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Chatterjee R, Setty SRG, Chakravortty D. SNAREs: a double-edged sword for intravacuolar bacterial pathogens within host cells. Trends Microbiol 2024; 32:477-493. [PMID: 38040624 DOI: 10.1016/j.tim.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 12/03/2023]
Abstract
In the tug-of-war between host and pathogen, both evolve to combat each other's defence arsenals. Intracellular phagosomal bacteria have developed strategies to modify the vacuolar niche to suit their requirements best. Conversely, the host tries to target the pathogen-containing vacuoles towards the degradative pathways. The host cells use a robust system through intracellular trafficking to maintain homeostasis inside the cellular milieu. In parallel, intracellular bacterial pathogens have coevolved with the host to harbour strategies to manipulate cellular pathways, organelles, and cargoes, facilitating the conversion of the phagosome into a modified pathogen-containing vacuole (PCV). Key molecular regulators of intracellular traffic, such as changes in the organelle (phospholipid) composition, recruitment of small GTPases and associated effectors, soluble N-ethylmaleimide-sensitive factor-activating protein receptors (SNAREs), etc., are hijacked to evade lysosomal degradation. Legionella, Salmonella, Coxiella, Chlamydia, Mycobacterium, and Brucella are examples of pathogens which diverge from the endocytic pathway by using effector-mediated mechanisms to overcome the challenges and establish their intracellular niches. These pathogens extensively utilise and modulate the end processes of secretory pathways, particularly SNAREs, in repurposing the PCV into specialised compartments resembling the host organelles within the secretory network; at the same time, they avoid being degraded by the host's cellular mechanisms. Here, we discuss the recent research advances on the host-pathogen interaction/crosstalk that involves host SNAREs, conserved cellular processes, and the ongoing host-pathogen defence mechanisms in the molecular arms race against each other. The current knowledge of SNAREs, and intravacuolar bacterial pathogen interactions, enables us to understand host cellular innate immune pathways, maintenance of homeostasis, and potential therapeutic strategies to combat ever-growing antimicrobial resistance.
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Affiliation(s)
- Ritika Chatterjee
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India
| | - Subba Rao Gangi Setty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India.
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India; Adjunct Faculty, Indian Institute of Science Research and Education, Thiruvananthapuram, Kerala, India.
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Marsilia C, Batra M, Pokrovskaya ID, Wang C, Chaput D, Naumova DA, Lupashin VV, Suvorova ES. Essential role of the conserved oligomeric Golgi complex in Toxoplasma gondii. mBio 2023; 14:e0251323. [PMID: 37966241 PMCID: PMC10746232 DOI: 10.1128/mbio.02513-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 10/05/2023] [Indexed: 11/16/2023] Open
Abstract
IMPORTANCE The Golgi is an essential eukaryotic organelle and a major place for protein sorting and glycosylation. Among apicomplexan parasites, Toxoplasma gondii retains the most developed Golgi structure and produces many glycosylated factors necessary for parasite survival. Despite its importance, Golgi function received little attention in the past. In the current study, we identified and characterized the conserved oligomeric Golgi complex and its novel partners critical for protein transport in T. gondii tachyzoites. Our results suggest that T. gondii broadened the role of the conserved elements and reinvented the missing components of the trafficking machinery to accommodate the specific needs of the opportunistic parasite T. gondii.
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Affiliation(s)
- Clem Marsilia
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Mrinalini Batra
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Irina D. Pokrovskaya
- Department of Physiology and Cell Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Changqi Wang
- College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Dale Chaput
- Proteomics Core, College of Arts and Sciences, University of South Florida, Tampa, Florida, USA
| | - Daria A. Naumova
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Vladimir V. Lupashin
- Department of Physiology and Cell Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Elena S. Suvorova
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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Clemente TM, Angara RK, Gilk SD. Establishing the intracellular niche of obligate intracellular vacuolar pathogens. Front Cell Infect Microbiol 2023; 13:1206037. [PMID: 37645379 PMCID: PMC10461009 DOI: 10.3389/fcimb.2023.1206037] [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: 04/14/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Obligate intracellular pathogens occupy one of two niches - free in the host cell cytoplasm or confined in a membrane-bound vacuole. Pathogens occupying membrane-bound vacuoles are sequestered from the innate immune system and have an extra layer of protection from antimicrobial drugs. However, this lifestyle presents several challenges. First, the bacteria must obtain membrane or membrane components to support vacuole expansion and provide space for the increasing bacteria numbers during the log phase of replication. Second, the vacuole microenvironment must be suitable for the unique metabolic needs of the pathogen. Third, as most obligate intracellular bacterial pathogens have undergone genomic reduction and are not capable of full metabolic independence, the bacteria must have mechanisms to obtain essential nutrients and resources from the host cell. Finally, because they are separated from the host cell by the vacuole membrane, the bacteria must possess mechanisms to manipulate the host cell, typically through a specialized secretion system which crosses the vacuole membrane. While there are common themes, each bacterial pathogen utilizes unique approach to establishing and maintaining their intracellular niches. In this review, we focus on the vacuole-bound intracellular niches of Anaplasma phagocytophilum, Ehrlichia chaffeensis, Chlamydia trachomatis, and Coxiella burnetii.
