mycobacterium tuberculosis. This confirms prior observations from chemical interaction studies and highlights the potential of targeting multiple enzymes involved in mycobacterial cell wall synthesis.
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Affiliation(s)
- Matthew B McNeil
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Kurt L Krause
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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2
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Sakallioglu IT, Maroli AS, Leite ADL, Marshall DD, Evans BW, Zinniel DK, Dussault PH, Barletta RG, Powers R. Multi-omics Investigation into the Mechanism of Action of an Anti-tubercular Fatty Acid Analogue. J Am Chem Soc 2022; 144:21157-21173. [PMID: 36367461 PMCID: PMC10948109 DOI: 10.1021/jacs.2c08238] [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] [Indexed: 11/13/2022]
Abstract
The mechanism of action (MoA) of a clickable fatty acid analogue 8-(2-cyclobuten-1-yl)octanoic acid (DA-CB) has been investigated for the first time. Proteomics, metabolomics, and lipidomics were combined with a network analysis to investigate the MoA of DA-CB against Mycobacterium smegmatis (Msm). The metabolomics results showed that DA-CB has a general MoA related to that of ethionamide (ETH), a mycolic acid inhibitor that targets enoyl-ACP reductase (InhA), but DA-CB likely inhibits a step downstream from InhA. Our combined multi-omics approach showed that DA-CB appears to disrupt the pathway leading to the biosynthesis of mycolic acids, an essential mycobacterial fatty acid for both Msm and Mycobacterium tuberculosis (Mtb). DA-CB decreased keto-meromycolic acid biosynthesis. This intermediate is essential in the formation of mature mycolic acid, which is a key component of the mycobacterial cell wall in a process that is catalyzed by the essential polyketide synthase Pks13 and the associated ligase FadD32. The multi-omics analysis revealed further collateral alterations in bacterial metabolism, including the overproduction of shorter carbon chain hydroxy fatty acids and branched chain fatty acids, alterations in pyrimidine metabolism, and a predominate downregulation of proteins involved in fatty acid biosynthesis. Overall, the results with DA-CB suggest the exploration of this and related compounds as a new class of tuberculosis (TB) therapeutics. Furthermore, the clickable nature of DA-CB may be leveraged to trace the cellular fate of the modified fatty acid or any derived metabolite or biosynthetic intermediate.
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Affiliation(s)
- Isin T. Sakallioglu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
| | - Amith S. Maroli
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
| | - Aline De Lima Leite
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
| | - Darrell D. Marshall
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
- Total Analysis LLC, Detroit, MI 48204-3268, United States
| | - Boone W. Evans
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
| | - Denise K. Zinniel
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583-0905, United States
| | - Patrick H. Dussault
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
| | - Raúl G. Barletta
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583-0905, United States
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
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3
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McNeil MB, Cheung CY, Waller NJE, Adolph C, Chapman CL, Seeto NEJ, Jowsey W, Li Z, Hameed HMA, Zhang T, Cook GM. Uncovering interactions between mycobacterial respiratory complexes to target drug-resistant Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:980844. [PMID: 36093195 PMCID: PMC9461714 DOI: 10.3389/fcimb.2022.980844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/03/2022] [Indexed: 11/24/2022] Open
Abstract
Mycobacterium tuberculosis remains a leading cause of infectious disease morbidity and mortality for which new drug combination therapies are needed. Mycobacterial bioenergetics has emerged as a promising space for the development of novel therapeutics. Further to this, unique combinations of respiratory inhibitors have been shown to have synergistic or synthetic lethal interactions, suggesting that combinations of bioenergetic inhibitors could drastically shorten treatment times. Realizing the full potential of this unique target space requires an understanding of which combinations of respiratory complexes, when inhibited, have the strongest interactions and potential in a clinical setting. In this review, we discuss (i) chemical-interaction, (ii) genetic-interaction and (iii) chemical-genetic interaction studies to explore the consequences of inhibiting multiple mycobacterial respiratory components. We provide potential mechanisms to describe the basis for the strongest interactions. Finally, whilst we place an emphasis on interactions that occur with existing bioenergetic inhibitors, by highlighting interactions that occur with alternative respiratory components we envision that this information will provide a rational to further explore alternative proteins as potential drug targets and as part of unique drug combinations.
