1
|
Liang X, Ishfaq S, Liu Y, Jijakli MH, Zhou X, Yang X, Guo W. Identification and genomic insights into a strain of Bacillus velezensis with phytopathogen-inhibiting and plant growth-promoting properties. Microbiol Res 2024; 285:127745. [PMID: 38733724 DOI: 10.1016/j.micres.2024.127745] [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: 11/20/2023] [Revised: 04/27/2024] [Accepted: 05/01/2024] [Indexed: 05/13/2024]
Abstract
The use of biological agents offers a sustainable alternative to chemical control in managing plant diseases. In this study, Bacillus velezensis IFST-221 was isolated from the rhizosphere of a healthy maize plant amidst a population showing severe disease symptoms. The investigation demonstrated a broad-spectrum antagonistic activity of IFST-221 against eight species of pathogenic ascomycetes and oomycetes, suggesting its potential utility in combating plant diseases like maize ear rot and cotton Verticillium wilt. Additionally, our study unveiled that IFST-221 has demonstrated significant plant growth-promoting properties, particularly in maize, cotton, tomato, and broccoli seedlings. This growth promotion was linked to its ability to produce indole-3-acetic acid, nitrogen fixation, phosphate and potassium solubilization, and biofilm formation in laboratory conditions. A complete genome sequencing of IFST-221 yielded a genome size of 3.858 M bp and a GC content of 46.71%. The genome analysis identified 3659 protein-coding genes, among which were nine secondary metabolite clusters with known antimicrobial properties. Additionally, three unknown compounds with potentially novel properties were also predicted from the genomic data. Genome mining also identified several key genes associated with plant growth regulation, colonization, and biofilm formation. These findings provide a compelling case for the application of B. velezensis IFST-221 in agricultural practices. The isolate's combined capabilities of plant growth promotion and antagonistic activity against common plant pathogens suggest its promise as an integrated biological agent in disease management and plant productivity enhancement.
Collapse
Affiliation(s)
- Xiaoyan Liang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, China; Gembloux Agro-Bio Tech, Liege University, Laboratory of Integrated and Urban Plant Pathology, Passage des déportés 2, Gembloux 5030, Belgium
| | - Shumila Ishfaq
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, China
| | - Yang Liu
- School of Food Science and Engineering, Foshan University/National Technical Center (Foshan) for Quality Control of Famous and Special Agricultural Products (CAQS-GAP-KZZX043)/Guangdong Key Laboratory of Food Intelligent Manufacturing, Foshan, Guangdong 528231, China
| | - M Haissam Jijakli
- Gembloux Agro-Bio Tech, Liege University, Laboratory of Integrated and Urban Plant Pathology, Passage des déportés 2, Gembloux 5030, Belgium
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Wei Guo
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, China.
| |
Collapse
|
2
|
Hu J, Yao J, Lei C, Sun X. c-di-AMP accumulation impairs toxin expression of Bacillus anthracis by down-regulating potassium importers. Microbiol Spectr 2024:e0378623. [PMID: 38899864 DOI: 10.1128/spectrum.03786-23] [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: 10/31/2023] [Accepted: 04/20/2024] [Indexed: 06/21/2024] Open
Abstract
The Gram-positive bacterium Bacillus anthracis is the causative agent of anthrax and a bioterrorism threat worldwide. As a crucial second messenger in many bacterial species, cyclic di-AMP (c-di-AMP) modulates various key processes for bacterial homeostasis and pathogenesis. Overaccumulation of c-di-AMP alters cellular growth and reduces anthrax toxin expression as well as virulence in Bacillus anthracis by unresolved underlying mechanisms. In this report, we discovered that c-di-AMP binds to a series of receptors involved in potassium uptake in B. anthracis. By analyzing Kdp and Ktr mutants for osmotic stress, gene expression, and anthrax toxin expression, we also showed that c-di-AMP inhibits Kdp operon expression through binding to the KdpD and ydaO riboswitch; up-regulating intracellular potassium promotes anthrax toxin expression in c-di-AMP accumulated B. anthracis. Decreased anthrax toxin expression at high c-di-AMP occurs through the inhibition of potassium uptake. Understanding the molecular basis of how potassium uptake affects anthrax toxin has the potential to provide new insight into the control of B. anthracis.IMPORTANCEThe bacterial second messenger cyclic di-AMP (c-di-AMP) is a conserved global regulator of potassium homeostasis. How c-di-AMP regulates bacterial virulence is unknown. With this study, we provide a link between potassium uptake and anthrax toxin expression in Bacillus anthracis. c-di-AMP accumulation might inhibit anthrax toxin expression by suppressing potassium uptake.
Collapse
Affiliation(s)
- Jia Hu
- Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Junmin Yao
- Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chengfeng Lei
- Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Xiulian Sun
- Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| |
Collapse
|
3
|
Foster AJ, van den Noort M, Poolman B. Bacterial cell volume regulation and the importance of cyclic di-AMP. Microbiol Mol Biol Rev 2024:e0018123. [PMID: 38856222 DOI: 10.1128/mmbr.00181-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
SUMMARYNucleotide-derived second messengers are present in all domains of life. In prokaryotes, most of their functionality is associated with general lifestyle and metabolic adaptations, often in response to environmental fluctuations of physical parameters. In the last two decades, cyclic di-AMP has emerged as an important signaling nucleotide in many prokaryotic lineages, including Firmicutes, Actinobacteria, and Cyanobacteria. Its importance is highlighted by the fact that both the lack and overproduction of cyclic di-AMP affect viability of prokaryotes that utilize cyclic di-AMP, and that it generates a strong innate immune response in eukaryotes. In bacteria that produce the second messenger, most molecular targets of cyclic di-AMP are associated with cell volume control. Besides, other evidence links the second messenger to cell wall remodeling, DNA damage repair, sporulation, central metabolism, and the regulation of glycogen turnover. In this review, we take a biochemical, quantitative approach to address the main cellular processes that are directly regulated by cyclic di-AMP and show that these processes are very connected and require regulation of a similar set of proteins to which cyclic di-AMP binds. Altogether, we argue that cyclic di-AMP is a master regulator of cell volume and that other cellular processes can be connected with cyclic di-AMP through this core function. We further highlight important directions in which the cyclic di-AMP field has to develop to gain a full understanding of the cyclic di-AMP signaling network and why some processes are regulated, while others are not.
Collapse
Affiliation(s)
- Alexander J Foster
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Marco van den Noort
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| |
Collapse
|
4
|
Warneke R, Herzberg C, Weiß M, Schramm T, Hertel D, Link H, Stülke J. DarA-the central processing unit for the integration of osmotic with potassium and amino acid homeostasis in Bacillus subtilis. J Bacteriol 2024:e0019024. [PMID: 38832794 DOI: 10.1128/jb.00190-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 05/08/2024] [Indexed: 06/05/2024] Open
Abstract
Cyclic di-adenosine monophosphate (c-di-AMP) is a second messenger involved in diverse metabolic processes including osmolyte uptake, cell wall homeostasis, as well as antibiotic and heat resistance. This study investigates the role of the c-di-AMP receptor protein DarA in the osmotic stress response in Bacillus subtilis. Through a series of experiments, we demonstrate that DarA plays a central role in the cellular response to osmotic fluctuations. Our findings show that DarA becomes essential under extreme potassium limitation as well as upon salt stress, highlighting its significance in mediating osmotic stress adaptation. Suppressor screens with darA mutants reveal compensatory mechanisms involving the accumulation of osmoprotectants, particularly potassium and citrulline. Mutations affecting various metabolic pathways, including the citric acid cycle as well as glutamate and arginine biosynthesis, indicate a complex interplay between the osmotic stress response and metabolic regulation. In addition, the growth defects of the darA mutant during potassium starvation and salt stress in a strain lacking the high-affinity potassium uptake systems KimA and KtrAB can be rescued by increased affinity of the remaining potassium channel KtrCD or by increased expression of ktrD, thus resulting in increased potassium uptake. Finally, the darA mutant can respond to salt stress by the increased expression of MleN , which can export sodium ions.IMPORTANCEEnvironmental bacteria are exposed to rapidly changing osmotic conditions making an effective adaptation to these changes crucial for the survival of the cells. In Gram-positive bacteria, the second messenger cyclic di-AMP plays a key role in this adaptation by controlling (i) the influx of physiologically compatible organic osmolytes and (ii) the biosynthesis of such osmolytes. In several bacteria, cyclic di-adenosine monophosphate (c-di-AMP) can bind to a signal transduction protein, called DarA, in Bacillus subtilis. So far, no function for DarA has been discovered in any organism. We have identified osmotically challenging conditions that make DarA essential and have identified suppressor mutations that help the bacteria to adapt to those conditions. Our results indicate that DarA is a central component in the integration of osmotic stress with the synthesis of compatible amino acid osmolytes and with the homeostasis of potassium, the first response to osmotic stress.
Collapse
Affiliation(s)
- Robert Warneke
- Department of General Microbiology, GZMB, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, GZMB, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Martin Weiß
- Department of General Microbiology, GZMB, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Thorben Schramm
- Interfaculty Institute for Microbiology and Infection Medicine, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Dietrich Hertel
- Department of Plant Ecology and Ecosystems Research, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Hannes Link
- Interfaculty Institute for Microbiology and Infection Medicine, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Jörg Stülke
- Interfaculty Institute for Microbiology and Infection Medicine, Eberhard Karls Universität Tübingen, Tübingen, Germany
| |
Collapse
|
5
|
Peng A, Yin G, Zuo W, Zhang L, Du G, Chen J, Wang Y, Kang Z. Regulatory RNAs in Bacillus subtilis: A review on regulatory mechanism and applications in synthetic biology. Synth Syst Biotechnol 2024; 9:223-233. [PMID: 38385150 PMCID: PMC10877136 DOI: 10.1016/j.synbio.2024.01.013] [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: 12/10/2023] [Revised: 01/15/2024] [Accepted: 01/31/2024] [Indexed: 02/23/2024] Open
Abstract
Bacteria exhibit a rich repertoire of RNA molecules that intricately regulate gene expression at multiple hierarchical levels, including small RNAs (sRNAs), riboswitches, and antisense RNAs. Notably, the majority of these regulatory RNAs lack or have limited protein-coding capacity but play pivotal roles in orchestrating gene expression by modulating transcription, post-transcription or translation processes. Leveraging and redesigning these regulatory RNA elements have emerged as pivotal strategies in the domains of metabolic engineering and synthetic biology. While previous investigations predominantly focused on delineating the roles of regulatory RNA in Gram-negative bacterial models such as Escherichia coli and Salmonella enterica, this review aims to summarize the mechanisms and functionalities of endogenous regulatory RNAs inherent to typical Gram-positive bacteria, notably Bacillus subtilis. Furthermore, we explore the engineering and practical applications of these regulatory RNA elements in the arena of synthetic biology, employing B. subtilis as a foundational chassis.
Collapse
Affiliation(s)
- Anqi Peng
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Guobin Yin
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Wenjie Zuo
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Luyao Zhang
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yang Wang
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Zhen Kang
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| |
Collapse
|
6
|
You D, Zhao LC, Fu Y, Peng ZY, Chen ZQ, Ye BC. Allosteric regulation by c-di-AMP modulates a complete N-acetylglucosamine signaling cascade in Saccharopolyspora erythraea. Nat Commun 2024; 15:3825. [PMID: 38714645 PMCID: PMC11076491 DOI: 10.1038/s41467-024-48063-0] [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: 06/14/2023] [Accepted: 04/18/2024] [Indexed: 05/10/2024] Open
Abstract
c-di-AMP is an essential and widespread nucleotide second messenger in bacterial signaling. For most c-di-AMP synthesizing organisms, c-di-AMP homeostasis and the molecular mechanisms pertaining to its signal transduction are of great concern. Here we show that c-di-AMP binds the N-acetylglucosamine (GlcNAc)-sensing regulator DasR, indicating a direct link between c-di-AMP and GlcNAc signaling. Beyond its foundational role in cell-surface structure, GlcNAc is attractive as a major nutrient and messenger molecule regulating multiple cellular processes from bacteria to humans. We show that increased c-di-AMP levels allosterically activate DasR as a master repressor of GlcNAc utilization, causing the shutdown of the DasR-mediated GlcNAc signaling cascade and leading to a consistent enhancement in the developmental transition and antibiotic production in Saccharopolyspora erythraea. The expression of disA, encoding diadenylate cyclase, is directly repressed by the regulator DasR in response to GlcNAc signaling, thus forming a self-sustaining transcriptional feedback loop for c-di-AMP synthesis. These findings shed light on the allosteric regulation by c-di-AMP, which appears to play a prominent role in global signal integration and c-di-AMP homeostasis in bacteria and is likely widespread in streptomycetes that produce c-di-AMP.
