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Xu Q, Gao S, Zhang S, Li K, Guo Y. Disruption of the cell division protein ftsK gene changes elemental selenium generation, selenite tolerance, and cell morphology in Rahnella aquatilis HX2. J Appl Microbiol 2024; 135:lxae142. [PMID: 38871681 DOI: 10.1093/jambio/lxae142] [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: 12/09/2023] [Revised: 05/31/2024] [Accepted: 06/12/2024] [Indexed: 06/15/2024]
Abstract
AIMS Some studies have indicated that the alterations in cellular morphology induced by selenite [Se(Ⅳ)] may be attributed to its inhibitory effects on cell division. However, whether the genes associated with cell division are implicated in Se(Ⅳ) metabolism remains unclear. METHODS AND RESULTS The ftsK gene in Rahnella aquatilis HX2 was mutated with an in-frame deletion strategy. The ftsK mutation strongly reduced the tolerance to selenite [Se(Ⅳ)] and the production of red elemental selenium [Se(0)] in R. aquatilis HX2, and this effect could not be attributed solely to the inhibition of cell growth. Deleting the ftsK gene also resulted in a significant decrease in bacterial growth of R. aquatilis HX2 during both exponential and stationary phases. The deletion of ftsK inhibited cell division, resulting in the development of elongated filamentous cells. Furthermore, the loss-of-function of FtsK significantly impacted the expression of seven genes linked to cell division and Se(Ⅳ) metabolism by at least 2-fold, as unveiled by real-time quantitative PCR (RT-qPCR) under Se(Ⅳ) treatment. CONCLUSIONS These findings suggest that FtsK is associated with Se(Ⅳ) tolerance and Se(0) generation and is a key player in coordinating bacterial growth and cell morphology in R. aquatilis HX2.
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Affiliation(s)
- Qiaolin Xu
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
- Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Shanshan Gao
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
- Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Sasa Zhang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
- Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Kui Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
- Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Yanbin Guo
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
- Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
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Chai WC, Whittall JJ, Polyak SW, Foo K, Li X, Dutschke CJ, Ogunniyi AD, Ma S, Sykes MJ, Semple SJ, Venter H. Cinnamaldehyde derivatives act as antimicrobial agents against Acinetobacter baumannii through the inhibition of cell division. Front Microbiol 2022; 13:967949. [PMID: 36106080 PMCID: PMC9465178 DOI: 10.3389/fmicb.2022.967949] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is a pathogen with high intrinsic antimicrobial resistance while multidrug resistant (MDR) and extensively drug resistant (XDR) strains of this pathogen are emerging. Treatment options for infections by these strains are very limited, hence new therapies are urgently needed. The bacterial cell division protein, FtsZ, is a promising drug target for the development of novel antimicrobial agents. We have previously reported limited activity of cinnamaldehyde analogs against Escherichia coli. In this study, we have determined the antimicrobial activity of six cinnamaldehyde analogs for antimicrobial activity against A. baumannii. Microscopic analysis was performed to determine if the compounds inhibit cell division. The on-target effect of the compounds was assessed by analyzing their effect on polymerization and on the GTPase activity of purified FtsZ from A. baumannii. In silico docking was used to assess the binding of cinnamaldehyde analogs. Finally, in vivo and in vitro safety assays were performed. All six compounds displayed antibacterial activity against the critical priority pathogen A. baumannii, with 4-bromophenyl-substituted 4 displaying the most potent antimicrobial activity (MIC 32 μg/mL). Bioactivity was significantly increased in the presence of an efflux pump inhibitor for A. baumannii ATCC 19606 (up to 32-fold) and significantly, for extensively drug resistant UW 5075 (greater than 4-fold), suggesting that efflux contributes to the intrinsic resistance of A. baumannii against these agents. The compounds inhibited cell division in A. baumannii as observed by the elongated phenotype and targeted the FtsZ protein as seen from the inhibition of polymerization and GTPase activity. In silico docking predicted that the compounds bind in the interdomain cleft adjacent to the H7 core helix. Di-chlorinated 6 was devoid of hemolytic activity and cytotoxicity against mammalian cells in vitro, as well as adverse activity in a Caenorhabditis elegans nematode model in vivo. Together, these findings present halogenated analogs 4 and 6 as promising candidates for further development as antimicrobial agents aimed at combating A. baumannii. This is also the first report of FtsZ-targeting compounds with activity against an XDR A. baumannii strain.