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Affiliation(s)
| | | | - Stacey D. Gilk
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
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Lorentzen EM, Henriksen S, Rinaldo CH. Modelling BK Polyomavirus dissemination and cytopathology using polarized human renal tubule epithelial cells. PLoS Pathog 2023; 19:e1011622. [PMID: 37639485 PMCID: PMC10491296 DOI: 10.1371/journal.ppat.1011622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/08/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
Most humans have a lifelong imperceptible BK Polyomavirus (BKPyV) infection in epithelial cells lining the reno-urinary tract. In kidney transplant recipients, unrestricted high-level replication of donor-derived BKPyV in the allograft underlies polyomavirus-associated nephropathy, a condition with massive epithelial cell loss and inflammation causing premature allograft failure. There is limited understanding on how BKPyV disseminates throughout the reno-urinary tract and sometimes causes kidney damage. Tubule epithelial cells are tightly connected and have unique apical and basolateral membrane domains with highly specialized functions but all in vitro BKPyV studies have been performed in non-polarized cells. We therefore generated a polarized cell model of primary renal proximal tubule epithelial cells (RPTECs) and characterized BKPyV entry and release. After 8 days on permeable inserts, RPTECs demonstrated apico-basal polarity. BKPyV entry was most efficient via the apical membrane, that in vivo faces the tubular lumen, and depended on sialic acids. Progeny release started between 48 and 58 hours post-infection (hpi), and was exclusively detected in the apical compartment. From 72 hpi, cell lysis and detachment gradually increased but cells were mainly shed by extrusion and the barrier function was therefore maintained. The decoy-like cells were BKPyV infected and could transmit BKPyV to uninfected cells. By 120 hpi, the epithelial barrier was disrupted by severe cytopathic effects, and BKPyV entered the basolateral compartment mimicking the interstitial space. Addition of BKPyV-specific neutralizing antibodies to this compartment inhibited new infections. Taken together, we propose that during in vivo low-level BKPyV replication, BKPyV disseminates inside the tubular system, thereby causing minimal damage and delaying immune detection. However, in kidney transplant recipients lacking a well-functioning immune system, replication in the allograft will progress and eventually cause denudation of the basement membrane, leading to an increased number of decoy cells, high-level BKPyV-DNAuria and DNAemia, the latter a marker of allograft damage.
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Affiliation(s)
- Elias Myrvoll Lorentzen
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
- Metabolic and Renal Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
| | - Stian Henriksen
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
- Metabolic and Renal Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
| | - Christine Hanssen Rinaldo
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
- Metabolic and Renal Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
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D'Souza Z, Pokrovskaya I, Lupashin VV. Syntaxin-5's flexibility in SNARE pairing supports Golgi functions. Traffic 2023; 24:355-379. [PMID: 37340984 PMCID: PMC10330844 DOI: 10.1111/tra.12903] [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: 03/07/2023] [Revised: 05/23/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023]
Abstract
Deficiency in the conserved oligomeric Golgi (COG) complex that orchestrates SNARE-mediated tethering/fusion of vesicles that recycle the Golgi's glycosylation machinery results in severe glycosylation defects. Although two major Golgi v-SNAREs, GS28/GOSR1, and GS15/BET1L, are depleted in COG-deficient cells, the complete knockout of GS28 and GS15 only modestly affects Golgi glycosylation, indicating the existence of an adaptation mechanism in Golgi SNARE. Indeed, quantitative mass-spectrometry analysis of STX5-interacting proteins revealed two novel Golgi SNARE complexes-STX5/SNAP29/VAMP7 and STX5/VTI1B/STX8/YKT6. These complexes are present in wild-type cells, but their usage is significantly increased in both GS28- and COG-deficient cells. Upon GS28 deletion, SNAP29 increased its Golgi residency in a STX5-dependent manner. While STX5 depletion and Retro2-induced diversion from the Golgi severely affect protein glycosylation, GS28/SNAP29 and GS28/VTI1B double knockouts alter glycosylation similarly to GS28 KO, indicating that a single STX5-based SNARE complex is sufficient to support Golgi glycosylation. Importantly, co-depletion of three Golgi SNARE complexes in GS28/SNAP29/VTI1B TKO cells resulted in severe glycosylation defects and a reduced capacity for glycosylation enzyme retention at the Golgi. This study demonstrates the remarkable plasticity in SXT5-mediated membrane trafficking, uncovering a novel adaptive response to the failure of canonical intra-Golgi vesicle tethering/fusion machinery.
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Affiliation(s)
- Zinia D'Souza
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Irina Pokrovskaya
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Vladimir V Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Huang Y, Li S, He S, Li Y, He Q, Wu Y. Chlamydia psittaci inclusion membrane protein CPSIT_0842 induces macrophage apoptosis through MAPK/ERK-mediated autophagy. Int J Biochem Cell Biol 2023; 157:106376. [PMID: 36716815 DOI: 10.1016/j.biocel.2023.106376] [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: 06/01/2022] [Revised: 12/20/2022] [Accepted: 01/26/2023] [Indexed: 01/29/2023]
Abstract
Chlamydia psittaci is a multi-host zoonotic pathogen, which mainly infects poultry and inflicts an appreciable economic burden on the livestock farming industry. C. psittaci inclusion membrane proteins are uniquely positioned at the host-pathogen interface and are important virulence proteins. We have previously confirmed that Incs regulate host cell survival to help Chlamydia sp. evade host-cell-mediated defense mechanisms. However, the role of the Inc, CPSIT_0842, in the regulation of cell death following the establishment of persistent C. psittaci infection remains unknown. This study explored the effect of CPSIT_0842 on the crosstalk between the autophagic and apoptotic pathways in macrophages. Results showed that CPSIT_0842 initiated autophagy and blocked autophagic flux in human macrophages, as indicated by autophagy-related protein LC3-II, Beclin-1, and p62 upregulation, autophagosome accumulation, and lysosomal protein LAMP1 diminution. We also showed that the disruption of autophagic flux had a regulatory effect on CPSIT_0842-induced apoptosis. Moreover, the suppression of autophagy initiation by 3-methyladenine attenuated CPSIT_0842-induced apoptosis. By contrast, the induction of autophagic flux by rapamycin did not significantly affect CPSIT_0842-induced apoptosis. Taken together, these findings demonstrate that CPSIT_0842 induced macrophage apoptosis by initiating incomplete autophagy through the MAPK/ERK/mTOR signaling pathway, which may be instrumental to the ability of C. psittaci to evade the host innate immune response and establish persistent infection. The improved understanding of the autophagic and cell death pathways triggered upon bacterial inclusion will likely help in the development of novel treatment strategies for chlamydia infection.