Collapse
Affiliation(s)
- Di You
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
| | - Liu-Chang Zhao
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Yu Fu
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Zhi-Yao Peng
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Zong-Qin Chen
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Bang-Ce Ye
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
- Institute of Engineering Biology and Health, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China.
| |
Collapse
|
7
|
Rocha R, Jorge JMP, Teixeira-Duarte CM, Figueiredo-Costa IR, Cereija TB, Ferreira-Teixeira PF, Herzberg C, Stülke J, Morais-Cabral JH. c-di-AMP determines the hierarchical organization of bacterial RCK proteins. Proc Natl Acad Sci U S A 2024; 121:e2318666121. [PMID: 38652747 PMCID: PMC11067040 DOI: 10.1073/pnas.2318666121] [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: 10/25/2023] [Accepted: 03/13/2024] [Indexed: 04/25/2024] Open
Abstract
In bacteria, intracellular K+ is involved in the regulation of membrane potential, cytosolic pH, and cell turgor as well as in spore germination, environmental adaptation, cell-to-cell communication in biofilms, antibiotic sensitivity, and infectivity. The second messenger cyclic-di-AMP (c-di-AMP) has a central role in modulating the intracellular K+ concentration in many bacterial species, controlling transcription and function of K+ channels and transporters. However, our understanding of how this regulatory network responds to c-di-AMP remains poor. We used the RCK (Regulator of Conductance of K+) proteins that control the activity of Ktr channels in Bacillus subtilis as a model system to analyze the regulatory function of c-di-AMP with a combination of in vivo and in vitro functional and structural characterization. We determined that the two RCK proteins (KtrA and KtrC) are neither physiologically redundant or functionally equivalent. KtrC is the physiologically dominant RCK protein in the regulation of Ktr channel activity. In explaining this hierarchical organization, we found that, unlike KtrA, KtrC is very sensitive to c-di-AMP inactivation and lack of c-di-AMP regulation results in RCK protein toxicity, most likely due to unregulated K+ flux. We also found that KtrC can assemble with KtrA, conferring c-di-AMP regulation to the functional KtrA/KtrC heteromers and potentially compensating KtrA toxicity. Altogether, we propose that the central role of c-di-AMP in the control of the K+ machinery, by modulating protein levels through gene transcription and by regulating protein activity, has determined the evolutionary selection of KtrC as the dominant RCK protein, shaping the hierarchical organization of regulatory components of the K+ machinery.
Collapse
Affiliation(s)
- Rita Rocha
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto4200-135, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto4200-135, Portugal
| | - João M. P. Jorge
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto4200-135, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto4200-135, Portugal
| | - Celso M. Teixeira-Duarte
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto4200-135, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto4200-135, Portugal
| | | | - Tatiana B. Cereija
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto4200-135, Portugal
| | | | - Christina Herzberg
- Department of General Microbiology, Institute for Microbiology and Genetics, Georg-August-University Göttingen, Göttingen37073, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology and Genetics, Georg-August-University Göttingen, Göttingen37073, Germany
| | - João H. Morais-Cabral
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto4200-135, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto4200-135, Portugal
| |
Collapse
|
8
|
Silberberg JM, Ketter S, Böhm PJN, Jordan K, Wittenberg M, Grass J, Hänelt I. KdpD is a tandem serine histidine kinase that controls K + pump KdpFABC transcriptionally and post-translationally. Nat Commun 2024; 15:3223. [PMID: 38622146 PMCID: PMC11018627 DOI: 10.1038/s41467-024-47526-8] [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: 12/19/2023] [Accepted: 04/04/2024] [Indexed: 04/17/2024] Open
Abstract
Two-component systems, consisting of a histidine kinase and a response regulator, serve signal transduction in bacteria, often regulating transcription in response to environmental stimuli. Here, we identify a tandem serine histidine kinase function for KdpD, previously described as a histidine kinase of the KdpDE two-component system, which controls production of the potassium pump KdpFABC. We show that KdpD additionally mediates an inhibitory serine phosphorylation of KdpFABC at high potassium levels, using not its C-terminal histidine kinase domain but an N-terminal atypical serine kinase domain. Sequence analysis of KdpDs from different species highlights that some KdpDs are much shorter than others. We show that, while Escherichia coli KdpD's atypical serine kinase domain responds directly to potassium levels, a shorter version from Deinococcus geothermalis is controlled by second messenger cyclic di-AMP. Our findings add to the growing functional diversity of sensor kinases while simultaneously expanding the framework for regulatory mechanisms in bacterial potassium homeostasis.
Collapse
Affiliation(s)
- Jakob M Silberberg
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany
| | - Sophie Ketter
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany
| | - Paul J N Böhm
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany
| | - Kristin Jordan
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany
| | - Marcel Wittenberg
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany
| | - Julia Grass
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany
| | - Inga Hänelt
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Straße 9, 60438, Frankfurt/Main, Germany.
| |
Collapse
|
9
|
Warneke R, Herzberg C, Daniel R, Hormes B, Stülke J. Control of three-carbon amino acid homeostasis by promiscuous importers and exporters in Bacillus subtilis: role of the "sleeping beauty" amino acid exporters. mBio 2024; 15:e0345623. [PMID: 38470260 PMCID: PMC11005379 DOI: 10.1128/mbio.03456-23] [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: 12/19/2023] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
The Gram-positive model bacterium Bacillus subtilis can acquire amino acids by import, de novo biosynthesis, or degradation of proteins and peptides. The accumulation of several amino acids inhibits the growth of B. subtilis, probably due to misincorporation into cellular macromolecules such as proteins or peptidoglycan or due to interference with other amino acid biosynthetic pathways. Here, we studied the adaptation of B. subtilis to toxic concentrations of the three-carbon amino acids L-alanine, β-alanine, and 2,3-diaminopropionic acid, as well as the two-carbon amino acid glycine. Resistance to the non-proteinogenic amino acid β-alanine, which is a precursor for coenzyme A biosynthesis, is achieved by mutations that either activate a cryptic amino acid exporter, AexA (previously YdeD), or inactivate the amino acid importers AimA, AimB (previously YbxG), and BcaP. The aexA gene is very poorly expressed under most conditions studied. However, mutations affecting the transcription factor AerA (previously YdeC) can result in strong constitutive aexA expression. AexA is the first characterized member of a group of amino acid exporters in B. subtilis, which are all very poorly expressed. Therefore, we suggest to call this group "sleeping beauty amino acid exporters." 2,3-Diaminopropionic acid can also be exported by AexA, and this amino acid also seems to be a natural substrate of AerA/AexA, as it can cause a slight but significant induction of aexA expression, and AexA also provides some natural resistance toward 2,3-diaminopropionic acid. Moreover, our work shows how low-specificity amino acid transporters contribute to amino acid homeostasis in B. subtilis.IMPORTANCEEven though Bacillus subtilis is one of the most-studied bacteria, amino acid homeostasis in this organism is not fully understood. We have identified import and export systems for the C2 and C3 amino acids. Our work demonstrates that the responsible amino acid permeases contribute in a rather promiscuitive way to amino acid uptake. In addition, we have discovered AexA, the first member of a group of very poorly expressed amino acid exporters in B. subtilis that we call "sleeping beauty amino acid exporters." The expression of these transporters is typically triggered by mutations in corresponding regulator genes that are acquired upon exposure to toxic amino acids. These exporters are ubiquitous in all domains of life. It is tempting to speculate that many of them are not expressed until the cells experience selective pressure by toxic compounds, and they protect the cells from rare but potentially dangerous encounters with such compounds.
Collapse
Affiliation(s)
- Robert Warneke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Richard Daniel
- Center for Bacterial Cell Biology, Biosciences Institute, Medical Faculty, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Björn Hormes
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| |
Collapse
|
10
|
Meißner J, Königshof M, Wrede K, Warneke R, Mardoukhi MSY, Commichau FM, Stülke J. Control of asparagine homeostasis in Bacillus subtilis: identification of promiscuous amino acid importers and exporters. J Bacteriol 2024; 206:e0042023. [PMID: 38193659 PMCID: PMC10882977 DOI: 10.1128/jb.00420-23] [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: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/10/2024] Open
Abstract
The Gram-positive model bacterium B. subtilis is able to import all proteinogenic amino acids from the environment as well as to synthesize them. However, the players involved in the acquisition of asparagine have not yet been identified for this bacterium. In this work, we used d-asparagine as a toxic analog of l-asparagine to identify asparagine transporters. This revealed that d- but not l-asparagine is taken up by the malate/lactate antiporter MleN. Specific strains that are sensitive to the presence of l-asparagine due to the lack of the second messenger cyclic di-AMP or due to the intracellular accumulation of this amino acid were used to isolate and characterize suppressor mutants that were resistant to the presence of otherwise growth-inhibiting concentrations of l-asparagine. These screens identified the broad-spectrum amino acid importers AimA and BcaP as responsible for the acquisition of l-asparagine. The amino acid exporter AzlCD allows detoxification of l-asparagine in addition to 4-azaleucine and histidine. This work supports the idea that amino acids are often transported by promiscuous importers and exporters. However, our work also shows that even stereo-enantiomeric amino acids do not necessarily use the same transport systems.IMPORTANCETransport of amino acid is a poorly studied function in many bacteria, including the model organism Bacillus subtilis. The identification of transporters is hampered by the redundancy of transport systems for most amino acids as well as by the poor specificity of the transporters. Here, we apply several strategies to use the growth-inhibitive effect of many amino acids under defined conditions to isolate suppressor mutants that exhibit either reduced uptake or enhanced export of asparagine, resulting in the identification of uptake and export systems for l-asparagine. The approaches used here may be useful for the identification of transporters for other amino acids both in B. subtilis and in other bacteria.
Collapse
Affiliation(s)
- Janek Meißner
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Manuel Königshof
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Katrin Wrede
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Robert Warneke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Fabian M. Commichau
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| |
Collapse
|
11
|
Bozsó Z, Lapat V, Ott PG, Móricz ÁM. Disparate Effects of Two Clerodane Diterpenes of Giant Goldenrod ( Solidago gigantea Ait.) on Bacillus spizizenii. Int J Mol Sci 2024; 25:1531. [PMID: 38338810 PMCID: PMC10855248 DOI: 10.3390/ijms25031531] [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: 12/30/2023] [Revised: 01/21/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
New substances with antimicrobial properties are needed to successfully treat emerging human, animal, or plant pathogens. Seven clerodane diterpenes, previously isolated from giant goldenrod (Solidago gigantea) root, were tested against Gram-positive Bacillus subtilis, Bacillus spizizenii and Rhodococcus fascians by measuring minimal bactericidal concentration (MBC), minimal inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC50). Two of them, Sg3a (a dialdehyde) and Sg6 (solidagoic acid B), were proved to be the most effective and were selected for further study. Bacillus spizizenii was incubated with the two diterpenes for shorter (1 h) or longer (5 h) periods and then subjected to genome-wide transcriptional analyses. Only a limited number of common genes (28 genes) were differentially regulated after each treatment, and these were mainly related to the restoration of cell membrane integrity and to membrane-related transports. Changes in gene activity indicated that, among other things, K+ and Na+ homeostasis, pH and membrane electron transport processes may have been affected. Activated export systems can be involved in the removal of harmful molecules from the bacterial cells. Inhibition of bacterial chemotaxis and flagellar assembly, as well as activation of genes for the biosynthesis of secondary metabolites, were observed as a general response. Depending on the diterpenes and the duration of the treatments, down-regulation of the protein synthesis-related, oxidative phosphorylation, signal transduction and transcription factor genes was found. In other cases, up-regulation of the genes of oxidation-reduction processes, sporulation and cell wall modification could be detected. Comparison of the effect of diterpenes with the changes induced by different environmental and nutritional conditions revealed several overlapping processes with stress responses. For example, the Sg6 treatment seems to have caused a starvation-like condition. In summary, there were both common and diterpene-specific changes in the transcriptome, and these changes were also dependent on the length of treatments. The results also indicated that Sg6 exerted its effect more slowly than Sg3a, but ultimately its effect was greater.
