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West KHJ, Ma SV, Pensinger DA, Tucholski T, Tiambeng TN, Eisenbraun EL, Yehuda A, Hayouka Z, Ge Y, Sauer JD, Blackwell HE. Characterization of an Autoinducing Peptide Signal Reveals Highly Efficacious Synthetic Inhibitors and Activators of Quorum Sensing and Biofilm Formation in Listeria monocytogenes. Biochemistry 2023; 62:2878-2892. [PMID: 37699554 PMCID: PMC10676741 DOI: 10.1021/acs.biochem.3c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Bacteria can use chemical signals to assess their local population density in a process called quorum sensing (QS). Many of these bacteria are common pathogens, including Gram-positive bacteria that utilize agr QS systems regulated by macrocyclic autoinducing peptide (AIP) signals. Listeria monocytogenes, an important foodborne pathogen, uses an agr system to regulate a variety of virulence factors and biofilm formation, yet little is known about the specific roles of agr in Listeria infection and its persistence in various environments. Herein, we report synthetic peptide tools that will enable the study of QS in Listeria. We identified a 6-mer AIP signal in L. monocytogenes supernatants and selected it as a scaffold around which a collection of non-native AIP mimics was designed and synthesized. These peptides were evaluated in cell-based agr reporter assays to generate structure-activity relationships for AIP-based agonism and antagonism in L. monocytogenes. We discovered synthetic agonists with increased potency relative to native AIP and a synthetic antagonist capable of reducing agr activity to basal levels. Notably, the latter peptide was able to reduce biofilm formation by over 90%, a first for a synthetic QS modulator in wild-type L. monocytogenes. The lead agr agonist and antagonist in L. monocytogenes were also capable of antagonizing agr signaling in the related pathogen Staphylococcus aureus, further extending their utility and suggesting different mechanisms of agr activation in these two pathogens. This study represents an important first step in the application of chemical methods to modulate QS and concomitant virulence outcomes in L. monocytogenes.
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Affiliation(s)
- Korbin H J West
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Stella V Ma
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Daniel A Pensinger
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Dr., Madison, Wisconsin 53706, United States
| | - Trisha Tucholski
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Timothy N Tiambeng
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Emma L Eisenbraun
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Avishag Yehuda
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Zvi Hayouka
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Wisconsin Institute for Medical Research, 1111 Highland Ave., Madison, Wisconsin 53705, United States
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Dr., Madison, Wisconsin 53706, United States
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
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Polaske TJ, West KHJ, Zhao K, Widner DL, York JT, Blackwell HE. Chemical and biomolecular insights into the Staphylococcus aureus agr quorum sensing system: Current progress and ongoing challenges. Isr J Chem 2023; 63:e202200096. [PMID: 38765792 PMCID: PMC11101167 DOI: 10.1002/ijch.202200096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Indexed: 03/19/2023]
Abstract
Staphylococcus aureus is a ubiquitous bacterium that has become a major threat to human health due to its extensive toxin production and tremendous capacity for antibiotic resistance (e.g., MRSA "superbug" infections). Amid a worsening antibiotic resistance crisis, new strategies to combat this deadly microbe that remove the selective pressure of traditional approaches are in high demand. S. aureus utilizes an accessory gene regulator (agr) quorum sensing network to monitor its local cellular population and trigger a devastating communal attack, like an invading horde, once a threshold cell density has been reached. The role of the agr system in a range of disease types is still being unraveled. Herein, we discuss the present-day biochemical understanding of agr along with unresolved details, describe its connection to the progression of infection, and review how chemical strategies have been implemented to study and intercept this signaling pathway. This research is illuminating the potential of agr as an anti-virulence target in S. aureus and should inform the study of similar, yet less studied, agr systems in related bacterial pathogens.
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Affiliation(s)
- Thomas J. Polaske
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706 USA
| | - Korbin H. J. West
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706 USA
| | - Ke Zhao
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706 USA
| | - Danielle L. Widner
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706 USA
| | - Jordan T. York
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706 USA
| | - Helen E. Blackwell
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706 USA
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Ongpipattanakul C, Desormeaux EK, DiCaprio A, van der Donk WA, Mitchell DA, Nair SK. Mechanism of Action of Ribosomally Synthesized and Post-Translationally Modified Peptides. Chem Rev 2022; 122:14722-14814. [PMID: 36049139 PMCID: PMC9897510 DOI: 10.1021/acs.chemrev.2c00210] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a natural product class that has undergone significant expansion due to the rapid growth in genome sequencing data and recognition that they are made by biosynthetic pathways that share many characteristic features. Their mode of actions cover a wide range of biological processes and include binding to membranes, receptors, enzymes, lipids, RNA, and metals as well as use as cofactors and signaling molecules. This review covers the currently known modes of action (MOA) of RiPPs. In turn, the mechanisms by which these molecules interact with their natural targets provide a rich set of molecular paradigms that can be used for the design or evolution of new or improved activities given the relative ease of engineering RiPPs. In this review, coverage is limited to RiPPs originating from bacteria.
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Affiliation(s)
- Chayanid Ongpipattanakul
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Emily K. Desormeaux
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Adam DiCaprio
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Wilfred A. van der Donk
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Department of Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA.,Corresponding authors Wilfred A. van der Donk, , 217-244-5360, Douglas A. Mitchell, , 217-333-1345, Satish K. Nair, , 217-333-0641
| | - Douglas A. Mitchell
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Department of Microbiology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA.,Corresponding authors Wilfred A. van der Donk, , 217-244-5360, Douglas A. Mitchell, , 217-333-1345, Satish K. Nair, , 217-333-0641
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.,Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA.,Corresponding authors Wilfred A. van der Donk, , 217-244-5360, Douglas A. Mitchell, , 217-333-1345, Satish K. Nair, , 217-333-0641
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Reconstitution of the S. aureus agr quorum sensing pathway reveals a direct role for the integral membrane protease MroQ in pheromone biosynthesis. Proc Natl Acad Sci U S A 2022; 119:e2202661119. [PMID: 35939668 PMCID: PMC9388083 DOI: 10.1073/pnas.2202661119] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In Staphylococcus aureus, virulence is under the control of a quorum sensing (QS) circuit encoded in the accessory gene regulator (agr) genomic locus. Key to this pathogenic behavior is the production and signaling activity of a secreted pheromone, the autoinducing peptide (AIP), generated following the ribosomal synthesis and posttranslational modification of a precursor polypeptide, AgrD, through two discrete cleavage steps. The integral membrane protease AgrB is known to catalyze the first processing event, generating the AIP biosynthetic intermediate, AgrD (1-32) thiolactone. However, the identity of the second protease in this biosynthetic pathway, which removes an N-terminal leader sequence, has remained ambiguous. Here, we show that membrane protease regulator of agr QS (MroQ), an integral membrane protease recently implicated in the agr response, is directly involved in AIP production. Genetic complementation and biochemical experiments reveal that MroQ proteolytic activity is required for AIP biosynthesis in agr specificity group I and group II, but not group III. Notably, as part of this effort, the biosynthesis and AIP-sensing arms of the QS circuit were reconstituted together in vitro. Our experiments also reveal the molecular features guiding MroQ cleavage activity, a critical factor in defining agr specificity group identity. Collectively, our study adds to the molecular understanding of the agr response and Staphylococcus aureus virulence.
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Durand BARN, Yahiaoui Martinez A, Baud D, François P, Lavigne JP, Dunyach-Remy C. Comparative genomics analysis of two Helcococcus kunzii strains co-isolated with Staphylococcus aureus from diabetic foot ulcers. Genomics 2022; 114:110365. [PMID: 35413435 DOI: 10.1016/j.ygeno.2022.110365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/01/2022] [Accepted: 04/06/2022] [Indexed: 01/14/2023]
Abstract
Helcococcus kunzii is a commensal Gram-positive bacterial species recovered from the human skin microbiota and considered as an opportunistic pathogen. Although little is known about its clinical significance, its increased abundance has been reported in infected wounds, particularly in foot ulcers in persons with diabetes. This species is usually detected in mixed cultures from human specimens and frequently isolated with Staphylococcus aureus. Modulation of staphylococci virulence by H. kunzii has been shown in an infection model of Caenorhabditis elegans. The aim of this study was to compare the genomes of two H. kunzii strains isolated from foot ulcers -isolate H13 and H10 showing high or low impact on S. aureus virulence, respectively- and the H. kunzii ATCC51366 strain. Whole genome analyses revealed some differences between the two strains: length (2.06 Mb (H13) and 2.05 Mb (H10) bp), GC content (29.3% (H13) and 29.5% (H10)) and gene content (1,884 (H13) and 1,786 (H10) predicted genes). The core-proteome phylogenies within the genus characterised H. kunzii H13 and H10 as genetically similar to their ancestor. The main differences between the strains were mainly in sugar-associated transporters and various hypothetical proteins. Five targets were identified as potentially involved in S. aureus virulence modulation in both genomes: the two-component iron export system and three autoinducer-like proteins. Moreover, H13 strain harbours a prophage inserted in 1,261,110-1,295,549 (attL-attR), which is absent in H10 strain. The prophage PhiCD38_2 was previously reported for its ability to modulate secretion profile, reinforcing the autoinducer-like hypothesis. In the future, transcriptomics or metaproteomics approaches could be performed to better characterize the H13 strain and possibly identify the underlying mechanism for S. aureus virulence modulation.