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Affiliation(s)
- Matthew B. McNeil
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins, Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
- *Correspondence: Matthew B. McNeil, ; Gregory M. Cook,
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Natalie J. E. Waller
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cara Adolph
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cassandra L. Chapman
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Noon E. J. Seeto
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - William Jowsey
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, China
| | - H. M. Adnan Hameed
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- China-New Zealand Joint Laboratory of Biomedicine and Health, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China
- University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Tianyu Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- China-New Zealand Joint Laboratory of Biomedicine and Health, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China
- University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Gregory M. Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins, Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
- *Correspondence: Matthew B. McNeil, ; Gregory M. Cook,
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4
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Impaired Succinate Oxidation Prevents Growth and Influences Drug Susceptibility in Mycobacterium tuberculosis. mBio 2022; 13:e0167222. [PMID: 35856639 PMCID: PMC9426501 DOI: 10.1128/mbio.01672-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Succinate is a major focal point in mycobacterial metabolism and respiration, serving as both an intermediate of the tricarboxylic acid (TCA) cycle and a direct electron donor for the respiratory chain. Mycobacterium tuberculosis encodes multiple enzymes predicted to be capable of catalyzing the oxidation of succinate to fumarate, including two different succinate dehydrogenases (Sdh1 and Sdh2) and a separate fumarate reductase (Frd) with possible bidirectional behavior. Previous attempts to investigate the essentiality of succinate oxidation in M. tuberculosis have relied on the use of single-gene deletion mutants, raising the possibility that the remaining enzymes could catalyze succinate oxidation in the absence of the other. To address this, we report on the use of mycobacterial CRISPR interference (CRISPRi) to construct single, double, and triple transcriptional knockdowns of sdhA1, sdhA2, and frdA in M. tuberculosis. We show that the simultaneous knockdown of sdhA1 and sdhA2 is required to prevent succinate oxidation and overcome the functional redundancy within these enzymes. Succinate oxidation was demonstrated to be essential for the optimal growth of M. tuberculosis, with the combined knockdown of sdhA1 and sdhA2 significantly impairing the activity of the respiratory chain and preventing growth on a range of carbon sources. Moreover, impaired succinate oxidation was shown to influence the activity of cell wall-targeting antibiotics and bioenergetic inhibitors against M. tuberculosis. Together, these data provide fundamental insights into mycobacterial physiology, energy metabolism, and antimicrobial susceptibility. IMPORTANCE New drugs are urgently required to combat the tuberculosis epidemic that claims 1.5 million lives annually. Inhibitors of mycobacterial energy metabolism have shown significant promise clinically; however, further advancing this nascent target space requires a more fundamental understanding of the respiratory enzymes and pathways used by Mycobacterium tuberculosis. Succinate is a major focal point in mycobacterial metabolism and respiration; yet, the essentiality of succinate oxidation and the consequences of inhibiting this process are poorly defined. In this study, we demonstrate that impaired succinate oxidation prevents the optimal growth of M. tuberculosis on a range of carbon sources and significantly reduces the activity of the electron transport chain. Moreover, we show that impaired succinate oxidation both positively and negatively influences the activity of a variety of antituberculosis drugs. Combined, these findings provide fundamental insights into mycobacterial physiology and drug susceptibility that will be useful in the continued development of bioenergetic inhibitors.