Collapse
Affiliation(s)
| | | | | | - Ágnes M. Móricz
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Herman Ottó Str. 15, H-1022 Budapest, Hungary; (Z.B.); (P.G.O.)
| |
Collapse
|
12
|
Benson CA, Olson KL, Patwa S, Kauer SD, King JF, Waxman SG, Tan AM. Conditional Astrocyte Rac1KO Attenuates Hyperreflexia after Spinal Cord Injury. J Neurosci 2024; 44:e1670222023. [PMID: 37963762 PMCID: PMC10851682 DOI: 10.1523/jneurosci.1670-22.2023] [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: 09/01/2022] [Revised: 08/24/2023] [Accepted: 09/19/2023] [Indexed: 11/16/2023] Open
Abstract
Spasticity is a hyperexcitability disorder that adversely impacts functional recovery and rehabilitative efforts after spinal cord injury (SCI). The loss of evoked rate-dependent depression (RDD) of the monosynaptic H-reflex is indicative of hyperreflexia, a physiological sign of spasticity. Given the intimate relationship between astrocytes and neurons, that is, the tripartite synapse, we hypothesized that astrocytes might have a significant role in post-injury hyperreflexia and plasticity of neighboring neuronal synaptic dendritic spines. Here, we investigated the effect of selective Rac1KO in astrocytes (i.e., adult male and female mice, transgenic cre-flox system) on SCI-induced spasticity. Three weeks after a mild contusion SCI, control Rac1wt animals displayed a loss of H-reflex RDD, that is, hyperreflexia. In contrast, transgenic animals with astrocytic Rac1KO demonstrated near-normal H-reflex RDD similar to pre-injury levels. Reduced hyperreflexia in astrocytic Rac1KO animals was accompanied by a loss of thin-shaped dendritic spine density on α-motor neurons in the ventral horn. In SCI-Rac1wt animals, as expected, we observed the development of dendritic spine dysgenesis on α-motor neurons associated with spasticity. As compared with WT animals, SCI animals with astrocytic Rac1KO expressed increased levels of the glial-specific glutamate transporter, glutamate transporter-1 in the ventral spinal cord, potentially enhancing glutamate clearance from the synaptic cleft and reducing hyperreflexia in astrocytic Rac1KO animals. Taken together, our findings show for the first time that Rac1 activity in astrocytes can contribute to hyperreflexia underlying spasticity following SCI. These results reveal an opportunity to target cell-specific molecular regulators of H-reflex excitability to manage spasticity after SCI.Significance Statement Spinal cord injury leads to stretch reflex hyperexcitability, which underlies the clinical symptom of spasticity. This study shows for the first time that astrocytic Rac1 contributes to the development of hyperreflexia after SCI. Specifically, astrocytic Rac1KO reduced SCI-related H-reflex hyperexcitability, decreased dendritic spine dysgenesis on α-motor neurons, and elevated the expression of the astrocytic glutamate transporter-1 (GLT-1). Overall, this study supports a distinct role for astrocytic Rac1 signaling within the spinal reflex circuit and the development of SCI-related spasticity.
Collapse
Affiliation(s)
- Curtis A Benson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Kai-Lan Olson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Siraj Patwa
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Sierra D Kauer
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Jared F King
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510,
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| |
Collapse
|
13
|
Otter CJ, Renner DM, Fausto A, Tan LH, Cohen NA, Weiss SR. Interferon signaling in the nasal epithelium distinguishes among lethal and common cold respiratory viruses and is critical for viral clearance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.18.571720. [PMID: 38187597 PMCID: PMC10769301 DOI: 10.1101/2023.12.18.571720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
All respiratory viruses establish primary infections in the nasal epithelium, where efficient innate immune induction may prevent dissemination to the lower airway and thus minimize pathogenesis. Human coronaviruses (HCoVs) cause a range of pathologies, but the host and viral determinants of disease during common cold versus lethal HCoV infections are poorly understood. We model the initial site of infection using primary nasal epithelial cells cultured at air-liquid interface (ALI). HCoV-229E, HCoV-NL63 and human rhinovirus-16 are common cold-associated viruses that exhibit unique features in this model: early induction of antiviral interferon (IFN) signaling, IFN-mediated viral clearance, and preferential replication at nasal airway temperature (33°C) which confers muted host IFN responses. In contrast, lethal SARS-CoV-2 and MERS-CoV encode antagonist proteins that prevent IFN-mediated clearance in nasal cultures. Our study identifies features shared among common cold-associated viruses, highlighting nasal innate immune responses as predictive of infection outcomes and nasally-directed IFNs as potential therapeutics.
Collapse
Affiliation(s)
- Clayton J. Otter
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David M. Renner
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandra Fausto
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Li Hui Tan
- Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Noam A. Cohen
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
- Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Susan R. Weiss
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
14
|
Schwedt I, Schöne K, Eckert M, Pizzinato M, Winkler L, Knotkova B, Richts B, Hau JL, Steuber J, Mireles R, Noda-Garcia L, Fritz G, Mittelstädt C, Hertel R, Commichau FM. The low mutational flexibility of the EPSP synthase in Bacillus subtilis is due to a higher demand for shikimate pathway intermediates. Environ Microbiol 2023; 25:3604-3622. [PMID: 37822042 DOI: 10.1111/1462-2920.16518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 09/21/2023] [Indexed: 10/13/2023]
Abstract
Glyphosate (GS) inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase that is required for aromatic amino acid, folate and quinone biosynthesis in Bacillus subtilis and Escherichia coli. The inhibition of the EPSP synthase by GS depletes the cell of these metabolites, resulting in cell death. Here, we show that like the laboratory B. subtilis strains also environmental and undomesticated isolates adapt to GS by reducing herbicide uptake. Although B. subtilis possesses a GS-insensitive EPSP synthase, the enzyme is strongly inhibited by GS in the native environment. Moreover, the B. subtilis EPSP synthase mutant was only viable in rich medium containing menaquinone, indicating that the bacteria require a catalytically efficient EPSP synthase under nutrient-poor conditions. The dependency of B. subtilis on the EPSP synthase probably limits its evolvability. In contrast, E. coli rapidly acquires GS resistance by target modification. However, the evolution of a GS-resistant EPSP synthase under non-selective growth conditions indicates that GS resistance causes fitness costs. Therefore, in both model organisms, the proper function of the EPSP synthase is critical for the cellular viability. This study also revealed that the uptake systems for folate precursors, phenylalanine and tyrosine need to be identified and characterized in B. subtilis.
Collapse
Affiliation(s)
- Inge Schwedt
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Kerstin Schöne
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Maike Eckert
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Manon Pizzinato
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Laura Winkler
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Barbora Knotkova
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University of Göttingen, Göttingen, Germany
| | - Björn Richts
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University of Göttingen, Göttingen, Germany
| | - Jann-Louis Hau
- FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Julia Steuber
- FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Raul Mireles
- Department of Plant Pathology and Microbiology, Hebrew University, Rehovot, Israel
| | - Lianet Noda-Garcia
- Department of Plant Pathology and Microbiology, Hebrew University, Rehovot, Israel
| | - Günter Fritz
- FG Cellular Microbiology, Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Carolin Mittelstädt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Fabian M Commichau
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| |
Collapse
|
15
|
Wright MJ, Bai G. Bacterial second messenger cyclic di-AMP in streptococci. Mol Microbiol 2023; 120:791-804. [PMID: 37898560 DOI: 10.1111/mmi.15187] [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: 08/04/2023] [Revised: 10/10/2023] [Accepted: 10/15/2023] [Indexed: 10/30/2023]
Abstract
Cyclic dimeric adenosine monophosphate (c-di-AMP) has been well studied in bacteria, including those of the genus Streptococcus, since the first recognition of this dinucleotide in 2008. Streptococci possess a sole diadenylate cyclase, CdaA, and distinct c-di-AMP phosphodiesterases. Interestingly, cdaA is required for viability of some streptococcal species but not all when streptococci are grown in standard laboratory media. Bacteria of this genus also have distinct c-di-AMP effector proteins, diverse c-di-AMP-signaling pathways, and subsequent biological outcomes. In streptococci, c-di-AMP may influence bacterial growth, morphology, biofilm formation, competence program, drug resistance, and bacterial pathogenesis. c-di-AMP secreted by streptococci has also been shown to interact with the mammalian host and induces immune responses including type I interferon production. In this review, we summarize the reported c-di-AMP networks in seven species of the genus Streptococcus, which cause diverse clinical manifestations, and propose future perspectives to investigate the signaling molecule in these streptococcal pathogens.
Collapse
Affiliation(s)
- Michael J Wright
- Department of Internal Medicine, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Guangchun Bai
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
| |
Collapse
|
16
|
Herzberg C, Meißner J, Warneke R, Stülke J. The many roles of cyclic di-AMP to control the physiology of Bacillus subtilis. MICROLIFE 2023; 4:uqad043. [PMID: 37954098 PMCID: PMC10636490 DOI: 10.1093/femsml/uqad043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/21/2023] [Accepted: 10/19/2023] [Indexed: 11/14/2023]
Abstract
The dinucleotide cyclic di-AMP (c-di-AMP) is synthesized as a second messenger in the Gram-positive model bacterium Bacillus subtilis as well as in many bacteria and archaea. Bacillus subtilis possesses three diadenylate cyclases and two phosphodiesterases that synthesize and degrade the molecule, respectively. Among the second messengers, c-di-AMP is unique since it is essential for B. subtilis on the one hand but toxic upon accumulation on the other. This role as an "essential poison" is related to the function of c-di-AMP in the control of potassium homeostasis. C-di-AMP inhibits the expression and activity of potassium uptake systems by binding to riboswitches and transporters and activates the activity of potassium exporters. In this way, c-di-AMP allows the adjustment of uptake and export systems to achieve a balanced intracellular potassium concentration. C-di-AMP also binds to two dedicated signal transduction proteins, DarA and DarB. Both proteins seem to interact with other proteins in their apo state, i.e. in the absence of c-di-AMP. For DarB, the (p)ppGpp synthetase/hydrolase Rel and the pyruvate carboxylase PycA have been identified as targets. The interactions trigger the synthesis of the alarmone (p)ppGpp and of the acceptor molecule for the citric acid cycle, oxaloacetate, respectively. In the absence of c-di-AMP, many amino acids inhibit the growth of B. subtilis. This feature can be used to identify novel players in amino acid homeostasis. In this review, we discuss the different functions of c-di-AMP and their physiological relevance.
Collapse
Affiliation(s)
- Christina Herzberg
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Janek Meißner
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Robert Warneke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| |
Collapse
|
17
|
Tveriakhina L, Scanavachi G, Egan ED, Correia RBDC, Martin AP, Rogers JM, Yodh JS, Aster JC, Kirchhausen T, Blacklow SC. Temporal Dynamics and Stoichiometry in Notch Signaling - from Notch Synaptic Complex Formation to NICD Nuclear Entry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559780. [PMID: 37808809 PMCID: PMC10557745 DOI: 10.1101/2023.09.27.559780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Mammalian Notch signaling occurs when binding of Delta or Jagged to Notch stimulates proteolytic release of the Notch intracellular domain (NICD), which enters the nucleus to regulate target gene expression. To determine the temporal dynamics of events associated with Notch signaling under native conditions, we fluorescently tagged Notch and Delta at their endogenous genomic loci and visualized them upon pairing of receiver (Notch) and sender (Delta) cells as a function of time after cell contact. At contact sites, Notch and Delta immediately accumulated at 1:1 stoichiometry in synapses, which resolved by 15-20 min after contact. Synapse formation preceded entrance of the Notch extracellular domain into the sender cell and accumulation of NICD in the nucleus of the receiver cell, which approached a maximum after ∼45 min and was prevented by chemical and genetic inhibitors of signaling. These findings directly link Notch-Delta synapse dynamics to NICD production with unprecedented spatiotemporal precision.
