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Zeinert R, Zhou F, Franco P, Zöller J, Lessen HJ, Aravind L, Langer JD, Sodt AJ, Storz G, Matthies D. Magnesium Transporter MgtA revealed as a Dimeric P-type ATPase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582502. [PMID: 38464158 PMCID: PMC10925321 DOI: 10.1101/2024.02.28.582502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Magnesium (Mg2+) uptake systems are present in all domains of life given the vital role of this ion. Bacteria acquire Mg2+ via conserved Mg2+ channels and transporters. The transporters are required for growth when Mg2+ is limiting or during bacterial pathogenesis, but, despite their significance, there are no known structures for these transporters. Here we report the first structure of the Mg2+ transporter MgtA solved by single particle cryo-electron microscopy (cryo-EM). Using mild membrane extraction, we obtained high resolution structures of both a homodimeric form (2.9 Å), the first for a P-type ATPase, and a monomeric form (3.6 Å). Each monomer unit of MgtA displays a structural architecture that is similar to other P-type ATPases with a transmembrane domain and two soluble domains. The dimer interface consists of contacts between residues in adjacent soluble nucleotide binding and phosphotransfer regions of the haloacid dehalogenase (HAD) domain. We suggest oligomerization is a conserved structural feature of the diverse family of P-type ATPase transporters. The ATP binding site and conformational dynamics upon nucleotide binding to MgtA were characterized using a combination of cryo-EM, molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and mutagenesis. Our structure also revealed a Mg2+ ion in the transmembrane segments, which, when combined with sequence conservation and mutagenesis studies, allowed us to propose a model for Mg2+ transport across the lipid bilayer. Finally, our work revealed the N-terminal domain structure and cytoplasmic Mg2+ binding sites, which have implications for related P-type ATPases defective in human disease.
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Affiliation(s)
- Rilee Zeinert
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Fei Zhou
- Unit on Structural Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Pedro Franco
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Jonathan Zöller
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Henry J. Lessen
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - L. Aravind
- National Center for Biotechnology Information, National Institutes of Health, Bethesda MD 20892, USA
| | - Julian D. Langer
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Alexander J. Sodt
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Doreen Matthies
- Unit on Structural Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
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Li Y, Wu Y, Li D, Du L, Zhao L, Wang R, Chen X, Jia X, Ma R, Wang T, Li J, Zhang G, Wang X, Hu M, Chen X, Wang X, Kang W, Sun H, Xu Y, Liu Y. Multicenter comparative genomic study of Klebsiella oxytoca complex reveals a highly antibiotic-resistant subspecies of Klebsiellamichiganensis. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2024; 57:138-147. [PMID: 37953085 DOI: 10.1016/j.jmii.2023.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/19/2023] [Accepted: 10/29/2023] [Indexed: 11/14/2023]
Abstract
BACKGROUND The Klebsiella oxytoca complex is an opportunistic pathogen that has been recently identified as an actual complex. However, the characteristics of each species remain largely unknown. We aimed to study the clinical prevalence, antimicrobial profiles, genetic differences, and interaction with the host of each species of this complex. METHODS One hundred and three clinical isolates of the K. oxytoca complex were collected from 33 hospitals belonging to 19 areas in China from 2020 to 2021. Species were identified using whole genome sequencing based on average nucleotide identity. Clinical infection characteristics of the species were analyzed. Comparative genomics and pan-genome analyses were performed on these isolates and an augmented dataset, including 622 assemblies from the National Center for Biotechnology Information. In vitro assays evaluating the adhesion ability of human respiratory epithelial cells and survivability against macrophages were performed on randomly selected isolates. RESULTS Klebsiella michiganensis (46.6%, 48/103) and K. oxytoca (35.92%, 37/103) were the major species of the complex causing human infections. K. michiganensis had a higher genomic diversity and larger pan-genome size than did K. oxytoca. K. michiganensis isolates with blaoxy-5 had a higher resistance rate to various antibiotics, antimicrobial gene carriage rate, adhesion ability to human respiratory epithelial cells, and survival rate against macrophages than isolates of other species. CONCLUSION Our study revealed the genetic diversity of K. michiganensis and firstly identified the highly antimicrobial-resistant profile of K. michiganensis carrying blaoxy-5.
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Affiliation(s)
- Yi Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, 100730, China; Graduate School, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, 100730, China
| | - Yun Wu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, 100730, China; Graduate School, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, 100730, China
| | - Dingding Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Lijun Du
- Department of Clinical Laboratory, Nanchong Central Hospital, The Second Clinical Medical College, North Sichuan Medical College, Nanchong, 637000, China
| | - Lu Zhao
- Laboratory of Xuchang Central Hospital, Xuchang, Henan Province, China
| | - Rongxue Wang
- Zhaotong Hospital of Traditional Chinese Medicine, Zhaotong, Yunnan Province, China
| | - Xinfei Chen
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, 100730, China; Graduate School, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, 100730, China
| | - Xinmiao Jia
- Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100730, Beijing, China
| | - Ruirui Ma
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tong Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Jin Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Ge Zhang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xing Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Mengting Hu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xingyu Chen
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xin Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Wei Kang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Hongli Sun
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, 100730, China
| | - Yingchun Xu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, 100730, China.
| | - Yali Liu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, 100730, China.
