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Bonato P, Camilios-Neto D, Tadra-Sfeir MZ, Mota FJT, Muller-Santos M, Wassem R, de Souza EM, de Oliveira Pedrosa F, Chubatsu LS. The role of NtrC in the adaptation of Herbaspirillum seropedicae SmR1 to nitrogen limitation and to nitrate. Arch Microbiol 2024; 206:310. [PMID: 38896324 DOI: 10.1007/s00203-024-04044-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/08/2024] [Accepted: 06/11/2024] [Indexed: 06/21/2024]
Abstract
The RNA-Seq profiling of Herbaspirillum seropedicae SmR1 wild-type and ntrC mutant was performed under aerobic and three nitrogen conditions (ammonium limitation, ammonium shock, and nitrate shock) to identify the major metabolic pathways modulated by these nitrogen sources and those dependent on NtrC. Under ammonium limitation, H. seropedicae scavenges nitrogen compounds by activating transporter systems and metabolic pathways to utilize different nitrogen sources and by increasing proteolysis, along with genes involved in carbon storage, cell protection, and redox balance, while downregulating those involved in energy metabolism and protein synthesis. Growth on nitrate depends on the narKnirBDHsero_2899nasA operon responding to nitrate and NtrC. Ammonium shock resulted in a higher number of genes differently expressed when compared to nitrate. Our results showed that NtrC activates a network of transcriptional regulators to prepare the cell for nitrogen starvation, and also synchronizes nitrogen metabolism with carbon and redox balance pathways.
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Affiliation(s)
- Paloma Bonato
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Doumit Camilios-Neto
- Department of Biochemistry and Biotechnology, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | | | - Francisco J Teles Mota
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Muller-Santos
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Roseli Wassem
- Department of Genetics, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Emanuel Maltempi de Souza
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Leda Satie Chubatsu
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil.
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2
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Simcox BS, Rohde KH. Orphan response regulator NnaR is critical for nitrate and nitrite assimilation in Mycobacterium abscessus. Front Cell Infect Microbiol 2024; 14:1411333. [PMID: 38854658 PMCID: PMC11162112 DOI: 10.3389/fcimb.2024.1411333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/10/2024] [Indexed: 06/11/2024] Open
Abstract
Mycobacterium abscessus (Mab) is an opportunistic pathogen afflicting individuals with underlying lung disease such as Cystic Fibrosis (CF) or immunodeficiencies. Current treatment strategies for Mab infections are limited by its inherent antibiotic resistance and limited drug access to Mab in its in vivo niches resulting in poor cure rates of 30-50%. Mab's ability to survive within macrophages, granulomas and the mucus laden airways of the CF lung requires adaptation via transcriptional remodeling to counteract stresses like hypoxia, increased levels of nitrate, nitrite, and reactive nitrogen intermediates. Mycobacterium tuberculosis (Mtb) is known to coordinate hypoxic adaptation via induction of respiratory nitrate assimilation through the nitrate reductase narGHJI. Mab, on the other hand, does not encode a respiratory nitrate reductase. In addition, our recent study of the transcriptional responses of Mab to hypoxia revealed marked down-regulation of a locus containing putative nitrate assimilation genes, including the orphan response regulator nnaR (nitrate/nitrite assimilation regulator). These putative nitrate assimilation genes, narK3 (nitrate/nitrite transporter), nirBD (nitrite reductase), nnaR, and sirB (ferrochelatase) are arranged contiguously while nasN (assimilatory nitrate reductase identified in this work) is encoded in a different locus. Absence of a respiratory nitrate reductase in Mab and down-regulation of nitrogen metabolism genes in hypoxia suggest interplay between hypoxia adaptation and nitrate assimilation are distinct from what was previously documented in Mtb. The mechanisms used by Mab to fine-tune the transcriptional regulation of nitrogen metabolism in the context of stresses e.g. hypoxia, particularly the role of NnaR, remain poorly understood. To evaluate the role of NnaR in nitrate metabolism we constructed a Mab nnaR knockout strain (MabΔnnaR ) and complement (MabΔnnaR+C ) to investigate transcriptional regulation and phenotypes. qRT-PCR revealed NnaR is necessary for regulating nitrate and nitrite reductases along with a putative nitrate transporter. Loss of NnaR compromised the ability of Mab to assimilate nitrate or nitrite as sole nitrogen sources highlighting its necessity. This work provides the first insights into the role of Mab NnaR setting a foundation for future work investigating NnaR's contribution to pathogenesis.
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Affiliation(s)
| | - Kyle H. Rohde
- Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, United States
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3
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Ensinck D, Gerhardt ECM, Rollan L, Huergo LF, Gramajo H, Diacovich L. The PII protein interacts with the Amt ammonium transport and modulates nitrate/nitrite assimilation in mycobacteria. Front Microbiol 2024; 15:1366111. [PMID: 38591044 PMCID: PMC11001197 DOI: 10.3389/fmicb.2024.1366111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/04/2024] [Indexed: 04/10/2024] Open
Abstract
PII proteins are signal transduction proteins that belong to a widely distributed family of proteins involved in the modulation of different metabolisms in bacteria. These proteins are homotrimers carrying a flexible loop, named T-loop, which changes its conformation due to the recognition of diverse key metabolites, ADP, ATP, and 2-oxoglutarate. PII proteins interact with different partners to primarily regulate a set of nitrogen pathways. In some organisms, PII proteins can also control carbon metabolism by interacting with the biotin carboxyl carrier protein (BCCP), a key component of the acetyl-CoA carboxylase (ACC) enzyme complex, inhibiting its activity with the consequent reduction of fatty acid biosynthesis. Most bacteria contain at least two PII proteins, named GlnB and GlnK, with different regulatory roles. In mycobacteria, only one PII protein was identified, and the three-dimensional structure was solved, however, its physiological role is unknown. In this study we purified the Mycobacterium tuberculosis (M. tb) PII protein, named GlnB, and showed that it weakly interacts with the AccA3 protein, the α subunit shared by the three different, and essential, Acyl-CoA carboxylase complexes (ACCase 4, 5, and 6) present in M. tb. A M. smegmatis deletion mutant, ∆MsPII, exhibited a growth deficiency on nitrate and nitrite as unique nitrogen sources, and accumulated nitrite in the culture supernatant. In addition, M. tb PII protein was able to interact with the C-terminal domain of the ammonium transporter Amt establishing the ancestral role for this PII protein as a GlnK functioning protein.
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Affiliation(s)
- Delfina Ensinck
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Edileusa C. M. Gerhardt
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Lara Rollan
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Luciano F. Huergo
- Setor Litoral, Federal University of Paraná, Universidade Federal do Paraná (UFPR), Matinhos, Paraná, Brazil
- Graduated Program in Sciences-Biochemistry, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, Brazil
| | - Hugo Gramajo
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Lautaro Diacovich
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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4
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Singh P, Kumar A, Chhabra R, Singh K, Kaur J. MSMEG_5850, a stress-induced TetR protein, involved in global transcription regulation in Mycobacterium smegmatis. Future Microbiol 2023; 18:563-580. [PMID: 37284769 DOI: 10.2217/fmb-2022-0238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Abstract
Aim: To decipher the role of MSMEG_5850 in the physiology of mycobacteria. Methods: MSMEG_5850 was knocked out and RNA sequencing was performed. MSMEG_5850 protein was purified from the Escherichia coli pET28a system. Electrophoretic mobility shift assay and size exclusion chromatography were used to determine the binding of MSMEG_5850 to its motif and binding stoichiometry. The effect of nutritional stress was monitored. Results: Transcriptome analysis revealed the differential expression of 148 genes in an MSMEG_5850 knockout strain. MSMEG_5850 had control over 50 genes because those genes had a binding motif upstream of their sequence. The electrophoretic mobility shift assay showed MSMEG_5850 bound to its motif as a monomer. MSMEG_5850 was upregulated under nutritional stress and promoted the survival of mycobacteria. Conclusion: The study confirms the role of MSMEG_5850 in global transcriptional regulation.
