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Ahsan R, Kifayat S, Pooniya KK, Kularia S, Adimalla BS, Sanapalli BKR, Sanapalli V, Sigalapalli DK. Bacterial Histidine Kinase and the Development of Its Inhibitors in the 21st Century. Antibiotics (Basel) 2024; 13:576. [PMID: 39061258 PMCID: PMC11274179 DOI: 10.3390/antibiotics13070576] [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: 05/17/2024] [Revised: 06/17/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Bacterial histidine kinase (BHK) is a constituent of the two-component signaling (TCS) pathway, which is responsible for the regulation of a number of processes connected to bacterial pathogenicity, virulence, biofilm development, antibiotic resistance, and bacterial persistence. As BHK regulation is diverse, inhibitors can be developed, such as antibiotic synergists, bacteriostatic/bactericidal agents, virulence inhibitors, and biofilm inhibitors. Inhibition of essential BHK has always been an amenable strategy due to the conserved binding sites of the domains across bacterial species and growth dependence. Hence, an inhibitor of BHK might block multiple TCS regulatory networks. This review describes the TCS system and the role of BHK in bacterial virulence and discusses the available inhibitors of BHK, which is a specific response regulator with essential structural features.
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Affiliation(s)
- Ragib Ahsan
- Department of Pharmacy, NIMS Institute of Pharmacy, NIMS University, Jaipur 303121, Rajasthan, India (S.K.)
| | - Sumaiya Kifayat
- Department of Pharmacy, NIMS Institute of Pharmacy, NIMS University, Jaipur 303121, Rajasthan, India (S.K.)
| | - Krishan Kumar Pooniya
- Department of Pharmacy, NIMS Institute of Pharmacy, NIMS University, Jaipur 303121, Rajasthan, India (S.K.)
| | - Sunita Kularia
- Department of Pharmacology, NIMS Institute of Pharmacy, NIMS University, Jaipur 303121, Rajasthan, India;
| | - Bhavani Sailu Adimalla
- Department of Pharmaceutical Analysis, Vignan Pharmacy College, Jawaharlal Nehru Technological University, Vadlamudi, Guntur 522213, Andhra Pradesh, India;
| | - Bharat Kumar Reddy Sanapalli
- Department of Pharmacology, School of Pharmacy & Technology Management, SVKM’s Narsee Monjee Institute of Management Studies (NMIMS) Deemed to-be-University, Jadcherla 509301, Hyderabad, India;
| | - Vidyasrilekha Sanapalli
- Department of Pharmaceutical Chemistry, School of Pharmacy & Technology Management, SVKM’s Narsee Monjee Institute of Management Studies (NMIMS) Deemed to-be-University, Jadcherla 509301, Hyderabad, India
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2
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Naha A, Ramaiah S. Structural chemistry and molecular-level interactome reveals histidine kinase EvgS to subvert both antimicrobial resistance and virulence in Shigella flexneri 2a str. 301. 3 Biotech 2022; 12:258. [PMID: 36068841 PMCID: PMC9440972 DOI: 10.1007/s13205-022-03325-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 08/22/2022] [Indexed: 11/25/2022] Open
Abstract
Multi-drug resistant (MDR) Shigella flexneri 2a, one of the leading bacterial agents of diarrhoeal mortality, has posed challenges in treatment strategies. The present study was conducted to identify potential therapeutic biomarkers using gene interaction network (GIN) in order to understand the cellular and molecular level interactions of both antimicrobial resistance (AMR) and virulence genes through topological and clustering metrics. Statistically significant differential gene expression (DGE), structural chemistry and dynamics were incorporated to elucidate biomarker for sustainable therapeutic regimen against MDR S. flexneri. Functional enrichments and topological metrics revealed evgS, ybjZ, tolC, gyrA, parC and their direct interactors to be associated with diverse AMR mechanisms. Histidine kinase EvgS was considered as the hub protein due to its highest prevalence in the molecular interactome profiles of both the AMR (71.6%) and virulence (45.8%) clusters interconnecting several genes concerning two-component system (TCS). DGE profiles of ΔPhoPQ (deleted regulatory PhoP and sensor PhoQ) led to the upregulation of TCS comprising EvgSA thereby validating EvgS as a promising therapeutic biomarker. Druggability and structural stability of EvgS was assessed through thermal shifts, backbone stability and coarse dynamics refinement. Structure-function relationship was established revealing the C-terminal extracellular domain as the drug-binding site which was further validated through molecular dynamics simulation. Structure elucidation of identified biomarker followed by secondary and tertiary structural validation would prove pivotal for future therapeutic interventions against subverting both AMR and virulence posed by this strain. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03325-w.
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Affiliation(s)
- Aniket Naha
- Medical and Biological Computing Laboratory, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
- Department of Bio-Medical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
| | - Sudha Ramaiah
- Medical and Biological Computing Laboratory, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
- Department of Bio-Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
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3
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Nitric oxide inhibits alginate biosynthesis in Pseudomonas aeruginosa and increases its sensitivity to tobramycin by downregulating algU gene expression. Nitric Oxide 2022; 128:50-58. [PMID: 35987450 DOI: 10.1016/j.niox.2022.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/23/2022]
Abstract
In the process of chronic cystic fibrosis (CF) infection, Pseudomonas aeruginosa (PA) is converted into a mucoid phenotype characterized by an overproduction of exopolysaccharide alginate. The alginate forms a thick mucus that causes difficulty in patient's breathing, drug resistance and contributes to both the morbidity and mortality of the patient. AlgU of PA, an extracytoplasmic function sigma factor, is responsible for the alginate overproduction and leads to mucoidy and chronic infection of CF patients. In this report, we found that endogenous and exogenous nitric oxide (NO) can significantly reduce algU expression, leading to down-regulation of a series of alginate synthesis-related genes (algD, alg8, algX, and algK), eventually down-regulated alginate synthesis. A fluorescent reporter strain was constructed to clarify the inhibitory effect of alginate synthesis through real-time monitoring in different conditions. The results showed that NO presented inhibitory effect on alginate synthesis in nine clinical PA isolates as in the PA reference strain, and the reduction of alginate was more significant in three mucoid strains (by about 51%, 70% and 61%, respectively, while 47% for the reference strain). In the co-culture system, effect of NO on PA fluorescence intensity is similar to that in monocultures, with the best effect at 10 μM NO donor sodium nitroprusside (SNP). Finally, we examined the changes in the antibiotic susceptibility of PA under NO-inhibited alginate conditions. In the presence of 10 μM SNP, the number of planktonic cells increased, and both adherent and planktonic PA cells showed increased susceptibility to tobramycin. We thus suggest that NO can potentially be employed as a therapeutic strategy to prevent cystic fibrosis lungs from PA infection.
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4
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Roncarati D, Scarlato V, Vannini A. Targeting of Regulators as a Promising Approach in the Search for Novel Antimicrobial Agents. Microorganisms 2022; 10:microorganisms10010185. [PMID: 35056634 PMCID: PMC8777881 DOI: 10.3390/microorganisms10010185] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 02/01/2023] Open
Abstract
Since the discovery of penicillin in the first half of the last century, antibiotics have become the pillars of modern medicine for fighting bacterial infections. However, pathogens resistant to antibiotic treatment have increased in recent decades, and efforts to discover new antibiotics have decreased. As a result, it is becoming increasingly difficult to treat bacterial infections successfully, and we look forward to more significant efforts from both governments and the scientific community to research new antibacterial drugs. This perspective article highlights the high potential of bacterial transcriptional and posttranscriptional regulators as targets for developing new drugs. We highlight some recent advances in the search for new compounds that inhibit their biological activity and, as such, appear very promising for treating bacterial infections.
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Affiliation(s)
- Davide Roncarati
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
- Correspondence: (D.R.); (V.S.); (A.V.)
| | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
- Correspondence: (D.R.); (V.S.); (A.V.)
| | - Andrea Vannini
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40126 Bologna, Italy
- Correspondence: (D.R.); (V.S.); (A.V.)
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5
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Ducret V, Perron K, Valentini M. Role of Two-Component System Networks in Pseudomonas aeruginosa Pathogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:371-395. [PMID: 36258080 DOI: 10.1007/978-3-031-08491-1_14] [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: 06/16/2023]
Abstract
Two-component systems (TCS) are the largest family of signaling systems in the bacterial kingdom. They enable bacteria to cope with a wide range of environmental conditions via the sensing of stimuli and the transduction of the signal into an appropriate cellular adaptation response. Pseudomonas aeruginosa possesses one of the richest arrays of TCSs in bacteria and they have been the subject of intense investigation for more than 20 years. Most of the P. aeruginosa TCSs characterized to date affect its pathogenesis, via the regulation of virulence factors expression, modulation of the synthesis of antibiotic/antimicrobial resistance mechanisms, and/or via linking virulence to energy metabolism. Here, we give an overview of the current knowledge on P. aeruginosa TCSs, citing key examples for each of the above-mentioned regulatory actions. We then conclude by mentioning few small molecule inhibitors of P. aeruginosa TCSs that have shown an antimicrobial action in vitro.
