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Govta N, Fatiukha A, Govta L, Pozniak C, Distelfeld A, Fahima T, Beckles DM, Krugman T. Nitrogen deficiency tolerance conferred by introgression of a QTL derived from wild emmer into bread wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:187. [PMID: 39020219 PMCID: PMC11255033 DOI: 10.1007/s00122-024-04692-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 07/04/2024] [Indexed: 07/19/2024]
Abstract
KEY MESSAGE Genetic dissection of a QTL from wild emmer wheat, QGpc.huj.uh-5B.2, introgressed into bread wheat, identified candidate genes associated with tolerance to nitrogen deficiency, and potentially useful for improving nitrogen-use efficiency. Nitrogen (N) is an important macronutrient critical to wheat growth and development; its deficiency is one of the main factors causing reductions in grain yield and quality. N availability is significantly affected by drought or flooding, that are dependent on additional factors including soil type or duration and severity of stress. In a previous study, we identified a high grain protein content QTL (QGpc.huj.uh-5B.2) derived from the 5B chromosome of wild emmer wheat, that showed a higher proportion of explained variation under water-stress conditions. We hypothesized that this QTL is associated with tolerance to N deficiency as a possible mechanism underlying the higher effect under stress. To validate this hypothesis, we introgressed the QTL into the elite bread wheat var. Ruta, and showed that under N-deficient field conditions the introgression IL99 had a 33% increase in GPC (p < 0.05) compared to the recipient parent. Furthermore, evaluation of IL99 response to severe N deficiency (10% N) for 14 days, applied using a semi-hydroponic system under controlled conditions, confirmed its tolerance to N deficiency. Fine-mapping of the QTL resulted in 26 homozygous near-isogenic lines (BC4F5) segregating to N-deficiency tolerance. The QTL was delimited from - 28.28 to - 1.29 Mb and included 13 candidate genes, most associated with N-stress response, N transport, and abiotic stress responses. These genes may improve N-use efficiency under severely N-deficient environments. Our study demonstrates the importance of WEW as a source of novel candidate genes for sustainable improvement in tolerance to N deficiency in wheat.
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Affiliation(s)
- Nikolai Govta
- Wild Cereal Gene Bank, Institute of Evolution, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Andrii Fatiukha
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
- Crop Development Centre and Department of Plant Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Liubov Govta
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Curtis Pozniak
- Crop Development Centre and Department of Plant Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Assaf Distelfeld
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Tzion Fahima
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Diane M Beckles
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Tamar Krugman
- Wild Cereal Gene Bank, Institute of Evolution, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel.
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A Regulatory SRNA Rli43 Is Involved in the Modulation of Biofilm Formation and Virulence in Listeria monocytogenes. Pathogens 2022; 11:pathogens11101137. [PMID: 36297193 PMCID: PMC9606912 DOI: 10.3390/pathogens11101137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/11/2022] [Accepted: 09/28/2022] [Indexed: 11/24/2022] Open
Abstract
Small RNAs (sRNAs) are a kind of regulatory molecule that can modulate gene expression at the post-transcriptional level, thereby involving alteration of the physiological characteristics of bacteria. However, the regulatory roles and mechanisms of most sRNAs remain unknown in Listeria monocytogenes(L. monocytogenes). To explore the regulatory roles of sRNA Rli43 in L. monocytogenes, the rli43 gene deletion strain LM-Δrli43 and complementation strain LM-Δrli43-rli43 were constructed to investigate the effects of Rli43 on responses to environmental stress, biofilm formation, and virulence, respectively. Additionally, Rli43-regulated target genes were identified using bioinformatic analysis tools and a bacterial dual plasmid reporter system based on E. coli. The results showed that the intracellular expression level of the rli43 gene was significantly upregulated compared with those under extracellular conditions. Compared with the parental and complementation strains, the environmental adaptation, motility, biofilm formation, adhesion, invasion, and intracellular survival of LM-Δrli43 were significantly reduced, respectively, whereas the LD50 of LM-Δrli43 was significantly elevated in BALB/c mice. Furthermore, the bacterial loads and pathological damages were alleviated, suggesting that sRNA Rli43 was involved in the modulation of the virulence of L. monocytogenes. It was confirmed that Rli43 may complementarily pair with the 5'-UTR (-47--55) of HtrA mRNA, thereby regulating the expression level of HtrA protein at the post-transcriptional level. These findings suggest that Rli43-mediated control was involved in the modulation of environmental adaptation, biofilm formation, and virulence in L. monocytogenes.
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3
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Qi W, Li XX, Guo YH, Bao YZ, Wang N, Luo XG, Yu CD, Zhang TC. Integrated metabonomic-proteomic analysis reveals the effect of glucose stress on metabolic adaptation of Lactococcus lactis ssp. lactis CICC23200. J Dairy Sci 2020; 103:7834-7850. [PMID: 32684472 DOI: 10.3168/jds.2019-17810] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 04/14/2020] [Indexed: 12/30/2022]
Abstract
A combined proteomic and metabonomic approach was used to investigate the metabolism of Lactococcus lactis ssp. lactis subjected to glucose stress treatment. A proteomic method was used to determine 1,427 altered proteins, including 278 proteins with increased expression and 255 proteins with decreased expression. A metabonomic approach was adopted to identify 98 altered metabolites, including 62 metabolites with increased expression and 26 metabolites with decreased expression. The integrated analysis indicated that the RNA and DNA mismatch repair process and energy metabolism were enhanced in response to high-glucose stress in L. lactis. Lactococcus lactis responded to glucose stress by up-regulating oxidoreductase activity, which acted on glycosyl bonds, hydrolase activity, and organic acid transmembrane transporter activity. This led to an improvement in the metabolic flux from glucose to pyruvate, lactate, acetate, and maltose. Down-regulation of amino acid transmembrane transporter, aminoacyl-transfer RNA ligase, hydroxymethyl-, formyl-, and related transferase activities resulted in a decrease in the nitrogen metabolism-associated metabolic pathway, which might be related to inhibition of the production of biogenic amines. Overall, we highlight the response of metabolism to glucose stress and provide potential possibilities for the reduced formation of biogenic amines in improved level of sugar in the dairy fermentation industry. Moreover, according to the demand for industrial production, sugar concentration in fermented foods should be higher, or lower, than a set value that is dependent on bacterial strain and biogenic amine yield.
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Affiliation(s)
- Wei Qi
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China.
| | - Xiao-Xue Li
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Yao-Hua Guo
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Yan-Zhou Bao
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Nan Wang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Xue-Gang Luo
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Chun-Di Yu
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, P.R. China
| | - Tong-Cun Zhang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China.
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Boehm M, Simson D, Escher U, Schmidt AM, Bereswill S, Tegtmeyer N, Backert S, Heimesaat MM. Function of Serine Protease HtrA in the Lifecycle of the Foodborne Pathogen Campylobacter jejuni. Eur J Microbiol Immunol (Bp) 2018; 8:70-77. [PMID: 30345086 PMCID: PMC6186014 DOI: 10.1556/1886.2018.00011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/18/2018] [Indexed: 12/19/2022] Open
Abstract
Campylobacter jejuni is a major food-borne zoonotic pathogen, responsible for a large proportion of bacterial gastroenteritis cases, as well as Guillian-Barré and Miller-Fisher syndromes. During infection, tissue damage is mainly caused by bacteria invading epithelial cells and traversing the intestinal barrier. C. jejuni is able to enter the lamina propria and the bloodstream and may move into other organs, such as spleen, liver, or mesenteric lymph nodes. However, the involved molecular mechanisms are not fully understood. C. jejuni can transmigrate effectively across polarized intestinal epithelial cells mainly by the paracellular route using the serine protease high-temperature requirement A (HtrA). However, it appears that HtrA has a dual function, as it also acts as a chaperone, interacting with denatured or misfolded periplasmic proteins under stress conditions. Here, we review recent progress on the role of HtrA in C. jejuni pathogenesis. HtrA can be transported into the extracellular space and cleaves cell-to-cell junction factors, such as E-cadherin and probably others, disrupting the epithelial barrier and enabling paracellular transmigration of the bacteria. The secretion of HtrA is a newly discovered strategy also utilized by other pathogens. Thus, secreted HtrA proteases represent highly attractive targets for anti-bacterial treatment and may provide a suitable candidate for vaccine development.
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Affiliation(s)
- Manja Boehm
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen/Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany
| | - Daniel Simson
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen/Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany
| | - Ulrike Escher
- Department of Microbiology and Infection Immunology, Charité - University Medicine Berlin, Berlin, Germany
| | - Anna-Maria Schmidt
- Department of Microbiology and Infection Immunology, Charité - University Medicine Berlin, Berlin, Germany
| | - Stefan Bereswill
- Department of Microbiology and Infection Immunology, Charité - University Medicine Berlin, Berlin, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen/Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany
| | - Steffen Backert
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen/Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany
| | - Markus M Heimesaat
- Department of Microbiology and Infection Immunology, Charité - University Medicine Berlin, Berlin, Germany
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5
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Miljkovic M, Marinkovic P, Novovic K, Jovcic B, Terzic-Vidojevic A, Kojic M. AggLr, a novel aggregation factor in Lactococcus raffinolactis BGTRK10-1: its role in surface adhesion. BIOFOULING 2018; 34:685-698. [PMID: 30027759 DOI: 10.1080/08927014.2018.1481956] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
The ability of lactic acid bacteria to form multi-cellular aggregates via self-aggregation is regarded as an important mechanism for stress tolerance, adhesion, colonization and genetic material exchange. The novel aggLr gene encoding for the auto-aggregation promoting protein (AggLr) of Lactococcus raffinolactis BGTRK10-1 was cloned. Heterologous expression of AggLr enabled auto-aggregation, higher hydrophobicity and collagen and fibronectin binding of the carrier strains. Domain analysis and the type of aggregates formed by cells expressing AggLr confirmed that this aggregation factor belongs to the family of high molecular weight proteins that the authors propose to be called Snow-flake Forming Collagen Binding Aggregation Factors (SFCBAF). An additional feature of SFCBAF is that they are rich in threonine and lysine and are free of cysteine in all of the aggregation factors described so far. In contrast to previously discovered SFCBAF, the gene encoding for AggLr is located on the chromosome in the strain BGTRK10-1.