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Affiliation(s)
- Parul Singh
- Department of Biotechnology, BMS Block-1, Sector-25, Panjab University, Chandigarh, 160014, India
| | - Arbind Kumar
- Department of Biotechnology, BMS Block-1, Sector-25, Panjab University, Chandigarh, 160014, India
- Current Address: Fellow Scientist, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, 176061, India
| | - Ravindresh Chhabra
- Department of Biochemistry, Central University of Punjab, Bathinda, 151001, India
| | - Kashmir Singh
- Department of Biotechnology, BMS Block-1, Sector-25, Panjab University, Chandigarh, 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, BMS Block-1, Sector-25, Panjab University, Chandigarh, 160014, India
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Shi J, Feng Z, Xu J, Li F, Zhang Y, Wen A, Wang F, Song Q, Wang L, Cui H, Tong S, Chen P, Zhu Y, Zhao G, Wang S, Feng Y, Lin W. Structural insights into the transcription activation mechanism of the global regulator GlnR from actinobacteria. Proc Natl Acad Sci U S A 2023; 120:e2300282120. [PMID: 37216560 PMCID: PMC10235972 DOI: 10.1073/pnas.2300282120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 04/27/2023] [Indexed: 05/24/2023] Open
Abstract
In actinobacteria, an OmpR/PhoB subfamily protein called GlnR acts as an orphan response regulator and globally coordinates the expression of genes responsible for nitrogen, carbon, and phosphate metabolism in actinobacteria. Although many researchers have attempted to elucidate the mechanisms of GlnR-dependent transcription activation, progress is impeded by lacking of an overall structure of GlnR-dependent transcription activation complex (GlnR-TAC). Here, we report a co-crystal structure of the C-terminal DNA-binding domain of GlnR (GlnR_DBD) in complex with its regulatory cis-element DNA and a cryo-EM structure of GlnR-TAC which comprises Mycobacterium tuberculosis RNA polymerase, GlnR, and a promoter containing four well-characterized conserved GlnR binding sites. These structures illustrate how four GlnR protomers coordinate to engage promoter DNA in a head-to-tail manner, with four N-terminal receiver domains of GlnR (GlnR-RECs) bridging GlnR_DBDs and the RNAP core enzyme. Structural analysis also unravels that GlnR-TAC is stabilized by complex protein-protein interactions between GlnR and the conserved β flap, σAR4, αCTD, and αNTD domains of RNAP, which are further confirmed by our biochemical assays. Taken together, these results reveal a global transcription activation mechanism for the master regulator GlnR and other OmpR/PhoB subfamily proteins and present a unique mode of bacterial transcription regulation.
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Affiliation(s)
- Jing Shi
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
- Department of Biophysics, Zhejiang University School of Medicine, 310058Hangzhou, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058Hangzhou, China
| | - Zhenzhen Feng
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Juncao Xu
- Key Laboratory of Synthetic Biology, Chinese Academy of Sciences (CAS) Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 200032Shanghai, China
| | - Fangfang Li
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Yuqiong Zhang
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, 510631Guangzhou, Guangdong, China
- Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, 510631Guangzhou, Guangdong, China
- Songshan Lake Materials Laboratory, 523808Dongguan, Guangdong, China
| | - Aijia Wen
- Department of Biophysics, Zhejiang University School of Medicine, 310058Hangzhou, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058Hangzhou, China
| | - Fulin Wang
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Qian Song
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Lu Wang
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Hong Cui
- Pasteurien College, Suzhou Medical College of Soochow University, Soochow University, 251000Soochow, China
| | - Shujuan Tong
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Peiying Chen
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Yejin Zhu
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Guoping Zhao
- Key Laboratory of Synthetic Biology, Chinese Academy of Sciences (CAS) Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 200032Shanghai, China
| | - Shuang Wang
- Songshan Lake Materials Laboratory, 523808Dongguan, Guangdong, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190Beijing, China
| | - Yu Feng
- Department of Biophysics, Zhejiang University School of Medicine, 310058Hangzhou, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058Hangzhou, China
| | - Wei Lin
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai200237, China
- Nanjing Drum Tower Hospital Clinical College, Nanjing University of Chinese Medicine, 210023Nanjing, China
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6
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He J, Kang X, Wu J, Shao Z, Zhang Z, Wu Y, Yuan H, Zhao G, Wang J. Transcriptional Self-Regulation of the Master Nitrogen Regulator GlnR in Mycobacteria. J Bacteriol 2023; 205:e0047922. [PMID: 36943048 PMCID: PMC10127674 DOI: 10.1128/jb.00479-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/27/2023] [Indexed: 03/23/2023] Open
Abstract
As a master nitrogen regulator in most actinomycetes, GlnR both governs central nitrogen metabolism and regulates many carbon, phosphate, and secondary metabolic pathways. To date, most studies have been focused on the GlnR regulon, while little is known about the transcriptional regulator for glnR itself. It has been observed that glnR transcription can be upregulated in Mycobacterium smegmatis under nitrogen-limited growth conditions; however, the detailed regulatory mechanism is still unclear. Here, we demonstrate that the glnR gene in M. smegmatis is transcriptionally activated by its product GlnR in response to nitrogen limitation. The precise GlnR binding site was successfully characterized in its promoter region using the electrophoretic mobility shift assay and the DNase I footprinting assay. Site mutagenesis and genetic analyses confirmed that the binding site was essential for in vivo self-activation of glnR transcription. Moreover, based on bioinformatic analyses, we discovered that most of the mycobacterial glnR promoter regions (144 out of 147) contain potential GlnR binding sites, and we subsequently proved that the purified M. smegmatis GlnR protein could specifically bind 16 promoter regions that represent 119 mycobacterial species, including Mycobacterium tuberculosis. Together, our findings not only elucidate the transcriptional self-regulation mechanism of glnR transcription in M. smegmatis but also indicate the ubiquity of the mechanism in other mycobacterial species. IMPORTANCE In actinomycetes, the nitrogen metabolism not only is essential for the construction of life macromolecules but also affects the biosynthesis of secondary metabolites and even virulence (e.g., Mycobacterium tuberculosis). The transcriptional regulation of genes involved in nitrogen metabolism has been thoroughly studied and involves the master nitrogen regulator GlnR. However, the transcriptional regulation of glnR itself remains elusive. Here, we demonstrated that GlnR functions as a transcriptional self-activator in response to nitrogen starvation in the fast-growing model Mycobacterium species Mycobacterium smegmatis. We further showed that this self-regulation mechanism could be widespread in other mycobacteria, which might be beneficial for those slow-growing mycobacteria to adapt to the nitrogen-starvation environments such as within human macrophages for M. tuberculosis.
