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Kędzierska-Mieszkowska S, Kędzierska B, Potrykus K. LIC_12757 from the pathogenic spirochaete Leptospira interrogans encodes an autoregulated ECF σ E-type factor. Vet Microbiol 2024; 293:110092. [PMID: 38615476 DOI: 10.1016/j.vetmic.2024.110092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 03/19/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
ECF (extracytoplasmic function) σ factors, members of the σ70-family, are the largest class of alternative σ factors which are stimulated in the presence of specific signals and direct RNA polymerase to transcribe a defined subset of genes. Thanks to them, bacterial pathogens can effectively reprogram their gene expression and, consequently, survive in the host and establish infection in a relatively short time. The number of ECF σ factors encoded within bacterial genomes is different depending on a given species and it reflects the likelihood that these bacteria will encounter harsh environmental conditions. The genome of L. interrogans, a zoonotic pathogen responsible for leptospirosis, is predicted to encode 11 ECF σE-type factors, but none of them have been characterized biochemically to date and their functions are still unknown. Here, we focused on one of the leptospiral ECF σ factors, namely LIC_12757, which was previously found to be up-regulated at elevated temperatures and may be related to the expression of clpB encoding an important L. interrogans virulence factor. We report cloning of the coding sequence of the LIC_12757 gene, its expression with the pET system and biochemical characterization of LIC_12757. By performing EMSA and in vitro transcription assays, we provide strong evidence that LIC_12757 indeed functions as a transcriptional factor that enables RNA polymerase to bind to the specific σE-type promoter and to initiate transcription. Interestingly, we demonstrate that LIC_12757 is autoregulated at the transcriptional level. Our study is a first step towards determining key aspects of LIC_12757 function in pathogenic Leptospira.
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Affiliation(s)
| | - Barbara Kędzierska
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk 80-308, Poland
| | - Katarzyna Potrykus
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk 80-308, Poland
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Kędzierska-Mieszkowska S, Arent Z. Immunoreactivity of a Putative ECF σ Factor, LIC_10559, from Leptospira interrogans with Sera from Leptospira-Infected Animals. Pathogens 2023; 12:pathogens12040512. [PMID: 37111398 PMCID: PMC10144590 DOI: 10.3390/pathogens12040512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/17/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
L. interrogans belongs to highly invasive spirochaetes causing leptospirosis in mammals, including humans. During infection, this pathogen is exposed to various stressors, and therefore, it must reprogram its gene expression to survive in the host and establish infection in a short duration of time. Host adaptation is possible thanks to molecular responses where appropriate regulators and signal transduction systems participate. Among the bacterial regulators, there are σ factors, including ECF (extracytoplasmic function) σ factors. The L. interrogans genome encodes 11 putative ECF σE-type factors. Currently, none of them has been characterized biochemically, and their functions are still unknown. One of them, LIC_10559, is the most likely to be active during infection because it is only found in the highly pathogenic Leptospira. The aim of this study was to achieve LIC_10559 overexpression to answer the question whether it may be a target of the humoral immune response during leptospiral infections. The immunoreactivity of the recombinant LIC_10559 was evaluated by SDS-PAGE, ECL Western blotting and ELISA assay using sera collected from Leptospira-infected animals and uninfected healthy controls. We found that LIC_10559 was recognized by IgG antibodies from the sera of infected animals and is, therefore, able to induce the host’s immune response to pathogenic Leptospira. This result suggests the involvement of LIC_10559 in the pathogenesis of leptospirosis.
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Affiliation(s)
- Sabina Kędzierska-Mieszkowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, 80-308 Gdańsk, Poland
- Correspondence: ; Tel.: +48-58-523-6064
| | - Zbigniew Arent
- University Centre of Veterinary Medicine UAK, University of Agriculture in Krakow, 30-059 Krakow, Poland;
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Hsp100 Molecular Chaperone ClpB and Its Role in Virulence of Bacterial Pathogens. Int J Mol Sci 2021; 22:ijms22105319. [PMID: 34070174 PMCID: PMC8158500 DOI: 10.3390/ijms22105319] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 01/05/2023] Open
Abstract
This review focuses on the molecular chaperone ClpB that belongs to the Hsp100/Clp subfamily of the AAA+ ATPases and its biological function in selected bacterial pathogens, causing a variety of human infectious diseases, including zoonoses. It has been established that ClpB disaggregates and reactivates aggregated cellular proteins. It has been postulated that ClpB’s protein disaggregation activity supports the survival of pathogenic bacteria under host-induced stresses (e.g., high temperature and oxidative stress), which allows them to rapidly adapt to the human host and establish infection. Interestingly, ClpB may also perform other functions in pathogenic bacteria, which are required for their virulence. Since ClpB is not found in human cells, this chaperone emerges as an attractive target for novel antimicrobial therapies in combating bacterial infections.