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Affiliation(s)
- Marija Miljkovic
- a Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering , University of Belgrade , Belgrade , Serbia
| | - Pavle Marinkovic
- a Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering , University of Belgrade , Belgrade , Serbia
| | - Katarina Novovic
- a Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering , University of Belgrade , Belgrade , Serbia
| | - Branko Jovcic
- a Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering , University of Belgrade , Belgrade , Serbia
- b Faculty of Biology , University of Belgrade , Belgrade , Serbia
| | - Amarela Terzic-Vidojevic
- a Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering , University of Belgrade , Belgrade , Serbia
| | - Milan Kojic
- a Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering , University of Belgrade , Belgrade , Serbia
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6
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Loss of HtrA1 serine protease induces synthetic modulation of aortic vascular smooth muscle cells. PLoS One 2018; 13:e0196628. [PMID: 29768431 PMCID: PMC5955505 DOI: 10.1371/journal.pone.0196628] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 04/15/2018] [Indexed: 01/01/2023] Open
Abstract
Homozygous mutations of human HTRA1 cause cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). HtrA1-/- mice were examined for arterial abnormalities. Although their cerebral arteries were normal, the thoracic aorta was affected in HtrA1-/- mice. The number of vascular smooth muscle cells (VSMCs) in the aorta was increased in HtrA1-/- mice of 40 weeks or younger, but decreased thereafter. The cross-sectional area of the aorta was increased in HtrA1-/- mice of 40 weeks or older. Aortic VSMCs isolated from HtrA1-/- mice rapidly proliferated and migrated, produced high MMP9 activity, and were prone to oxidative stress-induced cell death. HtrA1-/- VSMCs expressed less smooth muscle α-actin, and more vimentin and osteopontin, and responded to PDGF-BB more strongly than wild type VSMCs, indicating that HtrA1-/- VSMCs were in the synthetic phenotype. The elastic lamina was disrupted, and collagens were decreased in the aortic media. Calponin in the media was decreased, whereas vimentin and osteopontin were increased, suggesting a synthetic shift of VSMCs in vivo. Loss of HtrA1 therefore skews VSMCs toward the synthetic phenotype, induces MMP9 expression, and expedites cell death. We propose that the synthetic modulation is the primary event that leads to the vascular abnormalities caused by HtrA1 deficiency.
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Gonzalez EE, Olson D, Aryana K. Short communication: Salt tolerance of Lactococcus lactis R-604 as influenced by mild stresses from ethanol, heat, hydrogen peroxide, and UV light. J Dairy Sci 2017; 100:4290-4293. [DOI: 10.3168/jds.2016-12088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 02/12/2017] [Indexed: 11/19/2022]
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8
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Guillot A, Boulay M, Chambellon É, Gitton C, Monnet V, Juillard V. Mass Spectrometry Analysis of the Extracellular Peptidome of Lactococcus lactis: Lines of Evidence for the Coexistence of Extracellular Protein Hydrolysis and Intracellular Peptide Excretion. J Proteome Res 2016; 15:3214-24. [DOI: 10.1021/acs.jproteome.6b00424] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alain Guillot
- UMR Micalis,
INRA, AgroParisTech, Université Paris Saclay, F-78350 Jouy-en-Josas, France
| | - Mylène Boulay
- UMR Micalis,
INRA, AgroParisTech, Université Paris Saclay, F-78350 Jouy-en-Josas, France
| | - Émilie Chambellon
- UMR Micalis,
INRA, AgroParisTech, Université Paris Saclay, F-78350 Jouy-en-Josas, France
| | - Christophe Gitton
- UMR Micalis,
INRA, AgroParisTech, Université Paris Saclay, F-78350 Jouy-en-Josas, France
| | - Véronique Monnet
- UMR Micalis,
INRA, AgroParisTech, Université Paris Saclay, F-78350 Jouy-en-Josas, France
| | - Vincent Juillard
- UMR Micalis,
INRA, AgroParisTech, Université Paris Saclay, F-78350 Jouy-en-Josas, France
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Nicolai A, Rouland-Lefèvre C, Ansart A, Filser J, Lenz R, Pando A, Charrier M. Inter-Population Differences and Seasonal Dynamic of the Bacterial Gut Community in the Endangered Land SnailHelix pomatia(Gastropoda: Helicidae). MALACOLOGIA 2015. [DOI: 10.4002/040.059.0101] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Factors Affecting Inducible Expression of Outer Membrane Protein A (OmpA) of Shigella dysenteriae Type-1 in Lactococcus lactis Using Nisin Inducible Controlled Expression (NICE). Indian J Microbiol 2015; 56:80-7. [PMID: 26843700 DOI: 10.1007/s12088-015-0556-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/19/2015] [Indexed: 02/01/2023] Open
Abstract
Potential use of Lactococcus lactis (L. lactis) as a heterologous protein expression host as well as for delivery of multiple therapeutic proteins has been investigated extensively using Nisin Inducible Controlled Expression (NICE) system. Optimum inducible expression of heterologous protein by NICE system in L. lactis depends on multiple factors. To study the unexplored role of factors affecting heterologous protein expression in L. lactis using NICE, the present study outlines the optimization of various key parameters such as inducer concentration, host's proteases and precipitating agent using Outer membrane protein A (OmpA). For efficient expression and secretion of OmpA, pSEC:OmpA vector was successfully constructed. To circumvent the troubles encountered during detection of expressed OmpA, the precipitating agent was switched from TCA to methanol. Nevertheless, detection was achieved accompanied by degraded protein products. Speculating the accountability of observed degradation at higher inducer concentration, different nisin concentrations were evaluated. Lower nisin concentrations were found desirable for optimum expression of OmpA. Consistently observed degradation was eliminated by incorporation of protease inhibitor cocktail which inhibits intracellular proteases and expression in VEL1153 (NZ9000 ΔhtrA) strain which inhibits extracellular protease leading to optimum expression of OmpA. Versatility and complexity of NICE system in L. lactis requires fine-tuning of target protein specific parameters for optimum expression.
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Samazan F, Rokbi B, Seguin D, Telles F, Gautier V, Richarme G, Chevret D, Varela PF, Velours C, Poquet I. Production, secretion and purification of a correctly folded staphylococcal antigen in Lactococcus lactis. Microb Cell Fact 2015; 14:104. [PMID: 26178240 PMCID: PMC4502909 DOI: 10.1186/s12934-015-0271-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 05/08/2015] [Indexed: 11/23/2022] Open
Abstract
Background Lactococcus lactis, a lactic acid bacterium traditionally used to ferment milk and manufacture cheeses, is also, in the biotechnology field, an interesting host to produce proteins of medical interest, as it is “Generally Recognized As Safe”. Furthermore, as L. lactis naturally secretes only one major endogenous protein (Usp45), the secretion of heterologous proteins in this species facilitates their purification from a protein-poor culture medium. Here, we developed and optimized protein production and secretion in L. lactis to obtain proteins of high quality, both correctly folded and pure to a high extent. As proteins to be produced, we chose the two transmembrane members of the HtrA protease family in Staphylococcus aureus, an important extra-cellular pathogen, as these putative surface-exposed antigens could constitute good targets for vaccine development. Results A recombinant ORF encoding a C-terminal, soluble, proteolytically inactive and tagged form of each staphylococcal HtrA protein was cloned into a lactococcal expression-secretion vector. After growth and induction of recombinant gene expression, L. lactis was able to produce and secrete each recombinant rHtrA protein as a stable form that accumulated in the culture medium in similar amounts as the naturally secreted endogenous protein, Usp45. L. lactis growth in fermenters, in particular in a rich optimized medium, led to higher yields for each rHtrA protein. Protein purification from the lactococcal culture medium was easily achieved in one step and allowed recovery of highly pure and stable proteins whose identity was confirmed by mass spectrometry. Although rHtrA proteins were monomeric, they displayed the same secondary structure content, thermal stability and chaperone activity as many other HtrA family members, indicating that they were correctly folded. rHtrA protein immunogenicity was established in mice. The raised polyclonal antibodies allowed studying the expression and subcellular localization of wild type proteins in S. aureus: although both proteins were expressed, only HtrA1 was found to be, as predicted, exposed at the staphylococcal cell surface suggesting that it could be a better candidate for vaccine development. Conclusions In this study, an efficient process was developed to produce and secrete putative staphylococcal surface antigens in L. lactis and to purify them to homogeneity in one step from the culture supernatant. This allowed recovering fully folded, stable and pure proteins which constitute promising vaccine candidates to be tested for protection against staphylococcal infection. L. lactis thus proved to be an efficient and competitive cell factory to produce proteins of high quality for medical applications. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0271-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Frédéric Samazan
- INRA, UMR1319 Micalis (Microbiologie de l'Alimentation au service de la Santé), Domaine de Vilvert, 78352, Jouy-en-Josas Cedex, France. .,Institut Curie/CNRS, UMR3244, 25 rue d'Ulm, 75248, Paris Cedex 05, France.
| | - Bachra Rokbi
- Sanofi Pasteur, Campus Mérieux, 1541 avenue Marcel Mérieux, 69280, Marcy L'Etoile, France.
| | - Delphine Seguin
- Sanofi Pasteur, Campus Mérieux, 1541 avenue Marcel Mérieux, 69280, Marcy L'Etoile, France.
| | - Fabienne Telles
- Sanofi Pasteur, Campus Mérieux, 1541 avenue Marcel Mérieux, 69280, Marcy L'Etoile, France.
| | - Valérie Gautier
- Stress molecules, Institut Jacques Monod, Université Paris 7, 15 rue Hélène Brion, 75013, Paris, France.
| | - Gilbert Richarme
- Stress molecules, Institut Jacques Monod, Université Paris 7, 15 rue Hélène Brion, 75013, Paris, France.
| | - Didier Chevret
- INRA, UMR1319 Micalis (Microbiologie de l'Alimentation au service de la Santé), Domaine de Vilvert, 78352, Jouy-en-Josas Cedex, France.
| | | | | | - Isabelle Poquet
- INRA, UMR1319 Micalis (Microbiologie de l'Alimentation au service de la Santé), Domaine de Vilvert, 78352, Jouy-en-Josas Cedex, France. .,LPBA, Institut Pasteur, Bât. Calmette, 75015, Paris, France.