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5
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Call SN, Andrews LB. CRISPR-Based Approaches for Gene Regulation in Non-Model Bacteria. Front Genome Ed 2022; 4:892304. [PMID: 35813973 PMCID: PMC9260158 DOI: 10.3389/fgeed.2022.892304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/11/2022] [Indexed: 01/08/2023] Open
Abstract
CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) have become ubiquitous approaches to control gene expression in bacteria due to their simple design and effectiveness. By regulating transcription of a target gene(s), CRISPRi/a can dynamically engineer cellular metabolism, implement transcriptional regulation circuitry, or elucidate genotype-phenotype relationships from smaller targeted libraries up to whole genome-wide libraries. While CRISPRi/a has been primarily established in the model bacteria Escherichia coli and Bacillus subtilis, a growing numbering of studies have demonstrated the extension of these tools to other species of bacteria (here broadly referred to as non-model bacteria). In this mini-review, we discuss the challenges that contribute to the slower creation of CRISPRi/a tools in diverse, non-model bacteria and summarize the current state of these approaches across bacterial phyla. We find that despite the potential difficulties in establishing novel CRISPRi/a in non-model microbes, over 190 recent examples across eight bacterial phyla have been reported in the literature. Most studies have focused on tool development or used these CRISPRi/a approaches to interrogate gene function, with fewer examples applying CRISPRi/a gene regulation for metabolic engineering or high-throughput screens and selections. To date, most CRISPRi/a reports have been developed for common strains of non-model bacterial species, suggesting barriers remain to establish these genetic tools in undomesticated bacteria. More efficient and generalizable methods will help realize the immense potential of programmable CRISPR-based transcriptional control in diverse bacteria.
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Affiliation(s)
- Stephanie N. Call
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
| | - Lauren B. Andrews
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
- Biotechnology Training Program, University of Massachusetts Amherst, Amherst, MA, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA, United States
- *Correspondence: Lauren B. Andrews,
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6
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Harold LK, Jinich A, Hards K, Cordeiro A, Keighley LM, Cross A, McNeil MB, Rhee K, Cook GM. Deciphering functional redundancy and energetics of malate oxidation in mycobacteria. J Biol Chem 2022; 298:101859. [PMID: 35337802 PMCID: PMC9062433 DOI: 10.1016/j.jbc.2022.101859] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023] Open
Abstract
Oxidation of malate to oxaloacetate, catalyzed by either malate dehydrogenase (Mdh) or malate quinone oxidoreductase (Mqo), is a critical step of the tricarboxylic acid cycle. Both Mqo and Mdh are found in most bacterial genomes, but the level of functional redundancy between these enzymes remains unclear. A bioinformatic survey revealed that Mqo was not as widespread as Mdh in bacteria but that it was highly conserved in mycobacteria. We therefore used mycobacteria as a model genera to study the functional role(s) of Mqo and its redundancy with Mdh. We deleted mqo from the environmental saprophyte Mycobacterium smegmatis, which lacks Mdh, and found that Mqo was essential for growth on nonfermentable carbon sources. On fermentable carbon sources, the Δmqo mutant exhibited delayed growth and lowered oxygen consumption and secreted malate and fumarate as terminal end products. Furthermore, heterologous expression of Mdh from the pathogenic species Mycobacterium tuberculosis shortened the delayed growth on fermentable carbon sources and restored growth on nonfermentable carbon sources at a reduced growth rate. In M. tuberculosis, CRISPR interference of either mdh or mqo expression resulted in a slower growth rate compared to controls, which was further inhibited when both genes were knocked down simultaneously. These data reveal that exergonic Mqo activity powers mycobacterial growth under nonenergy limiting conditions and that endergonic Mdh activity complements Mqo activity, but at an energetic cost for mycobacterial growth. We propose Mdh is maintained in slow-growing mycobacterial pathogens for use under conditions such as hypoxia that require reductive tricarboxylic acid cycle activity.
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Affiliation(s)
- Liam K Harold
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand.
| | - Adrian Jinich
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Kiel Hards
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Alexandra Cordeiro
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Laura M Keighley
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Alec Cross
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Matthew B McNeil
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Kyu Rhee
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Gregory M Cook
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand.