Collapse
|
18
|
Kohm K, Jalomo-Khayrova E, Krüger A, Basu S, Steinchen W, Bange G, Frunzke J, Hertel R, Commichau F, Czech L. Structural and functional characterization of MrpR, the master repressor of the Bacillus subtilis prophage SPβ. Nucleic Acids Res 2023; 51:9452-9474. [PMID: 37602373 PMCID: PMC10516654 DOI: 10.1093/nar/gkad675] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/11/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
Prophages control their lifestyle to either be maintained within the host genome or enter the lytic cycle. Bacillus subtilis contains the SPβ prophage whose lysogenic state depends on the MrpR (YopR) protein, a key component of the lysis-lysogeny decision system. Using a historic B. subtilis strain harboring the heat-sensitive SPβ c2 mutant, we demonstrate that the lytic cycle of SPβ c2 can be induced by heat due to a single nucleotide exchange in the mrpR gene, rendering the encoded MrpRG136E protein temperature-sensitive. Structural characterization revealed that MrpR is a DNA-binding protein resembling the overall fold of tyrosine recombinases. MrpR has lost its recombinase function and the G136E exchange impairs its higher-order structure and DNA binding activity. Genome-wide profiling of MrpR binding revealed its association with the previously identified SPbeta repeated element (SPBRE) in the SPβ genome. MrpR functions as a master repressor of SPβ that binds to this conserved element to maintain lysogeny. The heat-inducible excision of the SPβ c2 mutant remains reliant on the serine recombinase SprA. A suppressor mutant analysis identified a previously unknown component of the lysis-lysogeny management system that is crucial for the induction of the lytic cycle of SPβ.
Collapse
Affiliation(s)
- Katharina Kohm
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Ekaterina Jalomo-Khayrova
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| | - Aileen Krüger
- Institute of Bio- and Geosciences, iBG-1: Biotechnology, FZ Jülich, Germany
| | - Syamantak Basu
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Wieland Steinchen
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| | - Gert Bange
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
- Max-Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, iBG-1: Biotechnology, FZ Jülich, Germany
| | - Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Göttingen, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Laura Czech
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| |
Collapse
|
19
|
Welsh CL, Madan LK. Allostery in Protein Tyrosine Phosphatases is Enabled by Divergent Dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.23.550226. [PMID: 37547015 PMCID: PMC10402003 DOI: 10.1101/2023.07.23.550226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Dynamics-driven allostery provides important insights into the working mechanics of proteins, especially enzymes. In this study we employ this paradigm to answer a basic question: in enzyme superfamilies where the catalytic mechanism, active sites and protein fold are conserved, what accounts for the difference in the catalytic prowess of the individual members? We show that when subtle changes in sequence do not translate to changes in structure, they do translate to changes in dynamics. We use sequentially diverse PTP1B, TbPTP1, and YopH as the representatives of the conserved Protein Tyrosine Phosphatase (PTP) superfamily. Using amino acid network analysis of group behavior (community analysis) and influential node dominance on networks (eigenvector centrality), we explain the dynamic basis of catalytic variations seen between the three proteins. Importantly, we explain how a dynamics-based blueprint makes PTP1B amenable to allosteric control and how the same is abstracted in TbPTP1 and YopH.
Collapse
|
20
|
Fuss MF, Wieferig JP, Corey RA, Hellmich Y, Tascón I, Sousa JS, Stansfeld PJ, Vonck J, Hänelt I. Cyclic di-AMP traps proton-coupled K + transporters of the KUP family in an inward-occluded conformation. Nat Commun 2023; 14:3683. [PMID: 37344476 DOI: 10.1038/s41467-023-38944-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/22/2023] [Indexed: 06/23/2023] Open
Abstract
Cyclic di-AMP is the only known essential second messenger in bacteria and archaea, regulating different proteins indispensable for numerous physiological processes. In particular, it controls various potassium and osmolyte transporters involved in osmoregulation. In Bacillus subtilis, the K+/H+ symporter KimA of the KUP family is inactivated by c-di-AMP. KimA sustains survival at potassium limitation at low external pH by mediating potassium ion uptake. However, at elevated intracellular K+ concentrations, further K+ accumulation would be toxic. In this study, we reveal the molecular basis of how c-di-AMP binding inhibits KimA. We report cryo-EM structures of KimA with bound c-di-AMP in detergent solution and reconstituted in amphipols. By combining structural data with functional assays and molecular dynamics simulations we reveal how c-di-AMP modulates transport. We show that an intracellular loop in the transmembrane domain interacts with c-di-AMP bound to the adjacent cytosolic domain. This reduces the mobility of transmembrane helices at the cytosolic side of the K+ binding site and therefore traps KimA in an inward-occluded conformation.
Collapse
Affiliation(s)
- Michael F Fuss
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jan-Philip Wieferig
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Robin A Corey
- Department of Biochemistry, University of Oxford, Oxford, UK
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Yvonne Hellmich
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Igor Tascón
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Joana S Sousa
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- UCB Pharma, UCB Biopharma UK, Slough, SL1 3WE, UK
| | - Phillip J Stansfeld
- School of Life Sciences & Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| | - Inga Hänelt
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
| |
Collapse
|
21
|
van der Does C, Braun F, Ren H, Albers SV. Putative nucleotide-based second messengers in archaea. MICROLIFE 2023; 4:uqad027. [PMID: 37305433 PMCID: PMC10249747 DOI: 10.1093/femsml/uqad027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/07/2023] [Accepted: 06/02/2023] [Indexed: 06/13/2023]
Abstract
Second messengers transfer signals from changing intra- and extracellular conditions to a cellular response. Over the last few decades, several nucleotide-based second messengers have been identified and characterized in especially bacteria and eukaryotes. Also in archaea, several nucleotide-based second messengers have been identified. This review will summarize our understanding of nucleotide-based second messengers in archaea. For some of the nucleotide-based second messengers, like cyclic di-AMP and cyclic oligoadenylates, their roles in archaea have become clear. Cyclic di-AMP plays a similar role in osmoregulation in euryarchaea as in bacteria, and cyclic oligoadenylates are important in the Type III CRISPR-Cas response to activate CRISPR ancillary proteins involved in antiviral defense. Other putative nucleotide-based second messengers, like 3',5'- and 2',3'-cyclic mononucleotides and adenine dinucleotides, have been identified in archaea, but their synthesis and degradation pathways, as well as their functions as secondary messengers, still remain to be demonstrated. In contrast, 3'-3'-cGAMP has not yet been identified in archaea, but the enzymes required to synthesize 3'-3'-cGAMP have been found in several euryarchaeotes. Finally, the widely distributed bacterial second messengers, cyclic diguanosine monophosphate and guanosine (penta-)/tetraphosphate, do not appear to be present in archaea.
Collapse
Affiliation(s)
- Chris van der Does
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Frank Braun
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Hongcheng Ren
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, 79104 Freiburg, Germany
| |
Collapse
|
22
|
Hengge R, Pruteanu M, Stülke J, Tschowri N, Turgay K. Recent advances and perspectives in nucleotide second messenger signaling in bacteria. MICROLIFE 2023; 4:uqad015. [PMID: 37223732 PMCID: PMC10118264 DOI: 10.1093/femsml/uqad015] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/28/2023] [Accepted: 04/13/2023] [Indexed: 05/25/2023]
Abstract
Nucleotide second messengers act as intracellular 'secondary' signals that represent environmental or cellular cues, i.e. the 'primary' signals. As such, they are linking sensory input with regulatory output in all living cells. The amazing physiological versatility, the mechanistic diversity of second messenger synthesis, degradation, and action as well as the high level of integration of second messenger pathways and networks in prokaryotes has only recently become apparent. In these networks, specific second messengers play conserved general roles. Thus, (p)ppGpp coordinates growth and survival in response to nutrient availability and various stresses, while c-di-GMP is the nucleotide signaling molecule to orchestrate bacterial adhesion and multicellularity. c-di-AMP links osmotic balance and metabolism and that it does so even in Archaea may suggest a very early evolutionary origin of second messenger signaling. Many of the enzymes that make or break second messengers show complex sensory domain architectures, which allow multisignal integration. The multiplicity of c-di-GMP-related enzymes in many species has led to the discovery that bacterial cells are even able to use the same freely diffusible second messenger in local signaling pathways that can act in parallel without cross-talking. On the other hand, signaling pathways operating with different nucleotides can intersect in elaborate signaling networks. Apart from the small number of common signaling nucleotides that bacteria use for controlling their cellular "business," diverse nucleotides were recently found to play very specific roles in phage defense. Furthermore, these systems represent the phylogenetic ancestors of cyclic nucleotide-activated immune signaling in eukaryotes.
Collapse
Affiliation(s)
- Regine Hengge
- Corresponding author. Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Philippstr. 13 – Haus 22, 10115 Berlin, Germany. Tel: +49-30-2093-49686; Fax: +49-30-2093-49682; E-mail:
| | | | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Natalia Tschowri
- Institute of Microbiology, Leibniz-Universität Hannover, 30419 Hannover, Germany
| | - Kürşad Turgay
- Institute of Microbiology, Leibniz-Universität Hannover, 30419 Hannover, Germany
- Max Planck Unit for the Science of Pathogens, 10115 Berlin, Germany
| |
Collapse
|
23
|
Neumann P, Kloskowski P, Ficner R. Computer-aided design of a cyclic di-AMP synthesizing enzyme CdaA inhibitor. MICROLIFE 2023; 4:uqad021. [PMID: 37223749 PMCID: PMC10167629 DOI: 10.1093/femsml/uqad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/24/2023] [Accepted: 04/13/2023] [Indexed: 05/25/2023]
Abstract
Cyclic di-AMP (c-di-AMP) is an essential secondary messenger regulating cell wall homeostasis and myriads of physiological processes in several Gram-positive and mycobacteria, including human pathogens. Hence, c-di-AMP synthesizing enzymes (DACs) have become a promising antibacterial drug target. To overcome a scarcity of small molecule inhibitors of c-di-AMP synthesizing enzyme CdaA, a computer-aided design of a new compound that should block the enzyme has been performed. This has led to the identification of a molecule comprising two thiazole rings and showing inhibitory potential based on ITC measurements. Thiazole scaffold is a good pharmacophore nucleus known due to its various pharmaceutical applications. It is contained in more than 18 FDA-approved drugs as well as in dozens of experimental drugs. Hence, the designed inhibitor can serve as a potent lead compound for further development of inhibitor against CdaA.
Collapse
Affiliation(s)
- Piotr Neumann
- Corresponding author. Department of Molecular Structural Biology, Georg-August-University Goettingen, Institute of Microbiology and Genetics, GZMB, Justus-von-Liebig Weg 11, 37077 Goettingen, Germany. Tel: +495513928624; Fax: +495513928629; E-mail:
| | - Patrick Kloskowski
- Department of Molecular Structural Biology, Georg-August-University Goettingen, Institute of Microbiology and Genetics, GZMB, Justus-von-Liebig Weg 11, 37077 Goettingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Georg-August-University Goettingen, Institute of Microbiology and Genetics, GZMB, Justus-von-Liebig Weg 11, 37077 Goettingen, Germany
| |
Collapse
|
24
|
Acciarri G, Gizzi FO, Torres Manno MA, Stülke J, Espariz M, Blancato VS, Magni C. Redundant potassium transporter systems guarantee the survival of Enterococcus faecalis under stress conditions. Front Microbiol 2023; 14:1117684. [PMID: 36846772 PMCID: PMC9945522 DOI: 10.3389/fmicb.2023.1117684] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023] Open
Abstract
Enterococcus is able to grow in media at pH from 5.0 to 9.0 and a high concentration of NaCl (8%). The ability to respond to these extreme conditions requires the rapid movement of three critical ions: proton (H+), sodium (Na+), and potassium (K+). The activity of the proton F0F1 ATPase and the sodium Na+ V0V1 type ATPase under acidic or alkaline conditions, respectively, is well established in these microorganisms. The potassium uptake transporters KtrI and KtrII were described in Enterococcus hirae, which were associated with growth in acidic and alkaline conditions, respectively. In Enterococcus faecalis, the presence of the Kdp (potassium ATPase) system was early established. However, the homeostasis of potassium in this microorganism is not completely explored. In this study, we demonstrate that Kup and KimA are high-affinity potassium transporters, and the inactivation of these genes in E. faecalis JH2-2 (a Kdp laboratory natural deficient strain) had no effect on the growth parameters. However, in KtrA defective strains (ΔktrA, ΔkupΔktrA) an impaired growth was observed under stress conditions, which was restored to wild type levels by external addition of K+ ions. Among the multiplicity of potassium transporters identify in the genus Enterococcus, Ktr channels (KtrAB and KtrAD), and Kup family symporters (Kup and KimA) are present and may contribute to the particular resistance of these microorganisms to different stress conditions. In addition, we found that the presence of the Kdp system in E. faecalis is strain-dependent, and this transporter is enriched in strains of clinical origin as compared to environmental, commensal, or food isolates.