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12
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Iejima D, Itabashi T, Kawamura Y, Noda T, Yuasa S, Fukuda K, Oka C, Iwata T. HTRA1 (high temperature requirement A serine peptidase 1) gene is transcriptionally regulated by insertion/deletion nucleotides located at the 3' end of the ARMS2 (age-related maculopathy susceptibility 2) gene in patients with age-related macular degeneration. J Biol Chem 2015; 290:2784-97. [PMID: 25519903 PMCID: PMC4317043 DOI: 10.1074/jbc.m114.593384] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 12/15/2014] [Indexed: 12/17/2022] Open
Abstract
Dry age-related macular degeneration (AMD) accounts for over 85% of AMD cases in the United States, whereas Japanese AMD patients predominantly progress to wet AMD or polypoidal choroidal vasculopathy. Recent genome-wide association studies have revealed a strong association between AMD and an insertion/deletion sequence between the ARMS2 (age-related maculopathy susceptibility 2) and HTRA1 (high temperature requirement A serine peptidase 1) genes. Transcription regulator activity was localized in mouse retinas using heterozygous HtrA1 knock-out mice in which HtrA1 exon 1 was replaced with β-galactosidase cDNA, thereby resulting in dominant expression of the photoreceptors. The insertion/deletion sequence significantly induced HTRA1 transcription regulator activity in photoreceptor cell lines but not in retinal pigmented epithelium or other cell types. A deletion construct of the HTRA1 regulatory region indicated that potential transcriptional suppressors and activators surround the insertion/deletion sequence. Ten double-stranded DNA probes for this region were designed, three of which interacted with nuclear extracts from 661W cells in EMSA. Liquid chromatography-mass spectrometry (LC-MS/MS) of these EMSA bands subsequently identified a protein that bound the insertion/deletion sequence, LYRIC (lysine-rich CEACAM1 co-isolated) protein. In addition, induced pluripotent stem cells from wet AMD patients carrying the insertion/deletion sequence showed significant up-regulation of the HTRA1 transcript compared with controls. These data suggest that the insertion/deletion sequence alters the suppressor and activator cis-elements of HTRA1 and triggers sustained up-regulation of HTRA1. These results are consistent with a transgenic mouse model that ubiquitously overexpresses HtrA1 and exhibits characteristics similar to those of wet AMD patients.
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Affiliation(s)
- Daisuke Iejima
- From the Division of Molecular and Cellular Biology, National Institute of Sensory Organs, and
| | - Takeshi Itabashi
- From the Division of Molecular and Cellular Biology, National Institute of Sensory Organs, and
| | - Yuich Kawamura
- From the Division of Molecular and Cellular Biology, National Institute of Sensory Organs, and
| | - Toru Noda
- the Division of Ophthalmology, National Hospital Organization Tokyo Medical Center, Tokyo 152-8902, Japan
| | - Shinsuke Yuasa
- the Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan, and
| | - Keiichi Fukuda
- the Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan, and
| | - Chio Oka
- the Division of Gene Function in Animals, Nara Institute of Science and Technology, Nara 630-0101, Japan
| | - Takeshi Iwata
- From the Division of Molecular and Cellular Biology, National Institute of Sensory Organs, and
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Bera S, Thillai K, Sriraman K, Jayaraman G. Process strategies for enhancing recombinant streptokinase production in Lactococcus lactis cultures using P170 expression system. Biochem Eng J 2015. [DOI: 10.1016/j.bej.2014.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Koleva Z, Dedov I, Kizheva J, Lipovanska R, Moncheva P, Hristova P. Lactic acid microflora of the gut of snail Cornu aspersum. BIOTECHNOL BIOTEC EQ 2014; 28:627-634. [PMID: 26019550 PMCID: PMC4433887 DOI: 10.1080/13102818.2014.947071] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 06/20/2014] [Indexed: 11/06/2022] Open
Abstract
The intestinal lactic acid microflora of the edible snail Cornu aspersum was studied by culture-based methods and was phenotypically and molecularly characterized. The antibacterial activity of lactic acid bacteria (LAB) isolates was investigated. Snails in different stages of development were collected from farms located in several regions of Bulgaria. One hundred twenty-two isolates, belonging to the group of LAB, were characterized morphologically and were divided into four groups. Representative isolates from each morphological type were subjected to phenotypic characterization and molecular identification. The snail gut lactic acid microflora was composed by Enterococcus (17 isolates), Lactococcus (12 isolates), Leuconostoc (7 isolates), Lactobacillus (18 isolates) and Weissella (1 isolate). The species affiliation of Lactococcus lactis (12), Leuconostoc mesenteroides (4) and Lactobacillus plantarum (2) was confirmed by species-specific primers. The Lactobacillus isolates were identified by sequence analysis of 16S rDNA as Lactobacillus brevis (12), L. plantarum (2), Lactobacillus graminis (1) and Lactobacillus curvatus (3). The species L. brevis, L. graminis and L. curvatus were found in snails in a phase of hibernation, whereas L. plantarum was identified both in active and hibernation phases. Antibacterial activity (bacteriocine-like) was shown only by one strain of L. mesentereoides P4/8 against Propionibacterium acnes. The present study showed that the LAB are a component of the microbial communities in the snail digestive system. This is the first report on Lactobacillus strains detected in the gut of C. aspersum.
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Affiliation(s)
- Zdravka Koleva
- Faculty of Biology, Sofia University ‘St. Kliment Ohridski’, Sofia, Bulgaria
| | - Ivaylo Dedov
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Joana Kizheva
- Faculty of Biology, Sofia University ‘St. Kliment Ohridski’, Sofia, Bulgaria
| | - Roxana Lipovanska
- Faculty of Biology, Sofia University ‘St. Kliment Ohridski’, Sofia, Bulgaria
| | - Penka Moncheva
- Faculty of Biology, Sofia University ‘St. Kliment Ohridski’, Sofia, Bulgaria
| | - Petya Hristova
- Faculty of Biology, Sofia University ‘St. Kliment Ohridski’, Sofia, Bulgaria
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Transcription profiling of interactions between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 during Cheddar cheese simulation. Int J Food Microbiol 2014; 178:76-86. [PMID: 24674930 DOI: 10.1016/j.ijfoodmicro.2014.03.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 02/27/2014] [Accepted: 03/03/2014] [Indexed: 01/17/2023]
Abstract
The starter cultures (Lactococcus sp.) and non-starter lactic acid bacteria (mostly Lactobacillus spp.) are essential to flavor development of Cheddar cheese. The aim of this study was to elucidate the transcriptional interaction between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 in mixed cultures during simulated Cheddar cheese manufacture (Pearce activity test) and ripening (slurry). Reverse transcription quantitative PCR (RT-qPCR) was used to quantify the expression of 34 genes common to both bacteria and for eight genes specific to either L. lactis subsp. cremoris SK11 or L. paracasei ATCC 334. The multifactorial analysis (MFA) performed on fold change results for each gene revealed that the genes linked to stress, protein and peptide degradation as well as carbohydrate metabolism of L. paracasei ATCC 334 were especially overexpressed in mixed culture with L. lactis subsp. cremoris SK11 during the ripening simulation. For L. lactis subsp. cremoris SK11, genes coding for amino acid metabolism were more expressed during the cheese manufacture simulation, especially in single culture. These results show how complementary functions of starter and NSLAB contribute to activities useful for flavor development.
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Supanji, Shimomachi M, Hasan MZ, Kawaichi M, Oka C. HtrA1 is induced by oxidative stress and enhances cell senescence through p38 MAPK pathway. Exp Eye Res 2013; 112:79-92. [PMID: 23623979 DOI: 10.1016/j.exer.2013.04.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/28/2013] [Accepted: 04/15/2013] [Indexed: 01/10/2023]
Abstract
Genetic predisposition and senescence of retinal pigment epithelium induced by oxidative stress are major contributors to age-related macular degeneration (AMD). Single-nucleotide polymorphisms in HTRA1 are strongly linked to the onset of AMD. In this study, we examine the role of HtrA1 in premature senescence and cell death induced by oxidative stress. HtrA1 mRNA and protein were up-regulated during premature senescence induced by H2O2 in both mouse embryonic fibroblasts (MEFs) and ARPE-19 cells. Expression of the senescence markers p21(CIP1/WAF1) and p16(INK4a), and SA-β-galactosidase activity, were higher in HtrA1+/- MEFs than in HtrA1-/- MEFs. HtrA1+/+ and HtrA1+/- MEFs were more resistant than HtrA1-/- MEFs to H2O2-induced cell death. Activation of p38 MAPK by oxidative stress was quicker in HtrA1+/- MEFs than in HtrA1-/- MEFs. The effects of excess HtrA1 were examined by transient transfection of cells with HtrA1 expression vectors or by addition of recombinant proteins. Excess wild type HtrA1 accelerated premature senescence of MEFs and ARPE-19 cells, while the protease-inactive HtrA1 S328A did not. HtrA1-induced senescence was abrogated by inhibition of p38 MAPK. We conclude that HtrA1 is induced by oxidative stress and promotes premature cell senescence through p38 MAPK in a protease activity-dependent manner.