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Affiliation(s)
- Verena Ducret
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Karl Perron
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Martina Valentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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6
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Sultan M, Arya R, Kim KK. Roles of Two-Component Systems in Pseudomonas aeruginosa Virulence. Int J Mol Sci 2021; 22:12152. [PMID: 34830033 PMCID: PMC8623646 DOI: 10.3390/ijms222212152] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 12/28/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that synthesizes and secretes a wide range of virulence factors. P. aeruginosa poses a potential threat to human health worldwide due to its omnipresent nature, robust host accumulation, high virulence, and significant resistance to multiple antibiotics. The pathogenicity of P. aeruginosa, which is associated with acute and chronic infections, is linked with multiple virulence factors and associated secretion systems, such as the ability to form and utilize a biofilm, pili, flagella, alginate, pyocyanin, proteases, and toxins. Two-component systems (TCSs) of P. aeruginosa perform an essential role in controlling virulence factors in response to internal and external stimuli. Therefore, understanding the mechanism of TCSs to perceive and respond to signals from the environment and control the production of virulence factors during infection is essential to understanding the diseases caused by P. aeruginosa infection and further develop new antibiotics to treat this pathogen. This review discusses the important virulence factors of P. aeruginosa and the understanding of their regulation through TCSs by focusing on biofilm, motility, pyocyanin, and cytotoxins.
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Affiliation(s)
| | - Rekha Arya
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Korea;
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Korea;
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Yang Q, Zou P, Cao Z, Wang Q, Fu S, Xie G, Huang J. QseC Inhibition as a Novel Antivirulence Strategy for the Prevention of Acute Hepatopancreatic Necrosis Disease (AHPND)-Causing Vibrio parahaemolyticus. Front Cell Infect Microbiol 2021; 10:594652. [PMID: 33553003 PMCID: PMC7859628 DOI: 10.3389/fcimb.2020.594652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/04/2020] [Indexed: 11/13/2022] Open
Abstract
Acute hepatopancreatic necrosis disease (AHPND) caused by Vibrio parahaemolyticus resulted in great economic losses in global shrimp aquaculture. There is an urgent need for development of novel strategies to combat AHPND-causing V. parahaemolyticus (Vp AHPND), given that one of the greatest challenges currently is the widespread use of antibiotics and subsequent emergence of multidrug-resistant bacteria. Here, we proposed a broad-spectrum antivirulence approach targeting a conserved histidine kinase, QseC, which has been demonstrated to activate virulence expression in several Gram-negative pathogens. Our results showed that QseC mediated the catecholamine stimulated effects on growth and flagellar motility of Vp AHPND. Transcriptome analysis revealed that QseC was involved in the global regulation of the virulence of Vp AHPND as the ΔqseC mutant exhibited a decreased expression of genes related to type IV pilin, flagellar motility, and biofilm formation, while an overexpression of type VI secretion system and cell wall biosynthesis. Subsequently, the bacterial catecholamine receptor antagonist LED209 not only neutralized the stimulatory effects of host catecholamines on the growth and motility of Vp AHPND in vitro, but also attenuated the virulence of Vp AHPND towards brine shrimp larvae and white shrimp in vivo. Additionally, LED209 presented no interference with pathogen growth, nor the toxicity to the experimental animals. These results suggest that QseC can be an attractive antivirulence therapy target, and LED209 is a promising candidate for development of broad-spectrum antivirulence agents. This is the first study that demonstrated the role of QseC in the global regulation of Vp AHPND infection and demonstrated the antivirulence potential of LED209, which provides insight into the use of an antivirulence approach for targeting not only Vp AHPND, but also a much larger collection of pathogenic bacteria.
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Affiliation(s)
- Qian Yang
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Qingdao, China.,Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Peizhuo Zou
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Qingdao, China.,Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Zhi Cao
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Qingdao, China.,Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Qingyao Wang
- College of Marine Science and Environment, Dalian Ocean University, Dalian, China.,Key Laboratory of Environment Controlled Aquaculture (KLECA), Ministry of Education, Dalian, China
| | - Songzhe Fu
- College of Marine Science and Environment, Dalian Ocean University, Dalian, China.,Key Laboratory of Environment Controlled Aquaculture (KLECA), Ministry of Education, Dalian, China
| | - Guosi Xie
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Qingdao, China.,Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Jie Huang
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Qingdao, China.,Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Network of Aquaculture Centers in Asia-Pacific, Bangkok, Thailand
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8
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Progress Overview of Bacterial Two-Component Regulatory Systems as Potential Targets for Antimicrobial Chemotherapy. Antibiotics (Basel) 2020; 9:antibiotics9100635. [PMID: 32977461 PMCID: PMC7598275 DOI: 10.3390/antibiotics9100635] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 12/18/2022] Open
Abstract
Bacteria adapt to changes in their environment using a mechanism known as the two-component regulatory system (TCS) (also called “two-component signal transduction system” or “two-component system”). It comprises a pair of at least two proteins, namely the sensor kinase and the response regulator. The former senses external stimuli while the latter alters the expression profile of bacterial genes for survival and adaptation. Although the first TCS was discovered and characterized in a non-pathogenic laboratory strain of Escherichia coli, it has been recognized that all bacteria, including pathogens, use this mechanism. Some TCSs are essential for cell growth and fitness, while others are associated with the induction of virulence and drug resistance/tolerance. Therefore, the TCS is proposed as a potential target for antimicrobial chemotherapy. This concept is based on the inhibition of bacterial growth with the substances acting like conventional antibiotics in some cases. Alternatively, TCS targeting may reduce the burden of bacterial virulence and drug resistance/tolerance, without causing cell death. Therefore, this approach may aid in the development of antimicrobial therapeutic strategies for refractory infections caused by multi-drug resistant (MDR) pathogens. Herein, we review the progress of TCS inhibitors based on natural and synthetic compounds.
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9
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Rosales-Hurtado M, Meffre P, Szurmant H, Benfodda Z. Synthesis of histidine kinase inhibitors and their biological properties. Med Res Rev 2019; 40:1440-1495. [PMID: 31802520 DOI: 10.1002/med.21651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 11/20/2019] [Accepted: 11/23/2019] [Indexed: 11/11/2022]
Abstract
Infections caused by multidrug-resistant bacteria represent a significant and ever-increasing cause of morbidity and mortality. There is thus an urgent need to develop efficient and well-tolerated antibacterials targeting unique cellular processes. Numerous studies have led to the identification of new biological targets to fight bacterial resistance. Two-component signal transduction systems are widely employed by bacteria to translate external and cellular signals into a cellular response. They are ubiquitous in bacteria, absent in the animal kingdom and are integrated into various virulence pathways. Several chemical series, including isothiazolidones, imidazolium salts, benzoxazines, salicylanilides, thiophenes, thiazolidiones, benzimidazoles, and other derivatives deduced by different approaches have been reported in the literature to have histidine kinase (HK) inhibitory activity. In this review, we report on the design and the synthesis of these HKs inhibitors and their potential to serve as antibacterial agents.
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Affiliation(s)
| | | | - Hendrik Szurmant
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California
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10
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De Silva PM, Kumar A. Signal Transduction Proteins in Acinetobacter baumannii: Role in Antibiotic Resistance, Virulence, and Potential as Drug Targets. Front Microbiol 2019; 10:49. [PMID: 30761101 PMCID: PMC6363711 DOI: 10.3389/fmicb.2019.00049] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 01/14/2019] [Indexed: 12/16/2022] Open
Abstract
Acinetobacter baumannii is a notorious pathogen in health care settings around the world, primarily due to high resistance to antibiotics. A. baumannii also shows an impressive capability to adapt to harsh conditions in clinical settings, which contributes to its persistence in such conditions. Following their traditional role, the Two Component Systems (TCSs) present in A. baumannii play a crucial role in sensing and adapting to the changing environmental conditions. This provides A. baumannii with a greater chance of survival even in unfavorable conditions. Since all the TCSs characterized to date in A. baumannii play a role in its antibiotic resistance and virulence, understanding the underlying molecular mechanisms behind TCSs can help with a better understanding of the pathways that regulate these phenotypes. This can also guide efforts to target TCSs as novel drug targets. In this review, we discuss the roles of TCSs in A. baumannii, their molecular mechanisms, and most importantly, the potential of using small molecule inhibitors of TCSs as potential novel drug targets.