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7
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Hards K, Cheung CY, Waller N, Adolph C, Keighley L, Tee ZS, Harold LK, Menorca A, Bujaroski RS, Buckley BJ, Tyndall JDA, McNeil MB, Rhee KY, Opel-Reading HK, Krause K, Preiss L, Langer JD, Meier T, Hasenoehrl EJ, Berney M, Kelso MJ, Cook GM. An amiloride derivative is active against the F 1F o-ATP synthase and cytochrome bd oxidase of Mycobacterium tuberculosis. Commun Biol 2022; 5:166. [PMID: 35210534 PMCID: PMC8873251 DOI: 10.1038/s42003-022-03110-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 02/03/2022] [Indexed: 12/15/2022] Open
Abstract
Increasing antimicrobial resistance compels the search for next-generation inhibitors with differing or multiple molecular targets. In this regard, energy conservation in Mycobacterium tuberculosis has been clinically validated as a promising new drug target for combatting drug-resistant strains of M. tuberculosis. Here, we show that HM2-16F, a 6-substituted derivative of the FDA-approved drug amiloride, is an anti-tubercular inhibitor with bactericidal properties comparable to the FDA-approved drug bedaquiline (BDQ; Sirturo®) and inhibits the growth of bedaquiline-resistant mutants. We show that HM2-16F weakly inhibits the F1Fo-ATP synthase, depletes ATP, and affects the entry of acetyl-CoA into the Krebs cycle. HM2-16F synergizes with the cytochrome bcc-aa3 oxidase inhibitor Q203 (Telacebec) and co-administration with Q203 sterilizes in vitro cultures in 14 days. Synergy with Q203 occurs via direct inhibition of the cytochrome bd oxidase by HM2-16F. This study shows that amiloride derivatives represent a promising discovery platform for targeting energy generation in drug-resistant tuberculosis. Derivatives of the FDA-approved drug, amiloride, can eliminate drug-resistant Mycobacterium tuberculosis in vitro by interfering with bacterial energy conservation.
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Affiliation(s)
- Kiel Hards
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Otago, Dunedin, New Zealand
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Natalie Waller
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cara Adolph
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Laura Keighley
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Zhi Shean Tee
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Liam K Harold
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Otago, Dunedin, New Zealand
| | - Ayana Menorca
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Richard S Bujaroski
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, Wollongong, Australia
| | - Benjamin J Buckley
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, Wollongong, Australia
| | | | - Matthew B McNeil
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Otago, Dunedin, New Zealand
| | - Kyu Y Rhee
- Weill Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | | | - Kurt Krause
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Otago, Dunedin, New Zealand
| | - Laura Preiss
- Department of Structural Biology, Max-Planck Institute of Biophysics, Frankfurt am Main, Germany.,Octapharma Biopharmaceuticals GmbH, Heidelberg, Germany
| | - Julian D Langer
- Department of Molecular Membrane Biology, Max-Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Thomas Meier
- Department of Life Sciences, Imperial College London, London, UK.,Private University in the Principality of Liechtenstein, Triesen, Liechtenstein
| | - Erik J Hasenoehrl
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY, USA
| | - Michael Berney
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY, USA
| | - Michael J Kelso
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia. .,Illawarra Health and Medical Research Institute, Wollongong, Australia.
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Otago, Dunedin, New Zealand.
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8
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Multiplexed transcriptional repression identifies a network of bactericidal interactions between mycobacterial respiratory complexes. iScience 2022; 25:103573. [PMID: 34984329 PMCID: PMC8692989 DOI: 10.1016/j.isci.2021.103573] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/07/2021] [Accepted: 12/02/2021] [Indexed: 12/28/2022] Open
Abstract
Mycobacterium tuberculosis remains a leading cause of infectious disease morbidity and mortality for which new drug combination therapies are needed. Combinations of respiratory inhibitors can have synergistic or synthetic lethal interactions with sterilizing activity, suggesting that regimens with multiple bioenergetic inhibitors could shorten treatment times. However, realizing this potential requires an understanding of which combinations of respiratory complexes, when inhibited, have the strongest consequences on bacterial growth and viability. Here we have used multiplex CRISPR interference (CRISPRi) and Mycobacterium smegmatis as a physiological and molecular model for mycobacterial respiration to identify interactions between respiratory complexes. In this study, we identified synthetic lethal and synergistic interactions between respiratory complexes and demonstrated how the engineering of CRISPRi-guide sequences can be used to further explore networks of interacting gene pairs. These results provide fundamental insights into the functions of and interactions between bioenergetic complexes and the utility of CRISPRi in designing drug combinations.
