1
|
Xiao C, Cao S, Li Y, Luo Y, Liu J, Chen Y, Bai Q, Chen L. Pyroptosis in microbial infectious diseases. Mol Biol Rep 2023; 51:42. [PMID: 38158461 DOI: 10.1007/s11033-023-09078-w] [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: 07/13/2023] [Accepted: 10/30/2023] [Indexed: 01/03/2024]
Abstract
Pyroptosis is a gasdermins-mediated programmed cell death that plays an essential role in immune regulation, and its role in autoimmune disease and cancer has been studied extensively. Increasing evidence shows that various microbial infections can lead to pyroptosis, associated with the occurrence and development of microbial infectious diseases. This study reviews the recent advances in pyroptosis in microbial infection, including bacterial, viral, and fungal infections. We also explore potential therapeutic strategies for treating microbial infection-related diseases by targeting pyroptosis.
Collapse
Affiliation(s)
- Cui Xiao
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Saihong Cao
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- Yiyang Medical College, School of Public Health and Laboratory Medicine, Yiyang, Hunan, 421000, China
| | - Yunfei Li
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Yuchen Luo
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Jian Liu
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Yuyu Chen
- The Affiliated Cancer Hospital of Xiangya School of Medicine, Hunan Cancer Hospital, Central South University Infection-Associated Hemophagocytic Syndrome, Changsha, Hunan, 421000, China
| | - Qinqin Bai
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Lili Chen
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| |
Collapse
|
2
|
Roberts CG, Franklin TG, Pruneda JN. Ubiquitin-targeted bacterial effectors: rule breakers of the ubiquitin system. EMBO J 2023; 42:e114318. [PMID: 37555693 PMCID: PMC10505922 DOI: 10.15252/embj.2023114318] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/10/2023] [Accepted: 07/18/2023] [Indexed: 08/10/2023] Open
Abstract
Regulation through post-translational ubiquitin signaling underlies a large portion of eukaryotic biology. This has not gone unnoticed by invading pathogens, many of which have evolved mechanisms to manipulate or subvert the host ubiquitin system. Bacteria are particularly adept at this and rely heavily upon ubiquitin-targeted virulence factors for invasion and replication. Despite lacking a conventional ubiquitin system of their own, many bacterial ubiquitin regulators loosely follow the structural and mechanistic rules established by eukaryotic ubiquitin machinery. Others completely break these rules and have evolved novel structural folds, exhibit distinct mechanisms of regulation, or catalyze foreign ubiquitin modifications. Studying these interactions can not only reveal important aspects of bacterial pathogenesis but also shed light on unexplored areas of ubiquitin signaling and regulation. In this review, we discuss the methods by which bacteria manipulate host ubiquitin and highlight aspects that follow or break the rules of ubiquitination.
Collapse
Affiliation(s)
- Cameron G Roberts
- Department of Molecular Microbiology & ImmunologyOregon Health & Science UniversityPortlandORUSA
| | - Tyler G Franklin
- Department of Molecular Microbiology & ImmunologyOregon Health & Science UniversityPortlandORUSA
| | - Jonathan N Pruneda
- Department of Molecular Microbiology & ImmunologyOregon Health & Science UniversityPortlandORUSA
| |
Collapse
|
3
|
Jiang Q, Zhu Z, Mao X. Ubiquitination is a major modulator for the activation of inflammasomes and pyroptosis. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194955. [PMID: 37331650 DOI: 10.1016/j.bbagrm.2023.194955] [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: 12/09/2022] [Revised: 05/25/2023] [Accepted: 06/12/2023] [Indexed: 06/20/2023]
Abstract
Inflammasomes are a central node of the innate immune defense system against the threat of homeostatic perturbance caused by pathogenic organisms or host-derived molecules. Inflammasomes are generally composed of multimeric protein complexes that assemble in the cytosol after sensing danger signals. Activated inflammasomes promote downstream proteolytic activation, which triggers the release of pro-inflammatory cytokines therefore inducing pyroptotic cell death. The inflammasome pathway is finely tuned by various mechanisms. Recent studies found that protein post-translational modifications such as ubiquitination also modulate inflammasome activation. Targeting the ubiquitination modification of the inflammasome pathway might be a promising strategy for related diseases. In this review, we extensively discuss the advances in inflammasome activation and pyroptosis modulated by ubiquitination which help in-depth understanding and controlling the inflammasome and pyroptosis in various diseases.