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Affiliation(s)
- P Malaka De Silva
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Ayush Kumar
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada.,Manitoba Chemosensory Biology Group, University of Manitoba, Winnipeg, MB, Canada
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11
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Xu Y, Zhang K, Reghu S, Lin Y, Chan-Park MB, Liu XW. Synthesis of Antibacterial Glycosylated Polycaprolactones Bearing Imidazoliums with Reduced Hemolytic Activity. Biomacromolecules 2019; 20:949-958. [DOI: 10.1021/acs.biomac.8b01577] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Yuan Xu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Republic of Singapore
| | - Kaixi Zhang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Republic of Singapore
| | - Sheethal Reghu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Republic of Singapore
| | - Yichao Lin
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Republic of Singapore
| | - Mary B. Chan-Park
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Republic of Singapore
- Centre for Antimicrobial
Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Republic of Singapore
| | - Xue-Wei Liu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Republic of Singapore
- Centre for Antimicrobial
Bioengineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Republic of Singapore
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12
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Cardona ST, Choy M, Hogan AM. Essential Two-Component Systems Regulating Cell Envelope Functions: Opportunities for Novel Antibiotic Therapies. J Membr Biol 2017; 251:75-89. [DOI: 10.1007/s00232-017-9995-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 01/22/2023]
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13
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Tiwari S, Jamal SB, Hassan SS, Carvalho PVSD, Almeida S, Barh D, Ghosh P, Silva A, Castro TLP, Azevedo V. Two-Component Signal Transduction Systems of Pathogenic Bacteria As Targets for Antimicrobial Therapy: An Overview. Front Microbiol 2017; 8:1878. [PMID: 29067003 PMCID: PMC5641358 DOI: 10.3389/fmicb.2017.01878] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022] Open
Abstract
The bacterial communities in a wide range of environmental niches sense and respond to numerous external stimuli for their survival. Primarily, a source they require to follow up this communication is the two-component signal transduction system (TCS), which typically comprises a sensor Histidine kinase for receiving external input signals and a response regulator that conveys a proper change in the bacterial cell physiology. For numerous reasons, TCSs have ascended as convincing targets for antibacterial drug design. Several studies have shown that TCSs are essential for the coordinated expression of virulence factors and, in some cases, for bacterial viability and growth. It has also been reported that the expression of antibiotic resistance determinants may be regulated by some TCSs. In addition, as a mode of signal transduction, phosphorylation of histidine in bacteria differs from normal serine/threonine and tyrosine phosphorylation in higher eukaryotes. Several studies have shown the molecular mechanisms by which TCSs regulate virulence and antibiotic resistance in pathogenic bacteria. In this review, we list some of the characteristics of the bacterial TCSs and their involvement in virulence and antibiotic resistance. Furthermore, this review lists and discusses inhibitors that have been reported to target TCSs in pathogenic bacteria.
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Affiliation(s)
- Sandeep Tiwari
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Syed B. Jamal
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Syed S. Hassan
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Biochemistry Group, Department of Chemistry, Islamia College University, Peshawar, Pakistan
| | - Paulo V. S. D. Carvalho
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sintia Almeida
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Debmalya Barh
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology, Purba Medinipur, India
| | - Preetam Ghosh
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA, United States
| | - Artur Silva
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Thiago L. P. Castro
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil
| | - Vasco Azevedo
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Abstract
Antibiotics are undoubtedly a pillar of modern medicine; their discovery in 1929 revolutionized the fight against infectious disease, instigating a worldwide decline in infection-associated mortality. Throughout the 1930s, 1940s, and 1950s the golden age of antibiotic discovery was underway with numerous new classes of antibiotics identified and brought to market. By 1962 all of our currently known families of antibiotics had been discovered, and it was a widely held belief, that humanity had conquered infectious disease. Despite varying bacterial cellular targets, most antibiotics targeted exponentially multiplying bacteria by interfering with integral processes such as peptidoglycan synthesis or ribosomal activity. The very nature of this targeted approach has driven the emergence of antibiotic-resistant bacteria.Methods of antibiotic identification relied solely on scientific observation, and while chemical analogues such as amoxicillin, derived from penicillin, continued to be developed, they retained the same mechanisms of action and hence the same bacterial targets. This article describes and discusses some of the emerging novel targets for antimicrobial treatments, highlighting pivotal research on which our ability to continue to successfully treat bacterial infection relies.
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Saini DK, Tyagi JS. High-Throughput Microplate Phosphorylation Assays Based on DevR-DevS/Rv2027c 2-Component Signal Transduction Pathway to Screen for Novel Antitubercular Compounds. ACTA ACUST UNITED AC 2016; 10:215-24. [PMID: 15809317 DOI: 10.1177/1087057104272090] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
DevR-DevS (Rv3133c-Rv3132c) and DevR-Rv2027c have been established through their autophosphorylation and phospho-transfer properties to constitute bonafide regulatory 2-component systems of Mycobacterium tuberculosis. DevR has also been shown by others to play a key regulatory role in the expression of M. tuberculosis genes comprising the dormancy regulon. The authors describe high-throughput phosphorylation assays in a microplate format using DevS and Rv2027c histidine kinases and DevR response regulator proteins from M. tuberculosis. The assays were designed to measure [γ-32P]ATP-dependent autophosphorylation of DevS/Rv2027c and also the phosphotransfer reaction to DevR. First, the optimal reaction conditions were established using the conventional method of radiolabeling the 2-component proteins by [γ-32P]ATP and followed by gel electrophoresis-based analysis. Next, the assays were converted to a high-throughput format in which the radiolabeled protein retained on a filter using mixed cellulose ester-based 96-well filter plates was analyzed for radioactivity retention by scintillation counting. The utility of these assays to screen for inhibitors is illustrated using 2-mercaptobenzimidazole, ethidium bromide, and EDTA. The high quality and flexibility of these assays will enable their use in high-throughput screening for new antitubercular compounds directed against 2-component systems that comprise a novel target in dormant mycobacteria.
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Affiliation(s)
- Deepak Kumar Saini
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi 110-029, India
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16
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Erickson MG, Ulijasz AT, Weisblum B. Bacterial 2-Component Signal Transduction Systems: A Fluorescence Polarization Screen for Response Regulator-Protein Binding. ACTA ACUST UNITED AC 2016; 10:270-4. [PMID: 15809323 DOI: 10.1177/1087057104273930] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two-component signal transduction systems are the primary means by which bacteria sense environmental change and integrate an adaptive response. In pathogenic bacteria, 2-component signal transduction (TCST) kinases are involved in the expression of virulence and antibiotic resistance. This makes bacterial TCST systems attractive targets for pharmacologic intervention. This paper describes a fluorescence polarization assay that quantifies the binding between bacterial DNA promoter segments and their cognate response regulator proteins. Using the Van RSTCST system from Enterococcus faecium, which encodes vancomycin resistance, the authors demonstrate inhibition of response regulator protein/promoter segment binding with a known inhibitor. Observed binding constants were comparable to those reported in surface plasmon resonance measurements and gel shift measurements.