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AAA+ Molecular Chaperone ClpB in Leptospira interrogans: Its Role and Significance in Leptospiral Virulence and Pathogenesis of Leptospirosis. Int J Mol Sci 2020; 21:ijms21186645. [PMID: 32932775 PMCID: PMC7555560 DOI: 10.3390/ijms21186645] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/31/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
Bacterial ClpB is an ATP-dependent disaggregase that belongs to the Hsp100/Clp subfamily of the AAA+ ATPases and cooperates with the DnaK chaperone system in the reactivation of aggregated proteins, as well as promotes bacterial survival under adverse environmental conditions, including thermal and oxidative stresses. In addition, extensive evidence indicates that ClpB supports the virulence of numerous bacteria, including pathogenic spirochaete Leptospira interrogans responsible for leptospirosis in animals and humans. However, the specific function of ClpB in leptospiral virulence still remains to be fully elucidated. Interestingly, ClpB was predicted as one of the L. interrogans hub proteins interacting with human proteins, and pathogen–host protein interactions are fundamental for successful invasion of the host immune system by bacteria. The aim of this review is to discuss the most important aspects of ClpB’s function in L. interrogans, including contribution of ClpB to leptospiral virulence and pathogenesis of leptospirosis, a zoonotic disease with a significant impact on public health worldwide.
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Kędzierska-Mieszkowska S, Potrykus K, Arent Z, Krajewska J. Identification of σ E-Dependent Promoter Upstream of clpB from the Pathogenic Spirochaete Leptospira interrogans by Applying an E. coli Two-Plasmid System. Int J Mol Sci 2019; 20:ijms20246325. [PMID: 31847479 PMCID: PMC6941012 DOI: 10.3390/ijms20246325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 11/16/2022] Open
Abstract
There is limited information on gene expression in the pathogenic spirochaete Leptospira interrogans and genetic mechanisms controlling its virulence. Transcription is the first step in gene expression that is often determined by environmental effects, including infection-induced stresses. Alterations in the environment result in significant changes in the transcription of many genes, allowing effective adaptation of Leptospira to mammalian hosts. Thus, promoter and transcriptional start site identification are crucial for determining gene expression regulation and for the understanding of genetic regulatory mechanisms existing in Leptospira. Here, we characterized the promoter region of the L. interrogans clpB gene (clpBLi) encoding an AAA+ molecular chaperone ClpB essential for the survival of this spirochaete under thermal and oxidative stresses, and also during infection of the host. Primer extension analysis demonstrated that transcription of clpB in L. interrogans initiates at a cytidine located 41 bp upstream of the ATG initiation codon, and, to a lesser extent, at an adenine located 2 bp downstream of the identified site. Transcription of both transcripts was heat-inducible. Determination of clpBLi transcription start site, combined with promoter transcriptional activity assays using a modified two-plasmid system in E. coli, revealed that clpBLi transcription is controlled by the ECF σE factor. Of the ten L. interrogans ECF σ factors, the factor encoded by LIC_12757 (LA0876) is most likely to be the key regulator of clpB gene expression in Leptospira cells, especially under thermal stress. Furthermore, clpB expression may be mediated by ppGpp in Leptospira.
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Affiliation(s)
- Sabina Kędzierska-Mieszkowska
- Department of General and Medical Biochemistry, University of Gdańsk, Faculty of Biology, 80-308 Gdańsk, Poland;
- Correspondence: ; Tel./Fax: +48-58-523-6064
| | - Katarzyna Potrykus
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, 80-308 Gdańsk, Poland;
| | - Zbigniew Arent
- University Centre of Veterinary Medicine, University of Agriculture in Krakow, 30-059 Krakow, Poland;
| | - Joanna Krajewska
- Department of General and Medical Biochemistry, University of Gdańsk, Faculty of Biology, 80-308 Gdańsk, Poland;
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Isolation and Identification of Putative Protein Substrates of the AAA+ Molecular Chaperone ClpB from the Pathogenic Spirochaete Leptospira interrogans. Int J Mol Sci 2018; 19:ijms19041234. [PMID: 29670056 PMCID: PMC5979558 DOI: 10.3390/ijms19041234] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/13/2018] [Accepted: 04/15/2018] [Indexed: 01/22/2023] Open
Abstract
Bacterial ClpB is an ATP-dependent Hsp100 chaperone that reactivates aggregated proteins in cooperation with the DnaK chaperone system and promotes survival of bacteria under stress conditions. A large number of publications also indicate that ClpB supports the virulence of bacteria, including a pathogenic spirochaete Leptospira interrogans responsible for leptospirosis in both animals and humans. However, the exact role of ClpB in bacterial pathogenicity remains poorly characterized. It can be assumed that ClpB, due to its role as the molecular chaperone, mediates refolding of essential bacterial proteins, including the known virulence factors, which may become prone to aggregation under infection-induced stresses. In this study, we identified putative substrates of ClpB from L. interrogans (ClpBLi). For this purpose, we used a proteomic approach combining the ClpB-Trap affinity pull-down assays, Liquid chromatography-tandem mass spectrometry (LC-MS-MS/MS), and bioinformatics analyses. Most of the identified proteins were enzymes predominantly associated with major metabolic pathways like the tricarboxylic acid (TCA) cycle, glycolysis–gluconeogenesis and amino acid and fatty acid metabolism. Based on our proteomic study, we suggest that ClpB can support the virulence of L.interrogans by protecting the conformational integrity and catalytic activity of multiple metabolic enzymes, thus maintaining energy homeostasis in pathogen cells.