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9
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Krah A, Grüber G, Bond PJ. Binding properties of the anti-TB drugs bedaquiline and TBAJ-876 to a mycobacterial F-ATP synthase. Curr Res Struct Biol 2022; 4:278-284. [PMID: 36186842 PMCID: PMC9516385 DOI: 10.1016/j.crstbi.2022.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/13/2022] [Accepted: 09/08/2022] [Indexed: 11/30/2022] Open
Abstract
Tuberculosis (TB), the deadly disease caused by Mycobacterium tuberculosis (Mtb), kills more people worldwide than any other bacterial infectious disease. There has been a recent resurgence of TB drug discovery activities, resulting in the identification of a number of novel enzyme inhibitors. Many of these inhibitors target the electron transport chain complexes and the F1FO-ATP synthase; these enzymes represent new target spaces for drug discovery, since the generation of ATP is essential for the bacterial pathogen's physiology, persistence, and pathogenicity. The anti-TB drug bedaquiline (BDQ) targets the Mtb F-ATP synthase and is used as salvage therapy against this disease. Medicinal chemistry efforts to improve the physio-chemical properties of BDQ resulted in the discovery of 3,5-dialkoxypyridine (DARQ) analogs to which TBAJ-876 belongs. TBAJ-876, a clinical development candidate, shows attractive in vitro and in vivo antitubercular activity. Both BDQ and TBAJ-876 inhibit the mycobacterial F1FO-ATP synthase by stopping rotation of the c-ring turbine within the FO domain, thereby preventing proton translocation and ATP synthesis to occur. While structural data for the BDQ bound state are available, no structural information about TBAJ-876 binding have been described. In this study, we show how TBAJ-876 binds to the FO domain of the M. smegmatis F1FO-ATP synthase. We further calculate the binding free energy of both drugs bound to their target and predict an increased affinity of TBAJ-876 for the FO domain. This approach will be useful in future efforts to design new and highly potent DARQ analogs targeting F-ATP synthases of Mtb, nontuberculosis mycobacteria (NTM) as well as the M. leprosis complex. BDQ inhibits mycobacterial F-ATP synthase. TBAJ-876 is a BDQ analogue with improved affinity for the enzyme. Simulations help to structurally clarify the FO domain binding sites of TBAJ-876. Insights will help guide development of multidrug-resistant tuberculosis drugs.
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Affiliation(s)
- Alexander Krah
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), 30 Biopolis Str., #07-01 Matrix, 138671, Singapore
- Corresponding author.
| | - Gerhard Grüber
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), 30 Biopolis Str., #07-01 Matrix, 138671, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Peter J. Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), 30 Biopolis Str., #07-01 Matrix, 138671, Singapore
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore
- Corresponding author. Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), 30 Biopolis Str., #07-01 Matrix, 138671, Singapore.
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10
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McNeil MB, Keighley LM, Cook JR, Cheung CY, Cook GM. CRISPR interference identifies vulnerable cellular pathways with bactericidal phenotypes in Mycobacterium tuberculosis. Mol Microbiol 2021; 116:1033-1043. [PMID: 34346123 DOI: 10.1111/mmi.14790] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/02/2021] [Accepted: 08/02/2021] [Indexed: 11/29/2022]
Abstract
Mycobacterium tuberculosis remains a leading cause of death for which new drugs are needed. The identification of drug targets has been advanced by high-throughput and targeted genetic deletion strategies. Each though has limitations including the inability to distinguish between levels of vulnerability, lethality and scalability as a molecular tool. Using mycobacterial CRISPR interference in combination with phenotypic screening we have overcome these individual issues to investigate essentiality, vulnerability and lethality for 94 target genes from a diverse array of cellular pathways, many of which are potential antibiotic targets. Essential genes involved in cell wall synthesis and central cellular functions were equally vulnerable and often had bactericidal consequences. Conversely, essential genes involved in metabolism, oxidative phosphorylation or amino acid synthesis were less vulnerable to inhibition and frequently bacteriostatic. In conclusion, this study provides novel insights into mycobacterial genetics and biology that will help to prioritise potential drug targets.