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Affiliation(s)
- Matthew G Erickson
- Pharmacology Department, University of Wisconsin Medical School, Madison, WI, USA
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The Response Regulator BfmR Is a Potential Drug Target for Acinetobacter baumannii. mSphere 2016; 1:mSphere00082-16. [PMID: 27303741 PMCID: PMC4888885 DOI: 10.1128/msphere.00082-16] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 04/12/2016] [Indexed: 11/24/2022] Open
Abstract
Increasing antibiotic resistance in bacteria, particularly Gram-negative bacilli, has significantly affected the ability of physicians to treat infections, with resultant increased morbidity, mortality, and health care costs. In fact, some strains of bacteria are resistant to all available antibiotics, such as Acinetobacter baumannii, which is the focus of this report. Therefore, the development of new antibiotics active against these resistant strains is urgently needed. In this study, BfmR is further validated as an intriguing target for a novel class of antibiotics. Successful inactivation of BfmR would confer the multiple benefits of a decreased ability of A. baumannii to survive in human body fluids, increased sensitivity to complement-mediated bactericidal activity and, importantly, increased sensitivity to other antibiotics. Structural studies support the potential for this “druggable” target, as they identify the potential for small-molecule binding at functionally relevant sites. Next-phase high-throughput screening studies utilizing BfmR are warranted. Identification and validation is the first phase of target-based antimicrobial development. BfmR (RstA), a response regulator in a two-component signal transduction system (TCS) in Acinetobacter baumannii, is an intriguing potential antimicrobial target. A unique characteristic of BfmR is that its inhibition would have the dual benefit of significantly decreasing in vivo survival and increasing sensitivity to selected antimicrobials. Studies on the clinically relevant strain AB307-0294 have shown BfmR to be essential in vivo. Here, we demonstrate that this phenotype in strains AB307-0294 and AB908 is mediated, in part, by enabling growth in human ascites fluid and serum. Further, BfmR conferred resistance to complement-mediated bactericidal activity that was independent of capsular polysaccharide. Importantly, BfmR also increased resistance to the clinically important antimicrobials meropenem and colistin. BfmR was highly conserved among A. baumannii strains. The crystal structure of the receiver domain of BfmR was determined, lending insight into putative ligand binding sites. This enabled an in silico ligand binding analysis and a blind docking strategy to assess use as a potential druggable target. Predicted binding hot spots exist at the homodimer interface and the phosphorylation site. These data support pursuing the next step in the development process, which includes determining the degree of inhibition needed to impact growth/survival and the development a BfmR activity assay amenable to high-throughput screening for the identification of inhibitors. Such agents would represent a new class of antimicrobials active against A. baumannii which could be active against other Gram-negative bacilli that possess a TCS with shared homology. IMPORTANCE Increasing antibiotic resistance in bacteria, particularly Gram-negative bacilli, has significantly affected the ability of physicians to treat infections, with resultant increased morbidity, mortality, and health care costs. In fact, some strains of bacteria are resistant to all available antibiotics, such as Acinetobacter baumannii, which is the focus of this report. Therefore, the development of new antibiotics active against these resistant strains is urgently needed. In this study, BfmR is further validated as an intriguing target for a novel class of antibiotics. Successful inactivation of BfmR would confer the multiple benefits of a decreased ability of A. baumannii to survive in human body fluids, increased sensitivity to complement-mediated bactericidal activity and, importantly, increased sensitivity to other antibiotics. Structural studies support the potential for this “druggable” target, as they identify the potential for small-molecule binding at functionally relevant sites. Next-phase high-throughput screening studies utilizing BfmR are warranted.
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Bem AE, Velikova N, Pellicer MT, Baarlen PV, Marina A, Wells JM. Bacterial histidine kinases as novel antibacterial drug targets. ACS Chem Biol 2015; 10:213-24. [PMID: 25436989 DOI: 10.1021/cb5007135] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bacterial histidine kinases (HKs) are promising targets for novel antibacterials. Bacterial HKs are part of bacterial two-component systems (TCSs), the main signal transduction pathways in bacteria, regulating various processes including virulence, secretion systems and antibiotic resistance. In this review, we discuss the biological importance of TCSs and bacterial HKs for the discovery of novel antibacterials, as well as published TCS and HK inhibitors that can be used as a starting point for structure-based approaches to develop novel antibacterials.
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Affiliation(s)
- Agnieszka E. Bem
- Host−Microbe
Interactomics, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands
| | - Nadya Velikova
- Instituto
de Biomedicina
de Valencia-Consejo Superior de Investigaciones Cientificas (IBV-CSIC), Jaume Roig 11, 46010-Valencia, Spain
| | - M. Teresa Pellicer
- R&D Department Interquim, Ferrer HealthTech, Joan Buscalla 10, 08137-Sant Cugat del Valles Barcelona, Spain
| | - Peter van Baarlen
- Host−Microbe
Interactomics, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands
| | - Alberto Marina
- Instituto
de Biomedicina
de Valencia-Consejo Superior de Investigaciones Cientificas (IBV-CSIC), Jaume Roig 11, 46010-Valencia, Spain
- Centro de Investigacion
Biomedica en Red de Enfermedades Raras (CIBER-ISCIII), Jaume Roig 11, 46010-Valencia, Spain
| | - Jerry M. Wells
- Host−Microbe
Interactomics, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands
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Sudhakar P, Reck M, Wang W, He FQ, Wagner-Döbler I, Dobler IW, Zeng AP. Construction and verification of the transcriptional regulatory response network of Streptococcus mutans upon treatment with the biofilm inhibitor carolacton. BMC Genomics 2014; 15:362. [PMID: 24884510 PMCID: PMC4048456 DOI: 10.1186/1471-2164-15-362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 04/17/2014] [Indexed: 11/26/2022] Open
Abstract
Background Carolacton is a newly identified secondary metabolite causing altered cell morphology and death of Streptococcus mutans biofilm cells. To unravel key regulators mediating these effects, the transcriptional regulatory response network of S. mutans biofilms upon carolacton treatment was constructed and analyzed. A systems biological approach integrating time-resolved transcriptomic data, reverse engineering, transcription factor binding sites, and experimental validation was carried out. Results The co-expression response network constructed from transcriptomic data using the reverse engineering algorithm called the Trend Correlation method consisted of 8284 gene pairs. The regulatory response network inferred by superimposing transcription factor binding site information into the co-expression network comprised 329 putative transcriptional regulatory interactions and could be classified into 27 sub-networks each co-regulated by a transcription factor. These sub-networks were significantly enriched with genes sharing common functions. The regulatory response network displayed global hierarchy and network motifs as observed in model organisms. The sub-networks modulated by the pyrimidine biosynthesis regulator PyrR, the glutamine synthetase repressor GlnR, the cysteine metabolism regulator CysR, global regulators CcpA and CodY and the two component system response regulators VicR and MbrC among others could putatively be related to the physiological effect of carolacton. The predicted interactions from the regulatory network between MbrC, known to be involved in cell envelope stress response, and the murMN-SMU_718c genes encoding peptidoglycan biosynthetic enzymes were experimentally confirmed using Electro Mobility Shift Assays. Furthermore, gene deletion mutants of five predicted key regulators from the response networks were constructed and their sensitivities towards carolacton were investigated. Deletion of cysR, the node having the highest connectivity among the regulators chosen from the regulatory network, resulted in a mutant which was insensitive to carolacton thus demonstrating not only the essentiality of cysR for the response of S. mutans biofilms to carolacton but also the relevance of the predicted network. Conclusion The network approach used in this study revealed important regulators and interactions as part of the response mechanisms of S. mutans biofilm cells to carolacton. It also opens a door for further studies into novel drug targets against streptococci. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-362) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Irene W Dobler
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, 21073 Hamburg, Germany.
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Njoroge JW, Sperandio V. Interference with Bacterial Cell-to-Cell Chemical Signaling in Development of New Anti-Infectives. Antibiotics (Basel) 2013. [DOI: 10.1002/9783527659685.ch10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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21
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Small-molecule inhibition of bacterial two-component systems to combat antibiotic resistance and virulence. Future Med Chem 2013; 5:1265-84. [DOI: 10.4155/fmc.13.58] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Infections caused by multidrug-resistant bacteria are a considerable and increasing global problem. The development of new antibiotics is not keeping pace with the rapid evolution of resistance to almost all clinically available drugs, and novel strategies are required to fight bacterial infections. One such strategy is the control of pathogenic behaviors, as opposed to simply killing bacteria. Bacterial two-component system (TCS) signal transduction pathways control many pathogenic bacterial behaviors, such as virulence, biofilm formation and antibiotic resistance and are, therefore, an attractive target for the development of new drugs. This review presents an overview of TCS that are potential targets for such a strategy, describes small-molecules inhibitors of TCS identified to date and discusses assays for the identification of novel inhibitors. The future perspective for the identification and use of inhibitors of TCS to potentially provide new therapeutic options for the treatment of drug-resistant bacterial infections is discussed.
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Francis S, Wilke KE, Brown DE, Carlson EE. Mechanistic insight into inhibition of two-component system signaling. MEDCHEMCOMM 2012; 4:269-277. [PMID: 23336064 DOI: 10.1039/c2md20308a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Two-component signal transduction systems (TCSs) are commonly used by bacteria to couple environmental stimuli to adaptive responses. Targeting the highly conserved kinase domain in these systems represents a promising strategy for the design of a broad-spectrum antibiotic; however, development of such compounds has been marred by an incomplete understanding of the conserved binding features within the active site that could be exploited in molecule design. Consequently, a large percentage of the available TCS inhibitors demonstrate poor target specificity and act via multiple mechanisms, with aggregation of the kinase being the most notable. In order to elucidate the mode of action of some of these compounds, molecular modeling was employed to dock a suite of molecules into the ATP-binding domain of several histidine kinases. This effort revealed a key structural feature of the domain that is likely interacting with several known inhibitors and is also highly conserved. Furthermore, generation of several simplified scaffolds derived from a reported inhibitor and characterization of these compounds using activity assays, protein aggregation studies and saturation transfer differential (STD) NMR suggests that targeting of this protein feature may provide a basis for the design of ATP-competitive compounds.