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Affiliation(s)
- Benjamin A R N Durand
- Bacterial Virulence and Chronic Infections, INSERM U1047, University of Montpellier, Department of Microbiology and Hospital Hygiene, University Hospital Nîmes, 30908 Nîmes, France
| | - Alex Yahiaoui Martinez
- Department of Microbiology and Hospital Hygiene, University Hospital Nîmes, University of Montpellier, 30029 Nîmes, France
| | - Damien Baud
- Department of Infectious Diseases, Genomic Research Laboratory, Geneva University Hospitals, 1205 Geneva, Switzerland
| | - Patrice François
- Department of Infectious Diseases, Genomic Research Laboratory, Geneva University Hospitals, 1205 Geneva, Switzerland
| | - Jean-Philippe Lavigne
- Bacterial Virulence and Chronic Infections, INSERM U1047, University of Montpellier, Department of Microbiology and Hospital Hygiene, University Hospital Nîmes, 30908 Nîmes, France.
| | - Catherine Dunyach-Remy
- Bacterial Virulence and Chronic Infections, INSERM U1047, University of Montpellier, Department of Microbiology and Hospital Hygiene, University Hospital Nîmes, 30908 Nîmes, France
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Matilla MA, Velando F, Martín-Mora D, Monteagudo-Cascales E, Krell T. A catalogue of signal molecules that interact with sensor kinases, chemoreceptors and transcriptional regulators. FEMS Microbiol Rev 2021; 46:6356564. [PMID: 34424339 DOI: 10.1093/femsre/fuab043] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022] Open
Abstract
Bacteria have evolved many different signal transduction systems that sense signals and generate a variety of responses. Generally, most abundant are transcriptional regulators, sensor histidine kinases and chemoreceptors. Typically, these systems recognize their signal molecules with dedicated ligand-binding domains (LBDs), which, in turn, generate a molecular stimulus that modulates the activity of the output module. There are an enormous number of different LBDs that recognize a similarly diverse set of signals. To give a global perspective of the signals that interact with transcriptional regulators, sensor kinases and chemoreceptors, we manually retrieved information on the protein-ligand interaction from about 1,200 publications and 3D structures. The resulting 811 proteins were classified according to the Pfam family into 127 groups. These data permit a delineation of the signal profiles of individual LBD families as well as distinguishing between families that recognize signals in a promiscuous manner and those that possess a well-defined ligand range. A major bottleneck in the field is the fact that the signal input of many signaling systems is unknown. The signal repertoire reported here will help the scientific community design experimental strategies to identify the signaling molecules for uncharacterised sensor proteins.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Félix Velando
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - David Martín-Mora
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Elizabet Monteagudo-Cascales
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
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Jalil MTM, Ibrahim D. Fungal Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 Inhibits the Growth of Skin Pathogenic Bacterium and Attenuates Biofilms of Methicillin-Resistant Staphylococcus aureus. Malays J Med Sci 2021; 28:24-36. [PMID: 34512128 PMCID: PMC8407792 DOI: 10.21315/mjms2021.28.4.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 04/23/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The emergence of multidrug-resistant pathogens associated with biofilm formation can cause life-threatening infections to humans. Therefore, the present study aims to evaluate the effects of the fungal extract of Lasiodiplodia pseudotheobromae (L. pseudotheobromae) Industrial Biotechnology Research Laboratory (IBRL) OS-64 on bacterial cells and the biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA). METHODS Broth microdilution and semi-quantitative adherence assays were conducted to determine the anti-biofilm activity of the fungal extract. Light and scanning electron microscopy (SEM) analyses were performed to observe the effect of the fungal extract on biofilm formation by MRSA. RESULTS The transmission electron microscopy (TEM) microphotographs showed that the bacterial cells were severely damaged upon 24 h exposure to the extract and displayed several symptoms such as cell shrinkage and breakage. Meanwhile, results from the antibiofilm study indicated the extract attenuated the initial and preformed biofilms of MRSA by 80.82% and 61.39%, respectively. The initial biofilm was more sensitive to the extract compared to the pre-formed biofilm, as evidenced by the light microscopy and SEM observations that demonstrated more severe bacterial cell damage on the initial biofilms compared to pre-formed biofilms. CONCLUSION The ethyl acetate extract of L. pseudotheobromae IBRL OS-64 significantly inhibited bacterial cells growth and eliminated biofilm formation by MRSA.
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Affiliation(s)
- Mohd Taufiq Mat Jalil
- School of Biology, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor, Malaysia
| | - Darah Ibrahim
- Industrial Biotechnology Research Laboratory, School of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang, Malaysia
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West KHJ, Shen W, Eisenbraun EL, Yang T, Vasquez JK, Horswill AR, Blackwell HE. Non-Native Peptides Capable of Pan-Activating the agr Quorum Sensing System across Multiple Specificity Groups of Staphylococcus epidermidis. ACS Chem Biol 2021; 16:1070-1078. [PMID: 33988969 DOI: 10.1021/acschembio.1c00240] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Staphylococcus epidermidis is a leading cause of hospital-acquired infections. Traditional antibiotics have significantly reduced efficacy against this pathogen due to its ability to form biofilms on abiotic surfaces and drug resistance. The accessory gene regulator (agr) quorum sensing system is directly involved in S. epidermidis pathogenesis. Activation of agr is achieved via binding of the autoinducing peptide (AIP) signal to the extracellular sensor domain of its cognate receptor, AgrC. Divergent evolution has given rise to four agr specificity groups in S. epidermidis defined by the unique AIP sequence used by each group (AIPs-I-IV) with observed cross-group activities. As agr agonism has been shown to reduce biofilm growth in S. epidermidis, the development of pan-group activators of the agr system is of interest as a potential antivirulence strategy. To date, no synthetic compounds have been identified that are capable of appreciably activating the agr system of more than one specificity group of S. epidermidis or, to our knowledge, of any of the other Staphylococci. Here, we report the characterization of the structure-activity relationships for agr agonism by S. epidermidis AIP-II and AIP-III and the application of these new SAR data and those previously reported for AIP-I for the design and synthesis of the first multigroup agr agonists. These non-native peptides were capable of inducing the expression of critical biofilm dispersal agents (i.e., phenol-soluble modulins) in cell culture and represent new tools to study the role of quorum sensing in S. epidermidis infections.
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Affiliation(s)
- Korbin H. J. West
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Wenqi Shen
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Emma L. Eisenbraun
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Tian Yang
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Joseph K. Vasquez
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, Anschutz Medical Campus, University of Colorado, Aurora, Colorado 80045, United States
| | - Helen E. Blackwell
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Xie Q, Wiedmann MM, Zhao A, Pagan IR, Novick RP, Suga H, Muir TW. Discovery of quorum quenchers targeting the membrane-embedded sensor domain of the Staphylococcus aureus receptor histidine kinase, AgrC. Chem Commun (Camb) 2021; 56:11223-11226. [PMID: 32820778 DOI: 10.1039/d0cc04873a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We combined mRNA display technology with lipid-nanodisc based selections and identified high-affinity ligands targeting the integral membrane sensor domain of the histidine kinase AgrC as potent inhibitors of Staphylococcus aureus quorum sensing-modulated virulence. Our study highlights the potential of this integrated approach for identifying functional modulators of integral membrane proteins.
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Affiliation(s)
- Qian Xie
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
| | - Mareike M Wiedmann
- Department of Chemistry, University of Tokyo, Graduate School of Science, Tokyo, Japan.
| | - Aishan Zhao
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
| | - Ivelisse R Pagan
- Skirball Institute, Department of Microbiology, NYU Medical Center, New York, NY, USA
| | - Richard P Novick
- Skirball Institute, Department of Microbiology, NYU Medical Center, New York, NY, USA
| | - Hiroaki Suga
- Department of Chemistry, University of Tokyo, Graduate School of Science, Tokyo, Japan.
| | - Tom W Muir
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
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El Sayed AM, AbdElSattar E, Khalil MN. New calogenin pregnane glycoside derivative from Huernia saudi- arabica and its Lipase and α-Glucosidase Inhibitory Activities. Biomed Pharmacother 2020; 127:110143. [PMID: 32339923 DOI: 10.1016/j.biopha.2020.110143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/30/2020] [Accepted: 03/30/2020] [Indexed: 01/01/2023] Open
Abstract
As ongoing investigation of Huernia saudi-arabica D.V.Field (Asclepiadaceae), a new steroidal pregnane glycoside (Huernioside A) was isolated from dichloromethane fraction (DCM); it was identified as 3β, 11, 14β, 20(R)-tetrahydroxy-pregna-5,9(11)-diene-3-O-β-D-thevetopyranosyl-(1-4)-β-D-cymaropyranoside(HCP) through analysis of 1D, 2D NMR besides ESI-MS data. The alcoholic extract of the aerial part (ALE), DCM and HCP showed inhibitory potential against pancreatic lipase compared to orilstat. Among the tested samples, the ALE and HCP exhibited a promising pancreatic lipase inhibitory commotion through IC50 values of 0.61 ± 0.15, 1.23 ± 0.07 mg/ml (equivalent to 88.8 μM), respectively. HCP was prevailed to have a mixed mode of inhibition as exposed by enzyme kinetic studies. Hydrophobic interactions were the major forces involved in ligand enzyme interactions. In contrast, moderate α-glucosidase inhibitory activities were evidenced for ALE and HCP (% inhibition: 24.8 ± 1.8 and 26.6 ± 2.5, respectively) compared to acarbose. This investigation is the first to report on the possible in vitro anti-obesity and anti-diabetic impact of H. saudi-arabica.