Collapse
Affiliation(s)
- Giuliana Acciarri
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina
| | - Fernán O. Gizzi
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina
| | - Mariano A. Torres Manno
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Área Bioinformática, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Jörg Stülke
- Department of General Microbiology, Georg August University, Göttingen, Germany
| | - Martín Espariz
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Área Bioinformática, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Víctor S. Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los Alimentos, FBioyF, UNR–Municipalidad de Granadero Baigorria, Rosario, Argentina
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los Alimentos, FBioyF, UNR–Municipalidad de Granadero Baigorria, Rosario, Argentina,*Correspondence: Christian Magni, ✉
| |
Collapse
|
25
|
Guo Y, Wang H, Wei X, Wang Z, Wang H, Chen J, Li J, Liu J. Utilization of high-K+-cane molasses for enhanced S-Adenosylmethionine production by manipulation of a K+ transport channel in Saccharomyces cerevisiae. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
26
|
C-di-AMP Is a Second Messenger in Corynebacterium glutamicum That Regulates Expression of a Cell Wall-Related Peptidase via a Riboswitch. Microorganisms 2023; 11:microorganisms11020296. [PMID: 36838266 PMCID: PMC9960051 DOI: 10.3390/microorganisms11020296] [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: 12/20/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
Cyclic di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger discovered in Bacillus subtilis and involved in potassium homeostasis, cell wall maintenance and/or DNA stress response. As the role of c-di-AMP has been mostly studied in Firmicutes, we sought to increase the understanding of its role in Actinobacteria, namely in Corynebacterium glutamicum. This organism is a well-known industrial production host and a model organism for pathogens, such as C. diphtheriae or Mycobacterium tuberculosis. Here, we identify and analyze the minimal set of two C. glutamicum enzymes, the diadenylate cyclase DisA and the phosphodiesterase PdeA, responsible for c-di-AMP metabolism. DisA synthesizes c-di-AMP from two molecules of ATP, whereas PdeA degrades c-di-AMP, as well as the linear degradation intermediate phosphoadenylyl-(3'→5')-adenosine (pApA) to two molecules of AMP. Here, we show that a ydaO/kimA-type c-di-AMP-dependent riboswitch controls the expression of the strictly regulated cell wall peptidase gene nlpC in C. glutamicum. In contrast to previously described members of the ydaO/kimA-type riboswitches, our results suggest that the C. glutamicum nlpC riboswitch likely affects the translation instead of the transcription of its downstream gene. Although strongly regulated by different mechanisms, we show that the absence of nlpC, the first known regulatory target of c-di-AMP in C. glutamicum, is not detrimental for this organism under the tested conditions.
Collapse
|
27
|
Ainelo A, Caballero-Montes J, Bulvas O, Ernits K, Coppieters ‘t Wallant K, Takada H, Craig SZ, Mazzucchelli G, Zedek S, Pichová I, Atkinson GC, Talavera A, Martens C, Hauryliuk V, Garcia-Pino A. The structure of DarB in complex with Rel NTD reveals nonribosomal activation of Rel stringent factors. SCIENCE ADVANCES 2023; 9:eade4077. [PMID: 36652515 PMCID: PMC9848473 DOI: 10.1126/sciadv.ade4077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Rel stringent factors are bifunctional ribosome-associated enzymes that catalyze both synthesis and hydrolysis of the alarmones (p)ppGpp. Besides the allosteric control by starved ribosomes and (p)ppGpp, Rel is regulated by various protein factors depending on specific stress conditions, including the c-di-AMP-binding protein DarB. However, how these effector proteins control Rel remains unknown. We have determined the crystal structure of the DarB2:RelNTD2 complex, uncovering that DarB directly engages the SYNTH domain of Rel to stimulate (p)ppGpp synthesis. This association with DarB promotes a SYNTH-primed conformation of the N-terminal domain region, markedly increasing the affinity of Rel for ATP while switching off the hydrolase activity of the enzyme. Binding to c-di-AMP rigidifies DarB, imposing an entropic penalty that precludes DarB-mediated control of Rel during normal growth. Our experiments provide the basis for understanding a previously unknown mechanism of allosteric regulation of Rel stringent factors independent of amino acid starvation.
Collapse
Affiliation(s)
- Andres Ainelo
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles 10 (ULB), Boulevard du Triomphe, Building BC (1C4 203), 1050 Brussels, Belgium
| | - Julien Caballero-Montes
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles 10 (ULB), Boulevard du Triomphe, Building BC (1C4 203), 1050 Brussels, Belgium
| | - Ondřej Bulvas
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nam. 2, 166 10 Prague 6, Czech Republic
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technicka 5, 166 28 Prague 6, Czech Republic
| | - Karin Ernits
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Kyo Coppieters ‘t Wallant
- Centre for Structural Biology and Bioinformatics, Universite Libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, 1050 Bruxelles, Belgium
| | - Hiraku Takada
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Sophie Z. Craig
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles 10 (ULB), Boulevard du Triomphe, Building BC (1C4 203), 1050 Brussels, Belgium
| | - Gabriel Mazzucchelli
- Mass Spectrometry Laboratory, MolSys Research Unit, Liège Université, B-4000 Liège, Belgium
| | - Safia Zedek
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles 10 (ULB), Boulevard du Triomphe, Building BC (1C4 203), 1050 Brussels, Belgium
| | - Iva Pichová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nam. 2, 166 10 Prague 6, Czech Republic
| | - Gemma C. Atkinson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Ariel Talavera
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles 10 (ULB), Boulevard du Triomphe, Building BC (1C4 203), 1050 Brussels, Belgium
| | - Chloe Martens
- Centre for Structural Biology and Bioinformatics, Universite Libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, 1050 Bruxelles, Belgium
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
- University of Tartu, Institute of Technology, 50411 Tartu, Estonia
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles 10 (ULB), Boulevard du Triomphe, Building BC (1C4 203), 1050 Brussels, Belgium
- WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium
| |
Collapse
|
28
|
Covaleda-Cortés G, Mechaly A, Brissac T, Baehre H, Devaux L, England P, Raynal B, Hoos S, Gominet M, Firon A, Trieu-Cuot P, Kaminski PA. The c-di-AMP-binding protein CbpB modulates the level of ppGpp alarmone in Streptococcus agalactiae. FEBS J 2023. [PMID: 36629470 DOI: 10.1111/febs.16724] [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: 08/17/2022] [Revised: 12/07/2022] [Accepted: 01/09/2023] [Indexed: 01/12/2023]
Abstract
Cyclic di-AMP is an essential signalling molecule in Gram-positive bacteria. This second messenger regulates the osmotic pressure of the cell by interacting directly with the regulatory domains, either RCK_C or CBS domains, of several potassium and osmolyte uptake membrane protein systems. Cyclic di-AMP also targets stand-alone CBS domain proteins such as DarB in Bacillus subtilis and CbpB in Listeria monocytogenes. We show here that the CbpB protein of Group B Streptococcus binds c-di-AMP with a very high affinity. Crystal structures of CbpB reveal the determinants of binding specificity and significant conformational changes occurring upon c-di-AMP binding. Deletion of the cbpB gene alters bacterial growth in low potassium conditions most likely due to a decrease in the amount of ppGpp caused by a loss of interaction between CbpB and Rel, the GTP/GDP pyrophosphokinase.
Collapse
Affiliation(s)
- Giovanni Covaleda-Cortés
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| | - Ariel Mechaly
- CNRS-UMR 3528, Crystallography Platform, Center for Technological Resources and Research, Institut Pasteur, Université Paris Cité, France
| | - Terry Brissac
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| | - Heike Baehre
- Research Core Unit Metabolomics, Hannover Medical School, Germany
| | - Laura Devaux
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| | - Patrick England
- CNRS UMR 3528, Molecular Biophysics Platform, Center for Technological Resources and Research, Institut Pasteur, Université Paris Cité, France
| | - Bertrand Raynal
- CNRS UMR 3528, Molecular Biophysics Platform, Center for Technological Resources and Research, Institut Pasteur, Université Paris Cité, France
| | - Sylviane Hoos
- CNRS UMR 3528, Molecular Biophysics Platform, Center for Technological Resources and Research, Institut Pasteur, Université Paris Cité, France
| | - Myriam Gominet
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| | - Arnaud Firon
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| | - Patrick Trieu-Cuot
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| | - Pierre Alexandre Kaminski
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR 6047, Institut Pasteur, Université Paris Cité, France
| |
Collapse
|
29
|
How To Deal with Toxic Amino Acids: the Bipartite AzlCD Complex Exports Histidine in Bacillus subtilis. J Bacteriol 2022; 204:e0035322. [PMID: 36377869 PMCID: PMC9765041 DOI: 10.1128/jb.00353-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The Gram-positive model bacterium Bacillus subtilis can use several amino acids as sources of carbon and nitrogen. However, some amino acids inhibit the growth of this bacterium. This amino acid toxicity is often enhanced in strains lacking the second messenger cyclic dimeric adenosine 3',5'-monophosphate (c-di-AMP). We observed that the presence of histidine is also toxic for a B. subtilis strain that lacks all three c-di-AMP synthesizing enzymes. However, suppressor mutants emerged, and whole-genome sequencing revealed mutations in the azlB gene that encode the repressor of the azl operon. This operon encodes an exporter and an importer for branched-chain amino acids. The suppressor mutations result in an overexpression of the azl operon. Deletion of the azlCD genes encoding the branched-chain amino acid exporter restored the toxicity of histidine, indicating that this exporter is required for histidine export and for resistance to otherwise toxic levels of the amino acid. The higher abundance of the amino acid exporter AzlCD increased the extracellular concentration of histidine, thus confirming the new function of AzlCD as a histidine exporter. Unexpectedly, the AzlB-mediated repression of the operon remains active even in the presence of amino acids, suggesting that the expression of the azl operon requires the mutational inactivation of AzlB. IMPORTANCE Amino acids are building blocks for protein biosynthesis in each living cell. However, due to their reactivity and the similarity between several amino acids, they may also be involved in harmful reactions or in noncognate interactions and thus may be toxic. Bacillus subtilis can deal with otherwise toxic histidine by overexpressing the bipartite amino acid exporter AzlCD. Although encoded in an operon that also contains a gene for an amino acid importer, the corresponding genes are not expressed, irrespective of the availability of amino acids in the medium. This suggests that the azl operon is a last resort by which to deal with histidine stress that can be expressed due to the mutational inactivation of the cognate repressor AzlB.
Collapse
|
30
|
Otter CJ, Fausto A, Tan LH, Cohen NA, Weiss SR. Infection of primary nasal epithelial cells differentiates among lethal and seasonal human coronaviruses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.10.17.512617. [PMID: 36299422 PMCID: PMC9603826 DOI: 10.1101/2022.10.17.512617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The nasal epithelium is the initial entry portal and primary barrier to infection by all human coronaviruses (HCoVs). We utilize primary nasal epithelial cells grown at air-liquid interface, which recapitulate the heterogeneous cellular population as well as mucociliary clearance functions of the in vivo nasal epithelium, to compare lethal (SARS-CoV-2 and MERS-CoV) and seasonal (HCoV-NL63 and HCoV-229E) HCoVs. All four HCoVs replicate productively in nasal cultures but diverge significantly in terms of cytotoxicity induced following infection, as the seasonal HCoVs as well as SARS-CoV-2 cause cellular cytotoxicity as well as epithelial barrier disruption, while MERS-CoV does not. Treatment of nasal cultures with type 2 cytokine IL-13 to mimic asthmatic airways differentially impacts HCoV replication, enhancing MERS-CoV replication but reducing that of SARS-CoV-2 and HCoV-NL63. This study highlights diversity among HCoVs during infection of the nasal epithelium, which is likely to influence downstream infection outcomes such as disease severity and transmissibility.