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Affiliation(s)
- Supanji
- Division of Gene Function in Animals, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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de Jong A, Hansen ME, Kuipers OP, Kilstrup M, Kok J. The transcriptional and gene regulatory network of Lactococcus lactis MG1363 during growth in milk. PLoS One 2013; 8:e53085. [PMID: 23349698 PMCID: PMC3547956 DOI: 10.1371/journal.pone.0053085] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 11/27/2012] [Indexed: 11/18/2022] Open
Abstract
In the present study we examine the changes in the expression of genes of Lactococcus lactis subspecies cremoris MG1363 during growth in milk. To reveal which specific classes of genes (pathways, operons, regulons, COGs) are important, we performed a transcriptome time series experiment. Global analysis of gene expression over time showed that L. lactis adapted quickly to the environmental changes. Using upstream sequences of genes with correlated gene expression profiles, we uncovered a substantial number of putative DNA binding motifs that may be relevant for L. lactis fermentative growth in milk. All available novel and literature-derived data were integrated into network reconstruction building blocks, which were used to reconstruct and visualize the L. lactis gene regulatory network. This network enables easy mining in the chrono-transcriptomics data. A freely available website at http://milkts.molgenrug.nl gives full access to all transcriptome data, to the reconstructed network and to the individual network building blocks.
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Affiliation(s)
- Anne de Jong
- Department of Molecular Genetics, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, The Netherlands
| | - Morten E. Hansen
- Center for Systems Microbiology, Institute of Systems Biology, Technical University of Denmark, Lyngby, Denmark
| | - Oscar P. Kuipers
- Department of Molecular Genetics, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, The Netherlands
| | - Mogens Kilstrup
- Center for Systems Microbiology, Institute of Systems Biology, Technical University of Denmark, Lyngby, Denmark
| | - Jan Kok
- Department of Molecular Genetics, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, The Netherlands
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18
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Kefir-isolated Lactococcus lactis subsp. lactis inhibits the cytotoxic effect of Clostridium difficile in vitro. J DAIRY RES 2012; 80:96-102. [PMID: 23217732 DOI: 10.1017/s0022029912000623] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Kefir is a dairy product obtained by fermentation of milk with a complex microbial population and several health-promoting properties have been attributed to its consumption. In this work, we tested the ability of different kefir-isolated bacterial and yeast strains (Lactobacillus kefir, Lb. plantarum, Lactococcus lactis subps. lactis, Saccharomyces cerevisiae and Kluyveromyces marxianus) or a mixture of them (MM) to antagonise the cytopathic effect of toxins from Clostridium difficile (TcdA and TcdB). Cell detachment assays and F-actin network staining using Vero cell line were performed. Although incubation with microbial cells did not reduce the damage induced by C. difficile spent culture supernatant (SCS), Lc. lactis CIDCA 8221 and MM supernatants were able to inhibit the cytotoxicity of SCS to Vero cells. Fraction of Lc. lactis CIDCA 8221 supernatant containing components higher than 10 kDa were responsible for the inhibitory activity and heating of this fraction for 15 min at 100 °C completely abrogated this ability. By dot-blot assay with anti-TcdA or anti-TcdB antibodies, concentration of both toxins seems to be reduced in SCS treated with Lc. lactis CIDCA 8221 supernatant. However, protective effect was not affected by treatment with proteases or proteases-inhibitors tested. In conclusion, we demonstrated that kefir-isolated Lc. lactis CIDCA 8221 secreted heat-sensitive products able to protect eukaryotic cells from cytopathic effect of C. difficile toxins in vitro. Our findings provide new insights into the probiotic action of microorganisms isolated from kefir against virulence factors from intestinal pathogens.
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Gullón S, Vicente RL, Mellado RP. A novel two-component system involved in secretion stress response in Streptomyces lividans. PLoS One 2012; 7:e48987. [PMID: 23155440 PMCID: PMC3498368 DOI: 10.1371/journal.pone.0048987] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/03/2012] [Indexed: 11/30/2022] Open
Abstract
Background Misfolded proteins accumulating outside the bacterial cytoplasmic membrane can interfere with the secretory machinery, hence the existence of quality factors to eliminate these misfolded proteins is of capital importance in bacteria that are efficient producers of secretory proteins. These bacteria normally use a specific two-component system to respond to the stress produced by the accumulation of the misfolded proteins, by activating the expression of HtrA-like proteases to specifically eliminate the incorrectly folded proteins. Methodology/Principal Findings Overproduction of alpha-amylase in S. lividans causing secretion stress permitted the identification of a two-component system (SCO4156-SCO4155) that regulates three HtrA-like proteases which appear to be involved in secretion stress response. Mutants in each of the genes forming part of the two-genes operon that encodes the sensor and regulator protein components accumulated misfolded proteins outside the cell, strongly suggesting the involvement of this two-component system in the S. lividans secretion stress response. Conclusions/Significance To our knowledge this is the first time that a specific secretion stress response two-component system is found to control the expression of three HtrA-like protease genes in S. lividans, a bacterium that has been repeatedly used as a host for the synthesis of homologous and heterologous secretory proteins of industrial application.
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Mechanism of action of the arylomycin antibiotics and effects of signal peptidase I inhibition. Antimicrob Agents Chemother 2012; 56:5054-60. [PMID: 22802255 DOI: 10.1128/aac.00785-12] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clinically approved antibiotics inhibit only a small number of conserved pathways that are essential for bacterial viability, and the physiological effects of inhibiting these pathways have been studied in great detail. Likewise, characterizing the effects of candidate antibiotics that function via novel mechanisms of action is critical for their development, which is of increasing importance due to the ever-growing problem of resistance. The arylomycins are a novel class of natural-product antibiotics that act via the inhibition of type I signal peptidase (SPase), which is an essential enzyme that functions as part of the general secretory pathway and is not the target of any clinically deployed antibiotic. Correspondingly, little is known about the effects of SPase inhibition or how bacteria may respond to mitigate the associated secretion stress. Using genetically sensitized Escherichia coli and Staphylococcus aureus as model organisms, we examine the activity of arylomycin as a function of its concentration, bacterial cell density, target expression levels, and bacterial growth phase. The results reveal that the activity of the arylomycins results from an insufficient flux of proteins through the secretion pathway and the resulting mislocalization of proteins. Interestingly, this has profoundly different effects on E. coli and S. aureus. Finally, we examine the activity of arylomycin in combination with distinct classes of antibiotics and demonstrate that SPase inhibition results in synergistic sensitivity when combined with an aminoglycoside.
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21
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Abstract
Staphylococcus aureus is an important human pathogen whose virulence relies on the secretion of many different proteins. In general, the secretion of most proteins in S. aureus, as well as other bacteria, is dependent on the type I signal peptidase (SPase)-mediated cleavage of the N-terminal signal peptide that targets a protein to the general secretory pathway. The arylomycins are a class of natural product antibiotics that inhibit SPase, suggesting that they may be useful chemical biology tools for characterizing the secretome. While wild-type S. aureus (NCTC 8325) is naturally resistant to the arylomycins, sensitivity is conferred via a point mutation in its SPase. Here, we use a synthetic arylomycin along with a sensitized strain of S. aureus and multidimensional protein identification technology (MudPIT) mass spectrometry to identify 46 proteins whose extracellular accumulation requires SPase activity. Forty-four possess identifiable Sec-type signal peptides and thus are likely canonically secreted proteins, while four also appear to possess cell wall retention signals. We also identified the soluble C-terminal domains of two transmembrane proteins, lipoteichoic acid synthase, LtaS, and O-acyteltransferase, OatA, both of which appear to have noncanonical, internal SPase cleavage sites. Lastly, we identified three proteins, HtrA, PrsA, and SAOUHSC_01761, whose secretion is induced by arylomycin treatment. In addition to elucidating fundamental aspects of the physiology and pathology of S. aureus, the data suggest that an arylomycin-based therapeutic would reduce virulence while simultaneously eradicating an infection.
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PpiA, a surface PPIase of the cyclophilin family in Lactococcus lactis. PLoS One 2012; 7:e33516. [PMID: 22442694 PMCID: PMC3307742 DOI: 10.1371/journal.pone.0033516] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 02/10/2012] [Indexed: 12/05/2022] Open
Abstract
Background Protein folding in the envelope is a crucial limiting step of protein export and secretion. In order to better understand this process in Lactococcus lactis, a lactic acid bacterium, genes encoding putative exported folding factors like Peptidyl Prolyl Isomerases (PPIases) were searched for in lactococcal genomes. Results In L. lactis, a new putative membrane PPIase of the cyclophilin subfamily, PpiA, was identified and characterized. ppiA gene was found to be constitutively expressed under normal and stress (heat shock, H2O2) conditions. Under normal conditions, PpiA protein was synthesized and released from intact cells by an exogenously added protease, showing that it was exposed at the cell surface. No obvious phenotype could be associated to a ppiA mutant strain under several laboratory conditions including stress conditions, except a very low sensitivity to H2O2. Induction of a ppiA copy provided in trans had no effect i) on the thermosensitivity of an mutant strain deficient for the lactococcal surface protease HtrA and ii) on the secretion and stability on four exported proteins (a highly degraded hybrid protein and three heterologous secreted proteins) in an otherwise wild-type strain background. However, a recombinant soluble form of PpiA that had been produced and secreted in L. lactis and purified from a culture supernatant displayed both PPIase and chaperone activities. Conclusions Although L. lactis PpiA, a protein produced and exposed at the cell surface under normal conditions, displayed a very moderate role in vivo, it was found, as a recombinant soluble form, to be endowed with folding activities in vitro.
