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Bhat M, Nambiar A, Edakkandiyil L, Abraham IM, Sen R, Negi M, Manjithaya R. A genetically-encoded fluorescence-based reporter to spatiotemporally investigate mannose-6-phosphate pathway. Mol Biol Cell 2024; 35:mr6. [PMID: 38888935 PMCID: PMC11321044 DOI: 10.1091/mbc.e23-09-0344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 06/04/2024] [Accepted: 06/12/2024] [Indexed: 06/20/2024] Open
Abstract
Maintenance of a pool of active lysosomes with acidic pH and degradative hydrolases is crucial for cell health. Abnormalities in lysosomal function are closely linked to diseases, such as lysosomal storage disorders, neurodegeneration, intracellular infections, and cancer among others. Emerging body of research suggests the malfunction of lysosomal hydrolase trafficking pathway to be a common denominator of several disease pathologies. However, available conventional tools to assess lysosomal hydrolase trafficking are insufficient and fail to provide a comprehensive picture about the trafficking flux and location of lysosomal hydrolases. To address some of the shortcomings, we designed a genetically-encoded fluorescent reporter containing a lysosomal hydrolase tandemly tagged with pH sensitive and insensitive fluorescent proteins, which can spatiotemporally trace the trafficking of lysosomal hydrolases. As a proof of principle, we demonstrate that the reporter can detect perturbations in hydrolase trafficking, that are induced by pharmacological manipulations and pathophysiological conditions like intracellular protein aggregates. This reporter can effectively serve as a probe for mapping the mechanistic intricacies of hydrolase trafficking pathway in health and disease and is a utilitarian tool to identify genetic and pharmacological modulators of this pathway, with potential therapeutic implications.
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Affiliation(s)
- Mallika Bhat
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | - Akshaya Nambiar
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | | | - Irine Maria Abraham
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | - Ritoprova Sen
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | - Mamta Negi
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | - Ravi Manjithaya
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
- Professor and chair, Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
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Bird LE, Edgington-Mitchell LE, Newton HJ. Eat, prey, love: Pathogen-mediated subversion of lysosomal biology. Curr Opin Immunol 2023; 83:102344. [PMID: 37245414 DOI: 10.1016/j.coi.2023.102344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/23/2023] [Accepted: 04/30/2023] [Indexed: 05/30/2023]
Abstract
The mammalian lysosome is classically considered the 'garbage can' of the cell, contributing to clearance of infection through its primary function as a degradative organelle. Intracellular pathogens have evolved several strategies to evade contact with this harsh environment through subversion of endolysosomal trafficking or escape into the cytosol. Pathogens can also manipulate pathways that lead to lysosomal biogenesis or alter the abundance or activity of lysosomal content. This pathogen-driven subversion of lysosomal biology is highly dynamic and depends on a range of factors, including cell type, stage of infection, intracellular niche and pathogen load. The growing body of literature in this field highlights the nuanced and complex relationship between intracellular pathogens and the host lysosome, which is critical for our understanding of infection biology.
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Affiliation(s)
- Lauren E Bird
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, VIC 3800, Australia
| | | | - Hayley J Newton
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, VIC 3800, Australia.
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3
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Dillard LR, Glass EM, Lewis AL, Thomas-White K, Papin JA. Metabolic Network Models of the Gardnerella Pangenome Identify Key Interactions with the Vaginal Environment. mSystems 2023; 8:e0068922. [PMID: 36511689 PMCID: PMC9948698 DOI: 10.1128/msystems.00689-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/13/2022] [Indexed: 12/15/2022] Open
Abstract
Gardnerella is the primary pathogenic bacterial genus present in the polymicrobial condition known as bacterial vaginosis (BV). Despite BV's high prevalence and associated chronic and acute women's health impacts, the Gardnerella pangenome is largely uncharacterized at both the genetic and functional metabolic levels. Here, we used genome-scale metabolic models to characterize in silico the Gardnerella pangenome metabolic content. We also assessed the metabolic functional capacity in a BV-positive cervicovaginal fluid context. The metabolic capacity varied widely across the pangenome, with 38.15% of all reactions being core to the genus, compared to 49.60% of reactions identified as being unique to a smaller subset of species. We identified 57 essential genes across the pangenome via in silico gene essentiality screens within two simulated vaginal metabolic environments. Four genes, gpsA, fas, suhB, and psd, were identified as core essential genes critical for the metabolic function of all analyzed bacterial species of the Gardnerella genus. Further understanding these core essential metabolic functions could inform novel therapeutic strategies to treat BV. Machine learning applied to simulated metabolic network flux distributions showed limited clustering based on the sample isolation source, which further supports the presence of extensive core metabolic functionality across this genus. These data represent the first metabolic modeling of the Gardnerella pangenome and illustrate strain-specific interactions with the vaginal metabolic environment across the pangenome. IMPORTANCE Bacterial vaginosis (BV) is the most common vaginal infection among reproductive-age women. Despite its prevalence and associated chronic and acute women's health impacts, the diverse bacteria involved in BV infection remain poorly characterized. Gardnerella is the genus of bacteria most commonly and most abundantly represented during BV. In this paper, we use metabolic models, which are a computational representation of the possible functional metabolism of an organism, to investigate metabolic conservation, gene essentiality, and pathway utilization across 110 Gardnerella strains. These models allow us to investigate in silico how strains may differ with respect to their metabolic interactions with the vaginal-host environment.