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Affiliation(s)
- Yanru Huang
- Institute of Pathogenic Biology, Hengyang Medical School, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang 421001, Hunan, China
| | - Sijia Li
- Institute of Pathogenic Biology, Hengyang Medical School, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang 421001, Hunan, China
| | - Siqin He
- Institute of Pathogenic Biology, Hengyang Medical School, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang 421001, Hunan, China
| | - Yumeng Li
- Institute of Pathogenic Biology, Hengyang Medical School, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang 421001, Hunan, China; Department of Clinical Laboratory, The First Affiliated Hospital of University of South China, Hengyang 421000, Hunan, China
| | - Qingzhi He
- School of Biotechnology, Guilin Medical University, Guilin 541199, China
| | - Yimou Wu
- Institute of Pathogenic Biology, Hengyang Medical School, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang 421001, Hunan, China.
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Pokrovskaya ID, Rhee SW, Ball KK, Kamykowski JA, Zhao OS, Cruz DRD, Cohen J, Aronova MA, Leapman RD, Storrie B. Tethered platelet capture provides a mechanism for restricting circulating platelet activation to the wound site. Res Pract Thromb Haemost 2023; 7:100058. [PMID: 36865905 PMCID: PMC9971284 DOI: 10.1016/j.rpth.2023.100058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/20/2022] [Accepted: 12/30/2022] [Indexed: 01/24/2023] Open
Abstract
Background Puncture wounding is a longstanding challenge to human health for which understanding is limited, in part, by a lack of detailed morphological data on how the circulating platelet capture to the vessel matrix leads to sustained, self-limiting platelet accumulation. Objectives The objective of this study was to produce a paradigm for self-limiting thrombus growth in a mouse jugular vein model. Methods Data mining of advanced electron microscopy images was performed from authors' laboratories. Results Wide-area transmission electron mcrographs revealed initial platelet capture to the exposed adventitia resulted in localized patches of degranulated, procoagulant-like platelets. Platelet activation to a procoagulant state was sensitive to dabigatran, a direct-acting PAR receptor inhibitor, but not to cangrelor, a P2Y12 receptor inhibitor. Subsequent thrombus growth was sensitive to both cangrelor and dabigatran and sustained by the capture of discoid platelet strings first to collagen-anchored platelets and later to loosely adherent peripheral platelets. Spatial examination indicated that staged platelet activation resulted in a discoid platelet tethering zone that was pushed progressively outward as platelets converted from one activation state to another. As thrombus growth slowed, discoid platelet recruitment became rare and loosely adherent intravascular platelets failed to convert to tightly adherent platelets. Conclusions In summary, the data support a model that we term Capture and Activate, in which the initial high platelet activation is directly linked to the exposed adventitia, all subsequent tethering of discoid platelets is to loosely adherent platelets that convert to tightly adherent platelets, and self-limiting, intravascular platelet activation over time is the result of decreased signaling intensity.
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Affiliation(s)
- Irina D Pokrovskaya
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Sung W Rhee
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kelly K Ball
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.,Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jeffrey A Kamykowski
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Oliver S Zhao
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
| | - Denzel R D Cruz
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
| | - Joshua Cohen
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
| | - Maria A Aronova
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
| | - Richard D Leapman
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
| | - Brian Storrie
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Khakurel A, Kudlyk T, Pokrovskaya I, D’Souza Z, Lupashin VV. GARP dysfunction results in COPI displacement, depletion of Golgi v-SNAREs and calcium homeostasis proteins. Front Cell Dev Biol 2022; 10:1066504. [PMID: 36578782 PMCID: PMC9791199 DOI: 10.3389/fcell.2022.1066504] [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: 10/10/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
Abstract
Golgi-associated retrograde protein (GARP) is an evolutionary conserved heterotetrameric protein complex that tethers endosome-derived vesicles and is vital for Golgi glycosylation. Microscopy and proteomic approaches were employed to investigate defects in Golgi physiology in RPE1 cells depleted for the GARP complex. Both cis and trans-Golgi compartments were significantly enlarged in GARP-knock-out (KO) cells. Proteomic analysis of Golgi-enriched membranes revealed significant depletion of a subset of Golgi residents, including Ca2+ binding proteins, enzymes, and SNAREs. Validation of proteomics studies revealed that SDF4 and ATP2C1, related to Golgi calcium homeostasis, as well as intra-Golgi v-SNAREs GOSR1 and BET1L, were significantly depleted in GARP-KO cells. Finding that GARP-KO is more deleterious to Golgi physiology than deletion of GARP-sensitive v-SNAREs, prompted a detailed investigation of COPI trafficking machinery. We discovered that in GARP-KO cells COPI is significantly displaced from the Golgi and partially relocalized to the ER-Golgi intermediate compartment (ERGIC). Moreover, COPI accessory proteins GOLPH3, ARFGAP1, GBF1, and BIG1 are also relocated to off-Golgi compartments. We propose that the dysregulation of COPI machinery, along with the depletion of Golgi v-SNAREs and alteration of Golgi Ca2+ homeostasis, are the major driving factors for the depletion of Golgi resident proteins, structural alterations, and glycosylation defects in GARP deficient cells.