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van Bokhorst-van de Veen H, Abee T, Tempelaars M, Bron PA, Kleerebezem M, Marco ML. Short- and long-term adaptation to ethanol stress and its cross-protective consequences in Lactobacillus plantarum. Appl Environ Microbiol 2011; 77:5247-56. [PMID: 21705551 PMCID: PMC3147428 DOI: 10.1128/aem.00515-11] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Accepted: 06/09/2011] [Indexed: 11/20/2022] Open
Abstract
This paper describes the molecular responses of Lactobacillus plantarum WCFS1 toward ethanol exposure. Global transcriptome profiling using DNA microarrays demonstrated adaptation of the microorganism to the presence of 8% ethanol over short (10-min and 30-min) and long (24-h) time intervals. A total of 57 genes were differentially expressed at all time points. Expression levels of an additional 859 and 873 genes were modulated after 30 min and 24 h of exposure to the solvent, respectively. Ethanol exposure led to induced expression of genes involved in citrate metabolism and cell envelope architecture, as well as canonical stress response pathways controlled by the central stress regulators HrcA and CtsR. Correspondingly, cells grown for 24 h in medium containing 8% ethanol exhibited higher levels of citrate consumption and modified cell membrane fatty acid composition and showed invaginating septa compared with cells grown in liquid medium without ethanol. In addition, these physiological changes resulted in cross-protection against high temperatures but not against several other stresses tested. To evaluate the role of HrcA and CtsR in ethanol tolerance, ctsR and hrcA gene deletion mutants were constructed. The growth rate of the L. plantarum ΔctsR::cat strain was impaired in de Man-Rogosa-Sharpe (MRS) medium containing 8% ethanol, whereas growth of the L. plantarum ΔhrcA::cat and ΔctsR ΔhrcA::cat mutants was indistinguishable from that of wild-type cells. Overall, these results suggest that the induction of CtsR class III stress responses provides cross-protection against heat stress.
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Affiliation(s)
- Hermien van Bokhorst-van de Veen
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands
- NIZO food research, P.O. Box 20, 6710 BA Ede, The Netherlands
- Laboratory of Microbiology, Wageningen University and Research Centre, P.O. Box 8033, 6700 EJ Wageningen, The Netherlands
| | - Tjakko Abee
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | - Marcel Tempelaars
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | - Peter A. Bron
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands
- NIZO food research, P.O. Box 20, 6710 BA Ede, The Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation/NCSB, P.O. Box 5057, 2600 GA Delft, The Netherlands
| | - Michiel Kleerebezem
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands
- NIZO food research, P.O. Box 20, 6710 BA Ede, The Netherlands
- Laboratory of Microbiology, Wageningen University and Research Centre, P.O. Box 8033, 6700 EJ Wageningen, The Netherlands
| | - Maria L. Marco
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands
- NIZO food research, P.O. Box 20, 6710 BA Ede, The Netherlands
- Department of Food Science and Technology, University of California, One Shields Avenue, Davis, California 95616
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Taïbi A, Dabour N, Lamoureux M, Roy D, LaPointe G. Comparative transcriptome analysis of Lactococcus lactis subsp. cremoris strains under conditions simulating Cheddar cheese manufacture. Int J Food Microbiol 2011; 146:263-75. [PMID: 21435733 DOI: 10.1016/j.ijfoodmicro.2011.02.034] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 02/17/2011] [Accepted: 02/26/2011] [Indexed: 10/18/2022]
Abstract
Gene expression in response to technological variations can influence fermentation and flavor generation in Cheddar cheese, and can vary from one lactococcal strain to another, perceived as differences in starter performance. The aim of this study was to determine the influence of cheese cooking temperature at 38 °C and salting on the transcriptional profiles of four closely related strains of L. lactis subsp. cremoris under simulated conditions of Cheddar cheese manufacture. Two responses could be distinguished, a core gene expression, corresponding to the common response of all strains and strain-specific response during the Cheddar simulating process. For the core gene expression after heating of inoculated milk at 38 °C, two groups of differentially expressed genes were identified: i) stress response and ii) carbohydrate and amino acid metabolism. The response to combined stresses of heat, acid and salt resulted in: i) general decrease of functions linked to cell division and metabolism, ii) specific responses related to stress such as the induction of genes coding for chaperones and proteases and iii) expression of prophage lytic systems for certain strains. Strain-specific responses were mainly observed in three of the four tested strains. These responses were the induction of genes related to osmotic stress or the release of CodY repression leading to the activation of oligopeptide transporters as well as the bcaT gene, related to amino acid degradation for the production of flavor. Comparing transcriptomes provides a core expression profile that contributes to understanding gene expression responses to environmental variations. The strain-specific responses identify predictive markers for the transcriptional state of starter strains before they enter the cheese ripening phase.
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Affiliation(s)
- Amel Taïbi
- STELA Dairy Research Centre, Institute of Nutraceuticals and Functional Foods, 2440 Hochelaga Blvd., Université Laval, Québec, QC, Canada G1V 0A6
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Abstract
Bile acid resistance by Lactococcus lactis depends on the ABC-type multidrug transporter LmrCD. Upon deletion of the lmrCD genes, cells can reacquire bile acid resistance upon prolonged exposure to cholate, yielding the ΔlmrCD(r) strain. The resistance mechanism in this strain is non-transporter based. Instead, cells show a high tendency to flocculate, suggesting cell surface alterations. Contact angle measurements demonstrate that the ΔlmrCD(r) cells are equipped with an increased cell surface hydrophilicity compared to those of the parental and wild-type strains, while the surface hydrophilicity is reduced in the presence of cholate. ΔlmrCD(r) cells are poor in biofilm formation on a hydrophobic polystyrene surface, but in the presence of subinhibitory concentrations of cholate, biofilm formation is strongly stimulated. Biofilm cells show an enhanced extracellular polymeric substance production and are highly resistant to bile acids. These data suggest that non-transporter-based cholate resistance in L. lactis is due to alterations in the cell surface that stimulate cells to form resistant biofilms.
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Gutiérrez-Méndez N, Rodríguez-Figueroa JC, González-Córdova AF, Nevárez-Moorillón GV, Rivera-Chavira B, Vallejo-Cordoba B. Phenotypic and genotypic characteristics of Lactococcus lactis strains isolated from different ecosystems. Can J Microbiol 2010; 56:432-9. [DOI: 10.1139/w10-026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lactococcus lactis is the lactic acid bacteria most used in the manufacture of dairy products because of its fast lactose fermentation and flavor production. In this study, L. lactis strains isolated from different sources and previously characterized and evaluated for their capability to produce flavor were compared with respect to their phenotypic and genotypic characteristics. The variability of phenotypes and genotypes in the L. lactis strains were influenced by the source of isolation. In general, strains that shared the same genotype presented different phenotypes, and only some genotypes were clearly related to the source of isolation. On the other hand, phenotypic characteristics such as coagulant activity and utilization of lactose, glucose, and arginine were closely related to the ecosystem of origin. Coagulant activity and lactose utilization, phenotypic characteristics that are of utmost importance for efficient flavor production by starters in the manufacture of dairy products, were better for strains isolated from raw milk dairy products than for those isolated from vegetables.
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Affiliation(s)
- Nestor Gutiérrez-Méndez
- Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a La Victoria km 0.6, Apartado 1735, Hermosillo, Sonora 83000, Mexico
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Apartado 28 1542-C, Chihuahua, Chihuahua 31170, Mexico
| | - José C. Rodríguez-Figueroa
- Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a La Victoria km 0.6, Apartado 1735, Hermosillo, Sonora 83000, Mexico
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Apartado 28 1542-C, Chihuahua, Chihuahua 31170, Mexico
| | - Aarón F. González-Córdova
- Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a La Victoria km 0.6, Apartado 1735, Hermosillo, Sonora 83000, Mexico
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Apartado 28 1542-C, Chihuahua, Chihuahua 31170, Mexico
| | - Guadalupe V. Nevárez-Moorillón
- Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a La Victoria km 0.6, Apartado 1735, Hermosillo, Sonora 83000, Mexico
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Apartado 28 1542-C, Chihuahua, Chihuahua 31170, Mexico
| | - Blanca Rivera-Chavira
- Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a La Victoria km 0.6, Apartado 1735, Hermosillo, Sonora 83000, Mexico
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Apartado 28 1542-C, Chihuahua, Chihuahua 31170, Mexico
| | - Belinda Vallejo-Cordoba
- Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a La Victoria km 0.6, Apartado 1735, Hermosillo, Sonora 83000, Mexico
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Apartado 28 1542-C, Chihuahua, Chihuahua 31170, Mexico
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Beganović J, Guillot A, van de Guchte M, Jouan A, Gitton C, Loux V, Roy K, Huet S, Monod H, Monnet V. Characterization of the Insoluble Proteome of Lactococcus lactis by SDS-PAGE LC-MS/MS Leads to the Identification of New Markers of Adaptation of the Bacteria to the Mouse Digestive Tract. J Proteome Res 2010; 9:677-88. [DOI: 10.1021/pr9000866] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jasna Beganović
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Alain Guillot
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Maarten van de Guchte
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Anne Jouan
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Christophe Gitton
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Valentin Loux
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Karine Roy
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Sylvie Huet
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Hervé Monod
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
| | - Véronique Monnet
- INRA, PAPPSO (Plate-Forme d’Analyse Protéomique de Paris Sud-Ouest), UR895 Génétique Microbienne, UR341 Mathématique et Informatique Appliquées, UR477 Biochimie Bactérienne, UR1077 Mathématique, Informatique, Génome, Domaine de Vilvert, F-78352 Jouy en Josas, France
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28
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López D, Kolter R. Extracellular signals that define distinct and coexisting cell fates in Bacillus subtilis. FEMS Microbiol Rev 2009; 34:134-49. [PMID: 20030732 DOI: 10.1111/j.1574-6976.2009.00199.x] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The soil-dwelling bacterium Bacillus subtilis differentiates into distinct subpopulations of specialized cells that coexist within highly structured communities. The coordination and interplay between these cell types requires extensive extracellular communication driven mostly by sensing self-generated secreted signals. These extracellular signals activate a set of sensor kinases, which respond by phosphorylating three major regulatory proteins, Spo0A, DegU and ComA. Each phosphorylated regulator triggers a specific differentiation program while at the same time repressing other differentiation programs. This allows a cell to differentiate in response to a specific cue, even in the presence of other, possibly conflicting, signals. The sensor kinases involved respond to an eclectic group of extracellular signals, such as quorum-sensing molecules, natural products, temperature, pH or scarcity of nutrients. This article reviews the cascades of cell differentiation pathways that are triggered by sensing extracellular signals. We also present a tentative developmental model in which the diverse cell types sequentially differentiate to achieve the proper development of the bacterial community.