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Affiliation(s)
- Abeer Mohamed El Sayed
- Pharmacognosy Department, College of Pharmacy, Cairo University, Kasr El-Einy Street, 11562, Cairo, Egypt.
| | - Essam AbdElSattar
- Pharmacognosy Department, College of Pharmacy, Cairo University, Kasr El-Einy Street, 11562, Cairo, Egypt.
| | - Mohammed Nabil Khalil
- Pharmacognosy Department, College of Pharmacy, Cairo University, Kasr El-Einy Street, 11562, Cairo, Egypt.
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Zafari M, Aghajani S, Mansouri Boroujeni M, Nosrati H. Vancomycin-loaded electrospun polycaprolactone/nano-hydroxyapatite membrane for the treatment of blood infections. Med Hypotheses 2020; 144:109992. [PMID: 32563972 DOI: 10.1016/j.mehy.2020.109992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 05/31/2020] [Accepted: 06/10/2020] [Indexed: 12/25/2022]
Abstract
Nowadays, because of the resistance of bacteria to antibiotics, researchers are trying to make new antibiotics or sometimes even bring them back into the treatment cycle so that they could eliminate the bacteria's resistance. On the other hand, the use of nanofibers has become widespread in many fields for their unique properties and convenient design. The present study focuses on the production of hydrophobic nanofibers to absorb the bacteria and their toxins from the bloodstream that contains the infection. Many bacterial surfaces have hydrophobic surfactant properties due to hydrophobic surface protein. According to the principle of binding two hydrophobic molecules to each other in an aqueous medium, the nanofibers are designed to physically absorb the bacteria. The use of antibiotics in the study can remove some unattached bacteria. In addition, using nanofiber manufacturing techniques can reduce the resistance of bacteria to antibiotics. The construction of the desired membrane can be used in subsequent studies as a replacement membrane for dialysis filters.
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Affiliation(s)
- Mahdi Zafari
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Sajad Aghajani
- Cellular and Molecular Research Center, Basic Health Science Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Milad Mansouri Boroujeni
- Cellular and Molecular Research Center, Basic Health Science Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Hamed Nosrati
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran.
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Asif M, Imran M. Quorum Sensing Inhibition: Current Advances of the Natural Antimicrobial Agents. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162019060049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Horswill AR, Gordon CP. Structure-Activity Relationship Studies of Small Molecule Modulators of the Staphylococcal Accessory Gene Regulator. J Med Chem 2019; 63:2705-2730. [PMID: 31658413 DOI: 10.1021/acs.jmedchem.9b00798] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The accessory gene regulator (agr) quorum-sensing system is arguably the most important regulator of Staphylococcus virulence. The agr-system serves a crucial role in pathogenesis by triggering substantive gene expression alterations to up-regulate the production of a wide variety of virulence determinants such as exoenzymes (proteases, lipases, nucleases) and downregulate the expression of surface binding proteins. Accordingly, the agr-system represents a compelling target for the development of antivirulence therapeutics as potential adjuncts, or alternatives, to conventional bactericidal and bacteriostatic antibiotics. Despite this potential, to date, no agr-system inhibitors have progressed to the clinic; however, several promising lead compounds have been identified through screens of synthetic and natural product libraries. On the basis of the molecular components within the agr-system, the current contingent of regulating compounds can be clustered into three broad groups, AgrA-P3 activation inhibitors, AgrB-AgrD processing inhibitors, and AgrC-AIP interaction inhibitors. This review aims to provide an overview of the development, structure-activity-relationships, and limitations of compounds within each of these groups in addition to the current opportunities for developing next-generation anologs.
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Affiliation(s)
- Alexander R Horswill
- Veterans Affairs Eastern Colorado Health Care System, Aurora, Colorado 80045, United States.,Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Christopher P Gordon
- School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith South DC, NSW 2751, Australia.,Molecular Medicine Research Group, School of Medicine, Westerm Sydney University, Building 30, Campbelltown, NSW 2560, Australia
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14
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Vasquez JK, Blackwell HE. Simplified Autoinducing Peptide Mimetics with Single-Nanomolar Activity Against the Staphylococcus aureus AgrC Quorum Sensing Receptor. ACS Infect Dis 2019; 5:484-492. [PMID: 30817121 DOI: 10.1021/acsinfecdis.9b00002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Staphylococcus aureus is a leading cause of hospital-acquired infections worldwide, and cases of community-acquired infections are becoming more prevalent. The production of numerous virulence factors in S. aureus is under the control of the accessory gene regulator (agr) quorum sensing (QS) system. S. aureus upregulates agr at high cell density by secreting a peptide pheromone, or autoinducing peptide (AIP), which is detected by its cognate transmembrane receptor, AgrC. The extracellular AIP binding site of AgrC represents an attractive target for inhibition of the agr system and, thereby, QS-controlled virulence in S. aureus. Nonnative peptides and, more recently, peptidomimetics have been reported to inhibit the AgrC receptor and represent useful chemical tools to study the role of QS in S. aureus infections. We seek to expand beyond peptide-like scaffolds to generate AgrC modulators with enhanced stability, solubility, and synthetic accessibility relative to these compounds, while maintaining their high potencies. Toward this goal, we report herein a study of the structure-activity relationships responsible for the activity of a recently reported simplified AIP mimetic and AgrC antagonist, n7OFF, and the discovery of a new AIP mimetic, Bnc3, which has low- to sub-nanomolar inhibitory activity in all four S. aureus agr specificity groups. NMR structural studies of Bnc3 revealed hydrophobic and hydrophilic faces that are likely critical for AgrC antagonism, in agreement with prior studies of peptide-derived inhibitors. Bnc3 represents an important transition compound toward the development of small-molecule AgrC antagonists.
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Affiliation(s)
- Joseph K. Vasquez
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Helen E. Blackwell
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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15
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Xu J, Pang L, Ma XX, Hu J, Tian Y, Yang YL, Sun DD. Phenotypic and Molecular Characterisation of Staphylococcus Aureus with Reduced Vancomycin Susceptibility Derivated in Vitro. Open Med (Wars) 2018; 13:475-486. [PMID: 30426085 PMCID: PMC6227741 DOI: 10.1515/med-2018-0071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 08/27/2018] [Indexed: 02/05/2023] Open
Abstract
Vancomycin has been the primary agent used to treat serious Methicillin-resistant Staphylococcus aureus (MRSA) infection for many years. However, the rise of MRSA infection rates and the extensive use of vancomycin have led to the emergence of reduced vancomycin susceptibility. Therefore, four typical Staphylococcus aureus (S. aureus) strains from different clinical specimens were derivated by vancomycin in vitro to better clarify their phenotypic and molecular characteristics. Some experiments, such as stepwise selection of vancomycin-resistant strains, pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility test, population analysis profile-area under the curve (PAP-AUC), molecular typing, transmission electron microscopy, δ-hemolysin expression, autolysis assay, biofilm assay and quantitative real-time polymerase chain reaction (qPCR) for gene expression were carried out to compare the derivated bacteria with their parental strains. Results showed that the observed phenotypes of vancomycin-resistant strains such as hemolysin, autolysis and biofilm significantly reduced, which were associated with vancomycin resistance capability of the selected strain. The changes of phenotype and regulatory genes expression were inversely proportional to the vancomycin minimum inhibitory concentration (MICvan). Most heterogeneous vancomycin intermediate Staphylococcus aureus (hVISA) or VISA strains belonged to spa type t570 and agr group II. In summary, the clinical isolated vancomycin susceptible Staphylococcus aureus (VSSA), hVISA and VISA could be derivated into high vancomycin-resistant VISA in vitro, but it was difficult for them to develop into vancomycin resistant Staphylococcus aureus (VRSA). VISA and hVISA could gradually adapt to the environment with the vancomycin concentration that continuously elevates.
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Affiliation(s)
- Jia Xu
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, PR China.,Department of Medical Microbiology, Key Laboratory of Environmental Pollution and Microecology of Liaoning Province, Shenyang Medical College, Shenyang, PR China
| | - Long Pang
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, PR China
| | - Xiao Xue Ma
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, P.R. China
| | - Jian Hu
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, PR China.,Department of Clinical Laboratory, Yixing Hospital of Traditional Chinese Medicine, Yixing, Jiangsu, PR China
| | - Yuan Tian
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, PR China
| | - Ya Li Yang
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, PR China
| | - Dan Dan Sun
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, PR China
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16
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Lakemeyer M, Zhao W, Mandl FA, Hammann P, Sieber SA. Thinking Outside the Box-Novel Antibacterials To Tackle the Resistance Crisis. Angew Chem Int Ed Engl 2018; 57:14440-14475. [PMID: 29939462 DOI: 10.1002/anie.201804971] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Indexed: 12/13/2022]
Abstract
The public view on antibiotics as reliable medicines changed when reports about "resistant superbugs" appeared in the news. While reasons for this resistance development are easily spotted, solutions for re-establishing effective antibiotics are still in their infancy. This Review encompasses several aspects of the antibiotic development pipeline from very early strategies to mature drugs. An interdisciplinary overview is given of methods suitable for mining novel antibiotics and strategies discussed to unravel their modes of action. Select examples of antibiotics recently identified by using these platforms not only illustrate the efficiency of these measures, but also highlight promising clinical candidates with therapeutic potential. Furthermore, the concept of molecules that disarm pathogens by addressing gatekeepers of virulence will be covered. The Review concludes with an evaluation of antibacterials currently in clinical development. Overall, this Review aims to connect select innovative antimicrobial approaches to stimulate interdisciplinary partnerships between chemists from academia and industry.