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Affiliation(s)
- Lillian R. Dillard
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA
| | - Emma M. Glass
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Amanda L. Lewis
- Department of Obstetrics and Gynecology, University of California—San Diego, La Jolla, California, USA
| | | | - Jason A. Papin
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
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do Nascimento Soares T, Silva Valadares V, Cardoso Amorim G, de Mattos Lacerda de Carvalho M, Berrêdo‐Pinho M, Ceneviva Lacerda Almeida F, Mascarello Bisch P, Batista PR, Miranda Santos Lery L. The C‐terminal extension of
VgrG4
from
Klebsiella pneumoniae
remodels host cell microfilaments. Proteins 2022; 90:1655-1668. [PMID: 35430767 PMCID: PMC9542434 DOI: 10.1002/prot.26344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 03/11/2022] [Accepted: 04/07/2022] [Indexed: 12/12/2022]
Abstract
Klebsiella pneumoniae is an opportunistic pathogen, which concerns public health systems worldwide, as multiple antibiotic‐resistant strains are frequent. One of its pathogenicity factors is the Type VI Secretion System (T6SS), a macromolecular complex assembled through the bacterial membranes. T6SS injects effector proteins inside target cells. Such effectors confer competitive advantages or modulate the target cell signaling and metabolism to favor bacterial infection. The VgrG protein is a T6SS core component. It may present a variable C‐terminal domain carrying an additional effector function. Kp52.145 genome encodes three VgrG proteins, one of them with a C‐terminal extension (VgrG4‐CTD). VgrG4‐CTD is 138 amino acids long, does not contain domains of known function, but is conserved in some Klebsiella, and non‐Klebsiella species. To get insights into its function, recombinant VgrG4‐CTD was used in pulldown experiments to capture ligands from macrophages and lung epithelial cells. A total of 254 proteins were identified: most of them are ribosomal proteins. Cytoskeleton‐associated and proteins involved in the phagosome maturation pathway were also identified. We further showed that VgrG4‐CTD binds actin and induces actin remodeling in macrophages. This study presents novel clues on the role of K. pneumoniae T6SS in pathogenesis.
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Affiliation(s)
| | | | | | | | - Marcia Berrêdo‐Pinho
- Laboratório de Microbiologia Celular Instituto Oswaldo Cruz Rio de Janeiro Brazil
| | - Fábio Ceneviva Lacerda Almeida
- Centro Nacional de Ressonância Magnética Nuclear Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
| | - Paulo Mascarello Bisch
- Laboratório de Física‐Biológica Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
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Bullones-Bolaños A, Bernal-Bayard J, Ramos-Morales F. The NEL Family of Bacterial E3 Ubiquitin Ligases. Int J Mol Sci 2022; 23:7725. [PMID: 35887072 PMCID: PMC9320238 DOI: 10.3390/ijms23147725] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 12/16/2022] Open
Abstract
Some pathogenic or symbiotic Gram-negative bacteria can manipulate the ubiquitination system of the eukaryotic host cell using a variety of strategies. Members of the genera Salmonella, Shigella, Sinorhizobium, and Ralstonia, among others, express E3 ubiquitin ligases that belong to the NEL family. These bacteria use type III secretion systems to translocate these proteins into host cells, where they will find their targets. In this review, we first introduce type III secretion systems and the ubiquitination process and consider the various ways bacteria use to alter the ubiquitin ligation machinery. We then focus on the members of the NEL family, their expression, translocation, and subcellular localization in the host cell, and we review what is known about the structure of these proteins, their function in virulence or symbiosis, and their specific targets.
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Affiliation(s)
| | | | - Francisco Ramos-Morales
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain; (A.B.-B.); (J.B.-B.)
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