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Ghazaei C. Pathogenic Leptospira: Advances in understanding the molecular pathogenesis and virulence. Open Vet J 2018; 8:13-24. [PMID: 29445617 PMCID: PMC5806663 DOI: 10.4314/ovj.v8i1.4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 01/08/2018] [Indexed: 12/16/2022] Open
Abstract
Leptospirosis is a common zoonotic disease has emerged as a major public health problem, with developing countries bearing disproportionate burdens. Although the diverse range of clinical manifestations of the leptospirosis in humans is widely documented, the mechanisms through which the pathogen causes disease remain undetermined. In addition, leptospirosis is a much-neglected life-threatening disease although it is one of the most important zoonoses occurring in a diverse range of epidemiological distribution. Recent advances in molecular profiling of pathogenic species of the genus Leptospira have improved our understanding of the evolutionary factors that determine virulence and mechanisms that the bacteria employ to survive. However, a major impediment to the formulation of intervention strategies has been the limited understanding of the disease determinants. Consequently, the association of the biological mechanisms to the pathogenesis of Leptospira, as well as the functions of numerous essential virulence factors still remain implicit. This review examines recent advances in genetic screening technologies, the underlying microbiological processes, the virulence factors and associated molecular mechanisms driving pathogenesis of Leptospira species.
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Affiliation(s)
- Ciamak Ghazaei
- Department of Microbiology, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, Iran
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Krajewska J, Modrak-Wójcik A, Arent ZJ, Więckowski D, Zolkiewski M, Bzowska A, Kędzierska-Mieszkowska S. Characterization of the molecular chaperone ClpB from the pathogenic spirochaete Leptospira interrogans. PLoS One 2017; 12:e0181118. [PMID: 28700685 PMCID: PMC5507356 DOI: 10.1371/journal.pone.0181118] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/26/2017] [Indexed: 11/18/2022] Open
Abstract
Leptospira interrogans is a spirochaete responsible for leptospirosis in mammals. The molecular mechanisms of the Leptospira virulence remain mostly unknown. Recently, it has been demonstrated that an AAA+ chaperone ClpB (a member of the Hsp100 family) from L. interrogans (ClpBLi) is not only essential for survival of Leptospira under the thermal and oxidative stresses, but also during infection of a host. The aim of this study was to provide further insight into the role of ClpB in the pathogenic spirochaetes and explore its biochemical properties. We found that a non-hydrolysable ATP analogue, ATPγS, but not AMP-PNP induces the formation of ClpBLi hexamers and stabilizes the associated form of the chaperone. ADP also induces structural changes in ClpBLi and promotes its self-assembly, but does not produce full association into the hexamers. We also demonstrated that ClpBLi exhibits a weak ATPase activity that is stimulated by κ-casein and poly-lysine, and may mediate protein disaggregation independently from the DnaK chaperone system. Unexpectedly, the presence of E. coli DnaK/DnaJ/GrpE did not significantly affect the disaggregation activity of ClpBLi and ClpBLi did not substitute for the ClpBEc function in the clpB-null E. coli strain. This result underscores the species-specificity of the ClpB cooperation with the co-chaperones and is most likely due to a loss of interactions between the ClpBLi middle domain and the E. coli DnaK. We also found that ClpBLi interacts more efficiently with the aggregated G6PDH in the presence of ATPγS rather than ATP. Our results indicate that ClpB's importance during infection might be due to its role as a molecular chaperone involved in reactivation of protein aggregates.
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Affiliation(s)
- Joanna Krajewska
- Department of General and Medical Biochemistry, University of Gdańsk, Faculty of Biology, Gdańsk, Poland
| | - Anna Modrak-Wójcik
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Zbigniew J. Arent
- University Centre of Veterinary Medicine UJ-UR, University of Agriculture in Krakow, Krakow, Poland
| | - Daniel Więckowski
- Department of General and Medical Biochemistry, University of Gdańsk, Faculty of Biology, Gdańsk, Poland
| | - Michal Zolkiewski
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas, United States of America
| | - Agnieszka Bzowska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
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