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Legionella pneumophila Infection of Human Macrophages Retains Golgi Structure but Reduces O-Glycans. Pathogens 2022; 11:pathogens11080908. [PMID: 36015029 PMCID: PMC9415278 DOI: 10.3390/pathogens11080908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/02/2022] [Accepted: 08/08/2022] [Indexed: 11/30/2022] Open
Abstract
Legionella pneumophila is an accidental pathogen that replicates intracellularly within the Legionella-containing vacuole (LCV) in macrophages. Within an hour of infection, L. pneumophila secretes effectors to manipulate Rab1 and intercept ER-derived vesicles to the LCV. The downstream consequences of interrupted ER trafficking on the Golgi of macrophages are not clear. We examined the Golgi structure and function in L. pneumophila-infected human U937 macrophages. Intriguingly, the size of the Golgi in infected macrophages remained similar to uninfected macrophages. Furthermore, TEM analysis also did not reveal any significant changes in the ultrastructure of the Golgi in L. pneumophila-infected cells. Drug-induced Golgi disruption impacted bacterial replication in human macrophages, suggesting that an intact organelle is important for bacteria growth. To probe for Golgi functionality after L. pneumophila infection, we assayed glycosylation levels using fluorescent lectins. Golgi O-glycosylation levels, visualized by the fluorescent cis-Golgi lectin, Helix pomatia agglutinin (HPA), significantly decreased over time as infection progressed, compared to control cells. N-glycosylation levels in the Golgi, as measured by L-PHA lectin staining, were not impacted by L. pneumophila infection. To understand the mechanism of reduced O-glycans in the Golgi we monitored UDP-GalNAc transporter levels in infected macrophages. The solute carrier family 35 membrane A2 (SLC35A2) protein levels were significantly reduced in L. pneumophila-infected U937 and HeLa cells and L. pneumophila growth in human macrophages benefitted from GalNAc supplementation. The pronounced reduction in Golgi HPA levels was dependent on the translocation apparatus DotA expression in bacteria and occurred in a ubiquitin-independent manner. Thus, L. pneumophila infection of human macrophages maintains and requires an intact host Golgi ultrastructure despite known interference of ER–Golgi trafficking. Finally, L. pneumophila infection blocks the formation of O-linked glycans and reduces SLC35A2 protein levels in infected human macrophages.
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Sumya FT, Pokrovskaya ID, Lupashin V. Development and Initial Characterization of Cellular Models for COG Complex-Related CDG-II Diseases. Front Genet 2021; 12:733048. [PMID: 34603392 PMCID: PMC8484713 DOI: 10.3389/fgene.2021.733048] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
Conserved Oligomeric Golgi (COG) is an octameric protein complex that orchestrates intra-Golgi trafficking of glycosylation enzymes. Over a hundred individuals with 31 different COG mutations have been identified until now. The cellular phenotypes and clinical presentations of COG-CDGs are heterogeneous, and patients primarily represent neurological, skeletal, and hepatic abnormalities. The establishment of a cellular COG disease model will benefit the molecular study of the disease, explaining the detailed sequence of the interplay between the COG complex and the trafficking machinery. Moreover, patient fibroblasts are not a good representative of all the organ systems and cell types that are affected by COG mutations. We developed and characterized cellular models for human COG4 mutations, specifically in RPE1 and HEK293T cell lines. Using a combination of CRISPR/Cas9 and lentiviral transduction technologies, both myc-tagged wild-type and mutant (G516R and R729W) COG4 proteins were expressed under the endogenous COG4 promoter. Constructed isogenic cell lines were comprehensively characterized using biochemical, microscopy (superresolution and electron), and proteomics approaches. The analysis revealed similar stability and localization of COG complex subunits, wild-type cell growth, and normal Golgi morphology in all three cell lines. Importantly, COG4-G516R cells demonstrated increased HPA-647 binding to the plasma membrane glycoconjugates, while COG4-R729W cells revealed high GNL-647 binding, indicating specific defects in O- and N-glycosylation. Both mutant cell lines express an elevated level of heparin sulfate proteoglycans. Moreover, a quantitative mass-spectrometry analysis of proteins secreted by COG-deficient cell lines revealed abnormal secretion of SIL1 and ERGIC-53 proteins by COG4-G516R cells. Interestingly, the clinical phenotype of patients with congenital mutations in the SIL1 gene (Marinesco-Sjogren syndrome) overlaps with the phenotype of COG4-G516R patients (Saul-Wilson syndrome). Our work is the first compressive study involving the creation of different COG mutations in different cell lines other than the patient's fibroblast. It may help to address the underlying cause of the phenotypic defects leading to the discovery of a proper treatment guideline for COG-CDGs.
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Affiliation(s)
| | | | - Vladimir Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, United States
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Venous puncture wound hemostasis results in a vaulted thrombus structured by locally nucleated platelet aggregates. Commun Biol 2021; 4:1090. [PMID: 34531522 PMCID: PMC8445961 DOI: 10.1038/s42003-021-02615-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 08/03/2021] [Indexed: 12/22/2022] Open
Abstract
Primary hemostasis results in a platelet-rich thrombus that has long been assumed to form a solid plug. Unexpectedly, our 3-dimensional (3D) electron microscopy of mouse jugular vein puncture wounds revealed that the resulting thrombi were structured about localized, nucleated platelet aggregates, pedestals and columns, that produced a vaulted thrombus capped by extravascular platelet adherence. Pedestal and column surfaces were lined by procoagulant platelets. Furthermore, early steps in thrombus assembly were sensitive to P2Y12 inhibition and late steps to thrombin inhibition. Based on these results, we propose a Cap and Build, puncture wound paradigm that should have translational implications for bleeding control and hemostasis. Rhee, Pokrovskaya et al. utilize 3D electron microscopy of mouse jugular vein puncture wounds to reveal thrombi structured around localized, nucleated platelet aggregates that produced a vaulted thrombus capped by extravascular platelet adherence. As a result, the authors propose a “Cap and Build” paradigm of primary hemostasis.