Collapse
Affiliation(s)
- Qiuyun Jiang
- Guangdong Institute of Cardiovascular Diseases, Guangdong Key Laboratory of Vascular Diseases, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, PR China; Guangdong Provincial Key Laboratory of Protein Modification and Degradation, State Key Laboratory of Respiratory Diseases, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, Guangdong 511436, China
| | - Zhigang Zhu
- Division of Hematology & Oncology, Department of Geriatrics, Guangzhou First People's Hospital, College of Medicine, South China University of Technology, Guangzhou, Guangdong 510180, China
| | - Xinliang Mao
- Guangdong Institute of Cardiovascular Diseases, Guangdong Key Laboratory of Vascular Diseases, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, PR China; Guangdong Provincial Key Laboratory of Protein Modification and Degradation, State Key Laboratory of Respiratory Diseases, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, Guangdong 511436, China.
| |
Collapse
|
4
|
Alberca GGF, Cardoso NSS, Solis-Castro RL, Nakano V, Alberca RW. Intestinal inflammation and the microbiota: Beyond diversity. World J Gastroenterol 2022; 28:3274-3278. [PMID: 36051343 PMCID: PMC9331525 DOI: 10.3748/wjg.v28.i26.3274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/05/2021] [Accepted: 06/26/2022] [Indexed: 02/06/2023] Open
Abstract
The recent manuscript entitled “Relationship between clinical features and intestinal microbiota in Chinese patients with ulcerative colitis” reported a difference in the intestinal microbiota of patients with ulcerative colitis according to the severity of the colitis. The influence of the intestinal microbiota on the development and progress of gastrointestinal disorders is well established. Besides the diversity in the microbiome, the presence of virulence factors and toxins by commensal bacteria may affect an extensive variety of cellular processes, contributing to the induction of a proinflammatory environment.
Collapse
Affiliation(s)
- Gabriela Gama Freire Alberca
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil
| | - Naiane Samira Souza Cardoso
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil
| | - Rosa Liliana Solis-Castro
- Departamento Académico de Biología Bioquímica, Facultad de Ciencias de la Salud, Universidad Nacional de Tumbes, Pampa Grande 24000, Tumbes, Peru
| | - Viviane Nakano
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil
| | - Ricardo Wesley Alberca
- Laboratorio de Dermatologia e Imunodeficiencias, Departamento de Dermatologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 01246-903, Brazil
| |
Collapse
|
5
|
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.
Collapse
Affiliation(s)
| | | | - Francisco Ramos-Morales
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain; (A.B.-B.); (J.B.-B.)
| |
Collapse
|
6
|
Huang Y, Li R, Yang Y. Role of Pyroptosis in Gynecological Oncology and Its Therapeutic Regulation. Biomolecules 2022; 12:biom12070924. [PMID: 35883480 PMCID: PMC9313147 DOI: 10.3390/biom12070924] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 02/04/2023] Open
Abstract
With the continuous advances in molecular biotechnology, many new cell death methods have been discovered. Pyroptosis is a programmed cell death process that differs from apoptosis and autophagy in cell morphology and function. Compared with apoptosis and autophagy, pyroptosis is primarily mediated by intracellular inflammasome and gasdermin D of the gasdermin protein family and involves the release of numerous inflammatory factors. Pyroptosis has been found to be involved in the occurrence and development of infectious diseases and other diseases involving the nervous system and the cardiovascular system. Recent studies have also reported the occurrence of pyroptosis in tumor cells. Accordingly, exploring its effect on tumors has become one of the research hotspots. Herein, recent research progress on pyroptosis is reviewed, especially its role in the development of gynecological tumors. As the pathogenesis of gynecological tumor is better understood, new targets have been introduced for the prevention and clinical treatment of gynecological tumors.