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Affiliation(s)
- Markus Lakemeyer
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
| | - Weining Zhao
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
| | - Franziska A Mandl
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
| | - Peter Hammann
- R&D Therapeutic Area Infectious Diseases, Sanofi-Aventis (Deutschland) GmbH, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Stephan A Sieber
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
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17
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Lakemeyer M, Zhao W, Mandl FA, Hammann P, Sieber SA. Über bisherige Denkweisen hinaus - neue Wirkstoffe zur Überwindung der Antibiotika-Krise. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804971] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Markus Lakemeyer
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Weining Zhao
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Franziska A. Mandl
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Peter Hammann
- R&D Therapeutic Area Infectious Diseases; Sanofi-Aventis (Deutschland) GmbH; Industriepark Höchst 65926 Frankfurt am Main Deutschland
| | - Stephan A. Sieber
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
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18
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Conversion of staphylococcal pathogenicity islands to CRISPR-carrying antibacterial agents that cure infections in mice. Nat Biotechnol 2018; 36:971-976. [PMID: 30247487 PMCID: PMC6511514 DOI: 10.1038/nbt.4203] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 07/03/2018] [Indexed: 01/21/2023]
Abstract
Staphylococcus aureus and other staphylococci continue to cause life-threatening infections in both hospital and community settings. They have become increasingly resistant to antibiotics, especially β-lactams and aminoglycosides, and their infections are now, in many cases, untreatable. Here, we present a non-antibiotic, non-phage method of treating staphylococcal infections by engineering of the highly mobile staphylococcal pathogenicity islands (SaPIs)4. We replaced the SaPIs’ toxin genes with antibacterial cargos to generate antibacterial drones (ABDs) that target the infecting bacteria in the animal host, express their cargo, kill or disarm the bacteria and thus abrogate the infection. As proof of concept, we have constructed ABDs with either a CRISPR-cas9 bactericidal or a CRISPR-dcas9 virulence-blocking module. We show that both ABDs block the development of a murine subcutaneous S. aureus abscess and that the bactericidal module rescues mice given a lethal dose of S. aureus intraperitoneally.
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19
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Control of Biofilm Formation in Healthcare: Recent Advances Exploiting Quorum-Sensing Interference Strategies and Multidrug Efflux Pump Inhibitors. MATERIALS 2018; 11:ma11091676. [PMID: 30201944 PMCID: PMC6163278 DOI: 10.3390/ma11091676] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/18/2018] [Accepted: 09/07/2018] [Indexed: 12/28/2022]
Abstract
Biofilm formation in healthcare is an issue of considerable concern, as it results in increased morbidity and mortality, imposing a significant financial burden on the healthcare system. Biofilms are highly resistant to conventional antimicrobial therapies and lead to persistent infections. Hence, there is a high demand for novel strategies other than conventional antibiotic therapies to control biofilm-based infections. There are two approaches which have been employed so far to control biofilm formation in healthcare settings: one is the development of biofilm inhibitors based on the understanding of the molecular mechanism of biofilm formation, and the other is to modify the biomaterials which are used in medical devices to prevent biofilm formation. This review will focus on the recent advances in anti-biofilm approaches by interrupting the quorum-sensing cellular communication system and the multidrug efflux pumps which play an important role in biofilm formation. Research efforts directed towards these promising strategies could eventually lead to the development of better anti-biofilm therapies than the conventional treatments.
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20
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Mull RW, Harrington A, Sanchez LA, Tal-Gan Y. Cyclic Peptides that Govern Signal Transduction Pathways: From Prokaryotes to Multi-Cellular Organisms. Curr Top Med Chem 2018; 18:625-644. [PMID: 29773060 DOI: 10.2174/1568026618666180518090705] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/30/2016] [Accepted: 12/17/2017] [Indexed: 12/16/2022]
Abstract
Cyclic peptide scaffolds are key components of signal transduction pathways in both prokaryotic and eukaryotic organisms since they act as chemical messengers that activate or inhibit specific cognate receptors. In prokaryotic organisms these peptides are utilized in non-essential pathways, such as quorum sensing, that are responsible for virulence and pathogenicity. In the more evolved eukaryotic systems, cyclic peptide hormones play a key role in the regulation of the overall function of multicellular organisms, mainly through the endocrine system. This review will highlight several prokaryote and eukaryote systems that use cyclic peptides as their primary signals and the potential associated with utilizing these scaffolds for the discovery of novel therapeutics for a wide range of diseases and illnesses.
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Affiliation(s)
- Ryan W Mull
- Department of Chemistry, University of Nevada, Reno, NV 89557, United States
| | - Anthony Harrington
- Department of Chemistry, University of Nevada, Reno, NV 89557, United States
| | - Lucia A Sanchez
- Department of Chemistry, University of Nevada, Reno, NV 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, NV 89557, United States
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21
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Antidromic neurogenic activity and cutaneous bacterial flora. Semin Immunopathol 2018; 40:281-289. [DOI: 10.1007/s00281-018-0671-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 03/06/2018] [Indexed: 12/13/2022]
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22
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Adam K, Hunter T. Histidine kinases and the missing phosphoproteome from prokaryotes to eukaryotes. J Transl Med 2018; 98:233-247. [PMID: 29058706 PMCID: PMC5815933 DOI: 10.1038/labinvest.2017.118] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/16/2017] [Accepted: 08/31/2017] [Indexed: 12/20/2022] Open
Abstract
Protein phosphorylation is the most common type of post-translational modification in eukaryotes. The phosphoproteome is defined as the complete set of experimentally detectable phosphorylation sites present in a cell's proteome under various conditions. However, we are still far from identifying all the phosphorylation sites in a cell mainly due to the lack of information about phosphorylation events involving residues other than Ser, Thr and Tyr. Four types of phosphate-protein linkage exist and these generate nine different phosphoresidues-pSer, pThr, pTyr, pHis, pLys, pArg, pAsp, pGlu and pCys. Most of the effort in studying protein phosphorylation has been focused on Ser, Thr and Tyr phosphorylation. The recent development of 1- and 3-pHis monoclonal antibodies promises to increase our understanding of His phosphorylation and the kinases and phosphatases involved. Several His kinases are well defined in prokaryotes, especially those involved in two-component system (TCS) signaling. However, in higher eukaryotes, NM23, a protein originally characterized as a nucleoside diphosphate kinase, is the only characterized protein-histidine kinase. This ubiquitous and conserved His kinase autophosphorylates its active site His, and transfers this phosphate either onto a nucleoside diphosphate or onto a protein His residue. Studies of NM23 protein targets using newly developed anti-pHis antibodies will surely help illuminate the elusive His phosphorylation-based signaling pathways. This review discusses the role that the NM23/NME/NDPK phosphotransferase has, how the addition of the pHis phosphoproteome will expand the phosphoproteome and make His phosphorylation part of the global phosphorylation world. It also summarizes why our understanding of phosphorylation is still largely restricted to the acid stable phosphoproteome, and highlights the study of NM23 histidine kinase as an entrée into the world of histidine phosphorylation.
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Affiliation(s)
- Kevin Adam
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
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23
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Abstract
Natural products have served as powerful therapeutics against pathogenic bacteria since the golden age of antibiotics of the mid-20th century. However, the increasing frequency of antibiotic-resistant infections clearly demonstrates that new antibiotics are critical for modern medicine. Because combinatorial approaches have not yielded effective drugs, we propose that the development of new antibiotics around proven natural scaffolds is the best short-term solution to the rising crisis of antibiotic resistance. We analyze herein synthetic approaches aiming to reengineer natural products into potent antibiotics. Furthermore, we discuss approaches in modulating quorum sensing and biofilm formation as a nonlethal method, as well as narrow-spectrum pathogen-specific antibiotics, which are of interest given new insights into the implications of disrupting the microbiome.