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Jorgenson LM, Olson-Wood MG, Rucks EA. Shifting proteomes: limitations in using the BioID proximity labeling system to study SNARE protein trafficking during infection with intracellular pathogens. Pathog Dis 2021; 79:ftab039. [PMID: 34323972 PMCID: PMC8379010 DOI: 10.1093/femspd/ftab039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 07/25/2021] [Indexed: 11/12/2022] Open
Abstract
We hypothesize that intracellular trafficking pathways are altered in chlamydial infected cells to maximize the ability of Chlamydia to scavenge nutrients while not overtly stressing the host cell. Previous data demonstrated the importance of two eukaryotic SNARE proteins, VAMP4 and syntaxin 10 (Stx10), in chlamydial growth and development. Although, the mechanism for these effects is still unknown. To interrogate whether chlamydial infection altered these proteins' networks, we created BirA*-VAMP4 and BirA*-Stx10 fusion constructs to use the BioID proximity labeling system. While we identified a novel eukaryotic protein-protein interaction between Stx10 and VAPB, we also identified caveats in using the BioID system to study the impact of infection by an obligate intracellular pathogen on SNARE protein networks. The addition of the BirA* altered the localization of VAMP4 and Stx10 during infection with Chlamydia trachomatis serovars L2 and D and Coxiella burnetii Nine Mile Phase II. We also discovered that BirA* traffics to and biotinylates Coxiella-containing vacuoles and, in general, has a propensity for labeling membrane or membrane-associated proteins. While the BioID system identified a novel association for Stx10, it is not a reliable methodology to examine intracellular trafficking pathway dynamics during infection with intracellular pathogens.
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Affiliation(s)
- Lisa M Jorgenson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Macy G Olson-Wood
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Elizabeth A Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA
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13
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Inclusion Membrane Growth and Composition Are Altered by Overexpression of Specific Inclusion Membrane Proteins in Chlamydia trachomatis L2. Infect Immun 2021; 89:e0009421. [PMID: 33875478 PMCID: PMC8208519 DOI: 10.1128/iai.00094-21] [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: 01/26/2023] Open
Abstract
Chlamydia trachomatis is the leading cause of bacterial sexually transmitted infections. This obligate intracellular bacterium develops within a membrane-bound vacuole called an inclusion, which sequesters the chlamydiae from the host cytoplasm. Host-pathogen interactions at this interface are mediated by chlamydial inclusion membrane proteins (Incs). However, the specific functions of most Incs are poorly characterized. Previous work from our laboratories indicated that expressing an IncF fusion protein at high levels in C. trachomatis L2 negatively impacted inclusion expansion and progeny production. We hypothesize that some Incs function in the structure and organization of the inclusion membrane and that overexpression of those Incs will alter the composition of endogenous Incs within the inclusion membrane. Consequently, inclusion biogenesis and chlamydial development are negatively impacted. To investigate this, C. trachomatis L2 was transformed with inducible expression plasmids encoding IncF-, CT813-, or CT226-FLAG. Overexpression of IncF-FLAG or CT813-FLAG, but not CT226-FLAG, altered chlamydial development, as demonstrated by smaller inclusions, fewer progeny, and increased plasmid loss. The overexpression of CT813-FLAG reduced the detectable levels of endogenous IncE and IncG in the inclusion membrane. Notably, recruitment of sorting nexin-6, a eukaryotic protein binding partner of IncE, was also reduced after CT813 overexpression. Gene expression studies and ultrastructural analysis of chlamydial organisms demonstrated that chlamydial development was altered when CT813-FLAG was overexpressed. Overall, these data indicate that disrupting the expression of specific Incs changed the composition of Incs within the inclusion membrane and the recruitment of associated host cell proteins, which negatively impacted C. trachomatis development.
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14
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Dolat L, Valdivia RH. An endometrial organoid model of interactions between Chlamydia and epithelial and immune cells. J Cell Sci 2021; 134:jcs.252403. [PMID: 33468625 DOI: 10.1242/jcs.252403] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Our understanding of how the obligate intracellular bacterial pathogen Chlamydia trachomatis reprograms the function of infected cells in the upper genital tract is largely based on observations made in cell culture with transformed epithelial cell lines. Here, we describe a primary organoid system derived from endometrial tissue to recapitulate epithelial cell diversity, polarity and ensuing responses to Chlamydia infection. Using high-resolution and time-lapse microscopy, we catalog the infection process in organoids from invasion to egress, including the reorganization of the cytoskeleton and positioning of intracellular organelles. We show this model is amenable to screening C. trachomatis mutants for defects in the fusion of pathogenic vacuoles, the recruitment of intracellular organelles and inhibition of cell death. Moreover, we reconstructed a primary immune cell response by co-culturing infected organoids with neutrophils, and determined that effectors like CPAF (also known as CT858) and TepP (also known as CT875) limit the recruitment of neutrophils to infected organoids. Collectively, our model can be applied to study the cell biology of Chlamydia infections in three-dimensional structures that better reflect the diversity of cell types and polarity encountered by Chlamydia in their animal hosts.