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Affiliation(s)
- Matthew B McNeil
- Department of Microbiology and Immunology, University of Otago, Otago, New Zealand.,Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Laura M Keighley
- Department of Microbiology and Immunology, University of Otago, Otago, New Zealand
| | - Josephine R Cook
- Department of Microbiology and Immunology, University of Otago, Otago, New Zealand
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, University of Otago, Otago, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Otago, New Zealand.,Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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Nicholson KR, Mousseau CB, Champion MM, Champion PA. The genetic proteome: Using genetics to inform the proteome of mycobacterial pathogens. PLoS Pathog 2021; 17:e1009124. [PMID: 33411813 PMCID: PMC7790235 DOI: 10.1371/journal.ppat.1009124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mycobacterial pathogens pose a sustained threat to human health. There is a critical need for new diagnostics, therapeutics, and vaccines targeting both tuberculous and nontuberculous mycobacterial species. Understanding the basic mechanisms used by diverse mycobacterial species to cause disease will facilitate efforts to design new approaches toward detection, treatment, and prevention of mycobacterial disease. Molecular, genetic, and biochemical approaches have been widely employed to define fundamental aspects of mycobacterial physiology and virulence. The recent expansion of genetic tools in mycobacteria has further increased the accessibility of forward genetic approaches. Proteomics has also emerged as a powerful approach to further our understanding of diverse mycobacterial species. Detection of large numbers of proteins and their modifications from complex mixtures of mycobacterial proteins is now routine, with efforts of quantification of these datasets becoming more robust. In this review, we discuss the “genetic proteome,” how the power of genetics, molecular biology, and biochemistry informs and amplifies the quality of subsequent analytical approaches and maximizes the potential of hypothesis-driven mycobacterial research. Published proteomics datasets can be used for hypothesis generation and effective post hoc supplementation to experimental data. Overall, we highlight how the integration of proteomics, genetic, molecular, and biochemical approaches can be employed successfully to define fundamental aspects of mycobacterial pathobiology.
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Affiliation(s)
- Kathleen R. Nicholson
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - C. Bruce Mousseau
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Matthew M. Champion
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, United States of America
- Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame Indiana, United States of America
- * E-mail: (MMC); (PAC)
| | - Patricia A. Champion
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
- Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame Indiana, United States of America
- * E-mail: (MMC); (PAC)
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Structure of mycobacterial ATP synthase bound to the tuberculosis drug bedaquiline. Nature 2020; 589:143-147. [PMID: 33299175 DOI: 10.1038/s41586-020-3004-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 10/21/2020] [Indexed: 01/01/2023]
Abstract
Tuberculosis-the world's leading cause of death by infectious disease-is increasingly resistant to current first-line antibiotics1. The bacterium Mycobacterium tuberculosis (which causes tuberculosis) can survive low-energy conditions, allowing infections to remain dormant and decreasing their susceptibility to many antibiotics2. Bedaquiline was developed in 2005 from a lead compound identified in a phenotypic screen against Mycobacterium smegmatis3. This drug can sterilize even latent M. tuberculosis infections4 and has become a cornerstone of treatment for multidrug-resistant and extensively drug-resistant tuberculosis1,5,6. Bedaquiline targets the mycobacterial ATP synthase3, which is an essential enzyme in the obligate aerobic Mycobacterium genus3,7, but how it binds the intact enzyme is unknown. Here we determined cryo-electron microscopy structures of M. smegmatis ATP synthase alone and in complex with bedaquiline. The drug-free structure suggests that hook-like extensions from the α-subunits prevent the enzyme from running in reverse, inhibiting ATP hydrolysis and preserving energy in hypoxic conditions. Bedaquiline binding induces large conformational changes in the ATP synthase, creating tight binding pockets at the interface of subunits a and c that explain the potency of this drug as an antibiotic for tuberculosis.
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