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Affiliation(s)
- Juanmei He
- CAS Key Laboratory of Synthetic Biology, Centre of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xiaoman Kang
- CAS Key Laboratory of Synthetic Biology, Centre of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jiacheng Wu
- CAS Key Laboratory of Synthetic Biology, Centre of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhihui Shao
- CAS Key Laboratory of Synthetic Biology, Centre of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | | | - Yuqian Wu
- Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hua Yuan
- College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Guoping Zhao
- CAS Key Laboratory of Synthetic Biology, Centre of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jin Wang
- Department of Clinical Laboratory, Shenzhen Second People’s Hospital & Institute of Translational Medicine/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
- Guangdong Provincial Key Laboratory of Systems Biology and Synthetic Biology for Urogenital Tumors, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital (Shenzhen Institute of Translational Medicine), Shenzhen, China
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7
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Krysenko S, Wohlleben W. Polyamine and Ethanolamine Metabolism in Bacteria as an Important Component of Nitrogen Assimilation for Survival and Pathogenicity. Med Sci (Basel) 2022; 10:40. [PMID: 35997332 PMCID: PMC9397018 DOI: 10.3390/medsci10030040] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
Nitrogen is an essential element required for bacterial growth. It serves as a building block for the biosynthesis of macromolecules and provides precursors for secondary metabolites. Bacteria have developed the ability to use various nitrogen sources and possess two enzyme systems for nitrogen assimilation involving glutamine synthetase/glutamate synthase and glutamate dehydrogenase. Microorganisms living in habitats with changeable availability of nutrients have developed strategies to survive under nitrogen limitation. One adaptation is the ability to acquire nitrogen from alternative sources including the polyamines putrescine, cadaverine, spermidine and spermine, as well as the monoamine ethanolamine. Bacterial polyamine and monoamine metabolism is not only important under low nitrogen availability, but it is also required to survive under high concentrations of these compounds. Such conditions can occur in diverse habitats such as soil, plant tissues and human cells. Strategies of pathogenic and non-pathogenic bacteria to survive in the presence of poly- and monoamines offer the possibility to combat pathogens by using their capability to metabolize polyamines as an antibiotic drug target. This work aims to summarize the knowledge on poly- and monoamine metabolism in bacteria and its role in nitrogen metabolism.
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Affiliation(s)
- Sergii Krysenko
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany;
- Cluster of Excellence ‘Controlling Microbes to Fight Infections’, University of Tübingen, 72076 Tübingen, Germany
| | - Wolfgang Wohlleben
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany;
- Cluster of Excellence ‘Controlling Microbes to Fight Infections’, University of Tübingen, 72076 Tübingen, Germany
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8
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CRISPR Interference Reveals That All- Trans-Retinoic Acid Promotes Macrophage Control of Mycobacterium tuberculosis by Limiting Bacterial Access to Cholesterol and Propionyl Coenzyme A. mBio 2022; 13:e0368321. [PMID: 35038923 PMCID: PMC8764544 DOI: 10.1128/mbio.03683-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Macrophages are a protective replicative niche for Mycobacterium tuberculosis (Mtb) but can kill the infecting bacterium when appropriately activated. To identify mechanisms of clearance, we compared levels of bacterial restriction by human macrophages after treatment with 26 compounds, including some currently in clinical trials for tuberculosis. All-trans-retinoic acid (ATRA), an active metabolite of vitamin A, drove the greatest increase in Mtb control. Bacterial clearance was transcriptionally and functionally associated with changes in macrophage cholesterol trafficking and lipid metabolism. To determine how these macrophage changes affected bacterial control, we performed the first Mtb CRISPR interference screen in an infection model, identifying Mtb genes specifically required to survive in ATRA-activated macrophages. These data showed that ATRA treatment starves Mtb of cholesterol and the downstream metabolite propionyl coenzyme A (propionyl-CoA). Supplementation with sources of propionyl-CoA, including cholesterol, abrogated the restrictive effect of ATRA. This work demonstrates that targeting the coupled metabolism of Mtb and the macrophage improves control of infection and that it is possible to genetically map the mode of bacterial death using CRISPR interference. IMPORTANCE Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, is a leading cause of death due to infectious disease. Improving the immune response to tuberculosis holds promise for fighting the disease but is limited by our lack of knowledge as to how the immune system kills M. tuberculosis. Our research identifies a potent way to make relevant immune cells more effective at fighting M. tuberculosis and then uses paired human and bacterial genomic methods to determine the mechanism of that improved bacterial clearance.
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9
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Apiyo D, Mouton JM, Louw C, Sampson SL, Louw TM. Dynamic mathematical model development and validation of in vitro Mycobacterium smegmatis growth under nutrient- and pH-stress. J Theor Biol 2022; 532:110921. [PMID: 34582827 DOI: 10.1016/j.jtbi.2021.110921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/27/2021] [Accepted: 09/21/2021] [Indexed: 10/20/2022]
Abstract
Mycobacterium tuberculosis can exist within a host for lengthy periods, tolerating even antibiotic challenge. This non-heritable, antibiotic tolerant "persister" state, is thought to underlie latent Tuberculosis (TB) infection and a deeper understanding thereof could inform treatment strategies. In addition to experimental studies, mathematical and computational modelling approaches are widely employed to study persistence from both an in vivo and in vitro perspective. However, specialized models (partial differential equations, agent-based, multiscale, etc.) rely on several difficult to determine parameters. In this study, a dynamic mathematical model was developed to predict the response of Mycobacterium smegmatis (a model organism for M. tuberculosis) grown in batch culture and subjected to a range of in vitro environmental stresses. Lag phase dynamics, pH variations and internal nitrogen storage were mechanistically modelled. Experimental results were used to train model parameters using global optimization, with extensive subsequent model validation to ensure extensibility to more complex modelling frameworks. This included an identifiability analysis which indicated that seven of the thirteen model parameters were uniquely identifiable. Non-identifiable parameters were critically evaluated. Model predictions compared to validation data (based on experimental results not used during training) were accurate with less than 16% maximum absolute percentage error, indicating that the model is accurate even when extrapolating to new experimental conditions. The bulk growth model can be extended to spatially heterogeneous simulations such as an agent-based model to simulate in vitro granuloma models or, eventually, in vivo conditions, where distributed environmental conditions are difficult to measure.
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Affiliation(s)
- D Apiyo
- Department of Process Engineering, Faculty of Engineering, Stellenbosch University, Stellenbosch, South Africa
| | - J M Mouton
- Department of Science and Innovation/National Research Foundation (DSI/NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - C Louw
- Department of Process Engineering, Faculty of Engineering, Stellenbosch University, Stellenbosch, South Africa
| | - S L Sampson
- Department of Science and Innovation/National Research Foundation (DSI/NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - T M Louw
- Department of Process Engineering, Faculty of Engineering, Stellenbosch University, Stellenbosch, South Africa.
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Mallick I, Santucci P, Poncin I, Point V, Kremer L, Cavalier JF, Canaan S. Intrabacterial lipid inclusions in mycobacteria: unexpected key players in survival and pathogenesis? FEMS Microbiol Rev 2021; 45:6283747. [PMID: 34036305 DOI: 10.1093/femsre/fuab029] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/21/2021] [Indexed: 12/12/2022] Open
Abstract
Mycobacterial species, including Mycobacterium tuberculosis, rely on lipids to survive and chronically persist within their hosts. Upon infection, opportunistic and strict pathogenic mycobacteria exploit metabolic pathways to import and process host-derived free fatty acids, subsequently stored as triacylglycerols under the form of intrabacterial lipid inclusions (ILI). Under nutrient-limiting conditions, ILI constitute a critical source of energy that fuels the carbon requirements and maintain redox homeostasis, promoting bacterial survival for extensive periods of time. In addition to their basic metabolic functions, these organelles display multiple other biological properties, emphasizing their central role in the mycobacterial lifecycle. However, despite of their importance, the dynamics of ILI metabolism and their contribution to mycobacterial adaptation/survival in the context of infection has not been thoroughly documented. Herein, we provide an overview of the historical ILI discoveries, their characterization, and current knowledge regarding the micro-environmental stimuli conveying ILI formation, storage and degradation. We also review new biological systems to monitor the dynamics of ILI metabolism in extra- and intracellular mycobacteria and describe major molecular actors in triacylglycerol biosynthesis, maintenance and breakdown. Finally, emerging concepts regarding to the role of ILI in mycobacterial survival, persistence, reactivation, antibiotic susceptibility and inter-individual transmission are also discuss.