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Affiliation(s)
- Daniel López
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA.
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29
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Kaushal G, Shao J. Genetically Engineered Normal Flora for Oral Polypeptide Delivery: Dose–Absorption Response. J Pharm Sci 2009; 98:2573-80. [DOI: 10.1002/jps.21615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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HtrA is essential for efficient secretion of recombinant proteins by Lactococcus lactis. Appl Environ Microbiol 2008; 74:7442-6. [PMID: 18836019 DOI: 10.1128/aem.00638-08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HtrA is a unique protease on the extracellular surface of Lactococcus lactis. It is known to take part in the proteolysis of many secreted recombinant proteins, and the mutation of htrA can lead to the complete stabilization of recombinant proteins. In this work, we have shown that htrA mutation also leads to significant reduction of the efficiency of recombinant-protein secretion. We also show that the level of HtrA can be lowered by the suppression of the acid tolerance response (ATR) in L. lactis. Instead of using an L. lactis htrA mutant, the reduction of the HtrA level in wild-type recombinant cultures of L. lactis by ATR suppression may serve as a better strategy for the production of secreted recombinant proteins.
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31
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Proteomic analysis of stationary phase in the marine bacterium "Candidatus Pelagibacter ubique". Appl Environ Microbiol 2008; 74:4091-100. [PMID: 18469119 DOI: 10.1128/aem.00599-08] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
"Candidatus Pelagibacter ubique," an abundant marine alphaproteobacterium, subsists in nature at low ambient nutrient concentrations and may often be exposed to nutrient limitation, but its genome reveals no evidence of global regulatory mechanisms for adaptation to stationary phase. High-resolution capillary liquid chromatography coupled online to an LTQ mass spectrometer was used to build an accurate mass and time (AMT) tag library that enabled quantitative examination of proteomic differences between exponential- and stationary-phase "Ca. Pelagibacter ubique" cells cultivated in a seawater medium. The AMT tag library represented 65% of the predicted protein-encoding genes. "Ca. Pelagibacter ubique" appears to respond adaptively to stationary phase by increasing the abundance of a suite of proteins that contribute to homeostasis rather than undergoing a major remodeling of its proteome. Stationary-phase abundances increased significantly for OsmC and thioredoxin reductase, which may mitigate oxidative damage in "Ca. Pelagibacter," as well as for molecular chaperones, enzymes involved in methionine and cysteine biosynthesis, proteins involved in rho-dependent transcription termination, and the signal transduction enzyme CheY-FisH. We speculate that this limited response may enable "Ca. Pelagibacter ubique" to cope with ambient conditions that deprive it of nutrients for short periods and, furthermore, that the ability to resume growth overrides the need for a more comprehensive global stationary-phase response to create a capacity for long-term survival.
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32
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Morello E, Bermúdez-Humarán LG, Llull D, Solé V, Miraglio N, Langella P, Poquet I. Lactococcus lactis, an efficient cell factory for recombinant protein production and secretion. J Mol Microbiol Biotechnol 2008; 14:48-58. [PMID: 17957110 DOI: 10.1159/000106082] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The use of Gram-positive bacteria for heterologous protein production proves to be a useful choice due to easy protein secretion and purification. The lactic acid bacterium Lactococcus lactis emerges as an attractive alternative to the Gram-positive model Bacillus subtilis. Here, we review recent work on the expression and secretion systems available for heterologous protein secretion in L. lactis, including promoters, signal peptides and mutant host strains known to overcome some bottlenecks of the process. Among the tools developed in our laboratory, inactivation of HtrA, the unique housekeeping protease at the cell surface, or complementation of the Sec machinery with B. subtilis SecDF accessory protein each result in the increase in heterologous protein yield. Furthermore, our lactococcal expression/secretion system, using both P(Zn)zitR, an expression cassette tightly controlled by environmental zinc, and a consensus signal peptide, SP(Exp4), allows efficient production and secretion of the staphylococcal nuclease, as evidenced by protein yields (protein amount/biomass) comparable to those obtained using NICE or P170 expression systems under similar laboratory conditions. Finally, the toolbox we are developing should contribute to enlarge the use of L. lactis as a protein cell factory.
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Affiliation(s)
- E Morello
- Unité des Bactéries Lactiques et pathogènes Opportunistes (UBLO), INRA, Jouy-en-Josas, France
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33
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Roy F, Vanterpool E, Fletcher HM. HtrA in Porphyromonas gingivalis can regulate growth and gingipain activity under stressful environmental conditions. MICROBIOLOGY (READING, ENGLAND) 2006; 152:3391-3398. [PMID: 17074908 DOI: 10.1099/mic.0.29147-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In several micro-organisms, HtrA, a serine periplasmic protease, is considered an important virulence factor that plays a regulatory role in oxidative and temperature stress. The authors have previously shown that the vimA gene product is an important virulence regulator in Porphyromonas gingivalis. Further, purified recombinant VimA physically interacted with the major gingipains and the HtrA from P. gingivalis. To further evaluate a role for HtrA in the pathogenicity of this organism, a 1.5 kb fragment containing the htrA gene was PCR-amplified from the chromosomal DNA of P. gingivalis W83. This gene was insertionally inactivated using the ermF-ermAM antibiotic-resistance cassette and used to create an htrA-deficient mutant by allelic exchange. In one randomly chosen isogenic mutant designated P. gingivalis FLL203, there was increased sensitivity to hydrogen peroxide. Growth of this mutant at an elevated temperature was more inhibited compared to the wild-type. Further, in contrast to the wild-type, there was a significant decrease in Arg-gingipain activity after heat shock in FLL203. However, the gingipain activity in the mutant returned to normal levels after a further 30 min incubation at room temperature. Collectively, these data suggest that HtrA may play a similar role in oxidative and temperature stress in P. gingivalis as observed in other organisms.
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Affiliation(s)
- F Roy
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - E Vanterpool
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - H M Fletcher
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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34
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Vanterpool E, Roy F, Zhan W, Sheets SM, Sangberg L, Fletcher HM. VimA is part of the maturation pathway for the major gingipains of Porphyromonas gingivalis W83. Microbiology (Reading) 2006; 152:3383-3389. [PMID: 17074907 DOI: 10.1099/mic.0.29146-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The authors have shown previously that the vimA gene, which is part of the bcp-recA-vimA operon, plays an important role in protease activation in Porphyromonas gingivalis. The gingipain RgpB proenzyme is secreted in the vimA-defective mutant P. gingivalis FLL92. An important question that is raised is whether the vimA gene product could directly interact with the proteases for their activation or regulate a pathway responsible for protease activation. To further study the mechanism(s) of VimA-dependent protease activation, the vimA gene product was further characterized. A 39 kDa protein consistent with the size of the predicted VimA protein was purified. In protein–protein interaction studies, the VimA protein was shown to interact with gingipains RgpA, RgpB and Kgp. Immune sera from mice immunized with P. gingivalis immunoreacted with the purified VimA protein. Taken together, these data suggest an interaction of VimA with the gingipains and further confirm the role of this protein in their regulation or maturation.
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Affiliation(s)
- E Vanterpool
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - F Roy
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - W Zhan
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - S M Sheets
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - L Sangberg
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - H M Fletcher
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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35
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Cortes-Perez NG, Poquet I, Oliveira M, Gratadoux JJ, Madsen SM, Miyoshi A, Corthier G, Azevedo V, Langella P, Bermúdez-Humarán LG. Construction and characterization of a Lactococcus lactis strain deficient in intracellular ClpP and extracellular HtrA proteases. MICROBIOLOGY-SGM 2006; 152:2611-2618. [PMID: 16946256 DOI: 10.1099/mic.0.28698-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A Lactococcus lactis strain deficient in both its major proteases, intracellular (ClpP) and extracellular (HtrA), was constructed and characterized. This strain, hereafter called clpP-htrA, could be obtained only by conjugation between a clpP donor strain and an htrA recipient strain in the NZ9000 context, allowing heterologous gene expression under the control of the NICE (nisin-controlled expression) system. The clpP-htrA double mutant showed both higher stress tolerance (e.g. high temperature and ethanol resistance) and higher viability than single clpP or htrA mutant strains. In addition, the secretion rate of two heterologous proteins (staphylococcal nuclease Nuc and Nuc-E7) was also higher in clpP-htrA than in the wild-type strain. This strain should be a useful host for high-level production and quality of stable heterologous proteins.