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Affiliation(s)
- Samson Francis
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana, USA. Tel: 812-855-3665;
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Ng WL, Perez L, Cong J, Semmelhack MF, Bassler BL. Broad spectrum pro-quorum-sensing molecules as inhibitors of virulence in vibrios. PLoS Pathog 2012; 8:e1002767. [PMID: 22761573 PMCID: PMC3386246 DOI: 10.1371/journal.ppat.1002767] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 05/07/2012] [Indexed: 01/30/2023] Open
Abstract
Quorum sensing (QS) is a bacterial cell-cell communication process that relies on the production and detection of extracellular signal molecules called autoinducers. QS allows bacteria to perform collective activities. Vibrio cholerae, a pathogen that causes an acute disease, uses QS to repress virulence factor production and biofilm formation. Thus, molecules that activate QS in V. cholerae have the potential to control pathogenicity in this globally important bacterium. Using a whole-cell high-throughput screen, we identified eleven molecules that activate V. cholerae QS: eight molecules are receptor agonists and three molecules are antagonists of LuxO, the central NtrC-type response regulator that controls the global V. cholerae QS cascade. The LuxO inhibitors act by an uncompetitive mechanism by binding to the pre-formed LuxO-ATP complex to inhibit ATP hydrolysis. Genetic analyses suggest that the inhibitors bind in close proximity to the Walker B motif. The inhibitors display broad-spectrum capability in activation of QS in Vibrio species that employ LuxO. To the best of our knowledge, these are the first molecules identified that inhibit the ATPase activity of a NtrC-type response regulator. Our discovery supports the idea that exploiting pro-QS molecules is a promising strategy for the development of novel anti-infectives.
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Affiliation(s)
- Wai-Leung Ng
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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Ji Y, Yang F, Ma D, Zhang J, Wan Z, Liu W, Li R. HOG-MAPK signaling regulates the adaptive responses of Aspergillus fumigatus to thermal stress and other related stress. Mycopathologia 2012; 174:273-82. [PMID: 22678624 DOI: 10.1007/s11046-012-9557-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 05/03/2012] [Indexed: 01/20/2023]
Abstract
Aspergillus fumigatus is naturally exposed to a highly variable environment and subjected to various kinds of stresses. High-osmolarity glycerol mitogen-activated protein kinase (HOG-MAPK) pathway plays a crucial role in regulating cellular homeostasis in response to environmental changes. Here, we explored the contribution of HOG-MAPK pathway to the adaptive responses to thermal stress and other related stresses in A. fumigatus. We observed the phenotype features of wild-type strains and their derived mutants at 37 and 48 °C, and the results suggested that tcsB participates in response to high temperature. Furthermore, susceptibility test for antifungal drugs showed that SHO1 branch is probably involved in the susceptibility of A. fumigatus to itraconazole at high temperature. Although sakA expression at mRNA level appeared unchanged in wild-type AF293 subjected to thermal stress, phosphorylated SakAp level increased significantly in the strains exposed to cold stress, 250 mmol/L nystatin or 10 % dimethyl sulfoxide in a manner dependent on the SLN1 branch and independent on the SHO1 branch. Taken together, these results indicate that HOG-MAPK pathway, especially the SLN1 branch, plays an important role in the adaptations of A. fumigatus to thermal stress and other related stresses.
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Affiliation(s)
- Yajuan Ji
- Department of Dermatology and Venereology, Peking University First Hospital, No. 8, Xi-Shi-Ku St., Xicheng District, Beijing 100034, People's Republic of China
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Kassem II, Zhang Q, Rajashekara G. The twin-arginine translocation system: contributions to the pathobiology of Campylobacter jejuni. Future Microbiol 2012; 6:1315-27. [PMID: 22082291 DOI: 10.2217/fmb.11.107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The twin-arginine translocation (Tat) system is specialized in the transport of folded proteins across the cytoplasmic membrane. Although the mechanisms that govern the Tat transport and its scope are not well understood, this system and its cognate substrates are involved in important functions that facilitate the adaptation and survival of bacteria. Evidence also exists that connects the Tat system to virulent traits of clinically relevant pathogens. Of interest is Campylobacter jejuni, an important foodborne pathogen that is capable of surviving in different hosts and environmental niches. Recent studies have shown that the Tat system in this bacterium mediates key metabolic and stress resistance traits. Furthermore, the majority of the identified Tat substrates in C. jejuni are cofactor-containing redox proteins that contribute to the bacterium?s branched electron transport chain, a component essential for survival under differing conditions. These studies as well as the absence of Tat homologs in the sequenced genomes of animals suggest that the Tat system might pose an attractive target for therapeutics against C. jejuni.
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Affiliation(s)
- Issmat I Kassem
- Food Animal Health Research Program, Ohio Agricultural Research & Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH 44691, USA
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Cai X, Zhang J, Chen M, Wu Y, Wang X, Chen J, Zhang J, Shen X, Qu D, Jiang H. The effect of the potential PhoQ histidine kinase inhibitors on Shigella flexneri virulence. PLoS One 2011; 6:e23100. [PMID: 21853073 PMCID: PMC3154276 DOI: 10.1371/journal.pone.0023100] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 07/11/2011] [Indexed: 02/03/2023] Open
Abstract
PhoQ/PhoP is an important two-component system that regulates Shigella virulence. We explored whether the PhoQ/PhoP system is a promising target for new antibiotics against S. flexneri infection. By using a high-throughput screen and enzymatic activity coupled assay, four compounds were found as potential PhoQ inhibitors. These compounds not only inhibited the activity of SF-PhoQc autophosphorylation but also displayed high binding affinities to the SF-PhoQc protein in the Surface Plasmon Resonance response. A S. flexneri cell invasion assay showed that three of these potential PhoQ inhibitors inhibit the invasion of HeLa cells by S. flexneri 9380. In a Mouse Sereny test, mice inoculated with S. flexneri 9380 pre-treated with the potential PhoQ inhibitors 1, 2, 3 or 4 displayed no inflammation, whereas mice inoculated with S. flexneri 9380 alone displayed severe keratoconjunctival inflammation. All four potential PhoQ inhibitors showed no significant cytotoxicity or hemolytic activity. These data suggest that the four potential PhoQ inhibitors inhibited the virulence of S. flexneri and that PhoQ/PhoP is a promising target for the development of drugs against S. flexneri infection.
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Affiliation(s)
- Xia Cai
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jian Zhang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Mingliang Chen
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China
| | - Yang Wu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xueqing Wang
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jiayu Chen
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Junqin Zhang
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xu Shen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Di Qu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- * E-mail: (DQ); (HJ)
| | - Hualiang Jiang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (DQ); (HJ)
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Iwai N, Nakayama K, Kitazume T. Antibacterial activities of imidazolium, pyrrolidinium and piperidinium salts. Bioorg Med Chem Lett 2011; 21:1728-30. [DOI: 10.1016/j.bmcl.2011.01.081] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/17/2011] [Accepted: 01/19/2011] [Indexed: 10/18/2022]
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Ghosh A, Ramamurthy T. Antimicrobials & cholera: are we stranded? Indian J Med Res 2011; 133:225-31. [PMID: 21415499 PMCID: PMC3089056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Antimicrobial resistance poses a major threat in the treatment of infectious diseases. Though significant progress in the management of diarrhoeal diseases has been achieved by improved hygiene, development of new antimicrobials and vaccines, the burden remains the same, especially in children below 5 yr of age. In the case of cholera, though oral rehydration treatment is the mainstay, antimicrobial therapy is mandatory at times to reduce the volume of stool and shorten the duration of the disease. Though for many pathogens, antimicrobial resistance emerged soon after the introduction of antibiotics, Vibrio cholerae remained sensitive to most of the antibiotics for quite a long period. However, the scenario changed over the years and today, V. cholerae strains isolated world over are resistant to multiple antibiotics. A myriad number of mechanisms underlie this phenomenon. These include production of extended-spectrum beta-lactamases, enhanced multi-drug efflux pump activity, plasmid-mediated quinolone and fluoroquinolone resistance, and chromosomal mutations. Horizontal transfer of resistance determinants with mobile genetic elements like integrons and the integrating conjugative elements (ICEs), SXTs help in the dissemination of drug resistance. Though all strains isolated are not resistant to all antibiotics and we are not as yet "stranded", expanding spectrum of drug resistance is a definite cause for concern. Pipelines of discovery of new antibiotics are drying up as major pharmaceutical companies are losing interest in investing money in this endeavour, mainly due to the short shelf-life of the antibiotics and also due to the fast emergence of drug resistance. To address this issue, attempts are now being made to discover drugs which are pathogen specific and target their "virulence mechanisms". It is expected that development of resistance against such antibiotics would take much longer. This review briefly focuses on all these issues.