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Affiliation(s)
- Ivy Mallick
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France.,IHU Méditerranée Infection, Aix-Marseille Univ., Marseille, France
| | - Pierre Santucci
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
| | - Isabelle Poncin
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
| | - Vanessa Point
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
| | - Laurent Kremer
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS, UMR 9004, Université de Montpellier, Montpellier, France.,IRIM, INSERM, Montpellier, France
| | | | - Stéphane Canaan
- Aix-Marseille Univ, CNRS, LISM, IMM FR3479, Marseille, France
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11
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Label-Free Comparative Proteomics of Differentially Expressed Mycobacterium tuberculosis Protein in Rifampicin-Related Drug-Resistant Strains. Pathogens 2021; 10:pathogens10050607. [PMID: 34063426 PMCID: PMC8157059 DOI: 10.3390/pathogens10050607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 11/26/2022] Open
Abstract
Rifampicin (RIF) is one of the most important first-line anti-tuberculosis (TB) drugs, and more than 90% of RIF-resistant (RR) Mycobacterium tuberculosis clinical isolates belong to multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. In order to identify specific candidate target proteins as diagnostic markers or drug targets, differential protein expression between drug-sensitive (DS) and drug-resistant (DR) strains remains to be investigated. In the present study, a label-free, quantitative proteomics technique was performed to compare the proteome of DS, RR, MDR, and XDR clinical strains. We found iniC, Rv2141c, folB, and Rv2561 were up-regulated in both RR and MDR strains, while fadE9, espB, espL, esxK, and Rv3175 were down-regulated in the three DR strains when compared to the DS strain. In addition, lprF, mce2R, mce2B, and Rv2627c were specifically expressed in the three DR strains, and 41 proteins were not detected in the DS strain. Functional category showed that these differentially expressed proteins were mainly involved in the cell wall and cell processes. When compared to the RR strain, Rv2272, smtB, lpqB, icd1, and folK were up-regulated, while esxK, PPE19, Rv1534, rpmI, ureA, tpx, mpt64, frr, Rv3678c, esxB, esxA, and espL were down-regulated in both MDR and XDR strains. Additionally, nrp, PPE3, mntH, Rv1188, Rv1473, nadB, PPE36, and sseA were specifically expressed in both MDR and XDR strains, whereas 292 proteins were not identified when compared to the RR strain. When compared between MDR and XDR strains, 52 proteins were up-regulated, while 45 proteins were down-regulated in the XDR strain. 316 proteins were especially expressed in the XDR strain, while 92 proteins were especially detected in the MDR strain. Protein interaction networks further revealed the mechanism of their involvement in virulence and drug resistance. Therefore, these differentially expressed proteins are of great significance for exploring effective control strategies of DR-TB.
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12
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Sousa EH, Carepo MS, Moura JJ. Nitrate-nitrite fate and oxygen sensing in dormant Mycobacterium tuberculosis: A bioinorganic approach highlighting the importance of transition metals. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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13
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Dong W, Wang R, Li P, Wang G, Ren X, Feng J, Lu H, Lu W, Wang X, Chen H, Tan C. Orphan response regulator Rv3143 increases antibiotic sensitivity by regulating cell wall permeability in Mycobacterium smegmatis. Arch Biochem Biophys 2020; 692:108522. [PMID: 32781051 DOI: 10.1016/j.abb.2020.108522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 12/20/2022]
Abstract
About one quarter of people worldwide are infected with tuberculosis, and multi-drug resistant tuberculosis (MDR-TB) remains a health threat. It is known that two-Component Signal Transduction Systems (TCSs) of Mycobacterium tuberculosis are closely related to tuberculosis resistance, but the mechanism by which orphan response protein Rv3143 regulates strain sensitivity to drug is still unclear. This study found that Rv3143 overexpression resulted in approximately two-fold increase in Mycobacterium smegmatis antibiotic sensitivity. Transcriptome sequencing indicated that 198 potential genes were regulated by Rv3143, affecting the sensitivity of the strain to rifampicin (RIF). MSMEG_4740 promoter binding with Rv3143, was screened out by surface plasmon resonance (SPR). Rv1524, the homologous gene of MSMEG_4740, belonging to the glycosyltransferase (Gtf) family, was related to cell wall modification. By measuring ethidium bromide (EB) accumulation, we found when Rv3143 or MSMEG_4740, or Rv1524 was overexpressed, the cell wall permeability of Mycobacterium smegmatis was increased. In addition, a combination of Rv3143 and RIF was observed. Our findings provide a new strategy for treating drug-resistant tuberculosis by increasing the expression of Rv3143 to enhance the strain sensitivity to antibiotics.
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Affiliation(s)
- Wenqi Dong
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Rui Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Pei Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; Department of Gastrointestinal Surgery, The Second Clinical Medical College of Jinan University, Shenzhen, Guangdong, 518020, China
| | - Gaoyan Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Xuanxiu Ren
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jiajia Feng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Hao Lu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Wenjia Lu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Xiangru Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, 430070, China; Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, Hubei, 430070, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, 430070, China; Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, Hubei, 430070, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, 430070, China; Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, Hubei, 430070, China.
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14
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Metabolic Switching of Mycobacterium tuberculosis during Hypoxia Is Controlled by the Virulence Regulator PhoP. J Bacteriol 2020; 202:JB.00705-19. [PMID: 31932312 DOI: 10.1128/jb.00705-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/06/2020] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis retains the ability to establish an asymptomatic latent infection. A fundamental question in mycobacterial physiology is to understand the mechanisms involved in hypoxic stress, a critical player in persistence. Here, we show that the virulence regulator PhoP responds to hypoxia, the dormancy signal, and effectively integrates hypoxia with nitrogen metabolism. We also provide evidence to demonstrate that both under nitrogen limiting conditions and during hypoxia, phoP locus controls key genes involved in nitrogen metabolism. Consistently, under hypoxia a ΔphoP strain shows growth attenuation even with surplus nitrogen, the alternate electron acceptor, and complementation of the mutant restores bacterial growth. Together, our observations provide new biological insights into the role of PhoP in integrating nitrogen metabolism with hypoxia by the assistance of the hypoxia regulator DosR. The results have significant implications on the mechanism of intracellular survival and growth of the tubercle bacilli under a hypoxic environment within the phagosome.IMPORTANCE M. tuberculosis retains the unique ability to establish an asymptomatic latent infection. To understand the mechanisms involved in hypoxic stress which play a critical role in persistence, we show that the virulence regulator PhoP is linked to hypoxia, the dormancy signal. In keeping with this, phoP was shown to play a major role in M. tuberculosis growth under hypoxia even in the presence of surplus nitrogen, the alternate electron acceptor. Our results showing regulation of hypoxia-responsive genes provide new biological insights into role of the virulence regulator in metabolic switching by sensing hypoxia and integrating nitrogen metabolism with hypoxia by the assistance of the hypoxia regulator DosR.