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Affiliation(s)
- Lee Dolat
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27701, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27701, USA
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15
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Lascu I, Mereuță I, Chiciudean I, Hansen H, Avramescu SM, Tănase A, Stoica I. Complete genome sequence of Photobacterium ganghwense C2.2: A new polyhydroxyalkanoate production candidate. Microbiologyopen 2021; 10:e1182. [PMID: 33970538 PMCID: PMC8087987 DOI: 10.1002/mbo3.1182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 12/30/2022] Open
Abstract
Polyhydroxyalkanoates (PHAs) are biodegradable bioplastics that can be manufactured sustainably and represent a promising green alternative to petrochemical-based plastics. Here, we describe the complete genome of a new marine PHA-producing bacterium-Photobacterium ganghwense (strain C2.2), which we have isolated from the Black Sea seashore. This new isolate is psychrotolerant and accumulates PHA when glycerol is provided as the main carbon source. Transmission electron microscopy, specific staining with Nile Red visualized via epifluorescence microscopy and gas chromatography analysis confirmed the accumulation of PHA. This is the only PHA-producing Photobacterium for which we now have a complete genome sequence, allowing us to investigate the pathways for PHA production and other secondary metabolite synthesis pathways. The de novo assembly genome, obtained using open-source tools, comprises two chromosomes (3.5, 2 Mbp) and a megaplasmid (202 kbp). We identify the entire PHA synthesis gene cluster that encodes a class I PHA synthase, a phasin, a 3-ketothiolase, and an acetoacetyl-CoA reductase. No conventional PHA depolymerase was identified in strain C2.2, but a putative lipase with extracellular amorphous PHA depolymerase activity was annotated, suggesting that C2.2 is unable to degrade intracellular PHA. A complete pathway for the conversion of glycerol to acetyl-CoA was annotated, in accordance with its ability to convert glycerol to PHA. Several secondary metabolite biosynthetic gene clusters and a low number of genes involved in antibiotic resistance and virulence were also identified, indicating the strain's suitability for biotechnological applications.
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Affiliation(s)
- Irina Lascu
- Department of GeneticsFaculty of BiologyUniversity of BucharestBucharestRomania
| | - Ioana Mereuță
- Department of GeneticsFaculty of BiologyUniversity of BucharestBucharestRomania
| | - Iulia Chiciudean
- Department of GeneticsFaculty of BiologyUniversity of BucharestBucharestRomania
| | - Hilde Hansen
- Department of ChemistryFaculty of Science and TechnologyUiT The Arctic University of NorwayTromsøNorway
| | - Sorin Marius Avramescu
- Department of Organic Chemistry, Biochemistry and CatalysisFaculty of ChemistryUniversity of BucharestBucharestRomania
| | - Ana‐Maria Tănase
- Department of GeneticsFaculty of BiologyUniversity of BucharestBucharestRomania
| | - Ileana Stoica
- Department of GeneticsFaculty of BiologyUniversity of BucharestBucharestRomania
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16
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D'Souza Z, Taher FS, Lupashin VV. Golgi inCOGnito: From vesicle tethering to human disease. Biochim Biophys Acta Gen Subj 2020; 1864:129694. [PMID: 32730773 PMCID: PMC7384418 DOI: 10.1016/j.bbagen.2020.129694] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 12/11/2022]
Abstract
The Conserved Oligomeric Golgi (COG) complex, a multi-subunit vesicle tethering complex of the CATCHR (Complexes Associated with Tethering Containing Helical Rods) family, controls several aspects of cellular homeostasis by orchestrating retrograde vesicle traffic within the Golgi. The COG complex interacts with all key players regulating intra-Golgi trafficking, namely SNAREs, SNARE-interacting proteins, Rabs, coiled-coil tethers, and vesicular coats. In cells, COG deficiencies result in the accumulation of non-tethered COG-complex dependent (CCD) vesicles, dramatic morphological and functional abnormalities of the Golgi and endosomes, severe defects in N- and O- glycosylation, Golgi retrograde trafficking, sorting and protein secretion. In humans, COG mutations lead to severe multi-systemic diseases known as COG-Congenital Disorders of Glycosylation (COG-CDG). In this report, we review the current knowledge of the COG complex and analyze COG-related trafficking and glycosylation defects in COG-CDG patients.
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Affiliation(s)
- Zinia D'Souza
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Farhana S Taher
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Vladimir V Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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17
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Realegeno S, Priyamvada L, Kumar A, Blackburn JB, Hartloge C, Puschnik AS, Sambhara S, Olson VA, Carette JE, Lupashin V, Satheshkumar PS. Conserved Oligomeric Golgi (COG) Complex Proteins Facilitate Orthopoxvirus Entry, Fusion and Spread. Viruses 2020; 12:v12070707. [PMID: 32629851 PMCID: PMC7411930 DOI: 10.3390/v12070707] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 06/25/2020] [Indexed: 02/07/2023] Open
Abstract
Although orthopoxviruses (OPXV) are known to encode a majority of the genes required for replication in host cells, genome-wide genetic screens have revealed that several host pathways are indispensable for OPXV infection. Through a haploid genetic screen, we previously identified several host genes required for monkeypox virus (MPXV) infection, including the individual genes that form the conserved oligomeric Golgi (COG) complex. The COG complex is an eight-protein (COG1-COG8) vesicle tethering complex important for regulating membrane trafficking, glycosylation enzymes, and maintaining Golgi structure. In this study, we investigated the role of the COG complex in OPXV infection using cell lines with individual COG gene knockout (KO) mutations. COG KO cells infected with MPXV and vaccinia virus (VACV) produced small plaques and a lower virus yield compared to wild type (WT) cells. In cells where the KO phenotype was reversed using a rescue plasmid, the size of virus plaques increased demonstrating a direct link between the decrease in viral spread and the KO of COG genes. KO cells infected with VACV displayed lower levels of viral fusion and entry compared to WT suggesting that the COG complex is important for early events in OPXV infection. Additionally, fewer actin tails were observed in VACV-infected KO cells compared to WT. Since COG complex proteins are required for cellular trafficking of glycosylated membrane proteins, the disruption of this process due to lack of individual COG complex proteins may potentially impair the virus-cell interactions required for viral entry and egress. These data validate that the COG complex previously identified in our genetic screens plays a role in OPXV infection.