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Rodrigues Alves LB, Freitas Neto OCD, Saraiva MDMS, do Monte DFM, de Lima BN, Cabrera JM, Barbosa FDO, Benevides VP, de Lima TS, Campos IC, Rubio MDS, Nascimento CDF, Arantes LCRV, Alves VV, de Almeida AM, Olsen JE, Berchieri Junior A. Salmonella Gallinarum mgtC mutant shows a delayed fowl typhoid progression in chicken. Gene 2024; 892:147827. [PMID: 37748627 DOI: 10.1016/j.gene.2023.147827] [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: 03/27/2023] [Revised: 08/29/2023] [Accepted: 09/22/2023] [Indexed: 09/27/2023]
Abstract
Salmonella Gallinarum (SG) provokes fowl typhoid, an infectious disease of acute clinical course that affects gallinaceous of any age and leads to high mortality rates. During the typhoid-like systemic infection of S. Typhimurium (STM) in mice, the bacterium expresses the mgtC gene, which is encoded in the Salmonella Pathogenecity Island - 3 (SPI-3). In this serovar, the function is linked to bacterial replication within macrophages, and its absence attenuates the pathogen. We hypothesized that deleting mgtC from SG genome would alter the microorganism pathogenicity in susceptible commercial poultry in a similar manner. Thus, the present study sought to elucidate the importance of mgtC on SG pathogenicity. For this, a mgtC-mutant lacking S. Gallinarum mutant was constructed (SG ΔmgtC). Its ability to replicate in medium that mimicries the mgtC-related intracellular environment of macrophages as well as in primary macrophages from chicken was evaluated. Moreover, the infection of susceptible chickens was performed to elucidate its pathogenicity and the elicited immune responses by measuring key interleukins by qRT-PCR and the population of macrophages and lymphocytes T CD4+ and CD8+ by means of immunohistochemistry. It was observed that mgtC was required for S. Gallinarum replication in acidified low-Mg2+ media and survival within macrophages. However, unlike its requirement for initial phase of STM infection in mice, lower bacterial counts were only observed at the late stage of macrophage infection without affecting the citotoxicity. Experiments showed that knocking-out the mgtC gene neither altered bacterial uptake by macrophages nor affects bacterial counts in liver and spleen and total chicken mortality. However, plotting a survival curve and analyzing the clinical-pathologic conditions, it was observed a slower progression of the disease in chickens infected by SG ΔmgtC compared to those challenged by the wild-type strain. Furthermore, the mRNA expression of IFN-γ and LITAF were similar between the infected chickens, but higher than in the uninfected group. The same was observed in macrophages and lymphocytes T CD4+ populations. On the other hand, the presence of lymphocytes T CD8+ was increased in the initial phase of the disease provoked by the wild-type strain over the mutant strain. We concluded that the role of mgtC in Fowl Typhoid in susceptible chickens differs from the role in typhoid-like infections in mammals. Thus, the deletion of mgtC gene from S. Gallinarum genome does not affect the overall pathogenicity, but slightly alters the pathogenesis.
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Affiliation(s)
- Lucas Bocchini Rodrigues Alves
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen (KU), Copenhagen, Denmark.
| | - Oliveiro Caetano de Freitas Neto
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil; Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.
| | - Mauro de Mesquita Souza Saraiva
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen (KU), Copenhagen, Denmark
| | - Daniel Farias Marinho do Monte
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Bruna Nestlehner de Lima
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Julia Memrava Cabrera
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Fernanda de Oliveira Barbosa
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Valdinete Pereira Benevides
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen (KU), Copenhagen, Denmark
| | - Túlio Spina de Lima
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Isabella Cardeal Campos
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Marcela da Silva Rubio
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Camila de Fatima Nascimento
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - Letícia Cury Rocha Veloso Arantes
- Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Victória Veiga Alves
- Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Adriana Maria de Almeida
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen (KU), Copenhagen, Denmark
| | - Angelo Berchieri Junior
- Veterinary Medicine Post-graduation Program (Animal Pathology), Avian Pathology Laboratory, Department of Pathology, Theriogenology, and One Health, School of Agricultural and Veterinary Sciences, Sao Paulo State University (FCAV/Unesp), Jaboticabal, São Paulo, Brazil.
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Elston R, Mulligan C, Thomas GH. Flipping the switch: dynamic modulation of membrane transporter activity in bacteria. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37948297 DOI: 10.1099/mic.0.001412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The controlled entry and expulsion of small molecules across the bacterial cytoplasmic membrane is essential for efficient cell growth and cellular homeostasis. While much is known about the transcriptional regulation of genes encoding transporters, less is understood about how transporter activity is modulated once the protein is functional in the membrane, a potentially more rapid and dynamic level of control. In this review, we bring together literature from the bacterial transport community exemplifying the extensive and diverse mechanisms that have evolved to rapidly modulate transporter function, predominantly by switching activity off. This includes small molecule feedback, inhibition by interaction with small peptides, regulation through binding larger signal transduction proteins and, finally, the emerging area of controlled proteolysis. Many of these examples have been discovered in the context of metal transport, which has to finely balance active accumulation of elements that are essential for growth but can also quickly become toxic if intracellular homeostasis is not tightly controlled. Consistent with this, these transporters appear to be regulated at multiple levels. Finally, we find common regulatory themes, most often through the fusion of additional regulatory domains to transporters, which suggest the potential for even more widespread regulation of transporter activity in biology.