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15
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Bishai WR, Timmins GS. Potential for breath test diagnosis of urease positive pathogens in lung infections. J Breath Res 2019; 13:032002. [DOI: 10.1088/1752-7163/ab2225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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16
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Zhu Y, Zhang P, Zhang J, Xu W, Wang X, Wu L, Sheng D, Ma W, Cao G, Chen XL, Lu Y, Zhang YZ, Pang X. The developmental regulator MtrA binds GlnR boxes and represses nitrogen metabolism genes in Streptomyces coelicolor. Mol Microbiol 2019; 112:29-46. [PMID: 30927282 DOI: 10.1111/mmi.14252] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2019] [Indexed: 12/25/2022]
Abstract
In Streptomyces, GlnR is an activator protein that activates nitrogen-assimilation genes under nitrogen-limiting conditions. However, less is known regarding the regulation of these genes under nitrogen-rich conditions. We determined that the developmental regulator MtrA represses nitrogen-assimilation genes in nitrogen-rich media and that it competes with GlnR for binding to GlnR boxes. The GlnR boxes upstream of multiple nitrogen genes, such as amtB, were confirmed as MtrA binding sites in vitro by electrophoretic mobility shift assays and in vivo by ChIP-qPCR analysis. Transcriptional analysis indicated that, on nutrient-rich medium, MtrA profoundly repressed expression of nitrogen-associated genes, indicating opposing roles for MtrA and GlnR in the control of nitrogen metabolism. Using in vitro and in vivo analysis, we also showed that glnR is itself a direct target of MtrA and that MtrA represses glnR transcription. We further demonstrated functional conservation of MtrA homologues in the recognition of GlnR boxes upstream of nitrogen genes from different actinobacterial species. As mtrA and glnR are widespread among actinomycetes, this mechanism of potential competitive control over nitrogen metabolism genes may be common in this group, adding a major new layer of complexity to the known regulatory network for nitrogen metabolism in Streptomyces and related species.
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Affiliation(s)
- Yanping Zhu
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Peipei Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.,Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, 250062, China
| | - Jing Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Wenhao Xu
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Xinyuan Wang
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Lili Wu
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Duohong Sheng
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Wei Ma
- The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Guangxiang Cao
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, 250062, China
| | - Xiu-Lan Chen
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Yinhua Lu
- College of Life Sciences, Shanghai Normal University, Shanghai, 200232, China
| | - Yu-Zhong Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.,College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xiuhua Pang
- The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
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17
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MacGilvary NJ, Kevorkian YL, Tan S. Potassium response and homeostasis in Mycobacterium tuberculosis modulates environmental adaptation and is important for host colonization. PLoS Pathog 2019; 15:e1007591. [PMID: 30716121 PMCID: PMC6375644 DOI: 10.1371/journal.ppat.1007591] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/14/2019] [Accepted: 01/22/2019] [Indexed: 11/19/2022] Open
Abstract
Successful host colonization by bacteria requires sensing and response to the local ionic milieu, and coordination of responses with the maintenance of ionic homeostasis in the face of changing conditions. We previously discovered that Mycobacterium tuberculosis (Mtb) responds synergistically to chloride (Cl-) and pH, as cues to the immune status of its host. This raised the intriguing concept of abundant ions as important environmental signals, and we have now uncovered potassium (K+) as an ion that can significantly impact colonization by Mtb. The bacterium has a unique transcriptional response to changes in environmental K+ levels, with both distinct and shared regulatory mechanisms controlling Mtb response to the ionic signals of K+, Cl-, and pH. We demonstrate that intraphagosomal K+ levels increase during macrophage phagosome maturation, and find using a novel fluorescent K+-responsive reporter Mtb strain that K+ is not limiting during macrophage infection. Disruption of Mtb K+ homeostasis by deletion of the Trk K+ uptake system results in dampening of the bacterial response to pH and Cl-, and attenuation in host colonization, both in primary murine bone marrow-derived macrophages and in vivo in a murine model of Mtb infection. Our study reveals how bacterial ionic homeostasis can impact environmental ionic responses, and highlights the important role that abundant ions can play during host colonization by Mtb.
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Affiliation(s)
- Nathan J. MacGilvary
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Yuzo L. Kevorkian
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts, United States of America
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts, United States of America
- * E-mail:
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18
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Christgen SL, Becker DF. Role of Proline in Pathogen and Host Interactions. Antioxid Redox Signal 2019; 30:683-709. [PMID: 29241353 PMCID: PMC6338583 DOI: 10.1089/ars.2017.7335] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/26/2017] [Accepted: 11/14/2017] [Indexed: 01/20/2023]
Abstract
SIGNIFICANCE Proline metabolism has complex roles in a variety of biological processes, including cell signaling, stress protection, and energy production. Proline also contributes to the pathogenesis of various disease-causing organisms. Understanding the mechanisms of how pathogens utilize proline is important for developing new strategies against infectious diseases. Recent Advances: The ability of pathogens to acquire amino acids is critical during infection. Besides protein biosynthesis, some amino acids, such as proline, serve as a carbon, nitrogen, or energy source in bacterial and protozoa pathogens. The role of proline during infection depends on the physiology of the host/pathogen interactions. Some pathogens rely on proline as a critical respiratory substrate, whereas others exploit proline for stress protection. CRITICAL ISSUES Disruption of proline metabolism and uptake has been shown to significantly attenuate virulence of certain pathogens, whereas in other pathogens the importance of proline during infection is not known. Inhibiting proline metabolism and transport may be a useful therapeutic strategy against some pathogens. Developing specific inhibitors to avoid off-target effects in the host, however, will be challenging. Also, potential treatments that target proline metabolism should consider the impact on intracellular levels of Δ1-pyrroline-5-carboxylate, a metabolite intermediate that can have opposing effects on pathogenesis. FUTURE DIRECTIONS Further characterization of how proline metabolism is regulated during infection would provide new insights into the role of proline in pathogenesis. Biochemical and structural characterization of proline metabolic enzymes from different pathogens could lead to new tools for exploring proline metabolism during infection and possibly new therapeutic compounds.
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Affiliation(s)
- Shelbi L. Christgen
- Department of Biochemistry, Redox Biology Center, University of Nebraska−Lincoln, Lincoln, Nebraska
| | - Donald F. Becker
- Department of Biochemistry, Redox Biology Center, University of Nebraska−Lincoln, Lincoln, Nebraska
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19
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Agapova A, Serafini A, Petridis M, Hunt DM, Garza-Garcia A, Sohaskey CD, de Carvalho LPS. Flexible nitrogen utilisation by the metabolic generalist pathogen Mycobacterium tuberculosis. eLife 2019; 8:e41129. [PMID: 30702426 PMCID: PMC6361586 DOI: 10.7554/elife.41129] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/22/2019] [Indexed: 12/13/2022] Open
Abstract
Bacterial metabolism is fundamental to survival and pathogenesis. We explore how Mycobacterium tuberculosis utilises amino acids as nitrogen sources, using a combination of bacterial physiology and stable isotope tracing coupled to mass spectrometry metabolomics methods. Our results define core properties of the nitrogen metabolic network from M. tuberculosis, such as: (i) the lack of homeostatic control of certain amino acid pool sizes; (ii) similar rates of utilisation of different amino acids as sole nitrogen sources; (iii) improved nitrogen utilisation from amino acids compared to ammonium; and (iv) co-metabolism of nitrogen sources. Finally, we discover that alanine dehydrogenase is involved in ammonium assimilation in M. tuberculosis, in addition to its essential role in alanine utilisation as a nitrogen source. This study represents the first in-depth analysis of nitrogen source utilisation by M. tuberculosis and reveals a flexible metabolic network with characteristics that are likely a product of evolution in the human host.