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Affiliation(s)
- Susan Realegeno
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (S.R.); (L.P.); (C.H.); (V.A.O.)
| | - Lalita Priyamvada
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (S.R.); (L.P.); (C.H.); (V.A.O.)
| | - Amrita Kumar
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (A.K.); (S.S.)
| | - Jessica B. Blackburn
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (J.B.B.); (V.L.)
| | - Claire Hartloge
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (S.R.); (L.P.); (C.H.); (V.A.O.)
| | - Andreas S. Puschnik
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94035, USA; (A.S.P.); (J.E.C.)
| | - Suryaprakash Sambhara
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (A.K.); (S.S.)
| | - Victoria A. Olson
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (S.R.); (L.P.); (C.H.); (V.A.O.)
| | - Jan E. Carette
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94035, USA; (A.S.P.); (J.E.C.)
| | - Vladimir Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (J.B.B.); (V.L.)
| | - Panayampalli Subbian Satheshkumar
- Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, GA 3033, USA; (S.R.); (L.P.); (C.H.); (V.A.O.)
- Correspondence:
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18
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Martínez JL, Arias CF. Role of the Guanine Nucleotide Exchange Factor GBF1 in the Replication of RNA Viruses. Viruses 2020; 12:E682. [PMID: 32599855 PMCID: PMC7354614 DOI: 10.3390/v12060682] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/06/2020] [Accepted: 04/06/2020] [Indexed: 12/12/2022] Open
Abstract
The guanine nucleotide exchange factor GBF1 is a well-known factor that can activate different ADP-ribosylation factor (Arf) proteins during the regulation of different cellular vesicular transport processes. In the last decade, it has become increasingly evident that GBF1 can also regulate different steps of the replication cycle of RNA viruses belonging to different virus families. GBF1 has been shown not only to facilitate the intracellular traffic of different viral and cellular elements during infection, but also to modulate the replication of viral RNA, the formation and maturation of viral replication complexes, and the processing of viral proteins through mechanisms that do not depend on its canonical role in intracellular transport. Here, we review the various roles that GBF1 plays during the replication of different RNA viruses.
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Affiliation(s)
| | - Carlos F. Arias
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 4510, Morelos, Mexico;
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19
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Gitsels A, Sanders N, Vanrompay D. Chlamydial Infection From Outside to Inside. Front Microbiol 2019; 10:2329. [PMID: 31649655 PMCID: PMC6795091 DOI: 10.3389/fmicb.2019.02329] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Chlamydia are obligate intracellular bacteria, characterized by a unique biphasic developmental cycle. Specific interactions with the host cell are crucial for the bacteria’s survival and amplification because of the reduced chlamydial genome. At the start of infection, pathogen-host interactions are set in place in order for Chlamydia to enter the host cell and reach the nutrient-rich peri-Golgi region. Once intracellular localization is established, interactions with organelles and pathways of the host cell enable the necessary hijacking of host-derived nutrients. Detailed information on the aforementioned processes will increase our understanding on the intracellular pathogenesis of chlamydiae and hence might lead to new strategies to battle chlamydial infection. This review summarizes how chlamydiae generate their intracellular niche in the host cell, acquire host-derived nutrients in order to enable their growth and finally exit the host cell in order to infect new cells. Moreover, the evolution in the development of molecular genetic tools, necessary for studying the chlamydial infection biology in more depth, is discussed in great detail.
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Affiliation(s)
- Arlieke Gitsels
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niek Sanders
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Daisy Vanrompay
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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20
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Blackburn JB, D'Souza Z, Lupashin VV. Maintaining order: COG complex controls Golgi trafficking, processing, and sorting. FEBS Lett 2019; 593:2466-2487. [PMID: 31381138 PMCID: PMC6771879 DOI: 10.1002/1873-3468.13570] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/31/2022]
Abstract
The conserved oligomeric Golgi (COG) complex, a multisubunit tethering complex of the CATCHR (complexes associated with tethering containing helical rods) family, controls membrane trafficking and ensures Golgi homeostasis by orchestrating retrograde vesicle targeting within the Golgi. In humans, COG defects lead to severe multisystemic diseases known as COG-congenital disorders of glycosylation (COG-CDG). The COG complex both physically and functionally interacts with all classes of molecules maintaining intra-Golgi trafficking, namely SNAREs, SNARE-interacting proteins, Rabs, coiled-coil tethers, and vesicular coats. Here, we review our current knowledge of COG-related trafficking and glycosylation defects in humans and model organisms, and analyze possible scenarios for the molecular mechanism of the COG orchestrated vesicle targeting.