Collapse
Affiliation(s)
- Clayton J. Otter
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandra Fausto
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Li Hui Tan
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Noam A. Cohen
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Susan R. Weiss
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Research on Coronaviruses and Other Emerging Pathogens, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
31
|
Oberkampf M, Hamiot A, Altamirano-Silva P, Bellés-Sancho P, Tremblay YDN, DiBenedetto N, Seifert R, Soutourina O, Bry L, Dupuy B, Peltier J. c-di-AMP signaling is required for bile salt resistance, osmotolerance, and long-term host colonization by Clostridioides difficile. Sci Signal 2022; 15:eabn8171. [PMID: 36067333 PMCID: PMC9831359 DOI: 10.1126/scisignal.abn8171] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To colonize the host and cause disease, the human enteropathogen Clostridioides difficile must sense, respond, and adapt to the harsh environment of the gastrointestinal tract. We showed that the production and degradation of cyclic diadenosine monophosphate (c-di-AMP) were necessary during different phases of C. difficile growth, environmental adaptation, and infection. The production of this nucleotide second messenger was essential for growth because it controlled the uptake of potassium and also contributed to biofilm formation and cell wall homeostasis, whereas its degradation was required for osmotolerance and resistance to detergents and bile salts. The c-di-AMP binding transcription factor BusR repressed the expression of genes encoding the compatible solute transporter BusAA-AB. Compared with the parental strain, a mutant lacking BusR was more resistant to hyperosmotic and bile salt stresses, whereas a mutant lacking BusAA was more susceptible. A short exposure of C. difficile cells to bile salts decreased intracellular c-di-AMP concentrations, suggesting that changes in membrane properties induce alterations in the intracellular c-di-AMP concentration. A C. difficile strain that could not degrade c-di-AMP failed to persist in a mouse gut colonization model as long as the wild-type strain did. Thus, the production and degradation of c-di-AMP in C. difficile have pleiotropic effects, including the control of osmolyte uptake to confer osmotolerance and bile salt resistance, and its degradation is important for host colonization.
Collapse
Affiliation(s)
- Marine Oberkampf
- Institut Pasteur, Université Paris Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
| | - Audrey Hamiot
- Institut Pasteur, Université Paris Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
| | - Pamela Altamirano-Silva
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Paula Bellés-Sancho
- Institut Pasteur, Université Paris Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
| | - Yannick D. N. Tremblay
- Institut Pasteur, Université Paris Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
| | - Nicholas DiBenedetto
- Massachusetts Host-Microbiome Center, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Roland Seifert
- Institute of Pharmacology and Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Olga Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Lynn Bry
- Massachusetts Host-Microbiome Center, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Clinical Microbiology Laboratory, Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA
| | - Bruno Dupuy
- Institut Pasteur, Université Paris Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
| | - Johann Peltier
- Institut Pasteur, Université Paris Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| |
Collapse
|
32
|
Pal AK, Ghosh A. c-di-AMP signaling plays important role in determining antibiotic tolerance phenotypes of Mycobacterium smegmatis. Sci Rep 2022; 12:13127. [PMID: 35907936 PMCID: PMC9338955 DOI: 10.1038/s41598-022-17051-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/20/2022] [Indexed: 11/09/2022] Open
Abstract
In this study, we probe the role of secondary messenger c-di-AMP in drug tolerance, which includes both persister and resistant mutant characterization of Mycobacterium smegmatis. Specifically, with the use of c-di-AMP null and overproducing mutants, we showed how c-di-AMP plays a significant role in resistance mutagenesis against antibiotics with different mechanisms of action. We elucidated the specific molecular mechanism linking the elevated intracellular c-di-AMP level and high mutant generation and highlighted the significance of non-homology-based DNA repair. Further investigation enabled us to identify the unique mutational landscape of target and non-target mutation categories linked to intracellular c-di-AMP levels. Overall fitness cost of unique target mutations was estimated in different strain backgrounds, and then we showed the critical role of c-di-AMP in driving epistatic interactions between resistance genes, resulting in the evolution of multi-drug tolerance. Finally, we identified the role of c-di-AMP in persister cells regrowth and mutant enrichment upon cessation of antibiotic treatment.
Collapse
Affiliation(s)
- Aditya Kumar Pal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Anirban Ghosh
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
| |
Collapse
|
33
|
Stecker D, Hoffmann T, Link H, Commichau FM, Bremer E. L-Proline Synthesis Mutants of Bacillus subtilis Overcome Osmotic Sensitivity by Genetically Adapting L-Arginine Metabolism. Front Microbiol 2022; 13:908304. [PMID: 35783388 PMCID: PMC9245794 DOI: 10.3389/fmicb.2022.908304] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
The accumulation of the compatible solute L-proline by Bacillus subtilis via synthesis is a cornerstone in the cell’s defense against high salinity as the genetic disruption of this biosynthetic process causes osmotic sensitivity. To understand how B. subtilis could potentially cope with high osmolarity surroundings without the functioning of its natural osmostress adaptive L-proline biosynthetic route (ProJ-ProA-ProH), we isolated suppressor strains of proA mutants under high-salinity growth conditions. These osmostress-tolerant strains carried mutations affecting either the AhrC transcriptional regulator or its operator positioned in front of the argCJBD-carAB-argF L-ornithine/L-citrulline/L-arginine biosynthetic operon. Osmostress protection assays, molecular analysis and targeted metabolomics showed that these mutations, in conjunction with regulatory mutations affecting rocR-rocDEF expression, connect and re-purpose three different physiological processes: (i) the biosynthetic pathway for L-arginine, (ii) the RocD-dependent degradation route for L-ornithine, and (iii) the last step in L-proline biosynthesis. Hence, osmostress adaptation without a functional ProJ-ProA-ProH route is made possible through a naturally existing, but inefficient, metabolic shunt that allows to substitute the enzyme activity of ProA by feeding the RocD-formed metabolite γ-glutamate-semialdehyde/Δ1-pyrroline-5-carboxylate into the biosynthetic route for the compatible solute L-proline. Notably, in one class of mutants, not only substantial L-proline pools but also large pools of L-citrulline were accumulated, a rather uncommon compatible solute in microorganisms. Collectively, our data provide an example of the considerable genetic plasticity and metabolic resourcefulness of B. subtilis to cope with everchanging environmental conditions.
Collapse
Affiliation(s)
- Daniela Stecker
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany
| | - Tamara Hoffmann
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Hannes Link
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Fabian M. Commichau
- Insitute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany
- Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Erhard Bremer
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
- *Correspondence: Erhard Bremer,
| |
Collapse
|
34
|
Heidemann JL, Neumann P, Krüger L, Wicke D, Vinhoven L, Linden A, Dickmanns A, Stülke J, Urlaub H, Ficner R. Structural basis for c-di-AMP-dependent regulation of the bacterial stringent response by receptor protein DarB. J Biol Chem 2022; 298:102144. [PMID: 35714772 PMCID: PMC9293649 DOI: 10.1016/j.jbc.2022.102144] [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: 06/01/2022] [Revised: 06/09/2022] [Accepted: 06/11/2022] [Indexed: 10/31/2022] Open
Abstract
The bacterial second messenger c-di-AMP controls essential cellular processes, including potassium and osmolyte homeostasis. This makes synthesizing enzymes and components involved in c-di-AMP signal transduction intriguing as potential targets for drug development. The c-di-AMP receptor protein DarB of Bacillus subtilis is known to bind the Rel protein and trigger the Rel-dependent stringent response to stress conditions; however, the structural basis for this trigger is unclear. Here we report crystal structures of DarB in the ligand-free state and of DarB complexed with c-di-AMP, 3´3´-cGAMP, and AMP. We show that DarB forms a homodimer with a parallel, head-to-head assembly of the monomers. We also confirm the DarB dimer binds two cyclic di-nucleotide molecules or two AMP molecules; only one adenine of bound c-di-AMP is specifically recognized by DarB, while the second protrudes out of the donut-shaped protein. This enables DarB to bind also 3´3´-cGAMP, as only the adenine fits in the active site. In absence of c-di-AMP, we show DarB binds to Rel and stimulates (p)ppGpp synthesis, whereas the presence of c-di-AMP abolishes this interaction. Furthermore, the DarB crystal structures reveal no conformational changes upon c-di-AMP binding, leading us to conclude the regulatory function of DarB on Rel must be controlled directly by the bound c-di-AMP. We thus derived a structural model of the DarB-Rel complex via in silico docking, which was validated with mass spectrometric analysis of the chemically cross-linked DarB-Rel complex and mutagenesis studies. We suggest, based on the predicted complex structure, a mechanism of stringent response regulation by c-di-AMP.
Collapse
Affiliation(s)
| | | | - Larissa Krüger
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Dennis Wicke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | | | - Andreas Linden
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | |
Collapse
|
35
|
Wang M, Wamp S, Gibhardt J, Holland G, Schwedt I, Schmidtke KU, Scheibner K, Halbedel S, Commichau FM. Adaptation of Listeria monocytogenes to perturbation of c-di-AMP metabolism underpins its role in osmoadaptation and identifies a fosfomycin uptake system. Environ Microbiol 2022; 24:4466-4488. [PMID: 35688634 DOI: 10.1111/1462-2920.16084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/25/2022] [Indexed: 11/29/2022]
Abstract
The human pathogen Listeria monocytogenes synthesizes and degrades c-di-AMP using the diadenylate cyclase CdaA and the phosphodiesterases PdeA and PgpH respectively. c-di-AMP is essential because it prevents the uncontrolled uptake of osmolytes. Here, we studied the phenotypes of cdaA, pdeA, pgpH and pdeA pgpH mutants with defects in c-di-AMP metabolism and characterized suppressor mutants restoring their growth defects. The characterization of the pdeA pgpH mutant revealed that the bacteria show growth defects in defined medium, a phenotype that is invariably suppressed by mutations in cdaA. The previously reported growth defect of the cdaA mutant in rich medium is suppressed by mutations that osmotically stabilize the c-di-AMP-free strain. We also found that the cdaA mutant has an increased sensitivity against isoleucine. The isoleucine-dependent growth inhibition of the cdaA mutant is suppressed by codY mutations that likely reduce the DNA-binding activity of encoded CodY variants. Moreover, the characterization of the cdaA suppressor mutants revealed that the Opp oligopeptide transport system is involved in the uptake of the antibiotic fosfomycin. In conclusion, the suppressor analysis corroborates a key function of c-di-AMP in controlling osmolyte homeostasis in L. monocytogenes.
Collapse
Affiliation(s)
- Mengyi Wang
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany.,Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany.,FG Molecular Microbiology, Institute of Biology, University of Hohenheim, 70599, Stuttgart, Germany
| | - Sabrina Wamp
- Division of Enteropathogenic Bacteria and Legionella, Robert-Koch-Institute, 38855, Wernigerode, Germany
| | - Johannes Gibhardt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany.,Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, 37077, Göttingen, Germany.,Research Complex NanoBio, Peter the Great Saint Petersburg Polytechnic University, Politekhnicheskaya ulitsa 29A, Saint Petersburg, 195251, Russia
| | - Gudrun Holland
- ZBS4 - Advanced Light and Electron Microscopy, Robert-Koch-Institute, Seestraße 10, 13353, Berlin, Germany
| | - Inge Schwedt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany.,FG Molecular Microbiology, Institute of Biology, University of Hohenheim, 70599, Stuttgart, Germany
| | - Kai-Uwe Schmidtke
- FG Enzyme Technology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany
| | - Katrin Scheibner
- FG Enzyme Technology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany
| | - Sven Halbedel
- Division of Enteropathogenic Bacteria and Legionella, Robert-Koch-Institute, 38855, Wernigerode, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany.,FG Molecular Microbiology, Institute of Biology, University of Hohenheim, 70599, Stuttgart, Germany
| |
Collapse
|
36
|
Bavaharan A, Skilbeck C. Electrical signalling in prokaryotes and its convergence with quorum sensing in Bacillus. Bioessays 2022; 44:e2100193. [PMID: 35195292 DOI: 10.1002/bies.202100193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/15/2022]
Abstract
The importance of electrical signalling in bacteria is an emerging paradigm. Bacillus subtilis biofilms exhibit electrical communication that regulates metabolic activity and biofilm growth. Starving cells initiate oscillatory extracellular potassium signals that help even the distribution of nutrients within the biofilm and thus help regulate biofilm development. Quorum sensing also regulates biofilm growth and crucially there is convergence between electrical and quorum sensing signalling axes. This makes B. subtilis an interesting model for cell signalling research. SpoOF is predicted to act as a logic gate for signalling pathway convergence, raising interesting questions about the functional nature of this gate and the relative importance of these disparate signals on biofilm behaviour. How is an oscillating signal integrated with a quorum signal? The model presented offers rich opportunities for future experimental and theoretical modelling research. The importance of direct cell-to-cell electrical signalling in prokaryotes, so characteristic of multicellular eukaryotes, is also discussed.