Collapse
Affiliation(s)
- Yi Huang
- The First Clinical Medical College, Lanzhou University, Lanzhou 730000, China; (Y.H.); (R.L.)
| | - Ruiyun Li
- The First Clinical Medical College, Lanzhou University, Lanzhou 730000, China; (Y.H.); (R.L.)
| | - Yuan Yang
- The Reproductive Medicine Center, The 1st Hospital of Lanzhou University, Lanzhou 730000, China
- Correspondence:
| |
Collapse
|
7
|
Vaughn B, Abu Kwaik Y. Idiosyncratic Biogenesis of Intracellular Pathogens-Containing Vacuoles. Front Cell Infect Microbiol 2021; 11:722433. [PMID: 34858868 PMCID: PMC8632064 DOI: 10.3389/fcimb.2021.722433] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
While most bacterial species taken up by macrophages are degraded through processing of the bacteria-containing vacuole through the endosomal-lysosomal degradation pathway, intravacuolar pathogens have evolved to evade degradation through the endosomal-lysosomal pathway. All intra-vacuolar pathogens possess specialized secretion systems (T3SS-T7SS) that inject effector proteins into the host cell cytosol to modulate myriad of host cell processes and remodel their vacuoles into proliferative niches. Although intravacuolar pathogens utilize similar secretion systems to interfere with their vacuole biogenesis, each pathogen has evolved a unique toolbox of protein effectors injected into the host cell to interact with, and modulate, distinct host cell targets. Thus, intravacuolar pathogens have evolved clear idiosyncrasies in their interference with their vacuole biogenesis to generate a unique intravacuolar niche suitable for their own proliferation. While there has been a quantum leap in our knowledge of modulation of phagosome biogenesis by intravacuolar pathogens, the detailed biochemical and cellular processes affected remain to be deciphered. Here we discuss how the intravacuolar bacterial pathogens Salmonella, Chlamydia, Mycobacteria, Legionella, Brucella, Coxiella, and Anaplasma utilize their unique set of effectors injected into the host cell to interfere with endocytic, exocytic, and ER-to-Golgi vesicle traffic. However, Coxiella is the main exception for a bacterial pathogen that proliferates within the hydrolytic lysosomal compartment, but its T4SS is essential for adaptation and proliferation within the lysosomal-like vacuole.
Collapse
Affiliation(s)
- Bethany Vaughn
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States.,Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY, United States
| |
Collapse
|
8
|
Sun J, Wang X, Lin H, Wan L, Chen J, Yang X, Li D, Zhang Y, He X, Wang B, Dong M, Zhong H, Wei C. Shigella escapes lysosomal degradation through inactivation of Rab31 by IpaH4.5. J Med Microbiol 2021; 70. [PMID: 34296983 DOI: 10.1099/jmm.0.001382] [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: 11/18/2022] Open
Abstract
Introduction. Shigella flexneri is an intracellular bacterial pathogen that utilizes a type III secretion apparatus to inject effector proteins into host cells.Hypothesis/Gap Statement. The T3SS effector IpaH4.5 is important for the virulence of Shigella.Aim. This study aimed to elucidate the molecular mechanism and host target of the IpaH4.5 as well as its roles in S. flexneri infection.Methodology. The GAP assay was used to identify substrate Rab GTPases of IpaH4.5. A coimmunoprecipitation assay was applied to identify the interaction of Rab GTPases with IpaH4.5. A confocal microscopy analysis was used to assess the effects of IpaH4.5 on mannose 6-phosphate receptor (MPR) trafficking. To identify the effects of IpaH4.5 GAP activity on the activity of lysosomal cathepsin B, the Magic Red-RR assay was used. Finally, the intracellular persistence assay was used to identify IpaH4.5 GAP activity in S. flexneri intracellular growth.Results. We found that the effector IpaH4.5 disrupts MPR trafficking and lysosomal function, thereby counteracting host lysosomal degradation. IpaH4.5 harbours TBC-like dual-finger motifs and exhibits potent RabGAP activities towards Rab31. IpaH4.5 disrupts the transport of the cation-dependent mannose 6-phosphate receptor (CD-MPR) from the Golgi to the endosome by targeting Rab31, thereby attenuating lysosomal function. As a result, the intracellular persistence of S. flexneri requires IpaH4.5 TBC-like GAP activity to mediate bacterial escape from host lysosome-mediated elimination.Conclusion. We identified an unknown function of IpaH4.5 and its potential role in S. flexneri infection.