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Affiliation(s)
- Sean E. Rossiter
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Madison H. Fletcher
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - William M. Wuest
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
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24
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Jones MB, Nierman WC, Shan Y, Frank BC, Spoering A, Ling L, Peoples A, Zullo A, Lewis K, Nelson KE. Reducing the Bottleneck in Discovery of Novel Antibiotics. MICROBIAL ECOLOGY 2017; 73:658-667. [PMID: 27896376 DOI: 10.1007/s00248-016-0889-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
Most antibiotics were discovered by screening soil actinomycetes, but the efficiency of the discovery platform collapsed in the 1960s. By now, more than 3000 antibiotics have been described and most of the current discovery effort is focused on the rediscovery of known compounds, making the approach impractical. The last marketed broad-spectrum antibiotics discovered were daptomycin, linezolid, and fidaxomicin. The current state of the art in the development of new anti-infectives is a non-existent pipeline in the absence of a discovery platform. This is particularly troubling given the emergence of pan-resistant pathogens. The current practice in dealing with the problem of the background of known compounds is to use chemical dereplication of extracts to assess the relative novelty of a compound it contains. Dereplication typically requires scale-up, extraction, and often fractionation before an accurate mass and structure can be produced by MS analysis in combination with 2D NMR. Here, we describe a transcriptome analysis approach using RNA sequencing (RNASeq) to identify promising novel antimicrobial compounds from microbial extracts. Our pipeline permits identification of antimicrobial compounds that produce distinct transcription profiles using unfractionated cell extracts. This efficient pipeline will eliminate the requirement for purification and structure determination of compounds from extracts and will facilitate high-throughput screen of cell extracts for identification of novel compounds.
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Affiliation(s)
- Marcus B Jones
- Genomic Medicine, J. Craig Venter Institute, La Jolla, CA, USA.
- Human Longevity, Inc, San Diego, CA, USA.
| | | | - Yue Shan
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Bryan C Frank
- Genomic Medicine, J. Craig Venter Institute, La Jolla, CA, USA
| | | | - Losee Ling
- NovoBiotic Pharmaceuticals, Cambridge, MA, USA
| | | | | | - Kim Lewis
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Karen E Nelson
- Genomic Medicine, J. Craig Venter Institute, La Jolla, CA, USA
- Human Longevity, Inc, San Diego, CA, USA
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25
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Vasquez JK, Tal-Gan Y, Cornilescu G, Tyler KA, Blackwell HE. Simplified AIP-II Peptidomimetics Are Potent Inhibitors of Staphylococcus aureus AgrC Quorum Sensing Receptors. Chembiochem 2017; 18:413-423. [PMID: 28006082 DOI: 10.1002/cbic.201600516] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Indexed: 01/13/2023]
Abstract
The bacterial pathogen Staphylococcus aureus controls many aspects of virulence by using the accessory gene regulator (agr) quorum sensing (QS) system. The agr system is activated by a macrocyclic peptide signal known as an autoinducing peptide (AIP). We sought to develop structurally simplified mimetics of AIPs for use as chemical tools to study QS in S. aureus. Herein, we report new peptidomimetic AgrC receptor inhibitors based on a tail-truncated AIP-II peptide that have almost analogous inhibitory activities to the parent peptide. Structural comparison of one of these peptidomimetics to the parent peptide and a highly potent, all-peptide-derived, S. aureus agr inhibitor (AIP-III D4A) revealed a conserved hydrophobic motif and overall amphipathic nature. Our results suggest that the AIP scaffold is amenable to structural mimicry and minimization for the development of synthetic agr inhibitors.
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Affiliation(s)
- Joseph K Vasquez
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI, 53706, USA
| | - Yftah Tal-Gan
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI, 53706, USA.,Present address: Department of Chemistry, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA
| | - Gabriel Cornilescu
- National Magnetic Resonance Facility at Madison, University of Wisconsin, 433 Babcock Drive, Madison, WI, 53706, USA
| | - Kimberly A Tyler
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI, 53706, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI, 53706, USA
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26
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N'Diaye A, Gannesen A, Borrel V, Maillot O, Enault J, Racine PJ, Plakunov V, Chevalier S, Lesouhaitier O, Feuilloley MGJ. Substance P and Calcitonin Gene-Related Peptide: Key Regulators of Cutaneous Microbiota Homeostasis. Front Endocrinol (Lausanne) 2017; 8:15. [PMID: 28194136 PMCID: PMC5277020 DOI: 10.3389/fendo.2017.00015] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/16/2017] [Indexed: 12/20/2022] Open
Abstract
Neurohormones diffuse in sweat and epidermis leading skin bacterial microflora to be largely exposed to these host factors. Bacteria can sense a multitude of neurohormones, but their role in skin homeostasis was only investigated recently. The first study focused on substance P (SP), a neuropeptide produced in abundance by skin nerve terminals. SP is without effect on the growth of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis) and Gram-negative (Pseudomonas fluorescens) bacteria. However, SP is stimulating the virulence of Bacillus and Staphylococci. The action of SP is highly specific with a threshold below the nanomolar level. Mechanisms involved in the response to SP are different between bacteria although they are all leading to increased adhesion and/or virulence. The moonlighting protein EfTu was identified as the SP-binding site in B. cereus and Staphylococci. In skin nerve terminals, SP is co-secreted with the calcitonin gene-related peptide (CGRP), which was shown to modulate the virulence of S. epidermidis. This effect is antagonized by SP. Identification of the CGRP sensor, DnaK, allowed understanding this phenomenon as EfTu and DnaK are apparently exported from the bacterium through a common system before acting as SP and CGRP sensors. Many other neuropeptides are expressed in skin, and their potential effects on skin bacteria remain to be investigated. Integration of these host signals by the cutaneous microbiota now appears as a key parameter in skin homeostasis.
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Affiliation(s)
- Awa N'Diaye
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Andrei Gannesen
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen, Evreux, France; Winogradsky Institute of Microbiology, Research Center of Biotechnology of Russian Academy of Science, Moscow, Russia
| | - Valérie Borrel
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Olivier Maillot
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Jeremy Enault
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Pierre-Jean Racine
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Vladimir Plakunov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of Russian Academy of Science , Moscow , Russia
| | - Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Olivier Lesouhaitier
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
| | - Marc G J Feuilloley
- Laboratory of Microbiology Signals and Microenvironment (LMSM), Normandie Université Rouen , Evreux , France
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27
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Canovas J, Baldry M, Bojer MS, Andersen PS, Grzeskowiak PK, Stegger M, Damborg P, Olsen CA, Ingmer H. Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System. Front Microbiol 2016; 7:1733. [PMID: 27877157 PMCID: PMC5099252 DOI: 10.3389/fmicb.2016.01733] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/17/2016] [Indexed: 11/13/2022] Open
Abstract
Staphylococci are associated with both humans and animals. While most are non-pathogenic colonizers, Staphylococcus aureus is an opportunistic pathogen capable of causing severe infections. S. aureus virulence is controlled by the agr quorum sensing system responding to secreted auto-inducing peptides (AIPs) sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus agr. The dog pathogen, Staphylococcus schleiferi, expressed the most potent inhibitory activity and was active against all four agr classes found in S. aureus. By employing a S. aureus strain encoding a constitutively active AIP receptor we show that the activity is mediated via agr. Subsequent cloning and heterologous expression of the S. schleiferi AIP in S. aureus demonstrated that this molecule was likely responsible for the inhibitory activity, and further proof was provided when pure synthetic S. schleiferi AIP was able to completely abolish agr induction of an S. aureus reporter strain. To assess impact on S. aureus virulence, we co-inoculated S. aureus and S. schleiferi in vivo in the Galleria mellonella wax moth larva, and found that expression of key S. aureus virulence factors was abrogated. Our data show that the S. aureus agr locus is highly responsive to other staphylococcal species suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci will significantly influence the ability of S. aureus to cause infection, and we propose that other staphylococci are potential sources of compounds that can be applied as anti-virulence therapy for combating S. aureus infections.
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Affiliation(s)
- Jaime Canovas
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Mara Baldry
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Martin S Bojer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Paal S Andersen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of CopenhagenFrederiksberg, Denmark; Department of Microbiology and Infection Control, Statens Serum InstitutCopenhagen, Denmark
| | - Piotr K Grzeskowiak
- Center for Biopharmaceuticals and Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Marc Stegger
- Department of Microbiology and Infection Control, Statens Serum Institut Copenhagen, Denmark
| | - Peter Damborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Christian A Olsen
- Center for Biopharmaceuticals and Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Hanne Ingmer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
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Hawver LA, Jung SA, Ng WL. Specificity and complexity in bacterial quorum-sensing systems. FEMS Microbiol Rev 2016; 40:738-52. [PMID: 27354348 PMCID: PMC5007282 DOI: 10.1093/femsre/fuw014] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2016] [Indexed: 12/15/2022] Open
Abstract
Quorum sensing (QS) is a microbial cell-to-cell communication process that relies on the production and detection of chemical signals called autoinducers (AIs) to monitor cell density and species complexity in the population. QS allows bacteria to behave as a cohesive group and coordinate collective behaviors. While most QS receptors display high specificity to their AI ligands, others are quite promiscuous in signal detection. How do specific QS receptors respond to their cognate signals with high fidelity? Why do some receptors maintain low signal recognition specificity? In addition, many QS systems are composed of multiple intersecting signaling pathways: what are the benefits of preserving such a complex signaling network when a simple linear ‘one-to-one’ regulatory pathway seems sufficient to monitor cell density? Here, we will discuss different molecular mechanisms employed by various QS systems that ensure productive and specific QS responses. Moreover, the network architectures of some well-characterized QS circuits will be reviewed to understand how the wiring of different regulatory components achieves different biological goals. This review focuses on the specificity and complexity of quorum-sensing circuits in both Gram-negative and Gram-positive bacterial species.