Collapse
|
37
|
Wendel BM, Pi H, Krüger L, Herzberg C, Stülke J, Helmann JD. A Central Role for Magnesium Homeostasis during Adaptation to Osmotic Stress. mBio 2022; 13:e0009222. [PMID: 35164567 PMCID: PMC8844918 DOI: 10.1128/mbio.00092-22] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 02/06/2023] Open
Abstract
Osmotic stress is a significant physical challenge for free-living cells. Cells from all three domains of life maintain viability during osmotic stress by tightly regulating the major cellular osmolyte potassium (K+) and by import or synthesis of compatible solutes. It has been widely established that in response to high salt stress, many bacteria transiently accumulate high levels of K+, leading to bacteriostasis, with growth resuming only when compatible solutes accumulate and K+ levels are restored to biocompatible levels. Using Bacillus subtilis as a model system, we provide evidence that K+ fluxes perturb Mg2+ homeostasis: import of K+ upon osmotic upshift is correlated with Mg2+ efflux, and Mg2+ reimport is critical for adaptation. The transient growth inhibition resulting from hyperosmotic stress is coincident with loss of Mg2+ and a decrease in protein translation. Conversely, the reimport of Mg2+ is a limiting factor during resumption of growth. Furthermore, we show the essential signaling dinucleotide cyclic di-AMP fluctuates dynamically in coordination with Mg2+ and K+ levels, consistent with the proposal that cyclic di-AMP orchestrates the cellular response to osmotic stress. IMPORTANCE Environments with high concentrations of salt or other solutes impose an osmotic stress on cells, ultimately limiting viability by dehydration of the cytosol. A very common cellular response to high osmolarity is to immediately import high levels of potassium ion (K+), which helps prevent dehydration and allows time for the import or synthesis of biocompatible solutes that allow a resumption of growth. Here, using Bacillus subtilis as a model, we demonstrate that concomitant with K+ import there is a large reduction in intracellular magnesium (Mg2+) mediated by specific efflux pumps. Further, it is the reimport of Mg2+ that is rate-limiting for the resumption of growth. These coordinated fluxes of K+ and Mg2+ are orchestrated by cyclic-di-AMP, an essential second messenger in Firmicutes. These findings amend the conventional model for osmoadaptation and reveal that Mg2+ limitation is the proximal cause of the bacteriostasis that precedes resumption of growth.
Collapse
Affiliation(s)
- Brian M. Wendel
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Hualiang Pi
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Larissa Krüger
- Department of General Microbiology, GZMB, Georg August University, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, GZMB, Georg August University, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg August University, Göttingen, Germany
| | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| |
Collapse
|
38
|
Hertel R, Schöne K, Mittelstädt C, Meißner J, Zschoche N, Collignon M, Kohler C, Friedrich I, Schneider D, Hoppert M, Kuhn R, Schwedt I, Scholz P, Poehlein A, Martienssen M, Ischebeck T, Daniel R, Commichau FM. Characterization of glyphosate-resistant Burkholderia anthina and Burkholderia cenocepacia isolates from a commercial Roundup® solution. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:70-84. [PMID: 34786867 DOI: 10.1111/1758-2229.13022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/29/2021] [Indexed: 06/13/2023]
Abstract
Roundup® is the brand name for herbicide solutions containing glyphosate, which specifically inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase of the shikimate pathway. The inhibition of the EPSP synthase causes plant death because EPSP is required for biosynthesis of aromatic amino acids. Glyphosate also inhibits the growth of archaea, bacteria, Apicomplexa, algae and fungi possessing an EPSP synthase. Here, we have characterized two glyphosate-resistant bacteria from a Roundup solution. Taxonomic classification revealed that the isolates 1CH1 and 2CH1 are Burkholderia anthina and Burkholderia cenocepacia strains respectively. Both isolates cannot utilize glyphosate as a source of phosphorus and synthesize glyphosate-sensitive EPSP synthase variants. Burkholderia. anthina 1CH1 and B. cenocepacia 2CH1 tolerate high levels of glyphosate because the herbicide is not taken up by the bacteria. Previously, it has been observed that the exposure of soil bacteria to herbicides like glyphosate promotes the development of antibiotic resistances. Antibiotic sensitivity testing revealed that the only the B. cenocepacia 2CH1 isolate showed increased resistance to a variety of antibiotics. Thus, the adaptation of B. anthina 1CH1 and B. cenocepacia 2CH1 to glyphosate did not generally increase the antibiotic resistance of both bacteria. However, our study confirms the genomic adaptability of bacteria belonging to the genus Burkholderia.
Collapse
Affiliation(s)
- Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Kerstin Schöne
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Carolin Mittelstädt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Janek Meißner
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Nick Zschoche
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Madeline Collignon
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Christian Kohler
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Ines Friedrich
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Dominik Schneider
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Michael Hoppert
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Ramona Kuhn
- Chair of Biotechnology of Water Treatment, Institute of Environmental Technology, BTU Cottbus-Senftenberg, Cottbus, 03046, Germany
| | - Inge Schwedt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center of Molecular Biosciences (GZMB), University of Goettingen, Göttingen, 37077, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Marion Martienssen
- Chair of Biotechnology of Water Treatment, Institute of Environmental Technology, BTU Cottbus-Senftenberg, Cottbus, 03046, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center of Molecular Biosciences (GZMB), University of Goettingen, Göttingen, 37077, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| |
Collapse
|
39
|
Mudgal S, Manikandan K, Mukherjee A, Krishnan A, Sinha KM. Cyclic di-AMP: Small molecule with big roles in bacteria. Microb Pathog 2021; 161:105264. [PMID: 34715302 DOI: 10.1016/j.micpath.2021.105264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/20/2021] [Accepted: 10/21/2021] [Indexed: 01/15/2023]
Abstract
Cyclic dinucleotides are second messengers that are present in all the three domains of life, bacteria, archaea, and eukaryotes. These dinucleotides have important physiological and pathophysiological roles in bacteria. Cyclic di-AMP (cdA) is one of the recently discovered cyclic dinucleotides present predominantly in gram-positive bacteria. cdA is synthesized through diadenylate cyclase (DAC) activity from ATP in a two-step process and hydrolyzed to linear dinucleotide pApA (and to 5' AMP in certain cases) by specific phosphodiesterases. cdA regulates various physiological processes like K+ transport and osmotic balance, DNA repair, cell wall homeostasis, drug resistance, central metabolism either by binding directly to the target protein or regulating its expression. It also participates in host-pathogen interaction by binding to host immune receptors ERAdP, RECON, and STING.
Collapse
Affiliation(s)
- Sudhanshu Mudgal
- Amity Institute of Biotechnology, Amity University Haryana, Haryana, India
| | - Kasi Manikandan
- Amity Institute of Biotechnology, Amity University Haryana, Haryana, India
| | - Ahana Mukherjee
- Amity Institute of Biotechnology, Amity University Haryana, Haryana, India
| | - Anuja Krishnan
- Department of Molecular Medicine, Jamia Hamdard, New Delhi, India.
| | | |
Collapse
|
40
|
Pathania M, Tosi T, Millership C, Hoshiga F, Morgan RML, Freemont PS, Gründling A. Structural basis for the inhibition of the Bacillus subtilis c-di-AMP cyclase CdaA by the phosphoglucomutase GlmM. J Biol Chem 2021; 297:101317. [PMID: 34678313 PMCID: PMC8573169 DOI: 10.1016/j.jbc.2021.101317] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 11/25/2022] Open
Abstract
Cyclic-di-adenosine monophosphate (c-di-AMP) is an important nucleotide signaling molecule that plays a key role in osmotic regulation in bacteria. c-di-AMP is produced from two molecules of ATP by proteins containing a diadenylate cyclase (DAC) domain. In Bacillus subtilis, the main c-di-AMP cyclase, CdaA, is a membrane-linked cyclase with an N-terminal transmembrane domain followed by the cytoplasmic DAC domain. As both high and low levels of c-di-AMP have a negative impact on bacterial growth, the cellular levels of this signaling nucleotide are tightly regulated. Here we investigated how the activity of the B. subtilis CdaA is regulated by the phosphoglucomutase GlmM, which has been shown to interact with the c-di-AMP cyclase. Using the soluble B. subtilis CdaACD catalytic domain and purified full-length GlmM or the GlmMF369 variant lacking the C-terminal flexible domain 4, we show that the cyclase and phosphoglucomutase form a stable complex in vitro and that GlmM is a potent cyclase inhibitor. We determined the crystal structure of the individual B. subtilis CdaACD and GlmM homodimers and of the CdaACD:GlmMF369 complex. In the complex structure, a CdaACD dimer is bound to a GlmMF369 dimer in such a manner that GlmM blocks the oligomerization of CdaACD and formation of active head-to-head cyclase oligomers, thus suggesting a mechanism by which GlmM acts as a cyclase inhibitor. As the amino acids at the CdaACD:GlmM interphase are conserved, we propose that the observed mechanism of inhibition of CdaA by GlmM may also be conserved among Firmicutes.
Collapse
Affiliation(s)
- Monisha Pathania
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Tommaso Tosi
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Charlotte Millership
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Fumiya Hoshiga
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Rhodri M L Morgan
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Paul S Freemont
- London Biofoundry, Imperial College Translation and Innovation Hub, White City Campus, London, United Kingdom; Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom; UK Dementia Research Institute Centre for Care Research and Technology, Imperial College London, London, United Kingdom.
| | - Angelika Gründling
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom.
| |
Collapse
|
41
|
Abstract
Second messenger nucleotides are produced by bacteria in response to environmental stimuli and play a major role in the regulation of processes associated with bacterial fitness, including but not limited to osmoregulation, envelope homeostasis, central metabolism, and biofilm formation. In this study, we uncovered the biological significance of c-di-AMP in the opportunistic pathogen Enterococcus faecalis by isolating and characterizing strains lacking genes responsible for c-di-AMP synthesis (cdaA) and degradation (dhhP and gdpP). Using complementary approaches, we demonstrated that either complete loss of c-di-AMP (ΔcdaA strain) or c-di-AMP accumulation (ΔdhhP, ΔgdpP, and ΔdhhP ΔgdpP strains) drastically impaired general cell fitness and virulence of E. faecalis. In particular, the ΔcdaA strain was highly sensitive to envelope-targeting antibiotics, was unable to multiply and quickly lost viability in human serum or urine ex vivo, and was virtually avirulent in an invertebrate (Galleria mellonella) and in two catheter-associated mouse infection models that recapitulate key aspects of enterococcal infections in humans. In addition to evidence linking these phenotypes to altered activity of metabolite and peptide transporters and inability to maintain osmobalance, we found that the attenuated virulence of the ΔcdaA strain also could be attributed to a defect in Ebp pilus production and activity that severely impaired biofilm formation under both in vitro and in vivo conditions. Collectively, these results demonstrate that c-di-AMP signaling is essential for E. faecalis pathogenesis and a desirable target for drug development.
Collapse
|
42
|
Bandera AM, Bartho J, Lammens K, Drexler DJ, Kleinschwärzer J, Hopfner KP, Witte G. BusR senses bipartite DNA binding motifs by a unique molecular ruler architecture. Nucleic Acids Res 2021; 49:10166-10177. [PMID: 34432045 PMCID: PMC8517857 DOI: 10.1093/nar/gkab736] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/27/2021] [Accepted: 08/12/2021] [Indexed: 12/18/2022] Open
Abstract
The cyclic dinucleotide second messenger c-di-AMP is a major player in regulation of potassium homeostasis and osmolyte transport in a variety of bacteria. Along with various direct interactions with proteins such as potassium channels, the second messenger also specifically binds to transcription factors, thereby altering the processes in the cell on the transcriptional level. We here describe the structural and biochemical characterization of BusR from the human pathogen Streptococcus agalactiae. BusR is a member of a yet structurally uncharacterized subfamily of the GntR family of transcription factors that downregulates transcription of the genes for the BusA (OpuA) glycine-betaine transporter upon c-di-AMP binding. We report crystal structures of full-length BusR, its apo and c-di-AMP bound effector domain, as well as cryo-EM structures of BusR bound to its operator DNA. Our structural data, supported by biochemical and biophysical data, reveal that BusR utilizes a unique domain assembly with a tetrameric coiled-coil in between the binding platforms, serving as a molecular ruler to specifically recognize a 22 bp separated bipartite binding motif. Binding of c-di-AMP to BusR induces a shift in equilibrium from an inactivated towards an activated state that allows BusR to bind the target DNA, leading to transcriptional repression.