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Affiliation(s)
- Amit Ghosh
- National Institute of Cholera & Enteric Diseases (ICMR), Kolkata, India,Reprint requests: Dr. Amit Ghosh, National Institute of Cholera & Enteric Diseases, P-33 CIT Road, Scheme XM, Beliaghata, Kolkata 700 010, India e-mail:
| | - T. Ramamurthy
- National Institute of Cholera & Enteric Diseases (ICMR), Kolkata, India
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Site-specific mutation of Staphylococcus aureus VraS reveals a crucial role for the VraR-VraS sensor in the emergence of glycopeptide resistance. Antimicrob Agents Chemother 2010; 55:1008-20. [PMID: 21173175 DOI: 10.1128/aac.00720-10] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An initial response of Staphylococcus aureus to encounter with cell wall-active antibiotics occurs by transmembrane signaling systems that orchestrate changes in gene expression to promote survival. Histidine kinase two-component sensor-response regulators such as VraRS contribute to this response. In this study, we examined VraS membrane sensor phosphotransfer signal transduction and explored the genetic consequences of disrupting signaling by engineering a site-specific vraS chromosomal mutation. We have used in vitro autophosphorylation assay with purified VraS[64-347] lacking its transmembrane anchor region and tested site-specific kinase domain histidine mutants. We identified VraS H156 as the probable site of autophosphorylation and show phosphotransfer in vitro using purified VraR. Genetic studies show that the vraS(H156A) mutation in three strain backgrounds (ISP794, Newman, and COL) fails to generate detectable first-step reduced susceptibility teicoplanin mutants and severely reduces first-step vancomycin mutants. The emergence of low-level glycopeptide resistance in strain ISP794, derived from strain 8325 (ΔrsbU), did not require a functional σ(B), but rsbU restoration could enhance the emergence frequency supporting a role for this alternative sigma factor in promoting glycopeptide resistance. Transcriptional analysis of vraS(H156A) strains revealed a pronounced reduction but not complete abrogation of the vraRS operon after exposure to cell wall-active antibiotics, suggesting that additional factors independent of VraS-driven phosphotransfer, or σ(B), exist for this promoter. Collectively, our results reveal important details of the VraRS signaling system and predict that pharmacologic blockade of the VraS sensor kinase will have profound effects on blocking emergence of cell wall-active antibiotic resistance in S. aureus.
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Ni N, Li M, Wang J, Wang B. Inhibitors and antagonists of bacterial quorum sensing. Med Res Rev 2009; 29:65-124. [DOI: 10.1002/med.20145] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Inhibitors targeting two-component signal transduction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 631:229-36. [PMID: 18792693 DOI: 10.1007/978-0-387-78885-2_16] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A two-component signal transduction system (TCS) is an attractive target for antibacterial agents. In this chapter, we review the TCS inhibitors developed during the past decade and introduce novel drug discovery systems to isolate the inhibitors of the YycG/YycF system, an essential TCS for bacterial growth, in an effort to develop a new class of antibacterial agents.
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Rasko DA, Moreira CG, Li DR, Reading NC, Ritchie JM, Waldor MK, Williams N, Taussig R, Wei S, Roth M, Hughes DT, Huntley JF, Fina MW, Falck JR, Sperandio V. Targeting QseC signaling and virulence for antibiotic development. Science 2008; 321:1078-80. [PMID: 18719281 PMCID: PMC2605406 DOI: 10.1126/science.1160354] [Citation(s) in RCA: 383] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Many bacterial pathogens rely on a conserved membrane histidine sensor kinase, QseC, to respond to host adrenergic signaling molecules and bacterial signals in order to promote the expression of virulence factors. Using a high-throughput screen, we identified a small molecule, LED209, that inhibits the binding of signals to QseC, preventing its autophosphorylation and consequently inhibiting QseC-mediated activation of virulence gene expression. LED209 is not toxic and does not inhibit pathogen growth; however, this compound markedly inhibits the virulence of several pathogens in vitro and in vivo in animals. Inhibition of signaling offers a strategy for the development of broad-spectrum antimicrobial drugs.
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Affiliation(s)
- David A. Rasko
- Department of Microbiology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Cristiano G. Moreira
- Department of Microbiology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - De Run Li
- Department of Biochemistry, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nicola C. Reading
- Department of Microbiology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer M. Ritchie
- Channing Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Matthew K. Waldor
- Channing Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Noelle Williams
- Department of Biochemistry, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ron Taussig
- Department of Pharmacology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shuguang Wei
- Department of Biochemistry, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Roth
- Department of Biochemistry, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - David T. Hughes
- Department of Microbiology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jason F. Huntley
- Department of Microbiology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Maggy W. Fina
- Department of Pharmacology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - John R. Falck
- Department of Biochemistry, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pharmacology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vanessa Sperandio
- Department of Microbiology, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Biochemistry, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA
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Hughes DT, Sperandio V. Inter-kingdom signalling: communication between bacteria and their hosts. Nat Rev Microbiol 2008; 6:111-20. [PMID: 18197168 PMCID: PMC2667375 DOI: 10.1038/nrmicro1836] [Citation(s) in RCA: 472] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Microorganisms and their hosts communicate with each other through an array of hormonal signals. This cross-kingdom cell-to-cell signalling involves small molecules, such as hormones that are produced by eukaryotes and hormone-like chemicals that are produced by bacteria. Cell-to-cell signalling between bacteria, usually referred to as quorum sensing, was initially described as a means by which bacteria achieve signalling in microbial communities to coordinate gene expression within a population. Recent evidence shows, however, that quorum-sensing signalling is not restricted to bacterial cell-to-cell communication, but also allows communication between microorganisms and their hosts.
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Affiliation(s)
- David T Hughes
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA
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35
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Erickson MG, Ulijasz AT, Weisblum B. Screening for compounds that affect the interaction between bacterial two-component signal transduction response regulator protein and cognate promoter DNA. METHODS IN MOLECULAR MEDICINE 2008; 142:215-222. [PMID: 18437317 DOI: 10.1007/978-1-59745-246-5_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Bacterial signal transduction systems can be used as drug targets. The signal transduction targets fall into two groups--sensor kinases and response regulators. Previously reported studies describe hits that were thought to inactivate sensor kinases but on closer examination were found to act elsewhere instead; a possible reason for this is that full-length sensor kinases are integral membrane proteins whose activity might reflect interaction with the cell membrane or with membrane components. We describe a model system that instead is based on the interaction between a test compound and a response regulator in a homogeneous phase reaction. In this system, response regulator-DNA complex formation and its inhibition by a test compound are measured by fluorescence polarization. The model system should be readily adaptable to drug discovery based on other bacterial two-component s transduction systems.
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Affiliation(s)
- Matthew G Erickson
- Department of Pharmacology, University of Wisconsin Medical School, Madison, WI, USA
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36
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Benghezal M, Adam E, Lucas A, Burn C, Orchard MG, Deuschel C, Valentino E, Braillard S, Paccaud JP, Cosson P. Inhibitors of bacterial virulence identified in a surrogate host model. Cell Microbiol 2007; 9:1336-42. [PMID: 17474906 DOI: 10.1111/j.1462-5822.2006.00877.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Antibiotic resistance continues to reduce the number of available antibiotics, increasing the need for novel antibacterial drugs. Since the seminal work of Sir Alexander Fleming, antibiotic identification has been based exclusively on the inhibition of bacterial growth in vitro. Recently, inhibitors of bacterial virulence which interfere with bacterial pathogenesis mechanisms have been proposed as an alternative to antibiotics, and a few were discovered using assays targeting specific virulence mechanisms. Here we designed a simple surrogate host model for the measurement of virulence and systematic discovery of anti-virulence molecules, based on the interaction of Tetrahymena pyriformis and Klebsiella pneumoniae cells. We screened a library of small molecules and identified several inhibitors of virulence. In a mouse pneumonia model we confirmed that an anti-virulence molecule displayed antibacterial activity against Klebsiella pneumoniae and Pseudomonas aeruginosa, by reducing dramatically the bacterial load in the lungs. This molecule did not inhibit bacterial growth in vitro but prevented biosynthesis of the Klebsiella capsule and lipopolysaccharides, a key requirement for virulence. Our results demonstrate that anti-virulence molecules represent an alternative to antibiotics and those can be discovered using non-animal host models.