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Affiliation(s)
- Rory Elston
- Department of Biology, University of York, York, UK
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Song H, Choi E, Lee EJ. Membrane-Bound Protease FtsH Protects PhoP from the Proteolysis by Cytoplasmic ClpAP Protease in Salmonella Typhimurium. J Microbiol Biotechnol 2023; 33:1130-1140. [PMID: 37330414 PMCID: PMC10580885 DOI: 10.4014/jmb.2306.06016] [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: 06/08/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 06/19/2023]
Abstract
Among the AAA+ proteases in bacteria, FtsH is a membrane-bound ATP-dependent metalloprotease, which is known to degrade many membrane proteins as well as some cytoplasmic proteins. In the intracellular pathogen Salmonella enterica serovar Typhimurium, FtsH is responsible for the proteolysis of several proteins including MgtC virulence factor and MgtA/MgtB Mg2+ transporters, the transcription of which is controlled by the PhoP/PhoQ two-component regulatory system. Given that PhoP response regulator itself is a cytoplasmic protein and also degraded by the cytoplasmic ClpAP protease, it seems unlikely that FtsH affects PhoP protein levels. Here we report an unexpected role of the FtsH protease protecting PhoP proteolysis from cytoplasmic ClpAP protease. In FtsH-depleted condition, PhoP protein levels decrease by ClpAP proteolysis, lowering protein levels of PhoP-controlled genes. This suggests that FtsH is required for normal activation of PhoP transcription factor. FtsH does not degrade PhoP protein but directly binds to PhoP, thus sequestering PhoP from ClpAP-mediated proteolysis. FtsH's protective effect on PhoP can be overcome by providing excess ClpP. Because PhoP is required for Salmonella's survival inside macrophages and mouse virulence, these data implicate that FtsH's sequestration of PhoP from ClpAP-mediated proteolysis is a mechanism ensuring the amount of PhoP protein during Salmonella infection.
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Affiliation(s)
- Hyungkeun Song
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Eunna Choi
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Eun-Jin Lee
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
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Pokorzynski ND, Groisman EA. How Bacterial Pathogens Coordinate Appetite with Virulence. Microbiol Mol Biol Rev 2023; 87:e0019822. [PMID: 37358444 PMCID: PMC10521370 DOI: 10.1128/mmbr.00198-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023] Open
Abstract
Cells adjust growth and metabolism to nutrient availability. Having access to a variety of carbon sources during infection of their animal hosts, facultative intracellular pathogens must efficiently prioritize carbon utilization. Here, we discuss how carbon source controls bacterial virulence, with an emphasis on Salmonella enterica serovar Typhimurium, which causes gastroenteritis in immunocompetent humans and a typhoid-like disease in mice, and propose that virulence factors can regulate carbon source prioritization by modifying cellular physiology. On the one hand, bacterial regulators of carbon metabolism control virulence programs, indicating that pathogenic traits appear in response to carbon source availability. On the other hand, signals controlling virulence regulators may impact carbon source utilization, suggesting that stimuli that bacterial pathogens experience within the host can directly impinge on carbon source prioritization. In addition, pathogen-triggered intestinal inflammation can disrupt the gut microbiota and thus the availability of carbon sources. By coordinating virulence factors with carbon utilization determinants, pathogens adopt metabolic pathways that may not be the most energy efficient because such pathways promote resistance to antimicrobial agents and also because host-imposed deprivation of specific nutrients may hinder the operation of certain pathways. We propose that metabolic prioritization by bacteria underlies the pathogenic outcome of an infection.
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Affiliation(s)
- Nick D. Pokorzynski
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Microbial Sciences Institute, West Haven, Connecticut, USA
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7
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Gibbs KD, Wang L, Yang Z, Anderson CE, Bourgeois JS, Cao Y, Gaggioli MR, Biel M, Puertollano R, Chen CC, Ko DC. Human variation impacting MCOLN2 restricts Salmonella Typhi replication by magnesium deprivation. CELL GENOMICS 2023; 3:100290. [PMID: 37228749 PMCID: PMC10203047 DOI: 10.1016/j.xgen.2023.100290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/24/2023] [Accepted: 02/27/2023] [Indexed: 05/27/2023]
Abstract
Human genetic diversity can reveal critical factors in host-pathogen interactions. This is especially useful for human-restricted pathogens like Salmonella enterica serovar Typhi (S. Typhi), the cause of typhoid fever. One key defense during bacterial infection is nutritional immunity: host cells attempt to restrict bacterial replication by denying bacteria access to key nutrients or supplying toxic metabolites. Here, a cellular genome-wide association study of intracellular replication by S. Typhi in nearly a thousand cell lines from around the world-and extensive follow-up using intracellular S. Typhi transcriptomics and manipulation of magnesium availability-demonstrates that the divalent cation channel mucolipin-2 (MCOLN2 or TRPML2) restricts S. Typhi intracellular replication through magnesium deprivation. Mg2+ currents, conducted through MCOLN2 and out of endolysosomes, were measured directly using patch-clamping of the endolysosomal membrane. Our results reveal Mg2+ limitation as a key component of nutritional immunity against S. Typhi and as a source of variable host resistance.