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Affiliation(s)
- Aleksandra Agapova
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Agnese Serafini
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Michael Petridis
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Debbie M Hunt
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Acely Garza-Garcia
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Charles D Sohaskey
- Department of Veterans Affairs Medical Center, Long Beach, United States
| | - Luiz Pedro Sório de Carvalho
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, London, United Kingdom
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20
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Antczak M, Płocińska R, Płociński P, Rumijowska-Galewicz A, Żaczek A, Strapagiel D, Dziadek J. The NnaR orphan response regulator is essential for the utilization of nitrate and nitrite as sole nitrogen sources in mycobacteria. Sci Rep 2018; 8:17552. [PMID: 30510199 PMCID: PMC6277429 DOI: 10.1038/s41598-018-35844-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 11/05/2018] [Indexed: 12/12/2022] Open
Abstract
Nitrogen is an essential component of biological molecules and an indispensable microelement required for the growth of cells. Nitrogen metabolism of Mycobacterium smegmatis is regulated by a number of transcription factors, with the glnR gene product playing a major role. Under nitrogen-depletion conditions, GlnR controls the expression of many genes involved in nitrogen assimilation, including the msmeg_0432 gene encoding NnaR, the homologue of a nitrite/nitrate transport regulator from Streptomyces coelicolor. In the present study, the role of NnaR in the nitrogen metabolism of M. smegmatis was evaluated. The ∆glnR and ∆nnaR mutant strains were generated and cultured under nitrogen-depletion conditions. Total RNA profiling was used to investigate the potential role of NnaR in the GlnR regulon under nitrogen-depletion and in nitrogen-rich media. We found that disruption of MSMEG_0432 affected the expression of genes involved in nitrite/nitrate uptake, and its removal rendered mycobacteria unable to assimilate nitrogen from those sources, leading to cell death. RNA-Seq results were validated using quantitative real-time polymerase chain reaction (qRT-PCR) and electrophoretic mobility shift assays (EMSAs). The ability of mutants to grow on various nitrogen sources was evaluated using the BIOLOG Phenotype screening platform and confirmed on minimal Sauton's medium containing various sources of nitrogen. The ∆glnR mutant was not able to convert nitrates to nitrites. Interestingly, NnaR required active GlnR to prevent nitrogen starvation, and both proteins cooperated in the regulation of gene expression associated with nitrate/nitrite assimilation. The ∆nnaR mutant was able to convert nitrates to nitrites, but it could not assimilate the products of this conversion. Importantly, NnaR was the key regulator of the expression of the truncated haemoglobin trHbN, which is required to improve the survival of bacteria under nitrosative stress.
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Affiliation(s)
- Magdalena Antczak
- Institute for Medical Biology, Polish Academy of Sciences, Łódź, Poland
| | - Renata Płocińska
- Institute for Medical Biology, Polish Academy of Sciences, Łódź, Poland
| | | | | | - Anna Żaczek
- Department of Biochemistry and Cell Biology, University of Rzeszów, Rzeszów, Poland
| | - Dominik Strapagiel
- Biobank Lab, Department of Molecular Biophysics, University of Łódź, Łódź, Poland
| | - Jarosław Dziadek
- Institute for Medical Biology, Polish Academy of Sciences, Łódź, Poland.
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21
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Rakovitsky N, Bar Oz M, Goldberg K, Gibbons S, Zimhony O, Barkan D. The Unexpected Essentiality of glnA2 in Mycobacterium smegmatis Is Salvaged by Overexpression of the Global Nitrogen Regulator glnR, but Not by L-, D- or Iso-Glutamine. Front Microbiol 2018; 9:2143. [PMID: 30271391 PMCID: PMC6142876 DOI: 10.3389/fmicb.2018.02143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 08/21/2018] [Indexed: 01/14/2023] Open
Abstract
Nitrogen metabolism plays a central role in the physiology of microorganisms, and Glutamine Synthetase (GS) genes are present in virtually all bacteria. In M. tuberculosis, four GS genes are present, but only glnA1 is essential, whereas glnA2 was shown to be non-essential for in-vitro as well as in-vivo growth and pathogenesis, and is postulated to be involved in D-glutamine and iso-glutamine synthesis. Whilst investigating the activity of an antimicrobial compound in M. smegmatis, we found a spontaneous temperature-sensitive mutant in glnA2 (I133F), and used it to investigate the role of glnA2 in M. smegmatis. We deleted the native glnA2 and replaced it with a mutated allele. This re-created the temperature sensitivity—as after 3–4 seemingly normal division cycles, glnA2 became essential for growth. This essentiality could not be salvaged by neither L, D- nor iso-glutamine, suggesting an additional role of glnA2 in M. smegmatis over its role in M. tuberculosis. We also found that overexpression of the global nitrogen regulator glnR enabled bypassing the essentiality of glnA2, allowing the creation of a complete deletion mutant. The discrepancy between the importance of glnA2 in Mtb and M. smegmatis stresses the caution in which results in one are extrapolated to the other.
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Affiliation(s)
- Nadya Rakovitsky
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michal Bar Oz
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Karin Goldberg
- Department of Pharmaceutical Engineering, Azrieli College of Engineering, Jerusalem, Israel
| | - Simon Gibbons
- Research Department of Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, London, United Kingdom
| | - Oren Zimhony
- Kaplan Medical Center, Rehovot, Israel.,The Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daniel Barkan
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Jerusalem, Israel
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22
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Huang X, Duan X, Li J, Niu J, Yuan S, Wang X, Lambert N, Li X, Xu J, Gong Z, Yan S, Xie L, Xie J. The Synergistic Effect of Exogenous Glutamine and Rifampicin Against Mycobacterium Persisters. Front Microbiol 2018; 9:1625. [PMID: 30079057 PMCID: PMC6062616 DOI: 10.3389/fmicb.2018.01625] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 06/28/2018] [Indexed: 12/22/2022] Open
Abstract
Persisters, stochastic dormant variants of normal bacteria cell, represent a significant portion of the survivors upon exposure to antibiotics and other environmental stresses, which contributes substantially to high level antibiotics tolerance. Glutamine is a crucial component of the Mycobacteria nitrogen pool that is indispensable for survival upon stresses. To study whether a synergistic effect exists between glutamine and antibiotics against Mycobacterial persisters, the efficacy of rifampicin alone or together with exogenous glutamine upon Mycobacterium smegmatis mc2 155 persisters was monitored. The result showed that glutamine decreases M. smegmatis tolerance to rifampicin upon starvation. The reactive oxygen species level of the strains treated with rifampicin and glutamine increased. The synergism of glutamine and rifampicin to kill persisters might derive from altering the oxidative phosphorylation and TCA cycle, as both evidenced by both ATP level increase and transcriptome change. Glutamine might represent a synergistic agent of rifampicin to kill Mycobacteria persisters.
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Affiliation(s)
- Xue Huang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Xiangke Duan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Jiang Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Jingjing Niu
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Siqi Yuan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Xiaoyu Wang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Nzungize Lambert
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Xue Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Junqi Xu
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Zhen Gong
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Shuangquan Yan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Longxiang Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
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Yang Y, Richards JP, Gundrum J, Ojha AK. GlnR Activation Induces Peroxide Resistance in Mycobacterial Biofilms. Front Microbiol 2018; 9:1428. [PMID: 30022971 PMCID: PMC6039565 DOI: 10.3389/fmicb.2018.01428] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/11/2018] [Indexed: 12/31/2022] Open
Abstract
Mycobacteria spontaneously form surface-associated multicellular communities, called biofilms, which display resistance to a wide range of exogenous stresses. A causal relationship between biofilm formation and emergence of stress resistance is not known. Here, we report that activation of a nitrogen starvation response regulator, GlnR, during the development of Mycobacterium smegmatis biofilms leads to peroxide resistance. The resistance arises from induction of a GlnR-dependent peroxide resistance (gpr) gene cluster comprising of 8 ORFs (MSMEG_0565-0572). Expression of gpr increases the NADPH to NADP ratio, suggesting that a reduced cytosolic environment of nitrogen-starved cells in biofilms contributes to peroxide resistance. Increased NADPH levels from gpr activity likely support the activity of enzymes involved in nitrogen assimilation, as suggested by a higher threshold of nitrogen supplement required by a gpr mutant to form biofilms. Together, our study uniquely interlinks a nutrient sensing mechanism with emergence of stress resistance during mycobacterial biofilm development. The gpr gene cluster is conserved in several mycobacteria that can cause nosocomial infections, offering a possible explanation for their resistance to peroxide-based sterilization of medical equipment.