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Affiliation(s)
- Wern Chern Chai
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Jonathan J. Whittall
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Steven W. Polyak
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Klyie Foo
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Xin Li
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Cameron J. Dutschke
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Abiodun D. Ogunniyi
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Shutao Ma
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Matthew J. Sykes
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Susan J. Semple
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Henrietta Venter
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- *Correspondence: Henrietta Venter,
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Wang J, Bulgheresi S, den Blaauwen T. The Longitudinal Dividing Bacterium Candidatus Thiosymbion Oneisti Has a Natural Temperature-Sensitive FtsZ Protein with Low GTPase Activity. Int J Mol Sci 2022; 23:3016. [PMID: 35328438 PMCID: PMC8953583 DOI: 10.3390/ijms23063016] [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: 01/24/2022] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 02/01/2023] Open
Abstract
FtsZ, the bacterial tubulin-homolog, plays a central role in cell division and polymerizes into a ring-like structure at midcell to coordinate other cell division proteins. The rod-shaped gamma-proteobacterium Candidatus Thiosymbion oneisti has a medial discontinuous ellipsoidal "Z-ring." Ca. T. oneisti FtsZ shows temperature-sensitive characteristics when it is expressed in Escherichia coli, where it localizes at midcell. The overexpression of Ca. T. oneisti FtsZ interferes with cell division and results in filamentous cells. In addition, it forms ring- and barrel-like structures independently of E. coli FtsZ, which suggests that the difference in shape and size of the Ca. T. oneisti FtsZ ring is likely the result of its interaction with Z-ring organizing proteins. Similar to some temperature-sensitive alleles of E. coli FtsZ, Ca. T. oneisti FtsZ has a weak GTPase and does not polymerize in vitro. The temperature sensitivity of Ca. Thiosymbion oneisti FtsZ is likely an adaptation to the preferred temperature of less than 30 °C of its host, the nematode Laxus oneistus.
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Affiliation(s)
- Jinglan Wang
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Silvia Bulgheresi
- Environmental Cell Biology, Department of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria;
| | - Tanneke den Blaauwen
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
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Ranjit DK, Liechti GW, Maurelli AT. Chlamydial MreB Directs Cell Division and Peptidoglycan Synthesis in Escherichia coli in the Absence of FtsZ Activity. mBio 2020; 11:e03222-19. [PMID: 32071268 PMCID: PMC7029139 DOI: 10.1128/mbio.03222-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/06/2020] [Indexed: 12/28/2022] Open
Abstract
Cell division is the ultimate process for the propagation of bacteria, and FtsZ is an essential protein used by nearly all bacteria for this function. Chlamydiae belong to a small group of bacteria that lack the universal cell division protein FtsZ but still divide by binary fission. Chlamydial MreB is a member of the shape-determining MreB/Mbl family of proteins responsible for rod shape morphology in Escherichia coliChlamydia also encodes a homolog of RodZ, an MreB assembly cytoskeletal protein that links MreB to cell wall synthesis proteins. We hypothesized that MreB directs cell division in Chlamydia and that chlamydial MreB could replace FtsZ function for cell division in E. coli Overexpression of chlamydial mreB-rodZ in E. coli induced prominent morphological changes with production of large swollen or oval bacteria, eventually resulting in bacterial lysis. Low-level expression of chlamydial mreB-rodZ restored viability of a lethal ΔmreB mutation in E. coli, although the bacteria lost their typical rod shape and grew as rounded cells. When FtsZ activity was inhibited by overexpression of SulA in the ΔmreB mutant of E. coli complemented with chlamydial mreB-rodZ, spherical E. coli grew and divided. Localization studies using a fluorescent fusion chlamydial MreB protein indicated that chlamydial RodZ directs chlamydial MreB to the E. coli division septum. These results demonstrate that chlamydial MreB, in partnership with chlamydial RodZ, acts as a cell division protein. Our findings suggest that an mreB-rodZ-based mechanism allows Chlamydia to divide without the universal division protein FtsZ.IMPORTANCE The study of Chlamydia growth and cell division is complicated by its obligate intracellular nature and biphasic lifestyle. Chlamydia also lacks the universal division protein FtsZ. We employed the cell division system of Escherichia coli as a surrogate to identify chlamydial cell division proteins. We demonstrate that chlamydial MreB, together with chlamydial RodZ, forms a cell division and growth complex that can replace FtsZ activity and support cell division in E. coli Chlamydial RodZ plays a major role in directing chlamydial MreB localization to the cell division site. It is likely that the evolution of chlamydial MreB and RodZ to form a functional cell division complex allowed Chlamydia to dispense with its FtsZ-based cell division machinery during genome reduction. Thus, MreB-RodZ represents a possible mechanism for cell division in other bacteria lacking FtsZ.
