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Bryan EJ, Qiao Q, Wang Y, Roberge JY, LaVoie EJ, Pilch DS. A FtsZ Inhibitor That Can Utilize Siderophore-Ferric Iron Uptake Transporter Systems for Activity against Gram-Negative Bacterial Pathogens. Antibiotics (Basel) 2024; 13:209. [PMID: 38534644 DOI: 10.3390/antibiotics13030209] [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: 02/02/2024] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/28/2024] Open
Abstract
The global threat of multidrug-resistant Gram-negative bacterial pathogens necessitates the development of new and effective antibiotics. FtsZ is an essential and highly conserved cytoskeletal protein that is an appealing antibacterial target for new antimicrobial therapeutics. However, the effectiveness of FtsZ inhibitors against Gram-negative species has been limited due in part to poor intracellular accumulation. To address this limitation, we have designed a FtsZ inhibitor (RUP4) that incorporates a chlorocatechol siderophore functionality that can chelate ferric iron (Fe3+) and utilizes endogenous siderophore uptake pathways to facilitate entry into Gram-negative pathogens. We show that RUP4 is active against both Klebsiella pneumoniae and Acinetobacter baumannii, with this activity being dependent on direct Fe3+ chelation and enhanced under Fe3+-limiting conditions. Genetic deletion studies in K. pneumoniae reveal that RUP4 gains entry through the FepA and CirA outer membrane transporters and the FhuBC inner membrane transporter. We also show that RUP4 exhibits bactericidal synergy against K. pneumoniae when combined with select antibiotics, with the strongest synergy observed with PBP2-targeting β-lactams or MreB inhibitors. In the aggregate, our studies indicate that incorporation of Fe3+-chelating moieties into FtsZ inhibitors is an appealing design strategy for enhancing activity against Gram-negative pathogens of global clinical significance.
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Affiliation(s)
- Eric J Bryan
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Qi Qiao
- Department of Molecular Design and Synthesis, Rutgers University Biomedical Innovation Cores, Piscataway, NJ 08854, USA
| | - Yuxuan Wang
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Jacques Y Roberge
- Department of Molecular Design and Synthesis, Rutgers University Biomedical Innovation Cores, Piscataway, NJ 08854, USA
| | - Edmond J LaVoie
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Daniel S Pilch
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
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Suigo L, Monterroso B, Sobrinos-Sanguino M, Alfonso C, Straniero V, Rivas G, Zorrilla S, Valoti E, Margolin W. Benzodioxane-benzamides as promising inhibitors of Escherichia coli FtsZ. Int J Biol Macromol 2023; 253:126398. [PMID: 37634788 DOI: 10.1016/j.ijbiomac.2023.126398] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/02/2023] [Accepted: 08/16/2023] [Indexed: 08/29/2023]
Abstract
The conserved process of cell division in bacteria has been a long-standing target for antimicrobials, although there are few examples of potent broad-spectrum compounds that inhibit this process. Most currently available compounds acting on division are directed towards the FtsZ protein, a self-assembling GTPase that is a central element of the division machinery in most bacteria. Benzodioxane-benzamides are promising candidates, but poorly explored in Gram-negatives. We have tested a number of these compounds on E. coli FtsZ and found that many of them significantly stabilized the polymers against disassembly and reduced the GTPase activity. Reconstitution in crowded cell-like conditions showed that FtsZ bundles were also susceptible to these compounds, including some compounds that were inactive on protofilaments in dilute conditions. They efficiently killed E. coli cells defective in the AcrAB efflux pump. The activity of the compounds on cell growth and division generally showed a good correlation with their effect in vitro, and our experiments are consistent with FtsZ being the target in vivo. Our results uncover the detrimental effects of benzodioxane-benzamides on permeable E. coli cells via its central division protein, implying that lead compounds may be found within this class for the development of antibiotics against Gram-negative bacteria.
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Affiliation(s)
- Lorenzo Suigo
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy
| | - Begoña Monterroso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Marta Sobrinos-Sanguino
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Carlos Alfonso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Valentina Straniero
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Silvia Zorrilla
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain.
| | - Ermanno Valoti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy.