Collapse
Affiliation(s)
- Jin Sun
- Basic Medical College, Qingdao University, Qingdao, PR China.,Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Xiaolin Wang
- Basic Medical College, Qingdao University, Qingdao, PR China.,Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Haotian Lin
- Basic Medical College, Qingdao University, Qingdao, PR China.,Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Luming Wan
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Ji Chen
- Basic Medical College, Qingdao University, Qingdao, PR China
| | - Xiaopan Yang
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Dongyu Li
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Yanhong Zhang
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Xiang He
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Bin Wang
- Basic Medical College, Qingdao University, Qingdao, PR China
| | - Mingxin Dong
- Basic Medical College, Qingdao University, Qingdao, PR China
| | - Hui Zhong
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| | - Congwen Wei
- Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China
| |
Collapse
|
9
|
Abstract
The Dot/Icm type IV secretion system (T4SS) of Legionella pneumophila is essential for lysosomal evasion and permissiveness of macrophages for intracellular proliferation of the pathogen. In contrast, we show that polymorphonuclear cells (PMNs) respond to a functional Dot/Icm system through rapid restriction of L. pneumophila. Specifically, we show that the L. pneumophila T4SS-injected amylase (LamA) effector catalyzes rapid glycogen degradation in the PMNs cytosol, leading to cytosolic hyperglucose. Neutrophils respond through immunometabolic reprogramming that includes upregulated aerobic glycolysis. The PMNs become activated with spatial generation of intracellular reactive oxygen species within the Legionella-containing phagosome (LCP) and fusion of specific and azurophilic granules to the LCP, leading to rapid restriction of L. pneumophila. We conclude that in contrast to macrophages, PMNs respond to a functional Dot/Icm system, and specifically to the effect of the injected amylase effector, through rapid engagement of major microbicidal processes and rapid restriction of the pathogen. IMPORTANCE Legionella pneumophila is commonly found in aquatic environments and resides within a wide variety of amoebal hosts. Upon aerosol transmission to humans, L. pneumophila invades and replicates with alveolar macrophages, causing pneumonia designated Legionnaires' disease. In addition to alveolar macrophages, neutrophils infiltrate into the lungs of infected patients. Unlike alveolar macrophages, neutrophils restrict and kill L. pneumophila, but the mechanisms were previously unclear. Here, we show that the pathogen secretes an amylase (LamA) enzyme that rapidly breakdowns glycogen stores within neutrophils, and this triggers increased glycolysis. Subsequently, the two major killing mechanisms of neutrophils, granule fusion and production of reactive oxygen species, are activated, resulting in rapid killing of L. pneumophila.
Collapse
|
10
|
He J, Liu J, Huang Y, Tang X, Xiao H, Hu Z. Oxidative Stress, Inflammation, and Autophagy: Potential Targets of Mesenchymal Stem Cells-Based Therapies in Ischemic Stroke. Front Neurosci 2021; 15:641157. [PMID: 33716657 PMCID: PMC7952613 DOI: 10.3389/fnins.2021.641157] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 01/26/2021] [Indexed: 12/14/2022] Open
Abstract
Ischemic stroke is a leading cause of death worldwide; currently available treatment approaches for ischemic stroke are to restore blood flow, which reduce disability but are time limited. The interruption of blood flow in ischemic stroke contributes to intricate pathophysiological processes. Oxidative stress and inflammatory activity are two early events in the cascade of cerebral ischemic injury. These two factors are reciprocal causation and directly trigger the development of autophagy. Appropriate autophagy activity contributes to brain recovery by reducing oxidative stress and inflammatory activity, while autophagy dysfunction aggravates cerebral injury. Abundant evidence demonstrates the beneficial impact of mesenchymal stem cells (MSCs) and secretome on cerebral ischemic injury. MSCs reduce oxidative stress through suppressing reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation and transferring healthy mitochondria to damaged cells. Meanwhile, MSCs exert anti-inflammation properties by the production of cytokines and extracellular vesicles, inhibiting proinflammatory cytokines and inflammatory cells activation, suppressing pyroptosis, and alleviating blood–brain barrier leakage. Additionally, MSCs regulation of autophagy imbalances gives rise to neuroprotection against cerebral ischemic injury. Altogether, MSCs have been a promising candidate for the treatment of ischemic stroke due to their pleiotropic effect.