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Affiliation(s)
- Kyle D. Gibbs
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
| | - Zhuo Yang
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Caroline E. Anderson
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
| | - Jeffrey S. Bourgeois
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
- University Program in Genetics and Genomics, Duke University, Durham, NC 27710, USA
| | - Yanlu Cao
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
| | - Margaret R. Gaggioli
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Rosa Puertollano
- Cell and Developmental Biology Center, National Heart, Lung, & Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Cheng-Chang Chen
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei 100, Taiwan
| | - Dennis C. Ko
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC 27710, USA
- University Program in Genetics and Genomics, Duke University, Durham, NC 27710, USA
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Duke University, Durham, NC 27710, USA
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8
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Tantoso E, Eisenhaber B, Sinha S, Jensen LJ, Eisenhaber F. About the dark corners in the gene function space of Escherichia coli remaining without illumination by scientific literature. Biol Direct 2023; 18:7. [PMID: 36855185 PMCID: PMC9976479 DOI: 10.1186/s13062-023-00362-0] [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: 12/11/2022] [Accepted: 02/21/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Although Escherichia coli (E. coli) is the most studied prokaryote organism in the history of life sciences, many molecular mechanisms and gene functions encoded in its genome remain to be discovered. This work aims at quantifying the illumination of the E. coli gene function space by the scientific literature and how close we are towards the goal of a complete list of E. coli gene functions. RESULTS The scientific literature about E. coli protein-coding genes has been mapped onto the genome via the mentioning of names for genomic regions in scientific articles both for the case of the strain K-12 MG1655 as well as for the 95%-threshold softcore genome of 1324 E. coli strains with known complete genome. The article match was quantified with the ratio of a given gene name's occurrence to the mentioning of any gene names in the paper. The various genome regions have an extremely uneven literature coverage. A group of elite genes with ≥ 100 full publication equivalents (FPEs, FPE = 1 is an idealized publication devoted to just a single gene) attracts the lion share of the papers. For K-12, ~ 65% of the literature covers just 342 elite genes; for the softcore genome, ~ 68% of the FPEs is about only 342 elite gene families (GFs). We also find that most genes/GFs have at least one mentioning in a dedicated scientific article (with the exception of at least 137 protein-coding transcripts for K-12 and 26 GFs from the softcore genome). Whereas the literature growth rates were highest for uncharacterized or understudied genes until 2005-2010 compared with other groups of genes, they became negative thereafter. At the same time, literature for anyhow well-studied genes started to grow explosively with threshold T10 (≥ 10 FPEs). Typically, a body of ~ 20 actual articles generated over ~ 15 years of research effort was necessary to reach T10. Lineage-specific co-occurrence analysis of genes belonging to the accessory genome of E. coli together with genomic co-localization and sequence-analytic exploration hints previously completely uncharacterized genes yahV and yddL being associated with osmotic stress response/motility mechanisms. CONCLUSION If the numbers of scientific articles about uncharacterized and understudied genes remain at least at present levels, full gene function lists for the strain K-12 MG1655 and the E. coli softcore genome are in reach within the next 25-30 years. Once the literature body for a gene crosses 10 FPEs, most of the critical fundamental research risk appears overcome and steady incremental research becomes possible.
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Affiliation(s)
- Erwin Tantoso
- Agency for Science, Technology and Research (A*STAR), Genome Institute of Singapore (GIS), 60 Biopolis Street, Singapore, 138672, Republic of Singapore.,Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore
| | - Birgit Eisenhaber
- Agency for Science, Technology and Research (A*STAR), Genome Institute of Singapore (GIS), 60 Biopolis Street, Singapore, 138672, Republic of Singapore.,Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore
| | - Swati Sinha
- Agency for Science, Technology and Research (A*STAR), Genome Institute of Singapore (GIS), 60 Biopolis Street, Singapore, 138672, Republic of Singapore.,Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore.,European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Lars Juhl Jensen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Frank Eisenhaber
- Agency for Science, Technology and Research (A*STAR), Genome Institute of Singapore (GIS), 60 Biopolis Street, Singapore, 138672, Republic of Singapore. .,Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute (BII), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore. .,School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore.
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9
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Pat- and Pta-mediated protein acetylation is required for horizontally-acquired virulence gene expression in Salmonella Typhimurium. J Microbiol 2022; 60:823-831. [DOI: 10.1007/s12275-022-2095-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 11/25/2022]
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10
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Coordination of Phosphate and Magnesium Metabolism in Bacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1362:135-150. [PMID: 35288878 DOI: 10.1007/978-3-030-91623-7_12] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The majority of cellular phosphate (PO4-3; Pi) exists as nucleoside triphosphates, mainly adenosine triphosphate (ATP), and ribosomal RNA (rRNA). ATP and rRNA are also the largest cytoplasmic reservoirs of magnesium (Mg2+), the most abundant divalent cation in living cells. The co-occurrence of these ionic species in the cytoplasm is not coincidental. Decades of work in the Pi and Mg2+ starvation responses of two model enteric bacteria, Escherichia coli and Salmonella enterica, have led to the realization that the metabolisms of Pi and Mg2+ are interconnected. Bacteria must acquire these nutrients in a coordinated manner to achieve balanced growth and avoid loss of viability. In this chapter, we will review how bacteria sense and respond to fluctuations in environmental and intracellular Pi and Mg2+ levels. We will also discuss how these two compounds are functionally linked, and how cells elicit physiological responses to maintain their homeostasis.