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston 77030, TX, USA.
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Sharma AK, Poddar SM, Chakraborty J, Nayak BS, Kalathil S, Mitra N, Gayathri P, Srinivasan R. A mechanism of salt bridge-mediated resistance to FtsZ inhibitor PC190723 revealed by a cell-based screen. Mol Biol Cell 2023; 34:ar16. [PMID: 36652338 PMCID: PMC10011733 DOI: 10.1091/mbc.e22-12-0538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Bacterial cell division proteins, especially the tubulin homologue FtsZ, have emerged as strong targets for developing new antibiotics. Here, we have utilized the fission yeast heterologous expression system to develop a cell-based assay to screen for small molecules that directly and specifically target the bacterial cell division protein FtsZ. The strategy also allows for simultaneous assessment of the toxicity of the drugs to eukaryotic yeast cells. As a proof-of-concept of the utility of this assay, we demonstrate the effect of the inhibitors sanguinarine, berberine, and PC190723 on FtsZ. Though sanguinarine and berberine affect FtsZ polymerization, they exert a toxic effect on the cells. Further, using this assay system, we show that PC190723 affects Helicobacter pylori FtsZ function and gain new insights into the molecular determinants of resistance to PC190723. On the basis of sequence and structural analysis and site-specific mutations, we demonstrate that the presence of salt bridge interactions between the central H7 helix and β-strands S9 and S10 mediates resistance to PC190723 in FtsZ. The single-step in vivo cell-based assay using fission yeast enabled us to dissect the contribution of sequence-specific features of FtsZ and cell permeability effects associated with bacterial cell envelopes. Thus, our assay serves as a potent tool to rapidly identify novel compounds targeting polymeric bacterial cytoskeletal proteins like FtsZ to understand how they alter polymerization dynamics and address resistance determinants in targets.
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Affiliation(s)
- Ajay Kumar Sharma
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Sakshi Mahesh Poddar
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Joyeeta Chakraborty
- Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Bhagyashri Soumya Nayak
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Srilakshmi Kalathil
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Nivedita Mitra
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Pananghat Gayathri
- Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
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Pradhan P, Margolin W, Beuria TK. Targeting the Achilles Heel of FtsZ: The Interdomain Cleft. Front Microbiol 2021; 12:732796. [PMID: 34566937 PMCID: PMC8456036 DOI: 10.3389/fmicb.2021.732796] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/16/2021] [Indexed: 02/03/2023] Open
Abstract
Widespread antimicrobial resistance among bacterial pathogens is a serious threat to public health. Thus, identification of new targets and development of new antibacterial agents are urgently needed. Although cell division is a major driver of bacterial colonization and pathogenesis, its targeting with antibacterial compounds is still in its infancy. FtsZ, a bacterial cytoskeletal homolog of eukaryotic tubulin, plays a highly conserved and foundational role in cell division and has been the primary focus of research on small molecule cell division inhibitors. FtsZ contains two drug-binding pockets: the GTP binding site situated at the interface between polymeric subunits, and the inter-domain cleft (IDC), located between the N-terminal and C-terminal segments of the core globular domain of FtsZ. The majority of anti-FtsZ molecules bind to the IDC. Compounds that bind instead to the GTP binding site are much less useful as potential antimicrobial therapeutics because they are often cytotoxic to mammalian cells, due to the high sequence similarity between the GTP binding sites of FtsZ and tubulin. Fortunately, the IDC has much less sequence and structural similarity with tubulin, making it a better potential target for drugs that are less toxic to humans. Over the last decade, a large number of natural and synthetic IDC inhibitors have been identified. Here we outline the molecular structure of IDC in detail and discuss how it has become a crucial target for broad spectrum and species-specific antibacterial agents. We also outline the drugs that bind to the IDC and their modes of action.
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Affiliation(s)
- Pinkilata Pradhan
- Institute of Life Sciences, Nalco Square, Bhubaneswar, India
- Regional Centre for Biotechnology, Faridabad, India
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, United States
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