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Affiliation(s)
- N G Cortes-Perez
- Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
| | - I Poquet
- Unité des Bactéries Lactiques et Pathogènes Opportunistes, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
| | - M Oliveira
- Institute of Biological Sciences, Federal University of Minas Gerais (UFMG-ICB), Belo Horizonte, Minas Gerais, Brazil
- Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
| | - J J Gratadoux
- Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
| | | | - A Miyoshi
- Institute of Biological Sciences, Federal University of Minas Gerais (UFMG-ICB), Belo Horizonte, Minas Gerais, Brazil
| | - G Corthier
- Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
| | - V Azevedo
- Institute of Biological Sciences, Federal University of Minas Gerais (UFMG-ICB), Belo Horizonte, Minas Gerais, Brazil
| | - P Langella
- Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
| | - L G Bermúdez-Humarán
- Unité d'Ecologie et de Physiologie du Système Digestif, INRA, Domaine de Vilvert, 78352 Jouy en Josas cedex, France
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36
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Mo E, Peters SE, Willers C, Maskell DJ, Charles IG. Single, double and triple mutants of Salmonella enterica serovar Typhimurium degP (htrA), degQ (hhoA) and degS (hhoB) have diverse phenotypes on exposure to elevated temperature and their growth in vivo is attenuated to different extents. Microb Pathog 2006; 41:174-82. [PMID: 16949246 DOI: 10.1016/j.micpath.2006.07.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Accepted: 07/11/2006] [Indexed: 11/23/2022]
Abstract
DegP (HtrA) is a well-studied protease involved in survival of bacteria under stress conditions in vitro and in vivo. There are two paralogues of DegP in the Salmonella enterica serovar Typhimurium genome, DegQ and DegS. In order to understand more about the biological significance of this gene family, a series of deg-deletion mutants was generated in S. Typhimurium strain SL3261 by allelic replacement. At elevated temperature in vitro, the viability of degP and degS mutants was reduced when compared with the parent strain whereas the viability of a degQ mutant was not significantly affected. The viability of a double degP-degS mutant at elevated temperature was severely decreased when compared with the respective single mutants or, interestingly, with a triple degP-degQ-degS mutant. All the deg deletions were transduced into the mouse-virulent strain SL1344 and the resultant mutants were injected intravenously into BALB/c mice to test virulence. degP and degS single mutants and all combinations of double and triple mutants were attenuated to different degrees, whereas the single degQ mutant was as virulent as the wild-type strain. Thus, within this gene family, degP and degS appear important for survival at elevated temperature and are necessary for full virulence, whereas a single degQ deletion appears to have no clear role in survival and growth at elevated temperature or in mice.
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Affiliation(s)
- Elaine Mo
- Wolfson Institute for Biomedical Research, University College London, Cruciform Building, Gower Street, London WC1E 6BT, UK.
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37
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Savijoki K, Ingmer H, Varmanen P. Proteolytic systems of lactic acid bacteria. Appl Microbiol Biotechnol 2006; 71:394-406. [PMID: 16628446 DOI: 10.1007/s00253-006-0427-1] [Citation(s) in RCA: 385] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 03/13/2006] [Accepted: 03/13/2006] [Indexed: 11/28/2022]
Abstract
Lactic acid bacteria (LAB) have a very long history of use in the manufacturing processes of fermented foods and a great deal of effort was made to investigate and manipulate the role of LAB in these processes. Today, the diverse group of LAB includes species that are among the best-studied microorganisms and proteolysis is one of the particular physiological traits of LAB of which detailed knowledge was obtained. The proteolytic system involved in casein utilization provides cells with essential amino acids during growth in milk and is also of industrial importance due to its contribution to the development of the organoleptic properties of fermented milk products. For the most extensively studied LAB, Lactococcus lactis, a model for casein proteolysis, transport, peptidolysis, and regulation thereof is now established. In addition to nutrient processing, cellular proteolysis plays a critical role in polypeptide quality control and in many regulatory circuits by keeping basal levels of regulatory proteins low and removing them when they are no longer needed. As part of the industrial processes, LAB are challenged by various stress conditions that are likely to affect metabolic activities, including proteolysis. While environmental stress responses of LAB have received increasing interest in recent years, our current knowledge on stress-related proteolysis in LAB is almost exclusively based on studies on L. lactis. This review provides the current status in the research of proteolytic systems of LAB with industrial relevance.
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Affiliation(s)
- Kirsi Savijoki
- Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, Helsinki, 00014, Finland.
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38
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Wilson RL, Brown LL, Kirkwood-Watts D, Warren TK, Lund SA, King DS, Jones KF, Hruby DE. Listeria monocytogenes 10403S HtrA is necessary for resistance to cellular stress and virulence. Infect Immun 2006; 74:765-8. [PMID: 16369036 PMCID: PMC1346606 DOI: 10.1128/iai.74.1.765-768.2006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The HtrA serine protease has been shown to be essential for bacterial virulence and for survival after exposure to many types of environmental and cellular stresses. A Listeria monocytogenes 10403S htrA mutant was found to be sensitive to oxidative and puromycin-induced stress at high temperatures, showed a reduced ability to form biofilms, and was attenuated for virulence in mice.
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Affiliation(s)
- Rebecca L Wilson
- SIGA Technologies, 4575 NW Research Way, Corvallis, OR 97330, USA
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39
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Kaushal G, Shao J. Oral delivery of beta-lactamase by Lactococcus lactis subsp. lactis transformed with Plasmid ss80. Int J Pharm 2006; 312:90-5. [PMID: 16451824 DOI: 10.1016/j.ijpharm.2006.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2005] [Revised: 12/24/2005] [Accepted: 01/03/2006] [Indexed: 10/25/2022]
Abstract
The objective was to use normal flora to deliver protein/peptide drugs orally. A probiotic bacterium, Lactococcus lactis subsp. lactis (L. lactis) transformed with Plasmid ss80, which made it able to synthesize and secrete beta-lactamase, a 29 kDa protein, was used as the delivery system for beta-lactamase. Oral absorption of beta-lactamase in rats when delivered by this L. lactis system was investigated. The oral bioavailability of beta-lactamase delivered by 3x10(7) of the L. lactis was equivalent to 209 mU of i.v. dose, and the estimated relative bioavailability was 16.7%. When delivered by beta-lactamase free solution form, the relative oral bioavailability was 4.7%, which increased to 6.0% when co-administered with 3x10(7) of the untransformed L. lactis. The results demonstrated that the L. lactis significantly increased the beta-lactamase oral bioavailability by 2-3-folds (p<0.01), the mean residence time (MRT) by 3-4 times (p<0.01), and the mean absorption time (MAT) by 6-14 times (p<0.01), as compared to the free solution form with/without the untransformed L. lactis. In conclusion, the L. lactis is more efficient in delivering beta-lactamase orally compared with the free solution form. It also provides a sustained delivery mechanism for beta-lactamase. Gene-transformed normal flora may be used as an efficient and sustained delivery system for protein drugs through oral route.
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Affiliation(s)
- Gagan Kaushal
- Biotechnology and Drug Delivery Laboratory, Department of Pharmacy and Administrative Sciences, College of Pharmacy and Allied Health Professions, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
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40
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Vermeulen N, Pavlovic M, Ehrmann MA, Gänzle MG, Vogel RF. Functional characterization of the proteolytic system of Lactobacillus sanfranciscensis DSM 20451T during growth in sourdough. Appl Environ Microbiol 2005; 71:6260-6. [PMID: 16204547 PMCID: PMC1266010 DOI: 10.1128/aem.71.10.6260-6266.2005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protein hydrolysis and amino acid metabolism contribute to the beneficial effects of sourdough fermentation on bread quality. In this work, genes of Lactobacillus sanfranciscensis strain DSM 20451 involved in peptide uptake and hydrolysis were identified and their expression during growth in sourdough was determined. Screening of the L. sanfranciscensis genome with degenerate primers targeting prt and analysis of proteolytic activity in vitro provided no indication for proteolytic activity. Proteolysis in aseptic doughs and sourdoughs fermented with L. sanfranciscensis was inhibited upon the addition of an aspartic protease inhibitor. These results indicate that proteolysis was not linked to the presence of L. sanfranciscensis DSM 20451 and that this strain does not harbor a proteinase. Genes encoding the peptide transport systems Opp and DtpT and the intracellular peptidases PepT, PepR, PepC, PepN, and PepX were identified. Both peptide uptake systems and the genes pepN, pepX, pepC, and pepT were expressed by L. sanfranciscensis growing exponentially in sourdough, whereas pepX was not transcribed. The regulation of the expression of Opp, DtpT, and PepT during growth of L. sanfranciscensis in sourdough was investigated. Expression of Opp and DtpT was reduced approximately 17-fold when the peptide supply in dough was increased. The expression of PepT was dependent on the peptide supply to a lesser extent. Thus, the accumulation of amino nitrogen by L. sanfranciscensis in dough is attributable to peptide hydrolysis rather than proteolysis and amino acid metabolism by L. sanfranciscensis during growth in sourdough is limited by the peptide availability.
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Affiliation(s)
- Nicoline Vermeulen
- Food Microbiology and Probiotics, Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada
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Stack HM, Sleator RD, Bowers M, Hill C, Gahan CGM. Role for HtrA in stress induction and virulence potential in Listeria monocytogenes. Appl Environ Microbiol 2005; 71:4241-7. [PMID: 16085809 PMCID: PMC1183364 DOI: 10.1128/aem.71.8.4241-4247.2005] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In silico analysis of the Listeria monocytogenes genome revealed lmo0292, a gene predicted to encode a HtrA-like serine protease. A stable insertion mutant was constructed, revealing a requirement for htrA in the listerial response to heat, acid, and penicillin stress. Transcriptional analysis revealed that htrA is not induced in response to heat shock but is induced in response to low pH and penicillin G stress. Furthermore, htrA expression was shown to be dependent upon the LisRK two-component sensor-kinase, a system known to respond to changes in integrity of the cell envelope. In addition, we demonstrated that a second in-frame start codon, upstream of that previously annotated for L. monocytogenes htrA, incorporating a putative signal sequence appears to influence virulence potential. Finally, a significant virulence defect was observed for the htrA mutant, indicating that this gene is required for full virulence in mice. Our findings suggest that L. monocytogenes lmo0292 encodes an HtrA-like serine protease that is not part of the classical heat shock response but is involved in stress responses and virulence.