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11
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Serec K, Babić SD, Tomić S. Magnesium ions reversibly bind to DNA double stranded helix in thin films. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 268:120663. [PMID: 34875504 DOI: 10.1016/j.saa.2021.120663] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/08/2021] [Accepted: 11/23/2021] [Indexed: 06/13/2023]
Abstract
Effects of magnesium (Mg2+) ions on the stability and structural properties of double-stranded DNA are vitally important for DNA folding and functional behavior. Complementing our previous study on highly hydrated thin films of DNA with sodium counterions, with no buffer (pH ≈ 6) and surrounded with Mg2+ cations, here we use Fourier transform infrared spectroscopy and band shape analysis to explore in detail the vibrational signatures of DNA-magnesium interaction in the case when DNA charges are neutralized solely by Mg2+ cations, hereafter called MgDNA. Ion atmosphere has been controlled by the magnesium to phosphate molar concentration ratio r which varied between 0.0067 and 10. For r = 0 we find that spectral features in the base region remain similar as in DNA, whereas changes in the backbone region indicate that the B conformation becomes fully stabilized. With increasing r a pronounced structural reshaping occurs in the phosphate backbone region indicating a blue shift of the asymmetric band, while the symmetric band does not show any displacement in frequency. The band shape analysis of overlapping peaks in the respective phosphate regions demonstrates that the number of constituent modes as well as their positions in frequency do not change, whereas their intensities and bandwidths display disparate changes. The results reflect a variety of local environments at the DNA backbone due to a heterogeneous ion atmosphere with randomly distributed magnesium ions and local patterns of hydrogen bonds which change with increasing r. Remarkably, after crowded r = 10 ion atmosphere is depleted, Mg induced spectral changes vanish and structural features of MgDNA (r ≈ 0) are fully restored. Overall results strongly suggest that in MgDNA on highly hydrated thin films the hydrogen-base pairing remains preserved and that Mg2+ ions, similar to sodium ions, retain their mobility and interact with double helix via water-mediated electrostatic forces.
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Affiliation(s)
- Kristina Serec
- Department of Physics and Biophysics, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; Centre of Excellence in Reproductive and Regenerative Medicine, University of Zagreb School of Medicine, 10000 Zagreb, Croatia.
| | - Sanja Dolanski Babić
- Department of Physics and Biophysics, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia; Centre of Excellence in Reproductive and Regenerative Medicine, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
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12
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Salvail H, Choi J, Groisman EA. Differential synthesis of novel small protein times Salmonella virulence program. PLoS Genet 2022; 18:e1010074. [PMID: 35245279 PMCID: PMC8896665 DOI: 10.1371/journal.pgen.1010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/03/2022] [Indexed: 11/18/2022] Open
Abstract
Gene organization in operons enables concerted transcription of functionally related genes and efficient control of cellular processes. Typically, an operon is transcribed as a polycistronic mRNA that is translated into corresponding proteins. Here, we identify a bicistronic operon transcribed as two mRNAs, yet only one allows translation of both genes. We establish that the novel gene ugtS forms an operon with virulence gene ugtL, an activator of the master virulence regulatory system PhoP/PhoQ in Salmonella enterica serovar Typhimurium. Only the longer ugtSugtL mRNA carries the ugtS ribosome binding site and therefore allows ugtS translation. Inside macrophages, the ugtSugtL mRNA species allowing translation of both genes is produced hours before that allowing translation solely of ugtL. The small protein UgtS controls the kinetics of PhoP phosphorylation by antagonizing UgtL activity, preventing premature activation of a critical virulence program. Moreover, S. enterica serovars that infect cold-blooded animals lack ugtS. Our results establish how foreign gene control of ancestral regulators enables pathogens to time their virulence programs. Pathogens must express their virulence genes at precisely the right time to cause disease. Here, we identify a novel small protein that governs a critical virulence program in the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium). We establish that the novel small protein UgtS prevents the virulence protein UgtL from activating the master virulence regulator PhoP inside macrophages. S. Typhimurium produces two ugtSugtL mRNAs, but only one of them allows ugtS translation. The absence of ugtS from S. enterica serovars that infect cold-blooded animals raises the possibility of UgtS playing a regulatory role during infection of warm-blooded animals. Our findings establish how a horizontally acquired bicistron enables pathogens to time their virulence programs by controlling ancestral regulators.
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Affiliation(s)
- Hubert Salvail
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Jeongjoon Choi
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
- Yale Microbial Sciences Institute, West Haven, Connecticut, United States of America
- * E-mail:
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13
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Liu X, Wu Y, Mao C, Shen J, Zhu K. Host-acting antibacterial compounds combat cytosolic bacteria. Trends Microbiol 2022; 30:761-777. [DOI: 10.1016/j.tim.2022.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/22/2021] [Accepted: 01/12/2022] [Indexed: 01/25/2023]
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14
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Abstract
In recent years, there has been increased appreciation that a whole category of proteins, small proteins of around 50 amino acids or fewer in length, has been missed by annotation as well as by genetic and biochemical assays. With the increased recognition that small proteins are stable within cells and have regulatory functions, there has been intensified study of these proteins. As a result, important questions about small proteins in bacteria and archaea are coming to the fore. Here, we give an overview of these questions, the initial answers, and the approaches needed to address these questions more fully. More detailed discussions of how small proteins can be identified by ribosome profiling and mass spectrometry approaches are provided by two accompanying reviews (N. Vazquez-Laslop, C. M. Sharma, A. S. Mankin, and A. R. Buskirk, J Bacteriol 204:e00294-21, 2022, https://doi.org/10.1128/JB.00294-21; C. H. Ahrens, J. T. Wade, M. M. Champion, and J. D. Langer, J Bacteriol 204:e00353-21, 2022, https://doi.org/10.1128/JB.00353-21). We are excited by the prospects of new insights and possible therapeutic approaches coming from this emerging field.