Collapse
Affiliation(s)
- Jialin He
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jianyang Liu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yan Huang
- National Health Commission Key Laboratory of Birth Defect for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, China
| | - Xiangqi Tang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Han Xiao
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhiping Hu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
11
|
Abstract
Intracellular proliferation of Legionella pneumophila within a vacuole in human alveolar macrophages is essential for manifestation of Legionnaires’ pneumonia. Intravacuolar growth of the pathogen is totally dependent on remodeling the L. pneumophila-containing vacuole (LCV) by the ER and on its evasion of the endosomal-lysosomal degradation pathway. Diversion of the Legionella pneumophila-containing vacuole (LCV) from the host endosomal-lysosomal degradation pathway is one of the main virulence features essential for manifestation of Legionnaires’ pneumonia. Many of the ∼350 Dot/Icm-injected effectors identified in L. pneumophila have been shown to interfere with various host pathways and processes, but no L. pneumophila effector has ever been identified to be indispensable for lysosomal evasion. While most single effector mutants of L. pneumophila do not exhibit a defective phenotype within macrophages, we show that the MavE effector is essential for intracellular growth of L. pneumophila in human monocyte-derived macrophages (hMDMs) and amoebae and for intrapulmonary proliferation in mice. The mavE null mutant fails to remodel the LCV with endoplasmic reticulum (ER)-derived vesicles and is trafficked to the lysosomes where it is degraded, similar to formalin-killed bacteria. During infection of hMDMs, the MavE effector localizes to the poles of the LCV membrane. The crystal structure of MavE, resolved to 1.8 Å, reveals a C-terminal transmembrane helix, three copies of tyrosine-based sorting motifs, and an NPxY eukaryotic motif, which binds phosphotyrosine-binding domains present on signaling and adaptor eukaryotic proteins. Two point mutations within the NPxY motif result in attenuation of L. pneumophila in both hMDMs and amoeba. The substitution defects of P78 and D64 are associated with failure of vacuoles harboring the mutant to be remodeled by the ER and results in fusion of the vacuole to the lysosomes leading to bacterial degradation. Therefore, the MavE effector of L. pneumophila is indispensable for phagosome biogenesis and lysosomal evasion.
Collapse
|
12
|
Price CT, Abu Kwaik Y. Evolution and Adaptation of Legionella pneumophila to Manipulate the Ubiquitination Machinery of Its Amoebae and Mammalian Hosts. Biomolecules 2021; 11:biom11010112. [PMID: 33467718 PMCID: PMC7830128 DOI: 10.3390/biom11010112] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 02/07/2023] Open
Abstract
The ubiquitin pathway is highly conserved across the eukaryotic domain of life and plays an essential role in a plethora of cellular processes. It is not surprising that many intracellular bacterial pathogens often target the essential host ubiquitin pathway. The intracellular bacterial pathogen Legionella pneumophila injects into the host cell cytosol multiple classes of classical and novel ubiquitin-modifying enzymes that modulate diverse ubiquitin-related processes in the host cell. Most of these pathogen-injected proteins, designated as effectors, mimic known E3-ubiquitin ligases through harboring F-box or U-box domains. The classical F-box effector, AnkB targets host proteins for K48-linked polyubiquitination, which leads to excessive proteasomal degradation that is required to generate adequate supplies of amino acids for metabolism of the pathogen. In contrast, the SidC and SdcA effectors share no structural similarity to known eukaryotic ligases despite having E3-ubiquitin ligase activity, suggesting that the number of E3-ligases in eukaryotes is under-represented. L. pneumophila also injects into the host many novel ubiquitin-modifying enzymes, which are the SidE family of effectors that catalyze phosphoribosyl-ubiquitination of serine residue of target proteins, independently of the canonical E1-2-3 enzymatic cascade. Interestingly, the environmental bacterium, L. pneumophila, has evolved within a diverse range of amoebal species, which serve as the natural hosts, while accidental transmission through contaminated aerosols can cause pneumonia in humans. Therefore, it is likely that the novel ubiquitin-modifying enzymes of L. pneumophila were acquired by the pathogen through interkingdom gene transfer from the diverse natural amoebal hosts. Furthermore, conservation of the ubiquitin pathway across eukaryotes has enabled these novel ubiquitin-modifying enzymes to function similarly in mammalian cells. Studies on the biological functions of these effectors are likely to reveal further novel ubiquitin biology and shed further lights on the evolution of ubiquitin.
Collapse
Affiliation(s)
- Christopher T.D. Price
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA;
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA;
- Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY 40202, USA
- Correspondence:
| |
Collapse
|