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Affiliation(s)
- Yong Yang
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Jacob P. Richards
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jennifer Gundrum
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Anil K. Ojha
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, University at Albany, Albany, NY, United States
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Hernández MA, Gleixner G, Sachse D, Alvarez HM. Carbon Allocation in Rhodococcus jostii RHA1 in Response to Disruption and Overexpression of nlpR Regulatory Gene, Based on 13C-labeling Analysis. Front Microbiol 2017; 8:1992. [PMID: 29075252 PMCID: PMC5641563 DOI: 10.3389/fmicb.2017.01992] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 09/27/2017] [Indexed: 12/23/2022] Open
Abstract
Nitrogen lipid regulator (NlpR) is a pleiotropic regulator that positively controls genes associated with both nitrogen and lipid metabolism in the oleaginous bacterium Rhodococcus jostii RHA1. In this study, we investigated the effect of nlpR disruption and overexpression on the assimilation of 13C-labeled glucose as carbon source, during cultivation of cells under nitrogen-limiting and nitrogen-rich conditions, respectively. Label incorporation into the total lipid extract (TLE) fraction was about 30% lower in the mutant strain in comparison with the wild type strain under low-nitrogen conditions. Moreover, a higher 13C abundance (∼60%) into the extracellular polymeric substance fraction was observed in the mutant strain. nlpR disruption also promoted a decrease in the label incorporation into several TLE-derivative fractions including neutral lipids (NL), glycolipids (GL), phospholipids (PL), triacylglycerols (TAG), diacylglycerols (DAG), and free fatty acids (FFA), with the DAG being the most affected. In contrast, the nlpR overexpression in RHA1 cells under nitrogen-rich conditions produced an increase of the label incorporation into the TLE and its derivative NL and PL fractions, the last one being the highest 13C enriched. In addition, a higher 13C enrichment occurred in the TAG, DAG, and FFA fractions after nlpR induction, with the FFA fraction being the most affected within the TLE. Isotopic-labeling experiments demonstrated that NlpR regulator is contributing in oleaginous phenotype of R. jostii RHA1 to the allocation of carbon into the different lipid fractions in response to nitrogen levels, increasing the rate of carbon flux into lipid metabolism.
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Affiliation(s)
- Martín A Hernández
- Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
| | - Gerd Gleixner
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Dirk Sachse
- Section 5.1: Geomorphology, GFZ German Research Centre for Geosciences, Potsdam, Germany.,Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
| | - Héctor M Alvarez
- Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
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25
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Marshall DD, Halouska S, Zinniel DK, Fenton RJ, Kenealy K, Chahal HK, Rathnaiah G, Barletta RG, Powers R. Assessment of Metabolic Changes in Mycobacterium smegmatis Wild-Type and alr Mutant Strains: Evidence of a New Pathway of d-Alanine Biosynthesis. J Proteome Res 2017; 16:1270-1279. [PMID: 28121156 DOI: 10.1021/acs.jproteome.6b00871] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In mycobacteria, d-alanine is an essential precursor for peptidoglycan biosynthesis. The only confirmed enzymatic pathway to form d-alanine is through the racemization of l-alanine by alanine racemase (Alr, EC 5.1.1.1). Nevertheless, the essentiality of Alr in Mycobacterium tuberculosis and Mycobacterium smegmatis for cell survivability in the absence of d-alanine has been a point of controversy with contradictory results reported in the literature. To address this issue, we examined the effects of alr inactivation on the cellular metabolism of M. smegmatis. The M. smegmatis alr insertion mutant TAM23 exhibited essentially identical growth to wild-type mc2155 in the absence of d-alanine. NMR metabolomics revealed drastically distinct phenotypes between mc2155 and TAM23. A metabolic switch was observed for TAM23 as a function of supplemented d-alanine. In the absence of d-alanine, the metabolic response directed carbon through an unidentified transaminase to provide the essential d-alanine required for survival. The process is reversed when d-alanine is available, in which the d-alanine is directed to peptidoglycan biosynthesis. Our results provide further support for the hypothesis that Alr is not an essential function of M. smegmatis and that specific Alr inhibitors will have no bactericidal action.
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Affiliation(s)
- Darrell D Marshall
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0304, United States
| | - Steven Halouska
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0304, United States
| | - Denise K Zinniel
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska 68583-0905, United States
| | - Robert J Fenton
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska 68583-0905, United States
| | - Katie Kenealy
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska 68583-0905, United States
| | - Harpreet K Chahal
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska 68583-0905, United States
| | - Govardhan Rathnaiah
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska 68583-0905, United States
| | - Raúl G Barletta
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska 68583-0905, United States.,Center for Redox Biology, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0662, United States
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0304, United States.,Center for Redox Biology, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0662, United States
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26
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Nunes-Costa D, Maranha A, Costa M, Alarico S, Empadinhas N. Glucosylglycerate metabolism, bioversatility and mycobacterial survival. Glycobiology 2016; 27:213-227. [DOI: 10.1093/glycob/cww132] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/14/2016] [Indexed: 12/17/2022] Open
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27
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Hernández MA, Lara J, Gago G, Gramajo H, Alvarez HM. The pleiotropic transcriptional regulator NlpR contributes to the modulation of nitrogen metabolism, lipogenesis and triacylglycerol accumulation in oleaginous rhodococci. Mol Microbiol 2016; 103:366-385. [DOI: 10.1111/mmi.13564] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Martín A. Hernández
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales; Universidad Nacional de la Patagonia San Juan Bosco; Ruta Provincial N° 1, Km 4-Ciudad Universitaria 9000 Comodoro Rivadavia Chubut Argentina
| | - Julia Lara
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Ocampo y Esmeralda 2000 Rosario Santa Fe Argentina
| | - Gabriela Gago
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Ocampo y Esmeralda 2000 Rosario Santa Fe Argentina
| | - Hugo Gramajo
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Ocampo y Esmeralda 2000 Rosario Santa Fe Argentina
| | - Héctor M. Alvarez
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales; Universidad Nacional de la Patagonia San Juan Bosco; Ruta Provincial N° 1, Km 4-Ciudad Universitaria 9000 Comodoro Rivadavia Chubut Argentina
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28
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Amin R, Franz-Wachtel M, Tiffert Y, Heberer M, Meky M, Ahmed Y, Matthews A, Krysenko S, Jakobi M, Hinder M, Moore J, Okoniewski N, Maček B, Wohlleben W, Bera A. Post-translational Serine/Threonine Phosphorylation and Lysine Acetylation: A Novel Regulatory Aspect of the Global Nitrogen Response Regulator GlnR in S. coelicolor M145. Front Mol Biosci 2016; 3:38. [PMID: 27556027 PMCID: PMC4977719 DOI: 10.3389/fmolb.2016.00038] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 07/25/2016] [Indexed: 01/03/2023] Open
Abstract
Soil-dwelling Streptomyces bacteria such as S.coelicolor have to constantly adapt to the nitrogen (N) availability in their habitat. Thus, strict transcriptional and post-translational control of the N-assimilation is fundamental for survival of this species. GlnR is a global response regulator that controls transcription of the genes related to the N-assimilation in S. coelicolor and other members of the Actinomycetales. GlnR represents an atypical orphan response regulator that is not activated by the phosphorylation of the conserved aspartate residue (Asp 50). We have applied transcriptional analysis, LC-MS/MS analysis and electrophoretic mobility shift assays (EMSAs) to understand the regulation of GlnR in S. coelicolor M145. The expression of glnR and GlnR-target genes was revisited under four different N-defined conditions and a complex N-rich condition. Although, the expression of selected GlnR-target genes was strongly responsive to changing N-concentrations, the glnR expression itself was independent of the N-availability. Using LC-MS/MSanalysis we demonstrated that GlnR was post-translationally modified. The post-translational modifications of GlnR comprise phosphorylation of the serine/threonine residues and acetylation of lysine residues. In the complex N-rich medium GlnR was phosphorylated on six serine/threonine residues and acetylated on one lysine residue. Under defined N-excess conditions only two phosphorylated residues were detected whereas under defined N-limiting conditions no phosphorylation was observed. GlnR phosphorylation is thus clearly correlated with N-rich conditions. Furthermore, GlnR was acetylated on four lysine residues independently of the N-concentration in the defined media and on only one lysine residue in the complex N-rich medium. Using EMSAs we demonstrated that phosphorylation inhibited the binding of GlnR to its targets genes, whereas acetylation had little influence on the formation of GlnR-DNA complex. This study clearly demonstrated that GlnR DNA-binding affinity is modulated by post-translational modifications in response to changing N-conditions in order to elicit a proper transcriptional response to the latter.