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Affiliation(s)
- Todd Gray
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
- Microverse Cluster, Friedrich Schiller University, Jena, Germany
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15
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Yadavalli SS, Yuan J. Bacterial Small Membrane Proteins: the Swiss Army Knife of Regulators at the Lipid Bilayer. J Bacteriol 2022; 204:e0034421. [PMID: 34516282 PMCID: PMC8765417 DOI: 10.1128/jb.00344-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small membrane proteins represent a subset of recently discovered small proteins (≤100 amino acids), which are a ubiquitous class of emerging regulators underlying bacterial adaptation to environmental stressors. Until relatively recently, small open reading frames encoding these proteins were not designated genes in genome annotations. Therefore, our understanding of small protein biology was primarily limited to a few candidates associated with previously characterized larger partner proteins. Following the first systematic analyses of small proteins in Escherichia coli over a decade ago, numerous small proteins across different bacteria have been uncovered. An estimated one-third of these newly discovered proteins in E. coli are localized to the cell membrane, where they may interact with distinct groups of membrane proteins, such as signal receptors, transporters, and enzymes, and affect their activities. Recently, there has been considerable progress in functionally characterizing small membrane protein regulators aided by innovative tools adapted specifically to study small proteins. Our review covers prototypical proteins that modulate a broad range of cellular processes, such as transport, signal transduction, stress response, respiration, cell division, sporulation, and membrane stability. Thus, small membrane proteins represent a versatile group of physiology regulators at the membrane and the whole cell. Additionally, small membrane proteins have the potential for clinical applications, where some of the proteins may act as antibacterial agents themselves while others serve as alternative drug targets for the development of novel antimicrobials.
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Affiliation(s)
- Srujana S. Yadavalli
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
- Department of Genetics, Rutgers University, Piscataway, New Jersey, USA
| | - Jing Yuan
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
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16
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Abstract
Mg2+ is the most abundant divalent cation in living cells. It is essential for charge neutralization, macromolecule stabilization, and the assembly and activity of ribosomes and as a cofactor for enzymatic reactions. When experiencing low cytoplasmic Mg2+, bacteria adopt two main strategies: They increase the abundance and activity of Mg2+ importers and decrease the abundance of Mg2+-chelating ATP and rRNA. These changes reduce regulated proteolysis by ATP-dependent proteases and protein synthesis in a systemic fashion. In many bacterial species, the transcriptional regulator PhoP controls expression of proteins mediating these changes. The 5' leader region of some mRNAs responds to low cytoplasmic Mg2+ or to disruptions in translation of open reading frames in the leader regions by furthering expression of the associated coding regions, which specify proteins mediating survival when the cytoplasmic Mg2+ concentration is low. Microbial species often utilize similar adaptation strategies to cope with low cytoplasmic Mg2+ despite relying on different genes to do so.
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Affiliation(s)
- Eduardo A Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, USA; .,Yale Microbial Sciences Institute, West Haven, Connecticut 06516, USA
| | - Carissa Chan
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, USA;
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17
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Abstract
Phosphorus (P) is essential for life. As the fifth-most-abundant element in living cells, P is required for the synthesis of an array of biological molecules including (d)NTPs, nucleic acids, and membranes. Organisms typically acquire environmental P as inorganic phosphate (Pi). While essential for growth and viability, excess intracellular Pi is toxic for both bacteria and eukaryotes. Using the bacterium Salmonella enterica serovar Typhimurium as a model, we establish that Pi cytotoxicity is manifested following its assimilation into adenosine triphosphate (ATP), which acts as a chelating agent for Mg2+ and other cations. Our findings identify physiological processes disrupted by excessive Pi and how bacteria tune P assimilation to cytoplasmic Mg2+ levels. Phosphorus (P) is an essential component of core biological molecules. In bacteria, P is acquired mainly as inorganic orthophosphate (Pi) and assimilated into adenosine triphosphate (ATP) in the cytoplasm. Although P is essential, excess cytosolic Pi hinders growth. We now report that bacteria limit Pi uptake to avoid disruption of Mg2+-dependent processes that result, in part, from Mg2+ chelation by ATP. We establish that the MgtC protein inhibits uptake of the ATP precursor Pi when Salmonella enterica serovar Typhimurium experiences cytoplasmic Mg2+ starvation. This response prevents ATP accumulation and overproduction of ribosomal RNA that together ultimately hinder bacterial growth and result in loss of viability. Even when cytoplasmic Mg2+ is not limiting, excessive Pi uptake increases ATP synthesis, depletes free cytoplasmic Mg2+, inhibits protein synthesis, and hinders growth. Our results provide a framework to understand the molecular basis for Pi toxicity. Furthermore, they suggest a regulatory logic that governs P assimilation based on its intimate connection to cytoplasmic Mg2+ homeostasis.