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Affiliation(s)
- Lisa A Hawver
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Sarah A Jung
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Wai-Leung Ng
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
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N'Diaye A, Mijouin L, Hillion M, Diaz S, Konto-Ghiorghi Y, Percoco G, Chevalier S, Lefeuvre L, Harmer NJ, Lesouhaitier O, Feuilloley MGJ. Effect of Substance P in Staphylococcus aureus and Staphylococcus epidermidis Virulence: Implication for Skin Homeostasis. Front Microbiol 2016; 7:506. [PMID: 27148195 PMCID: PMC4832252 DOI: 10.3389/fmicb.2016.00506] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/29/2016] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus and Staphylococcus epidermidis are two major skin associated bacteria, and Substance P (SP) is a major skin neuropeptide. Since bacteria are known to sense and response to many human hormones, we investigated the effects of SP on Staphylococci virulence in reconstructed human epidermis model and HaCaT keratinocytes. We show that SP is stimulating the virulence of S. aureus and S. epidermidis in a reconstructed human epidermis model. qRT-PCR array analysis of 64 genes expressed by keratinocytes in the response to bacterial infection revealed a potential link between the action of SP on Staphylococci and skin physiopathology. qRT-PCR and direct assay of cathelicidin and human β-defensin 2 secretion also provided that demonstration that the action of SP on bacteria is independent of antimicrobial peptide expression by keratinocytes. Considering an effect of SP on S. aureus and S. epidermidis, we observed that SP increases the adhesion potential of both bacteria on keratinocytes. However, SP modulates the virulence of S. aureus and S. epidermidis through different mechanisms. The response of S. aureus is associated with an increase in Staphylococcal Enterotoxin C2 (SEC2) production and a reduction of exolipase processing whereas in S. epidermidis the effect of SP appears mediated by a rise in biofilm formation activity. The Thermo unstable ribosomal Elongation factor Ef-Tu was identified as the SP-interacting protein in S. aureus and S. epidermidis. SP appears as an inter-kingdom communication factor involved in the regulation of bacterial virulence and essential for skin microflora homeostasis.
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Affiliation(s)
- Awa N'Diaye
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
| | - Lily Mijouin
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
| | - Mélanie Hillion
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
| | - Suraya Diaz
- Department of Biosciences, University of Exeter Exeter, UK
| | - Yoan Konto-Ghiorghi
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
| | - Giuseppe Percoco
- GlycoMev EA 4358, Normandie Université, Université de RouenMont-Saint-Aignan, France; Bio-EC LaboratoryLongjumeau, France
| | - Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
| | - Luc Lefeuvre
- Dermatologic Laboratories Uriage Neuilly-Sur-Seine, France
| | | | - Olivier Lesouhaitier
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
| | - Marc G J Feuilloley
- Laboratory of Microbiology Signals and Microenvironnement LMSM, EA 4312, Normandie Université, Université de Rouen Evreux, France
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Quorum Quenching Strategy Targeting Gram-Positive Pathogenic Bacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 901:109-30. [PMID: 27167409 DOI: 10.1007/5584_2016_1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Quorum sensing (QS) is a cell density-dependent regulatory system that orchestrates the group behavior of unicellular organisms by synchronizing the expression of certain gene(s) within the clonal community of same species. Bacterial pathogens often employ QS system to establish efficiently an infection. A large part of low GC Gram-positive bacteria belonging to phylum Firmicutes use thiolactone/lactone peptides as communication signals so-called autoinducing peptides (AIPs) to coordinate QS circuit. In particular, QS of staphylococci, enterococci, and clostridia have been intensively studied in terms of alternative target of anti-pathogenic chemotherapy independent of bactericidal antibiotics. Thus far, a number of quorum quenching (QQ) agents that targeting the QS circuit of these Gram-positive pathogens have been developed by random screening of natural compounds or rationale design of AIP antagonists. This review summarizes those QQ agents and previews their potential as post-antibiotic drugs.
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Johnson JG, Wang B, Debelouchina GT, Novick RP, Muir TW. Increasing AIP Macrocycle Size Reveals Key Features of agr Activation in Staphylococcus aureus. Chembiochem 2015; 16:1093-100. [PMID: 25801678 DOI: 10.1002/cbic.201500006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Indexed: 11/09/2022]
Abstract
The agr locus in the commensal human pathogen, Staphylococcus aureus, is a two-promoter regulon with allelic variability that produces a quorum-sensing circuit involved in regulating virulence within the bacterium. Secretion of unique autoinducing peptides (AIPs) and detection of their concentrations by AgrC, a transmembrane receptor histidine kinase, coordinates local bacterial population density with global changes in gene expression. The finding that staphylococcal virulence can be inhibited through antagonism of this quorum-sensing pathway has fueled tremendous interest in understanding the structure-activity relationships underlying the AIP-AgrC interaction. The defining structural feature of the AIP is a 16-membered, thiolactone-containing macrocycle. Surprisingly, the importance of ring size on agr activation or inhibition has not been explored. In this study, we address this deficiency through the synthesis and functional analysis of AIP analogues featuring enlarged and reduced macrocycles. Notably, this study is the first to interrogate AIP function by using both established cell-based reporter gene assays and newly developed in vitro AgrC-I binding and autophosphorylation activity assays. Based on our data, we present a model for robust agr activation involving a cooperative, three-points-of-contact interaction between the AIP macrocycle and AgrC.
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Affiliation(s)
- Jeffrey G Johnson
- Department of Chemistry, Princeton University, Frick Chemistry Building, Washington Road, Princeton, NJ 08544 (USA); Graduate Program, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (USA); Tri-Institutional Training Program in Chemical Biology, Weil-Cornell/Memorial Sloan Kettering/Rockefeller University, New York, NY 10065 (USA)
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An electrostatic interaction between BlpC and BlpH dictates pheromone specificity in the control of bacteriocin production and immunity in Streptococcus pneumoniae. J Bacteriol 2015; 197:1236-48. [PMID: 25622617 DOI: 10.1128/jb.02432-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
UNLABELLED The blp locus of Streptococcus pneumoniae secretes and regulates bacteriocins, which mediate both intra- and interspecific competition in the human nasopharynx. There are four major alleles of the gene blpH, which encodes the receptor responsible for activating the blp locus when bound to one of four distinct peptide pheromones (BlpC). The allelic variation of blpH is presumably explained by a need to restrict cross talk between competing strains. The BlpH protein sequences have polymorphisms distributed throughout the sequence, making identification of the peptide binding site difficult to predict. To identify the pheromone binding sites that dictate pheromone specificity, we have characterized the four major variants and two naturally occurring chimeric versions of blpH in which recombination events appear to have joined two distinct blpH alleles together. Using these allelic variants, a series of laboratory-generated chimeric blpH alleles, and site-directed mutants of both the receptor and peptide, we have demonstrated that BlpC binding to some BlpH types involves an electrostatic interaction between the oppositely charged residues of BlpC and the first transmembrane domain of BlpH. An additional recognition site was identified in the second extracellular loop. We identified naturally occurring BlpH types that have the capacity to respond to more than one BlpC type; however, this change in specificity results in a commensurate drop in overall sensitivity. These natural recombination events were presumably selected for to balance the need to sense bacteriocin-secreting neighbors with the need to turn on bacteriocin production at a low density. IMPORTANCE Bacteria use quorum sensing to optimize gene expression to accommodate for local bacterial density and diffusion rates. To prevent interception of quorum-sensing signals by neighboring strains, the genomes of single species often encode strain-specific signal/receptor pairs. The blp locus in Streptococcus pneumoniae that drives bacteriocin secretion is controlled by quorum sensing that involves the interaction of the signal/receptor pair BlpC/BlpH. We show that the pneumococcal population can be divided into several distinct BlpC/BlpH pairs; however, there are examples of naturally occurring chimeric receptors that can bind to more than one BlpC type. The trade-off for this broadened specificity is a loss of overall receptor sensitivity. This suggests that under certain conditions, the advantage of signal interception can trump the requirements for self-induction.
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Chung PY, Toh YS. Anti-biofilm agents: recent breakthrough against multi-drug resistantStaphylococcus aureus. Pathog Dis 2014; 70:231-9. [DOI: 10.1111/2049-632x.12141] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/12/2014] [Accepted: 01/13/2014] [Indexed: 01/22/2023] Open
Affiliation(s)
- Pooi Y. Chung
- Department of Pathology; School of Medicine; International Medical University; Kuala Lumpur Malaysia
| | - Yien S. Toh
- Biomedical Science Program; School of Medicine; International Medical University; Kuala Lumpur Malaysia
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Identification of four new agr quorum sensing-interfering cyclodepsipeptides from a marine Photobacterium. Mar Drugs 2013; 11:5051-62. [PMID: 24351904 PMCID: PMC3877902 DOI: 10.3390/md11125051] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/21/2013] [Accepted: 12/02/2013] [Indexed: 12/21/2022] Open
Abstract
During our search for new natural products from the marine environment, we discovered a wide range of cyclic peptides from a marine Photobacterium, closely related to P. halotolerans. The chemical fingerprint of the bacterium showed primarily non-ribosomal peptide synthetase (NRPS)-like compounds, including the known pyrrothine antibiotic holomycin and a wide range of peptides, from diketopiperazines to cyclodepsipeptides of 500–900 Da. Purification of components from the pellet fraction led to the isolation and structure elucidation of four new cyclodepsipeptides, ngercheumicin F, G, H, and I. The ngercheumicins interfered with expression of virulence genes known to be controlled by the agr quorum sensing system of Staphylococcus aureus, although to a lesser extent than the previously described solonamides from the same strain of Photobacterium.