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Affiliation(s)
- Helena M Stack
- Department of Microbiology and Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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Savijoki K, Suokko A, Palva A, Valmu L, Kalkkinen N, Varmanen P. Effect of heat-shock and bile salts on protein synthesis of Bifidobacterium longum revealed by [35S]methionine labelling and two-dimensional gel electrophoresis. FEMS Microbiol Lett 2005; 248:207-15. [PMID: 15990254 DOI: 10.1016/j.femsle.2005.05.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 05/18/2005] [Accepted: 05/20/2005] [Indexed: 10/25/2022] Open
Abstract
Experimental conditions for efficient protein radiolabelling and two-dimensional gel electrophoresis were developed for Bifidobacterium longum. Using these tools, protein synthesis in cells before and after heat-shock and bile salts treatment was investigated. Following heat-stress, 13 proteins were upregulated, of which HtrA, DnaK and GroEL were also moderately induced by bile salts, indicating close relationship between the heat and bile salts responses in bifidobacteria. Our work indicated that, as a consequence of prolonged heat-stress, HtrA undergoes sequential modification and proteolysis, and that this mechanism could be employed by bifidobacteria to respond to heat-stress.
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Affiliation(s)
- Kirsi Savijoki
- University of Helsinki, Faculty of Veterinary Medicine, Department of Basic Veterinary Sciences, Division of Microbiology and Epidemiology, P.O. Box 66, FIN-00014 University of Helsinki, Finland.
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Sebert ME, Patel KP, Plotnick M, Weiser JN. Pneumococcal HtrA protease mediates inhibition of competence by the CiaRH two-component signaling system. J Bacteriol 2005; 187:3969-79. [PMID: 15937159 PMCID: PMC1151733 DOI: 10.1128/jb.187.12.3969-3979.2005] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Activation of the CiaRH two-component signaling system prevents the development of competence for genetic transformation in Streptococcus pneumoniae through a previously unknown mechanism. Earlier studies have shown that CiaRH controls the expression of htrA, which we show encodes a surface-expressed serine protease. We found that mutagenesis of the putative catalytic serine of HtrA, while not impacting the competence of a ciaRH+ strain, restored a normal competence profile to a strain having a mutation that constitutively activates the CiaH histidine kinase. This result implies that activity of HtrA is necessary for the CiaRH system to inhibit competence. Consistent with this finding, recombinant HtrA (rHtrA) decreased the competence of pneumococcal cultures. The rHtrA-mediated decline in transformation efficiency could not be corrected with excess competence-stimulating peptide (CSP), suggesting that HtrA does not act through degradation of this signaling molecule. The inhibitory effects of rHtrA and activated CiaH, however, were largely overcome in a strain having constitutive activation of the competence pathway through a mutation in the cytoplasmic domain of the ComD histidine kinase. Although these results suggested that HtrA might act through degradation of the extracellular portion of the ComD receptor, Western immunoblots for ComD did not reveal changes in protein levels attributable to HtrA. We therefore postulate that HtrA may act on an unknown protein target that potentiates the activation of the ComDE system by CSP. These findings suggest a novel regulatory role for pneumococcal HtrA in modulating the activity of a two-component signaling system that controls the development of genetic competence.
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Affiliation(s)
- M E Sebert
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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Redon E, Loubiere P, Cocaign-Bousquet M. Transcriptome analysis of the progressive adaptation of Lactococcus lactis to carbon starvation. J Bacteriol 2005; 187:3589-92. [PMID: 15866950 PMCID: PMC1111995 DOI: 10.1128/jb.187.10.3589-3592.2005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adaptation of Lactococcus lactis towards progressive carbon starvation is mediated by three different types of transcriptomic responses: (i) global responses, i.e., general decreases of functions linked to bacterial growth and lack of induction of the general stress response; (ii) specific responses functionally related to glucose exhaustion, i.e., underexpression of central metabolism genes, induction of alternative sugar transport and metabolism, and induction of the arginine deiminase pathway; and (iii) other responses never described previously during carbon starvation.
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Affiliation(s)
- Emma Redon
- Laboratoire Biotechnologie-Bioprocédés, UMR 5504 INSA/CNRS and UMR792 INSA/INRA, Institut National des Sciences Appliquées, 135 Avenue de Rangueil, 31077 Toulouse cedex 4, France
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Uguen P, Hindré T, Didelot S, Marty C, Haras D, Le Pennec JP, Vallée-Réhel K, Dufour A. Maturation by LctT is required for biosynthesis of full-length lantibiotic lacticin 481. Appl Environ Microbiol 2005; 71:562-5. [PMID: 15640237 PMCID: PMC544215 DOI: 10.1128/aem.71.1.562-565.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In lantibiotic lacticin 481 biosynthesis, LctT cleaves the precursor peptide and exports mature lantibiotic. Matrix-assisted laser desorption ionization-time of flight mass spectrometry revealed that a truncated form of lacticin 481 is produced in the absence of LctT or after cleavage site inactivation. Production of truncated lacticin 481 is 4-fold less efficient, and its specific activity is about 10-fold lower.
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Affiliation(s)
- Patricia Uguen
- Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, BP 92116, 56321 Lorient Cedex, France
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Rigoulay C, Entenza JM, Halpern D, Widmer E, Moreillon P, Poquet I, Gruss A. Comparative analysis of the roles of HtrA-like surface proteases in two virulent Staphylococcus aureus strains. Infect Immun 2005; 73:563-72. [PMID: 15618196 PMCID: PMC538960 DOI: 10.1128/iai.73.1.563-572.2005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The HtrA surface protease is involved in the virulence of many pathogens, mainly by its role in stress resistance and bacterial survival. Staphylococcus aureus encodes two putative HtrA-like proteases, referred to as HtrA(1) and HtrA(2). To investigate the roles of HtrA proteins in S. aureus, we constructed htrA(1), htrA(2), and htrA(1) htrA(2) insertion mutants in two genetically different virulent strains, RN6390 and COL. In the RN6390 context, htrA(1) inactivation resulted in sensitivity to puromycin-induced stress. The RN6390 htrA(1) htrA(2) mutant was affected in the expression of several secreted virulence factors comprising the agr regulon. This observation was correlated with the disappearance of the agr RNA III transcript in the RN6390 htrA(1) htrA(2) mutant. The virulence of this mutant was diminished in a rat model of endocarditis. In the COL context, both HtrA(1) and HtrA(2) were essential for thermal stress survival. However, only HtrA(1) had a slight effect on exoprotein expression. The htrA mutations did not diminish the virulence of the COL strain in the rat model of endocarditis. Our results indicate that HtrA proteins have different roles in S. aureus according to the strain, probably depending on specific differences in the regulation of virulence factor and stress protein expression. We propose that HtrA(1) and HtrA(2) contribute to pathogenicity by controlling the production of certain extracellular factors that are crucial for bacterial dissemination, as revealed in the RN6390 background. We speculate that HtrA proteins act in the agr-dependent regulation pathway by assuring folding and/or maturation of some surface components of the agr system.
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Affiliation(s)
- Candice Rigoulay
- Unité de Recherches Laitières et Génétique Appliquée, INRA, 78352 Jouy-en-Josas Cedex, France.
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Shao J, Kaushal G. Normal flora: living vehicles for non-invasive protein drug delivery. Int J Pharm 2004; 286:117-24. [PMID: 15501008 DOI: 10.1016/j.ijpharm.2004.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 07/12/2004] [Accepted: 08/12/2004] [Indexed: 11/16/2022]
Abstract
Feasibility to use probiotic bacteria as a living protein delivery system through oral route was assessed in vitro. Lactococcus lactis transformed with a plasmid to express and secret beta-lactamase was used to deliver beta-lactamase through Caco-2 monolayer, an intestine epithelium. Transport of beta-lactamase through Caco-2 monolayer was carried out in the transwells. The viability and integrity of the cell monolayers co-cultured with L. lactis was examined by trypan blue exclusion method and by measuring the transport of mannitol and propranolol as well as the transepithelial electrical resistance (TEER). Results show that it is feasible to use cell culture technique to evaluate the drug delivery by normal flora. The transport rate of beta-lactamase when delivered by L. lactis was 2.0 +/- 0.1 x 10(-2)h(-1) (n = 9) and through free solution form was 1.0 +/- 0.1 x 10(-2)h-1. When co-cultured with L. lactis, Caco-2 cell viability decreased to 98, 96, and 94% at 6, 8, and 10h, respectively. Transport of mannitol through Caco-2 cell monolayer was significantly increased and the transport of propranolol through Caco-2 cell monolayer was significantly decreased in the presence of L. lactis. Increase in the amount of protein delivered is probably due to the concentrate of the protein by L. lactis on the monolayer (absorption surface) and the opening of the tight junction of Caco-2 monolayer by L. lactis.
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Affiliation(s)
- Jun Shao
- Biotechnology and Drug Delivery Laboratory, Department of Pharmacy and Administrative Sciences, College of Pharmacy and Allied Health Professions, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA.
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48
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Rigoulay C, Poquet I, Madsen SÃM, Gruss A. Expression of the Staphylococcus aureus surface proteins HtrA1 and HtrA2 in Lactococcus lactis. FEMS Microbiol Lett 2004. [DOI: 10.1111/j.1574-6968.2004.tb09708.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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