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Shakhnovich EA, Hung DT, Pierson E, Lee K, Mekalanos JJ. Virstatin inhibits dimerization of the transcriptional activator ToxT. Proc Natl Acad Sci U S A 2007; 104:2372-7. [PMID: 17283330 PMCID: PMC1892951 DOI: 10.1073/pnas.0611643104] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The development of antimicrobials is critical in this time of increasing antibiotic resistance of most clinically relevant bacteria. To date, all current antibiotics focus on inhibiting crucial enzymatic activities of their protein targets (i.e., trimethoprim for dihydrofolate reductase), thus disrupting in vitro essential gene functions. In contrast, we have previously reported the identification of virstatin, a small molecule that inhibits virulence regulation in Vibrio cholerae, thereby preventing intestinal colonization in an infant mouse model for cholera. Virstatin prevents expression of the two major V. cholerae virulence factors, cholera toxin (CT) and the toxin coregulated pilus, by inhibiting the virulence transcriptional activator ToxT. It has previously been described that the N-terminal domain of ToxT has the ability to form homodimers. We now demonstrate that virstatin inhibits ToxT dimerization, thus demonstrating that it further falls into a unique class of inhibitors that works by disrupting protein-protein interactions, particularly homodimerization. Using virstatin, truncation mutants of ToxT, and a virstatin-resistant mutant, we show that dimerization is required for ToxT activation of the ctx promoter. In contrast, ToxT dimerization does not appear to be required at all of the other ToxT-regulated promoters, suggesting multiple mechanisms may exist for its transcriptional activity.
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Affiliation(s)
- Elizabeth A. Shakhnovich
- *Department of Microbiology and Molecular Genetics, Harvard Medical School, Armenise Building, Room 425, 200 Longwood Avenue, Boston, MA 02115
| | - Deborah T. Hung
- *Department of Microbiology and Molecular Genetics, Harvard Medical School, Armenise Building, Room 425, 200 Longwood Avenue, Boston, MA 02115
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Simches Research Building 7208, 185 Cambridge Street, Boston, MA 02114
- Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142; and
| | - Emily Pierson
- *Department of Microbiology and Molecular Genetics, Harvard Medical School, Armenise Building, Room 425, 200 Longwood Avenue, Boston, MA 02115
- Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Simches Research Building 7208, 185 Cambridge Street, Boston, MA 02114
- Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142; and
| | - Kyungae Lee
- New England Regional Center of Excellence, 200 Longwood Avenue, Boston, MA 02114
| | - John J. Mekalanos
- *Department of Microbiology and Molecular Genetics, Harvard Medical School, Armenise Building, Room 425, 200 Longwood Avenue, Boston, MA 02115
- To whom correspondence should be addressed. E-mail:
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38
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Fleischer R, Heermann R, Jung K, Hunke S. Purification, reconstitution, and characterization of the CpxRAP envelope stress system of Escherichia coli. J Biol Chem 2007; 282:8583-93. [PMID: 17259177 DOI: 10.1074/jbc.m605785200] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Escherichia coli the Cpx sensor regulator system senses different kinds of envelope stress and responds by triggering the expression of periplasmic folding factors and proteases. It consists of the membrane-anchored sensor kinase CpxA, the response regulator CpxR, and the periplasmic protein CpxP. The Cpx pathway is induced in vivo by a variety of signals including pH variation, osmotic stress, and misfolded envelope proteins and is inhibited by overproduced CpxP. Because it is not clear how the Cpx pathway is able to recognize and correspond to so many different signals we overproduced, solubilized, purified, and incorporated the complete membrane-integral CpxA protein into proteoliposomes to analyze its biochemical properties in more detail. Autokinase and phosphotransfer activities of the reconstituted CpxA-His6 protein were stimulated by KCl. NaCl also stimulated the activities but to a lesser extent. Other osmotic active solutes as glycine betaine, sucrose, and proline had no effect. The system was further characterized by testing for susceptibility to sensor kinase inhibitors. Among these, Closantel inhibited the activities of solubilized but not of the reconstituted CpxA-His6 protein. We further analyzed the effect of CpxP on CpxA activities. Purified tagless CpxP protein reduced the phosphorylation status of CpxA to 50% but had no effect on CpxA phosphotransfer or phosphatase activities. As the in vitro system excludes the involvement of other factors our finding is the first biochemical evidence for direct protein-protein interaction between the sensor kinase CpxA and the periplasmic protein CpxP resulting in a down-regulation of the autokinase activity of CpxA.
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Affiliation(s)
- Rebecca Fleischer
- Institut für Biologie, Abteilung Physiologie der Mikroorganismen, Humboldt Universität zu Berlin, D-10115 Berlin, Germany
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39
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Clarke MB, Hughes DT, Zhu C, Boedeker EC, Sperandio V. The QseC sensor kinase: a bacterial adrenergic receptor. Proc Natl Acad Sci U S A 2006; 103:10420-10425. [PMID: 16803956 PMCID: PMC1482837 DOI: 10.1073/pnas.0604343103] [Citation(s) in RCA: 420] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quorum sensing is a cell-to-cell signaling mechanism in which bacteria respond to hormone-like molecules called autoinducers (AIs). The AI-3 quorum-sensing system is also involved in interkingdom signaling with the eukaryotic hormones epinephrine/norepinephrine. This signaling activates transcription of virulence genes in enterohemorrhagic Escherichia coli O157:H7. However, this signaling system has never been shown to be involved in virulence in vivo, and the bacterial receptor for these signals had not been identified. Here, we show that the QseC sensor kinase is a bacterial receptor for the host epinephrine/norepinephrine and the AI-3 produced by the gastrointestinal microbial flora. We also found that an alpha-adrenergic antagonist can specifically block the QseC response to these signals. Furthermore, we demonstrated that a qseC mutant is attenuated for virulence in a rabbit animal model, underscoring the importance of this signaling system in virulence in vivo. Finally, an in silico search found that the periplasmic sensing domain of QseC is conserved among several bacterial species. Thus, QseC is a bacterial adrenergic receptor that activates virulence genes in response to interkingdom cross-signaling. We anticipate that these studies will be a starting point in understanding bacterial-host hormone signaling at the biochemical level. Given the role that this system plays in bacterial virulence, further characterization of this unique signaling mechanism may be important for developing novel classes of antimicrobials.
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Affiliation(s)
- Marcie B Clarke
- *Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9048; and
| | - David T Hughes
- *Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9048; and
| | - Chengru Zhu
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Edgar C Boedeker
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Vanessa Sperandio
- *Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9048; and
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40
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Gilmour R, Foster JE, Sheng Q, McClain JR, Riley A, Sun PM, Ng WL, Yan D, Nicas TI, Henry K, Winkler ME. New class of competitive inhibitor of bacterial histidine kinases. J Bacteriol 2005; 187:8196-200. [PMID: 16291694 PMCID: PMC1291283 DOI: 10.1128/jb.187.23.8196-8200.2005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial histidine kinases have been proposed as targets for the discovery of new antibiotics, yet few specific inhibitors of bacterial histidine kinases have been reported. We report here a novel thienopyridine (TEP) compound that inhibits bacterial histidine kinases competitively with respect to ATP but does not comparably inhibit mammalian serine/threonine kinases. Although it partitions into membranes and does not inhibit the growth of bacterial or mammalian cells, TEP could serve as a starting compound for a new class of histidine kinase inhibitors with antibacterial activity.
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41
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Hung DT, Shakhnovich EA, Pierson E, Mekalanos JJ. Small-molecule inhibitor of Vibrio cholerae virulence and intestinal colonization. Science 2005; 310:670-4. [PMID: 16223984 DOI: 10.1126/science.1116739] [Citation(s) in RCA: 263] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Increasing antibiotic resistance requires the development of new approaches to combating infection. Virulence gene expression in vivo represents a target for antibiotic discovery that has not yet been explored. A high-throughput, phenotypic screen was used to identify a small molecule 4-[N-(1,8-naphthalimide)]-n-butyric acid, virstatin, that inhibits virulence regulation in Vibrio cholerae. By inhibiting the transcriptional regulator ToxT, virstatin prevents expression of two critical V. cholerae virulence factors, cholera toxin and the toxin coregulated pilus. Orogastric administration of virstatin protects infant mice from intestinal colonization by V. cholerae.