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18
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Groisman EA, Duprey A, Choi J. How the PhoP/PhoQ System Controls Virulence and Mg 2+ Homeostasis: Lessons in Signal Transduction, Pathogenesis, Physiology, and Evolution. Microbiol Mol Biol Rev 2021; 85:e0017620. [PMID: 34191587 PMCID: PMC8483708 DOI: 10.1128/mmbr.00176-20] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The PhoP/PhoQ two-component system governs virulence, Mg2+ homeostasis, and resistance to a variety of antimicrobial agents, including acidic pH and cationic antimicrobial peptides, in several Gram-negative bacterial species. Best understood in Salmonella enterica serovar Typhimurium, the PhoP/PhoQ system consists o-regulated gene products alter PhoP-P amounts, even under constant inducing conditions. PhoP-P controls the abundance of hundreds of proteins both directly, by having transcriptional effects on the corresponding genes, and indirectly, by modifying the abundance, activity, or stability of other transcription factors, regulatory RNAs, protease regulators, and metabolites. The investigation of PhoP/PhoQ has uncovered novel forms of signal transduction and the physiological consequences of regulon evolution.
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Affiliation(s)
- Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Microbial Sciences Institute, West Haven, Connecticut, USA
| | - Alexandre Duprey
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jeongjoon Choi
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
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19
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Low Cytoplasmic Magnesium Increases the Specificity of the Lon and ClpAP Proteases. J Bacteriol 2021; 203:e0014321. [PMID: 33941609 DOI: 10.1128/jb.00143-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteolysis is a fundamental property of all living cells. In the bacterium Salmonella enterica serovar Typhimurium, the HspQ protein controls the specificities of the Lon and ClpAP proteases. Upon acetylation, HspQ stops being a Lon substrate and no longer enhances proteolysis of the Lon substrate Hha. The accumulated HspQ protein binds to the protease adaptor ClpS, hindering proteolysis of ClpS-dependent substrates of ClpAP, such as Oat, a promoter of antibiotic persistence. HspQ is acetylated by the protein acetyltransferase Pat from acetyl coenzyme A (acetyl-CoA) bound to the acetyl-CoA binding protein Qad. We now report that low cytoplasmic Mg2+ promotes qad expression, which protects substrates of Lon and ClpSAP by increasing HspQ amounts. The qad promoter is activated by PhoP, a regulatory protein highly activated in low cytoplasmic Mg2+ that also represses clpS transcription. Both the qad gene and PhoP repression of the clpS promoter are necessary for antibiotic persistence. PhoP also promotes qad transcription in Escherichia coli, which shares a similar PhoP box in the qad promoter region with S. Typhimurium, Salmonella bongori, and Enterobacter cloacae. Our findings identify cytoplasmic Mg2+ and the PhoP protein as critical regulators of protease specificity in multiple enteric bacteria. IMPORTANCE The bacterium Salmonella enterica serovar Typhimurium narrows down the spectrum of substrates degraded by the proteases Lon and ClpAP in response to low cytoplasmic Mg2+, a condition that decreases protein synthesis. This control is exerted by PhoP, a transcriptional regulator activated in low cytoplasmic Mg2+ that governs proteostasis and is conserved in enteric bacteria. The uncovered mechanism enables bacteria to control the abundance of preexisting proteins.
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20
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Charged Residues Flanking the Transmembrane Domain of Two Related Toxin-Antitoxin System Toxins Affect Host Response. Toxins (Basel) 2021; 13:toxins13050329. [PMID: 34062876 PMCID: PMC8147318 DOI: 10.3390/toxins13050329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 11/30/2022] Open
Abstract
A majority of toxins produced by type I toxin–antitoxin (TA-1) systems are small membrane-localized proteins that were initially proposed to kill cells by forming non-specific pores in the cytoplasmic membrane. The examination of the effects of numerous TA-1 systems indicates that this is not the mechanism of action of many of these proteins. Enterococcus faecalis produces two toxins of the Fst/Ldr family, one encoded on pheromone-responsive conjugative plasmids (FstpAD1) and the other on the chromosome, FstEF0409. Previous results demonstrated that overexpression of the toxins produced a differential transcriptomic response in E. faecalis cells. In this report, we identify the specific amino acid differences between the two toxins responsible for the differential response of a gene highly induced by FstpAD1 but not FstEF0409. In addition, we demonstrate that a transporter protein that is genetically linked to the chromosomal version of the TA-1 system functions to limit the toxicity of the protein.
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21
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A Translation-Aborting Small Open Reading Frame in the Intergenic Region Promotes Translation of a Mg 2+ Transporter in Salmonella Typhimurium. mBio 2021; 12:mBio.03376-20. [PMID: 33849981 PMCID: PMC8092293 DOI: 10.1128/mbio.03376-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Translation initiation regions in mRNAs that include the ribosome-binding site (RBS) and the start codon are often sequestered within a secondary structure. Therefore, to initiate protein synthesis, the mRNA secondary structure must be unfolded to allow the RBS to be accessible to the ribosome. Bacterial mRNAs often harbor upstream open reading frames (uORFs) in the 5′ untranslated regions (UTRs). Translation of the uORF usually affects downstream gene expression at the levels of transcription and/or translation initiation. Unlike other uORFs mostly located in the 5′ UTR, we discovered an 8-amino-acid ORF, designated mgtQ, in the intergenic region between the mgtC virulence gene and the mgtB Mg2+ transporter gene in the Salmonella mgtCBRU operon. Translation of mgtQ promotes downstream mgtB Mg2+ transporter expression at the level of translation by releasing the ribosome-binding sequence of the mgtB gene that is sequestered in a translation-inhibitory stem-loop structure. Interestingly, mgtQ Asp2 and Glu5 codons that induce ribosome destabilization are required for mgtQ-mediated mgtB translation. Moreover, the mgtQ Asp and Glu codons-mediated mgtB translation is counteracted by the ribosomal subunit L31 that stabilizes ribosome. Substitution of the Asp2 and Glu5 codons in mgtQ decreases MgtB Mg2+ transporter production and thus attenuates Salmonella virulence in mice, likely by limiting Mg2+ acquisition during infection.