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35
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Tal-Gan Y, Ivancic M, Cornilescu G, Cornilescu CC, Blackwell HE. Structural characterization of native autoinducing peptides and abiotic analogues reveals key features essential for activation and inhibition of an AgrC quorum sensing receptor in Staphylococcus aureus. J Am Chem Soc 2013; 135:18436-44. [PMID: 24219181 DOI: 10.1021/ja407533e] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Staphylococcus aureus is a major human pathogen that uses quorum sensing (QS) to control virulence. Its QS system is regulated by macrocyclic peptide signals (or autoinducing peptides (AIPs)) and their cognate transmembrane receptors (AgrCs). Four different specificity groups of S. aureus have been identified to date (groups I-IV), each of which uses a different AIP:AgrC pair. Non-native ligands capable of intercepting AIP:AgrC binding, and thereby QS, in S. aureus have attracted considerable interest as chemical tools to study QS pathways and as possible antivirulence strategies for the treatment of infection. We recently reported a set of analogues of the group-III AIP that are capable of strongly modulating the activity of all four AgrC receptors. Critical to the further development of such ligands is a detailed understanding of the structural features of both native AIPs and non-native analogues that are essential for activity. Herein, we report the first three-dimensional structural analysis of the known native AIP signals (AIPs-I-IV) and several AIP-III analogues with varied biological activities using NMR spectroscopy. Integration of these NMR studies with the known agonism and antagonism profiles of these peptides in AgrC-III revealed two key structural elements that control AIP-III (and non-native peptide) activity: (1) a tri-residue hydrophobic "knob" essential for both activation and inhibition and (2) a fourth anchor point on the exocyclic tail needed for receptor activation. These results provide strong structural support for a mechanism of AIP-mediated AgrC activation and inhibition in S. aureus , and should facilitate the design of new AgrC ligands with enhanced activities (as agonists or antagonists) and simplified chemical structures.
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Affiliation(s)
- Yftah Tal-Gan
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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Arya R, Princy SA. An insight into pleiotropic regulators Agr and Sar: molecular probes paving the new way for antivirulent therapy. Future Microbiol 2013; 8:1339-53. [DOI: 10.2217/fmb.13.92] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Staphylococcus aureus pathogenesis is an intricate process involving a diverse array of extracellular proteins, biofilm and cell wall components that are coordinately expressed in different stages of infection. The expression of two divergent loci, agr and sar, is increasingly recognized as a key regulator of virulence in S. aureus, and there is mounting evidence for the role of these loci in staphylococcal infections. The functional agr regulon is critical for the production of virulence factors, including α, β and δ hemolysins. The sar locus encodes SarA protein, which regulates the expression of cell wall-associated and certain extracellular proteins in agr-dependent and agr-independent pathways. Multidrug-resistant S. aureus is a leading cause of morbidity and mortality in the world and its management, especially in community-acquired methicillin-resistant S. aureus infections, has evolved comparatively little. In particular, no novel targets have been incorporated into its treatment to date. Hence, these loci appear to be the most significant and are currently at the attention of intense investigation regarding their therapeutic prospects.
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Affiliation(s)
- Rekha Arya
- Quorum Sensing Laboratory, SASTRA‘s Hub for Research & Innovation (SHRI), School of Chemical & Biotechnology, SASTRA University, Tirumalaisamudrum 613401, Thanjavur, Tamil Nadu, India
| | - S Adline Princy
- Quorum Sensing Laboratory, SASTRA‘s Hub for Research & Innovation (SHRI), School of Chemical & Biotechnology, SASTRA University, Tirumalaisamudrum 613401, Thanjavur, Tamil Nadu, India
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Interactions of the intact FsrC membrane histidine kinase with its pheromone ligand GBAP revealed through synchrotron radiation circular dichroism. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:1595-602. [DOI: 10.1016/j.bbamem.2012.02.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 02/08/2012] [Accepted: 02/10/2012] [Indexed: 11/22/2022]
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Allele-dependent differences in quorum-sensing dynamics result in variant expression of virulence genes in Staphylococcus aureus. J Bacteriol 2012; 194:2854-64. [PMID: 22467783 DOI: 10.1128/jb.06685-11] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Agr is an autoinducing, quorum-sensing system that functions in many Gram-positive species and is best characterized in the pathogen Staphylococcus aureus, in which it is a global regulator of virulence gene expression. Allelic variations in the agr genes have resulted in the emergence of four quorum-sensing specificity groups in S. aureus, which correlate with different strain pathotypes. The basis for these predilections is unclear but is hypothesized to involve the phenomenon of quorum-sensing interference between strains of different agr groups, which may drive S. aureus strain isolation and divergence. Whether properties intrinsic to each agr allele directly influence virulence phenotypes within S. aureus is unknown. In this study, we examined group-specific differences in agr autoinduction and virulence gene regulation by utilizing congenic strains, each harboring a unique S. aureus agr allele, enabling a dissection of agr locus-dependent versus genotype-dependent effects on quorum-sensing dynamics and virulence factor production. Employing a reporter fusion to the principal agr promoter, P3, we observed allele-dependent differences in the timing and magnitude of agr activation. These differences were mediated by polymorphisms within the agrBDCA genes and translated to significant variations in the expression of a key transcriptional regulator, Rot, and of several important exoproteins and surface factors involved in pathogenesis. This work uncovers the contribution of divergent quorum-sensing alleles to variant expression of virulence determinants within a bacterial species.
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Kirchdoerfer RN, Garner AL, Flack CE, Mee JM, Horswill AR, Janda KD, Kaufmann GF, Wilson IA. Structural basis for ligand recognition and discrimination of a quorum-quenching antibody. J Biol Chem 2011; 286:17351-8. [PMID: 21454495 PMCID: PMC3089576 DOI: 10.1074/jbc.m111.231258] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 03/13/2011] [Indexed: 11/06/2022] Open
Abstract
In the postantibiotic era, available treatment options for severe bacterial infections caused by methicillin-resistant Staphylococcus aureus have become limited. Therefore, new and innovative approaches are needed to combat such life-threatening infections. Virulence factor expression in S. aureus is regulated in a cell density-dependent manner using "quorum sensing," which involves generation and secretion of autoinducing peptides (AIPs) into the surrounding environment to activate a bacterial sensor kinase at a particular threshold concentration. Mouse monoclonal antibody AP4-24H11 was shown previously to blunt quorum sensing-mediated changes in gene expression in vitro and protect mice from a lethal dose of S. aureus by sequestering the AIP signal. We have elucidated the crystal structure of the AP4-24H11 Fab in complex with AIP-4 at 2.5 Å resolution to determine its mechanism of ligand recognition. A key Glu(H95) provides much of the binding specificity through formation of hydrogen bonds with each of the four amide nitrogens in the AIP-4 macrocyclic ring. Importantly, these structural data give clues as to the interactions between the cognate staphylococcal AIP receptors AgrC and the AIPs, as AP4-24H11·AIP-4 binding recapitulates features that have been proposed for AgrC-AIP recognition. Additionally, these structural insights may enable the engineering of AIP cross-reactive antibodies or quorum quenching vaccines for use in active or passive immunotherapy for prevention or treatment of S. aureus infections.
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Affiliation(s)
| | | | - Caralyn E. Flack
- the Department of Microbiology, University of Iowa, Iowa City, Iowa 52242
| | | | | | - Kim D. Janda
- Chemistry and Immunology & Microbial Science
- The Skaggs Institute for Chemical Biology
- Worm Institute for Research and Medicine, The Scripps Research Institute, La Jolla, California 92037 and
| | | | - Ian A. Wilson
- From the Departments of Molecular Biology and
- The Skaggs Institute for Chemical Biology
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40
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Perry J, Koteva K, Wright G. Receptor domains of two-component signal transduction systems. MOLECULAR BIOSYSTEMS 2011; 7:1388-98. [PMID: 21347487 DOI: 10.1039/c0mb00329h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Two-component signal transduction systems are found ubiquitously in prokaryotes, and in archaea, fungi, yeast and some plants, where they regulate physiologic and molecular processes at both transcriptional and post-transcriptional levels. Two-component systems sense changes in environmental conditions when a specific ligand binds to the receptor domain of the histidine kinase sensory component. The structures of many histidine kinase receptors are known, including those which sense extracellular and cytoplasmic signals. In this review, we discuss the basic architecture of two-component signalling circuits, including known system ligands, structure and function of both receptor and signalling domains, the chemistry of phosphotransfer, and cross-talk between different two-component pathways. Given the importance of these systems in regulating cellular responses, many biochemical techniques have been developed for their study and analysis. We therefore also review current methods used to study two-component signalling, including a new affinity-based proteomics approach used to study inducible resistance to the antibiotic vancomycin through the VanSR two-component signal transduction system.