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Affiliation(s)
- Deborah T Hung
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
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42
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Abstract
The emergence of widespread antibiotic resistance as an impediment in the treatment of bacterial diseases is of growing concern. In some instances, clinicians are left with few or no antibiotics for treatment of infections and this problem will more than likely grow in magnitude. One approach to get around the problem of antibiotic resistance is to develop new drugs with novel targets and mechanisms of action. Due to the 'newness' of these novel targets as therapeutic targets, the likelihood that resistance will initially be widespread is low. Three approaches are discussed in this overview: discovery of new essential genes that are expressed exclusively in vivo development of compounds that act on global bacterial gene regulators; and interference with virulence determinants. By exploiting virulence related attributes or genes expressed exclusively in vivo, the risk of resistance is reduced since inhibiting these products will probably alter the ecology (habitats) of these organisms rather than causing direct cell death. This might also lead to a selective targeting of pathogens with the beneficial consequence of ignoring organisms growing in their normal habitat, such as in the gastrointestinal tract or skin.
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Affiliation(s)
- R E Isaacson
- Department of Veterinary Pathobiology, Center for Zoonosis Research and Infectious Diseases, University of Illinois, Urbana, Illinois 61802, USA
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43
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Abstract
The progress made in a multidisciplinary research programme designed to elucidate the molecular basis of the interaction of Staphylococcus aureus secreted autoinducing peptides (AIPs) with their respective cell surface receptors is reviewed.
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Affiliation(s)
- Tom W Muir
- Laboratory of Synthetic Protein Chemistry, The Rockefeller University, NY 10021, USA.
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44
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Blue CE, Mitchell TJ. Contribution of a response regulator to the virulence of Streptococcus pneumoniae is strain dependent. Infect Immun 2003; 71:4405-13. [PMID: 12874319 PMCID: PMC166049 DOI: 10.1128/iai.71.8.4405-4413.2003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bacterial two-component signal transduction systems (TCS) enable bacteria to respond to environmental changes and regulate a range of genes accordingly. They have a crucial role in regulating many cellular responses and have excellent potential as antibacterial-drug targets. We have constructed mutations in a TCS response regulator gene for two different strains of the human pathogen Streptococcus pneumoniae. These mutants have been analyzed in our murine model of infection. Data suggest that in a D39 background the response regulator gene is essential for virulence; an isogenic mutant is avirulent via intraperitoneal, intranasal, and intravenous routes of infection. This mutant, which does not show impaired growth in vitro, is unable to grow in the lung tissue or in blood. Mutation of the response regulator in a 0100993 background results in a strain that is fully virulent intraperitoneally and intravenously but shows decreased levels of bacteremia and increased murine survival following intranasal infection. The ability to grow in the lung tissue is not impaired in this mutant, suggesting that it has an impaired ability to disseminate from the lungs to the systemic circulation. Our data highlight the importance of assessing the contribution of putative virulence factors to the infection process at different sites of infection and provide evidence that virulence determinants can behave very differently based on the genetic background of the bacterial strain. These important findings may be relevant to other bacterial pathogens.
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Affiliation(s)
- Clare E Blue
- Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
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45
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Abstract
The emergence and spread of hospital acquired multi drug resistant bacteria present a need for new antibiotics with innovative mode of action. Advances in molecular microbiology and genomics have led to the identification of numerous bacterial genes coding for proteins that could potentially serve as targets for antibacterial compounds. Histidine kinase promoted two-component systems are extremely common in bacteria and play an important role in essential signal transduction for adapting to bacterial stress. Since signal transduction in mammals occurs by a different mechanism, inhibition of histidine kinases could be a potential target for antimicrobial agents. This review will summarize our current knowledge of the structure and function of histidine kinase and the development of antibiotics with a new mode of action: targeting histidine kinase promoted signal transduction and its subsequent regulation of gene expression system.
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Affiliation(s)
- Masayuki Matsushita
- The Scripps Research Institute, Department of Chemistry BCC-582, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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46
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47
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Santos JL, Shiozaki K. Fungal histidine kinases. SCIENCE'S STKE : SIGNAL TRANSDUCTION KNOWLEDGE ENVIRONMENT 2001; 2001:re1. [PMID: 11752677 DOI: 10.1126/stke.2001.98.re1] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Eukaryotic cells predominantly use serine, threonine, and tyrosine phosphorylation in various intracellular signal transduction pathways. In contrast, prokaryotic organisms employ numerous "two-component" systems, in which signaling is achieved by transferring a phosphoryl group from phosphohistidine in the "sensor kinase" component to aspartate in the "response regulator" component. In the last several years, genetic screens and genome projects have identified sensor kinases and response regulators in lower eukaryotes and plants, revealing that eukaryotic organisms also make use of His-Asp phosphotransfer in a limited number of signaling pathways. Extensive studies in yeasts have demonstrated that a variation of the two-component system, a multistep "phosphorelay," is the prevailing mechanism among distantly related yeast species. In the budding yeast Saccharomyces cerevisiae, a His-Asp-His-Asp phosphorelay transmits osmotic stress signals to a mitogen-activated protein kinase (MAPK) cascade to induce adaptive responses. A phosphorelay in the fission yeast Schizosaccharomyces pombe, analogous to the S. cerevisiae phosphorelay, is responsible for MAPK activation in response to peroxide stress. Mammalian cells do not have any two-component or phosphorelay systems, although protein histidine kinases unrelated to the sensor kinase may be involved in cellular signaling. Because some phosphorelay proteins are essential for virulence of microbial pathogens, including the yeast fungus Candida albicans, novel antibiotics targeted to phosphorelays may be effective against eukaryotic pathogens without causing host cell damage.
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Affiliation(s)
- J L Santos
- Biochemistry and Molecular Biology Graduate Program, University of California, Davis, CA 95616, USA.
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48
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Abstract
Most prokaryotic signal-transduction systems and a few eukaryotic pathways use phosphotransfer schemes involving two conserved components, a histidine protein kinase and a response regulator protein. The histidine protein kinase, which is regulated by environmental stimuli, autophosphorylates at a histidine residue, creating a high-energy phosphoryl group that is subsequently transferred to an aspartate residue in the response regulator protein. Phosphorylation induces a conformational change in the regulatory domain that results in activation of an associated domain that effects the response. The basic scheme is highly adaptable, and numerous variations have provided optimization within specific signaling systems. The domains of two-component proteins are modular and can be integrated into proteins and pathways in a variety of ways, but the core structures and activities are maintained. Thus detailed analyses of a relatively small number of representative proteins provide a foundation for understanding this large family of signaling proteins.
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Affiliation(s)
- A M Stock
- Center for Advanced Biotechnology and Medicine and Howard Hughes Medical Institute, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
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49
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Abstract
So far, two strategies have been applied to develop new anti-infective agents: (a) the synthesis of analogs of classical antibiotics with enhanced activity against resistant pathogens and (b) the screening of naturally occurring substances and libraries of synthetic compounds for antimicrobial activity in whole-cell assays. Today, the same principles are being used; however, the search for antimicrobial compounds with novel modes of action is based on targeting specific resistance and virulence factors. Novel targets for anti-infective agents are currently being discovered as a consequence of a better understanding of cell biology, the molecular basis of bacterial resistance, the gene-pathogenicity relationship and the mechanism of the infection process.
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Affiliation(s)
- E L Setti
- Axys Pharmaceuticals, Inc., South San Francisco, California 94080, USA
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50
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Stephenson K, Yamaguchi Y, Hoch JA. The mechanism of action of inhibitors of bacterial two-component signal transduction systems. J Biol Chem 2000; 275:38900-4. [PMID: 10978341 DOI: 10.1074/jbc.m006633200] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Two-component signal transduction systems allow bacteria to sense and respond rapidly to changes in their environment leading to specific gene activation or repression. These two-component systems are integral in the ability of pathogenic bacteria to mount and establish a successful infection within the host and, consequently, have been recognized as targets for new anti-microbial agents. In this paper, we define the site and mechanism of action of several previously identified inhibitors of bacterial two-component systems. We show that the most potent inhibitors target the carboxyl-terminal catalytic domain of the sensor kinase and exert their affect by causing structural alterations of the kinase leading to aggregation. Recognition of this phenomenon has important implications for the development of novel inhibitors of two-component systems and should facilitate the rapid identification and elimination of compounds with nonspecific affects from medicinal chemistry drug discovery programs.
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Affiliation(s)
- K Stephenson
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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