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22
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Steinberg R, Koch HG. The largely unexplored biology of small proteins in pro- and eukaryotes. FEBS J 2021; 288:7002-7024. [PMID: 33780127 DOI: 10.1111/febs.15845] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/11/2021] [Accepted: 03/26/2021] [Indexed: 12/29/2022]
Abstract
The large abundance of small open reading frames (smORFs) in prokaryotic and eukaryotic genomes and the plethora of smORF-encoded small proteins became only apparent with the constant advancements in bioinformatic, genomic, proteomic, and biochemical tools. Small proteins are typically defined as proteins of < 50 amino acids in prokaryotes and of less than 100 amino acids in eukaryotes, and their importance for cell physiology and cellular adaptation is only beginning to emerge. In contrast to antimicrobial peptides, which are secreted by prokaryotic and eukaryotic cells for combatting pathogens and competitors, small proteins act within the producing cell mainly by stabilizing protein assemblies and by modifying the activity of larger proteins. Production of small proteins is frequently linked to stress conditions or environmental changes, and therefore, cells seem to use small proteins as intracellular modifiers for adjusting cell metabolism to different intra- and extracellular cues. However, the size of small proteins imposes a major challenge for the cellular machinery required for protein folding and intracellular trafficking and recent data indicate that small proteins can engage distinct trafficking pathways. In the current review, we describe the diversity of small proteins in prokaryotes and eukaryotes, highlight distinct and common features, and illustrate how they are handled by the protein trafficking machineries in prokaryotic and eukaryotic cells. Finally, we also discuss future topics of research on this fascinating but largely unexplored group of proteins.
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Affiliation(s)
- Ruth Steinberg
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Germany
| | - Hans-Georg Koch
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Germany
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23
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Röder J, Felgner P, Hensel M. Comprehensive Single Cell Analyses of the Nutritional Environment of Intracellular Salmonella enterica. Front Cell Infect Microbiol 2021; 11:624650. [PMID: 33834004 PMCID: PMC8021861 DOI: 10.3389/fcimb.2021.624650] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/25/2021] [Indexed: 12/11/2022] Open
Abstract
The facultative intracellular pathogen Salmonella enterica Typhimurium (STM) resides in a specific membrane-bound compartment termed the Salmonella-containing vacuole (SCV). STM is able to obtain all nutrients required for rapid proliferation, although being separated from direct access to host cell metabolites. The formation of specific tubular membrane compartments, called Salmonella-induced filaments (SIFs) are known to provides bacterial nutrition by giving STM access to endocytosed material and enabling proliferation. Additionally, STM expresses a range of nutrient uptake system for growth in nutrient limited environments to overcome the nutrition depletion inside the host. By utilizing dual fluorescence reporters, we shed light on the nutritional environment of intracellular STM in various host cells and distinct intracellular niches. We showed that STM uses nutrients of the host cell and adapts uniquely to the different nutrient conditions. In addition, we provide further evidence for improved nutrient supply by SIF formation or presence in the cytosol of epithelial cells, and the correlation of nutrient supply to bacterial proliferation.
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Affiliation(s)
- Jennifer Röder
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Pascal Felgner
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
- CellNanOs – Center of Cellular Nanoanalytics, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
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24
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Blanc-Potard AB, Groisman EA. How Pathogens Feel and Overcome Magnesium Limitation When in Host Tissues. Trends Microbiol 2020; 29:98-106. [PMID: 32807623 DOI: 10.1016/j.tim.2020.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/16/2020] [Accepted: 07/22/2020] [Indexed: 12/29/2022]
Abstract
Host organisms utilize nutritional immunity to limit the availability of nutrients essential to an invading pathogen. Nutrients may include amino acids, nucleotide bases, and transition metals, the essentiality of which varies among pathogens. The mammalian macrophage protein Slc11a1 (previously Nramp1) mediates resistance to several intracellular pathogens. Slc11a1 is proposed to restrict growth of Salmonella enterica serovar Typhimurium in host tissues by causing magnesium deprivation. This is intriguing because magnesium is the most abundant divalent cation in all living cells. A pathogen's response to factors such as Slc11a1 that promote nutritional immunity may therefore reflect what the pathogen 'feels' in its cytoplasm, rather than the nutrient concentration in host cell compartments.
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Affiliation(s)
- Anne-Béatrice Blanc-Potard
- Laboratory of Pathogen Host Interactions, Université Montpellier, case 107, Place Eugène Bataillon, 34095, Montpellier cedex 5, France; CNRS, UMR5235, 34095, Montpellier Cedex 05, France.
| | - Eduardo A Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA; Yale Microbial Sciences Institute, P.O. Box 27389, West Haven, CT 06516, USA.
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