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Affiliation(s)
- Julie Perry
- MG DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1200 Main St W, Hamilton, Ontario, Canada
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Kalia VC, Purohit HJ. Quenching the quorum sensing system: potential antibacterial drug targets. Crit Rev Microbiol 2011; 37:121-40. [PMID: 21271798 DOI: 10.3109/1040841x.2010.532479] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Emergence of antibiotic and multi-drug resistant pathogenic bacteria has created the need for new drugs and drug targets. During pathogenesis bacteria release signals which regulate virulence and pathogenicity related genes. Such bacteria co-ordinate their virulent behaviour in a cell density dependent phenomenon termed as quorum sensing (QS). In contrast, microbes interfere with QS system by quenching the signals, termed quorum quenching (QQ). As a consequence of disrupted QS, pathogens become susceptible to antibiotics and drugs. In this article, the biodiversity of organisms with potential to quench QS signals and the use of QQ molecules as antibacterial drugs have been reviewed.
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Affiliation(s)
- Vipin Chandra Kalia
- Microbial Biotechnology and Genomics, Institute of Genomics and Integrative Biology (IGIB), CSIR, Delhi University Campus, Mall Road, Delhi-110007, India.
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42
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Thoendel M, Kavanaugh JS, Flack CE, Horswill AR. Peptide signaling in the staphylococci. Chem Rev 2010; 111:117-51. [PMID: 21174435 DOI: 10.1021/cr100370n] [Citation(s) in RCA: 288] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Matthew Thoendel
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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Amara N, Krom BP, Kaufmann GF, Meijler MM. Macromolecular inhibition of quorum sensing: enzymes, antibodies, and beyond. Chem Rev 2010; 111:195-208. [PMID: 21087050 DOI: 10.1021/cr100101c] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Neri Amara
- Department of Chemistry and National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva, Israel
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Combining Biofilm-Controlling Compounds and Antibiotics as a Promising New Way to Control Biofilm Infections. Pharmaceuticals (Basel) 2010; 3:1374-1393. [PMID: 27713308 PMCID: PMC4033987 DOI: 10.3390/ph3051374] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 04/20/2010] [Accepted: 04/30/2010] [Indexed: 12/24/2022] Open
Abstract
Many bacteria grow on surfaces forming biofilms. In this structure, they are well protected and often high dosages of antibiotics cannot clear infectious biofilms. The formation and stabilization of biofilms are mediated by diffusible autoinducers (e.g. N-acyl homoserine lactones, small peptides, furanosyl borate diester). Metabolites interfering with this process have been identified in plants, animals and microbes, and synthetic analogues are known. Additionally, this seems to be not the only way to control biofilms. Enzymes capable of cleaving essential components of the biofilm matrix, e.g. polysaccharides or extracellular DNA, and thus weakening the biofilm architecture have been identified. Bacteria also have mechanisms to dissolve their biofilms and return to planktonic lifestyle. Only a few compounds responsible for the signalling of these processes are known, but they may open a completely novel line of biofilm control. All these approaches lead to the destruction of the biofilm but not the killing of the pathogens. Therefore, a combination of biofilm-destroying compounds and antibiotics to handle biofilm infections is proposed. In this article, different approaches to combine biofilm-controlling compounds and antibiotics to fight biofilm infections are discussed, as well as the balance between biofilm formation and virulence.
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45
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Probing bacterial transmembrane histidine kinase receptor-ligand interactions with natural and synthetic molecules. Proc Natl Acad Sci U S A 2010; 107:5575-80. [PMID: 20212168 DOI: 10.1073/pnas.1001392107] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacterial histidine kinases transduce extracellular signals into the cytoplasm. Most stimuli are chemically undefined; therefore, despite intensive study, signal recognition mechanisms remain mysterious. We exploit the fact that quorum-sensing signals are known molecules to identify mutants in the Vibrio cholerae quorum-sensing receptor CqsS that display altered responses to natural and synthetic ligands. Using this chemical-genetics approach, we assign particular amino acids of the CqsS sensor to particular roles in recognition of the native ligand, CAI-1 (S-3 hydroxytridecan-4-one) as well as ligand analogues. Amino acids W104 and S107 dictate receptor preference for the carbon-3 moiety. Residues F162 and C170 specify ligand head size and tail length, respectively. By combining mutations, we can build CqsS receptors responsive to ligand analogues altered at both the head and tail. We suggest that rationally designed ligands can be employed to study, and ultimately to control, histidine kinase activity.
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Chen LC, Tsou LT, Chen FJ. Ligand-receptor recognition for activation of quorum sensing in Staphylococcus aureus. J Microbiol 2009; 47:572-81. [PMID: 19851730 DOI: 10.1007/s12275-009-0004-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 06/16/2009] [Indexed: 12/22/2022]
Abstract
The accessory gene regulator (agr) locus controls many of the virulence toxins involved in Staphylococcus aureus pathogenesis, and can be divided into four specificity groups. AgrC is the only group-specific receptor to mediate both intra-group activation and inter-group inhibition. We studied the ligand-receptor recognition of the agr system in depth by using a luciferase reporter system to identify the key residues responsible for AgrC activation in two closely related agr groups, AgrC-I, and AgrC-IV. Fusion PCR and site-directed mutagenesis were used to screen for functional residues of AgrC. Our data suggest that for AgrC-IV activation, residue 101 is critical for activating the receptor. In contrast, the key residues for the activation of AgrC-I are located at residues 49 approximately 59, 107, and 116. However, three residue changes, T101A, V107S, I116S, are sufficient to convert the AIP recognizing specificity from AgrC-IV to AgrC-I.
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Affiliation(s)
- Li-Chun Chen
- Division of Infectious Diseases, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
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47
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Abstract
The staphylococcal agr locus encodes a quorum sensing (QS) system that controls the expression of virulence and other accessory genes by a classical two-component signaling module. Like QS modalities in other Gram-positive bacteria, agr encodes an autoactivating peptide (AIP) that is the inducing ligand for AgrC, the agr signal receptor. Unlike other such systems, agr variants have arisen that show strong cross-inhibition in heterologous combinations, with important evolutionary implications. Also unlike other systems, the effector of global gene regulation in the agr system is a major regulatory RNA, RNAIII. In this review, we describe the functions of the agr system's elements, show how they interact to bring about the regulatory response, and discuss the role of QS in staphylococcal pathobiology. We conclude with the suggestion that agr autoactivation, unlike classical enzyme induction, can occur under suboptimal conditions and can distinguish self from non-self by inducing an exclusive and coordinated population wide response.
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Affiliation(s)
- Richard P Novick
- Kimmel Center for Biology and Medicine, New York University Medical Center, New York, New York 10016, USA.
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48
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agr receptor mutants reveal distinct modes of inhibition by staphylococcal autoinducing peptides. Proc Natl Acad Sci U S A 2009; 106:1216-21. [PMID: 19147840 DOI: 10.1073/pnas.0807760106] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Through the agr quorum-sensing system, staphylococci secrete unique autoinducing peptides (AIPs) and detect their concentration via the AgrC transmembrane receptor, coordinating local bacterial population density with global changes in gene expression. Unique AIP and AgrC variants exist within and between species, and although autologous interactions lead to agr activation, heterologous interactions usually lead to cross-inhibition, resulting in natural quorum-sensing interference. To gain insight into the mechanisms responsible for these phenomena at the level of the receptor, we used random mutagenesis to isolate variants of Staphylococcus aureus AgrC-I with constitutive activity. Constitutive mutations in the sensor domain of the receptor were localized to the last transmembrane helix, whereas those in the histidine kinase domain were mostly clustered to a region near the phosphorylation site histidine. Analysis of these mutants with a range of noncognate AIPs revealed that inhibition is manifested by inverse agonism in certain heterologous pairings and by neutral antagonism in others. In addition, we isolated and characterized an AgrC sensor domain mutant with dramatically broadened activation specificity and reduced sensitivity to inhibition, identifying a single amino acid as a critical determinant of ligand-mediated inhibition. These results suggest that certain noncognate AIPs stabilize an inhibitory receptor conformation that may be a critical feature of the ligand-receptor interaction not initially appreciated in previous analyses of agr inhibition.
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49
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Peterson MM, Mack JL, Hall PR, Alsup AA, Alexander SM, Sully EK, Sawires YS, Cheung AL, Otto M, Gresham HD. Apolipoprotein B Is an innate barrier against invasive Staphylococcus aureus infection. Cell Host Microbe 2009; 4:555-66. [PMID: 19064256 DOI: 10.1016/j.chom.2008.10.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Revised: 08/08/2008] [Accepted: 10/06/2008] [Indexed: 11/17/2022]
Abstract
Staphylococcus aureus is both a colonizer of humans and a cause of severe invasive infections. Although the genetic basis for phenotype switching from colonizing to invasive has received significant study, knowledge of host factors that antagonize the switch is limited. We show that VLDL and LDL lipoproteins interfere with this switch by antagonizing the S. aureus agr quorum-sensing system that upregulates genes required for invasive infection. The mechanism of antagonism entails binding of the major structural protein of these lipoproteins, apolipoprotein B, to an S. aureus autoinducing pheromone, preventing attachment of this pheromone to the bacteria and subsequent signaling through its receptor, AgrC. Mice deficient in plasma apolipoprotein B, either genetically or pharmacologically, are more susceptible to invasive agr+ bacterial infection, but not to infection with an agr deletion mutant. Therefore, apolipoprotein B at homeostatic levels in blood is an essential innate defense effector against invasive S. aureus infection.
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Affiliation(s)
- M Michal Peterson
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
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50
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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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