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Affiliation(s)
- Dev K Ranjit
- Emerging Pathogens Institute and Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
| | - George W Liechti
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Anthony T Maurelli
- Emerging Pathogens Institute and Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
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Nev OA, Van Den Berg HA. Mathematical models of microbial growth and metabolism: a whole-organism perspective. Sci Prog 2017; 100:343-362. [PMID: 29113620 PMCID: PMC10365175 DOI: 10.3184/003685017x15063357842583] [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: 11/17/2022]
Abstract
We review the principles underpinning the development of mathematical models of the metabolic activities of micro-organisms. Such models are important to understand and chart the substantial contributions made by micro-organisms to geochemical cycles, and also to optimise the performance of bioreactors that exploit the biochemical capabilities of these organisms. We advocate an approach based on the principle of dynamic allocation. We survey the biological background that motivates this approach, including nutrient assimilation, the regulation of gene expression, and the principles of microbial growth. In addition, we discuss the classic models of microbial growth as well as contemporary approaches. The dynamic allocation theory generalises these classic models in a natural manner and is readily amenable to the additional information provided by transcriptomics and proteomics approaches. Finally, we touch upon these organising principles in the context of the transition from the free-living unicellular mode of life to multicellularity.
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Abstract
The use of styrene maleic acid lipid particles (SMALPs) for the purification of membrane proteins (MPs) is a rapidly developing technology. The amphiphilic copolymer of styrene and maleic acid (SMA) disrupts biological membranes and can extract membrane proteins in nanodiscs of approximately 10 nm diameter. These discs contain SMA, protein and membrane lipids. There is evidence that MPs in SMALPs retain their native structures and functions, in some cases with enhanced thermal stability. In addition, the method is compatible with biological buffers and a wide variety of biophysical and structural analysis techniques. The use of SMALPs to solubilize and stabilize MPs offers a new approach in our attempts to understand, and influence, the structure and function of MPs and biological membranes. In this review, we critically assess progress with this method, address some of the associated technical challenges, and discuss opportunities for exploiting SMA and SMALPs to expand our understanding of MP biology.
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Broughton CE, Van Den Berg HA, Wemyss AM, Roper DI, Rodger A. Beyond the Discovery Void: New targets for antibacterial compounds. Sci Prog 2016; 99:153-182. [PMID: 28742471 PMCID: PMC10365418 DOI: 10.3184/003685016x14616130512308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Antibiotics save many lives, but their efficacy is under threat: overprescription, population growth, and global travel all contribute to the rapid origination and spread of resistant strains. Exacerbating this threat is the fact that no new major classes of antibiotics have been discovered in the last 30 years: this is the "discovery void." We discuss the traditional molecular targets of antibiotics as well as putative novel targets.
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Affiliation(s)
| | | | - Alan M. Wemyss
- Molecular Organisation and Assembly in Cells Doctoral Training Centre
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