Collapse
Affiliation(s)
- Adrian M Bandera
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Joseph Bartho
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Katja Lammens
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - David Jan Drexler
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Jasmin Kleinschwärzer
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Karl-Peter Hopfner
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Gregor Witte
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| |
Collapse
|
43
|
Abstract
Bacteriophage predation is an important factor in bacterial community dynamics and evolution. Phage-bacterium interaction has mainly been studied in lab cultures, while dynamics in natural habitats, and especially in the plant root niche, are underexplored. To better understand this process, we characterized infection of the soil bacterium Bacillus subtilis NCBI 3610 by the lytic phage SPO1 during growth in LB medium and compared it to root colonization. Resistance in vitro was primarily through modification of the phage receptor. However, this type of resistance reduced the ability to colonize the root. From a line that survived phage infection while retaining the ability to colonize the root, we identified a new phage resistance mechanism involving potassium (K+) ion influx modulation and enhanced biofilm formation. Furthermore, we show that potassium serves as a stimulator of root colonization among diverse growth-promoting bacilli species, with implications for plant health.
Collapse
|
44
|
Abstract
Potassium is an essential mineral nutrient required by all living cells for normal physiological function. Therefore, maintaining intracellular potassium homeostasis during bacterial infection is a requirement for the survival of both host and pathogen. However, pathogenic bacteria require potassium transport to fulfill nutritional and chemiosmotic requirements, and potassium has been shown to directly modulate virulence gene expression, antimicrobial resistance, and biofilm formation. Host cells also require potassium to maintain fundamental biological processes, such as renal function, muscle contraction, and neuronal transmission; however, potassium flux also contributes to critical immunological and antimicrobial processes, such as cytokine production and inflammasome activation. Here, we review the role and regulation of potassium transport and signaling during infection in both mammalian and bacterial cells and highlight the importance of potassium to the success and survival of each organism.
Collapse
|
45
|
The Diadenylate Cyclase CdaA Is Critical for Borrelia turicatae Virulence and Physiology. Infect Immun 2021; 89:IAI.00787-20. [PMID: 33846120 PMCID: PMC8316131 DOI: 10.1128/iai.00787-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/22/2021] [Indexed: 12/16/2022] Open
Abstract
Relapsing fever (RF), caused by spirochetes of the genus Borrelia, is a globally distributed, vector-borne disease with high prevalence in developing countries. To date, signaling pathways required for infection and virulence of RF Borrelia spirochetes are unknown. Cyclic di-AMP (c-di-AMP), synthesized by diadenylate cyclases (DACs), is a second messenger predominantly found in Gram-positive organisms that is linked to virulence and essential physiological processes. Although Borrelia is Gram-negative, it encodes one DAC (CdaA), and its importance remains undefined. To investigate the contribution of c-di-AMP signaling in the RF bacterium Borrelia turicatae, a cdaA mutant was generated. The mutant was significantly attenuated during murine infection, and genetic complementation reversed this phenotype. Because c-di-AMP is essential for viability in many bacteria, whole-genome sequencing was performed on cdaA mutants, and single-nucleotide polymorphisms identified potential suppressor mutations. Additionally, conditional mutation of cdaA confirmed that CdaA is important for normal growth and physiology. Interestingly, mutation of cdaA did not affect expression of homologs of virulence regulators whose levels are impacted by c-di-AMP signaling in the Lyme disease bacterium Borrelia burgdorferi Finally, the cdaA mutant had a significant growth defect when grown with salts, at decreased osmolarity, and without pyruvate. While the salt treatment phenotype was not reversed by genetic complementation, possibly due to suppressor mutations, growth defects at decreased osmolarity and in media lacking pyruvate could be attributed directly to cdaA inactivation. Overall, these results indicate CdaA is critical for B. turicatae pathogenesis and link c-di-AMP to osmoregulation and central metabolism in RF spirochetes.
Collapse
|
46
|
Ford N, Fisher G, Prindle A, Chopp D. A Two-Dimensional Model of Potassium Signaling and Oscillatory Growth in a Biofilm. Bull Math Biol 2021; 83:60. [PMID: 33856558 PMCID: PMC8857140 DOI: 10.1007/s11538-021-00887-3] [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: 06/23/2020] [Accepted: 03/11/2021] [Indexed: 12/01/2022]
Abstract
Biofilms are complex communities of bacteria that exhibit a variety of collective behaviors. These behaviors improve their ability to survive in many different environments. One of these collective behaviors seen in Bacillus subtilis is the ability for starving cells to stop the growth of other cells using potassium signaling and voltage changes. This signaling produces an oscillatory growth pattern so that during periods of low growth the nutrients diffuse deeper into the biofilm and reach the nutrient-starved, interior regions of the biomass. In this paper, we develop a mathematical model to describe this oscillatory behavior, and we use this model to develop a two-dimensional simulation that reproduces many of the important features seen in the experimental data. This simulation allows us to examine the spatial patterning of the oscillatory behavior to better understand the relationships between the various regions of the biofilm. Studying the spatial components of the metabolic and voltage oscillations could allow for the development of new control techniques for biofilms with complex shapes.
Collapse
Affiliation(s)
- Noah Ford
- Engineering Sciences and Applied Mathematics Department, Northwestern University, Evanston, IL, 60208, USA.
| | - Garth Fisher
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.,Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Arthur Prindle
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.,Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA.,Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - David Chopp
- Engineering Sciences and Applied Mathematics Department, Northwestern University, Evanston, IL, 60208, USA
| |
Collapse
|
47
|
Cyclic di-AMP Oversight of Counter-Ion Osmolyte Pools Impacts Intrinsic Cefuroxime Resistance in Lactococcus lactis. mBio 2021; 12:mBio.00324-21. [PMID: 33832972 PMCID: PMC8092236 DOI: 10.1128/mbio.00324-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The bacterial second messenger cyclic di-AMP (c-di-AMP) is a global regulator of potassium homeostasis and compatible solute uptake in many Gram-positive bacteria, making it essential for osmoregulation. The role that c-di-AMP plays in β-lactam resistance, however, is unclear despite being first identified a decade ago. The broadly conserved cyclic di-AMP (c-di-AMP) is a conditionally essential bacterial second messenger. The pool of c-di-AMP is fine-tuned through diadenylate cyclase and phosphodiesterase activities, and direct binding of c-di-AMP to proteins and riboswitches allows the regulation of a broad spectrum of cellular processes. c-di-AMP has a significant impact on intrinsic β-lactam antibiotic resistance in Gram-positive bacteria; however, the reason for this is currently unclear. In this work, genetic studies revealed that suppressor mutations that decrease the activity of the potassium (K+) importer KupB or the glutamine importer GlnPQ restore cefuroxime (CEF) resistance in diadenylate cyclase (cdaA) mutants of Lactococcus lactis. Metabolite analyses showed that glutamine is imported by GlnPQ and then rapidly converted to glutamate, and GlnPQ mutations or c-di-AMP negatively affects the pools of the most abundant free amino acids (glutamate and aspartate) during growth. In a high-c-di-AMP mutant, GlnPQ activity could be increased by raising the internal K+ level through the overexpression of a c-di-AMP-insensitive KupB variant. These results demonstrate that c-di-AMP reduces GlnPQ activity and, therefore, the level of the major free anions in L. lactis through its inhibition of K+ import. Excessive ion accumulation in cdaA mutants results in greater spontaneous cell lysis under hypotonic conditions, while CEF-resistant suppressors exhibit reduced cell lysis and lower osmoresistance. This work demonstrates that the overaccumulation of major counter-ion osmolyte pools in c-di-AMP-defective mutants of L. lactis causes cefuroxime sensitivity.
Collapse
|
48
|
Richts B, Lentes S, Poehlein A, Daniel R, Commichau FM. A Bacillus subtilis ΔpdxT mutant suppresses vitamin B6 limitation by acquiring mutations enhancing pdxS gene dosage and ammonium assimilation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:218-233. [PMID: 33559288 DOI: 10.1111/1758-2229.12936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
Pyridoxal-5'-phosphate (PLP), the biologically active form of vitamin B6, serves as a cofactor for many enzymes. The Gram-positive model bacterium Bacillus subtilis synthesizes PLP via the PdxST enzyme complex, consisting of the PdxT glutaminase and the PdxS PLP synthase subunits, respectively. PdxT converts glutamine to glutamate and ammonia of which the latter is channelled to PdxS. At high extracellular ammonium concentrations, the PdxS PLP synthase subunit does not depend on PdxT. Here, we assessed the potential of a B. subtilis ΔpdxT mutant to adapt to PLP limitation at the genome level. The majority of ΔpdxT suppressors had amplified a genomic region containing the pdxS gene. We also identified mutants having acquired as yet undescribed mutations in ammonium assimilation genes, indicating that the overproduction of PdxS and the NrgA ammonium transporter partially relieve vitamin B6 limitation in a ΔpdxT mutant when extracellular ammonium is scarce. Furthermore, we found that PdxS positively affects complex colony formation in B. subtilis. The catalytic mechanism of the PdxS PLP synthase subunit could be the reason for the limited evolution of the enzyme and why we could not identify a PdxS variant producing PLP independently of PdxT at low ammonium concentrations.
Collapse
Affiliation(s)
- Björn Richts
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Sabine Lentes
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| |
Collapse
|
49
|
c-di-AMP, a likely master regulator of bacterial K + homeostasis machinery, activates a K + exporter. Proc Natl Acad Sci U S A 2021; 118:2020653118. [PMID: 33790011 DOI: 10.1073/pnas.2020653118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
bis-(3',5')-cyclic diadenosine monophosphate (c-di-AMP) is a second messenger with roles in virulence, cell wall and biofilm formation, and surveillance of DNA integrity in many bacterial species, including pathogens. Strikingly, it has also been proposed to coordinate the activity of the components of K+ homeostasis machinery, inhibiting K+ import, and activating K+ export. However, there is a lack of quantitative evidence supporting the direct functional impact of c-di-AMP on K+ transporters. To gain a detailed understanding of the role of c-di-AMP on the activity of a component of the K+ homeostasis machinery in B. subtilis, we have characterized the impact of c-di-AMP on the functional, biochemical, and physiological properties of KhtTU, a K+/H+ antiporter composed of the membrane protein KhtU and the cytosolic protein KhtT. We have confirmed c-di-AMP binding to KhtT and determined the crystal structure of this complex. We have characterized in vitro the functional properties of KhtTU and KhtU alone and quantified the impact of c-di-AMP and of pH on their activity, demonstrating that c-di-AMP activates KhtTU and that pH increases its sensitivity to this nucleotide. Based on our functional and structural data, we were able to propose a mechanism for the activation of KhtTU by c-di-AMP. In addition, we have analyzed the impact of KhtTU in its native bacterium, providing a physiological context for the regulatory function of c-di-AMP and pH. Overall, we provide unique information that supports the proposal that c-di-AMP is a master regulator of K+ homeostasis machinery.
Collapse
|
50
|
Stautz J, Hellmich Y, Fuss MF, Silberberg JM, Devlin JR, Stockbridge RB, Hänelt I. Molecular Mechanisms for Bacterial Potassium Homeostasis. J Mol Biol 2021; 433:166968. [PMID: 33798529 DOI: 10.1016/j.jmb.2021.166968] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/11/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
Potassium ion homeostasis is essential for bacterial survival, playing roles in osmoregulation, pH homeostasis, regulation of protein synthesis, enzyme activation, membrane potential adjustment and electrical signaling. To accomplish such diverse physiological tasks, it is not surprising that a single bacterium typically encodes several potassium uptake and release systems. To understand the role each individual protein fulfills and how these proteins work in concert, it is important to identify the molecular details of their function. One needs to understand whether the systems transport ions actively or passively, and what mechanisms or ligands lead to the activation or inactivation of individual systems. Combining mechanistic information with knowledge about the physiology under different stress situations, such as osmostress, pH stress or nutrient limitation, one can identify the task of each system and deduce how they are coordinated with each other. By reviewing the general principles of bacterial membrane physiology and describing the molecular architecture and function of several bacterial K+-transporting systems, we aim to provide a framework for microbiologists studying bacterial potassium homeostasis and the many K+-translocating systems that are still poorly understood.
Collapse
Affiliation(s)
- Janina Stautz
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Yvonne Hellmich
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Michael F Fuss
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jakob M Silberberg
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jason R Devlin
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Randy B Stockbridge
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States.
| | - Inga Hänelt
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
| |
Collapse
|