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Affiliation(s)
- Rafat Amin
- Department of Pathology, Dow International Medical College, Dow Research Institute of Biotechnology and Biomedical Sciences, Dow University of Health Sciences Karachi, Pakistan
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, Interdepartmental Institute for Cell Biology (IFIZ), University of Tübingen Tübingen, Germany
| | - Yvonne Tiffert
- B.R.A.I.N. Biotechnology Research and Information Network AG Zwingenberg, Germany
| | - Martin Heberer
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Mohamed Meky
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Yousra Ahmed
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of TübingenTübingen, Germany; Department of Pharmaceutical Biotechnology, Helmholtz Institute for Pharmaceutical Research Saarland, Saarland University CampusSaarbrücken, Germany
| | - Arne Matthews
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Sergii Krysenko
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Marco Jakobi
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Markus Hinder
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Jane Moore
- John Innes Center, Norwich Research Park Norwich, UK
| | - Nicole Okoniewski
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Boris Maček
- Proteome Center Tübingen, Interdepartmental Institute for Cell Biology (IFIZ), University of Tübingen Tübingen, Germany
| | - Wolfgang Wohlleben
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
| | - Agnieszka Bera
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen Tübingen, Germany
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29
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Kim WS, Kim JS, Cha SB, Kim SJ, Kim H, Kwon KW, Han SJ, Choi SY, Shin SJ. Mycobacterium tuberculosis PE27 activates dendritic cells and contributes to Th1-polarized memory immune responses during in vivo infection. Immunobiology 2015; 221:440-53. [PMID: 26655143 DOI: 10.1016/j.imbio.2015.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/29/2015] [Accepted: 11/17/2015] [Indexed: 02/07/2023]
Abstract
A gradual understanding of the proline-glutamate (PE) and proline-proline-glutamate (PPE) families, which compromise 10% of the coding regions in the Mycobacterium tuberculosis (Mtb) genome, has uncovered unique roles in host-pathogen interactions. However, the immunological function of PE27 (Rv2769c), the largest PE member, remains unclear. Here, we explored the functional roles and related signaling mechanisms of PE27 in the interaction with dendritic cells (DCs) to shape the T cell response. PE27 phenotypically and functionally induces DC maturation by up-regulating CD80, CD86, MHC class I and MHC class II expression on the DC surface to promote the production of TNF-α, IL-1β, IL-6, and IL-12p70 but not IL-10. Additionally, we found that PE27-mediated DC activation requires the participation of mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NF-κB) signaling pathways. Interestingly, PE27-treated DCs directed naïve CD4(+) T cells to secrete IFN-γ and activate T-bet but not GATA-3. PE27 also induced IFN-γ-producing memory T cell responses in Mtb-infected mice, indicating that PE27 contributes to Th1-polarization. Taken together, these findings suggest that PE27 possesses Th1-polarizing potential through DC maturation and could be useful in the design of TB vaccines.
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Affiliation(s)
- Woo Sik Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Jong-Seok Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Seung Bin Cha
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - So Jeong Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Hongmin Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Kee Woong Kwon
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Seung Jung Han
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Soo Young Choi
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Sung Jae Shin
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea.
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30
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Petridis M, Benjak A, Cook GM. Defining the nitrogen regulated transcriptome of Mycobacterium smegmatis using continuous culture. BMC Genomics 2015; 16:821. [PMID: 26482235 PMCID: PMC4617892 DOI: 10.1186/s12864-015-2051-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 10/06/2015] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Nitrogen is essential for microbial growth and its importance is demonstrated by the complex regulatory systems used to control the transport, assimilation and metabolism of nitrogen. Recent studies are beginning to shed light on how mycobacteria respond to nitrogen limitation and several regulators (e.g., GlnR, PII) have been characterized at a molecular level. However, despite this progress, our knowledge of the transcriptional response of mycobacteria to nitrogen limitation and its regulation is confined to batch culture. METHODS To gain further insight into the response of mycobacteria to nitrogen limitation, we developed a nitrogen-limited chemostat. We compared the transcriptional response of nitrogen-limited cells to carbon-limited cells using RNA-seq analysis in a continuous culture model at a constant growth rate. CONCLUSIONS Our findings revealed significant changes in the expression of 357 genes (208 upregulated, 149 downregulated; >2-fold change, false discovery rate <5 %) in response to nitrogen limitation in continuous culture. The vast majority of the GlnR regulon (68 %) was differentially expressed under nitrogen limitation in continuous culture and approximately 52 % of the 357 genes overlapped with a previously published study investigating the response of M. smegmatis to nitrogen limitation in batch culture, while expression of only 17 % of the genes identified in batch culture were affected in our chemostat model. Moreover, we identified a unique set of 45 genes involved in the uptake and metabolism of nitrogen that were exclusive to our chemostat model. We observed strong downregulation of pathways for amino acid catabolism (i.e., alanine, aspartate, valine, proline and lysine), suggesting preservation of these amino acids for critical cellular function. We found 16 novel transcriptional regulators that were directly or indirectly involved in the global transcriptomic response of M. smegmatis to nitrogen limitation and identified several non-coding RNAs that might be involved in the transcriptional or post-transcriptional regulation of nitrogen-regulated gene expression. RESULTS Using nitrogen-limited continuous culture we identified the nitrogen-responsive transcriptome of M. smegmatis, including a number of small non-coding RNAs implicated in controlling nitrogen-regulated gene expression.
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Affiliation(s)
- Michael Petridis
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, P.O. Box 56, Dunedin, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland, 1042, New Zealand.
| | - Andrej Benjak
- Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland.
| | - Gregory M Cook
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, P.O. Box 56, Dunedin, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland, 1042, New Zealand.
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