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Affiliation(s)
- Jessica B. Blackburn
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
- Present address:
Division of Allergy, Pulmonary and Critical Care MedicineDepartment of MedicineVanderbilt University Medical CenterNashvilleTNUSA
| | - Zinia D'Souza
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Vladimir V. Lupashin
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
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21
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Make It a Sweet Home: Responses of Chlamydia trachomatis to the Challenges of an Intravacuolar Lifestyle. Microbiol Spectr 2019; 7. [PMID: 30848236 DOI: 10.1128/microbiolspec.bai-0005-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Intravacuolar development has been adopted by several bacteria that grow inside a host cell. Remaining in a vacuole, as opposed to breaching the cytosol, protects the bacteria from some aspects of the cytosolic innate host defense and allows them to build an environment perfectly adapted to their needs. However, this raises new challenges: the host resources are separated from the bacteria by a lipid bilayer that is nonpermeable to most nutrients. In addition, the area of this lipid bilayer needs to expand to accommodate bacterial multiplication. This requires building material and energy that are not directly invested in bacterial growth. This article describes the strategies acquired by the obligate intracellular pathogen Chlamydia trachomatis to circumvent the difficulties raised by an intravacuolar lifestyle. We start with an overview of the origin and composition of the vacuolar membrane. Acquisition of host resources is largely, although not exclusively, mediated by interactions with membranous compartments of the eukaryotic cell, and we describe how the inclusion modifies the architecture of the cell and distribution of the neighboring compartments. The second part of this review describes the four mechanisms characterized so far by which the bacteria acquire resources from the host: (i) transport/diffusion across the vacuole membrane, (ii) fusion of this membrane with host compartments, (iii) direct transfer of lipids at membrane contact sites, and (iv) engulfment by the vacuole membrane of large cytoplasmic entities.
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22
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NK Cell-Mediated Processing Of Chlamydia psittaci Drives Potent Anti-Bacterial Th1 Immunity. Sci Rep 2019; 9:4799. [PMID: 30886314 PMCID: PMC6423132 DOI: 10.1038/s41598-019-41264-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/05/2019] [Indexed: 11/08/2022] Open
Abstract
Natural killer (NK) cells are innate immune cells critically involved in the early immune response against various pathogens including chlamydia. Here, we demonstrate that chlamydia-infected NK cells prevent the intracellular establishment and growth of the bacteria. Upon infection, they display functional maturation characterized by enhanced IFN-γ secretion, CD146 induction, PKCϴ activation, and granule secretion. Eventually, chlamydia are released in a non-infectious, highly immunogenic form driving a potent Th1 immune response. Further, anti-chlamydial antibodies generated during immunization neutralize the infection of epithelial cells. The release of chlamydia from NK cells requires PKCϴ function and active degranulation, while granule-associated granzyme B drives the loss of chlamydial infectivity. Cellular infection and bacterial release can be undergone repeatedly and do not affect NK cell function. Strikingly, NK cells passing through such an infection cycle significantly improve their cytotoxicity. Thus, NK cells not only protect themselves against productive chlamydial infections but also actively trigger potent anti-bacterial responses.
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23
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Blackburn JB, Kudlyk T, Pokrovskaya I, Lupashin VV. More than just sugars: Conserved oligomeric Golgi complex deficiency causes glycosylation-independent cellular defects. Traffic 2018; 19:463-480. [PMID: 29573151 PMCID: PMC5948163 DOI: 10.1111/tra.12564] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 01/03/2023]
Abstract
The conserved oligomeric Golgi (COG) complex controls membrane trafficking and ensures Golgi homeostasis by orchestrating retrograde vesicle trafficking within the Golgi. Human COG defects lead to severe multisystemic diseases known as COG-congenital disorders of glycosylation (COG-CDG). To gain better understanding of COG-CDGs, we compared COG knockout cells with cells deficient to 2 key enzymes, Alpha-1,3-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase and uridine diphosphate-glucose 4-epimerase (GALE), which contribute to proper N- and O-glycosylation. While all knockout cells share similar defects in glycosylation, these defects only account for a small fraction of observed COG knockout phenotypes. Glycosylation deficiencies were not associated with the fragmented Golgi, abnormal endolysosomes, defective sorting and secretion or delayed retrograde trafficking, indicating that these phenotypes are probably not due to hypoglycosylation, but to other specific interactions or roles of the COG complex. Importantly, these COG deficiency specific phenotypes were also apparent in COG7-CDG patient fibroblasts, proving the human disease relevance of our CRISPR knockout findings. The knowledge gained from this study has important implications, both for understanding the physiological role of COG complex in Golgi homeostasis in eukaryotic cells, and for better understanding human diseases associated with COG/Golgi impairment.
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Affiliation(s)
- Jessica B Blackburn
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Tetyana Kudlyk
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Irina Pokrovskaya
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Vladimir V Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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24
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Banhart S, Rose L, Aeberhard L, Koch-Edelmann S, Heuer D. Chlamydia trachomatis and its interaction with the cellular retromer. Int J Med Microbiol 2017; 308:197-205. [PMID: 29122514 DOI: 10.1016/j.ijmm.2017.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/16/2017] [Accepted: 10/24/2017] [Indexed: 11/26/2022] Open
Abstract
Chlamydia trachomatis is an important human pathogen. This obligate intracellular bacterium grows inside the eukaryotic cell in a membrane-bound compartment, the inclusion. Recent global approaches describe the interactions of C. trachomatis with its host cell and indicate the inclusion is an intracellular trafficking hub embedded into the cellular vesicular trafficking pathways recruiting subunits of the retromer protein complex of the host cell. Here we review these recent developments in deciphering Chlamydia-host cell interactions with emphasis on the role of the retromer complex.
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Affiliation(s)
- Sebastian Banhart
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Laura Rose
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Lukas Aeberhard
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Sophia Koch-Edelmann
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Dagmar Heuer
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany.
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25
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Dolat L, Valdivia RH. Bacterial Subversion of COG-Dependent Membrane Traffic. Trends Cell Biol 2017; 27:877-878. [PMID: 28988619 DOI: 10.1016/j.tcb.2017.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 09/22/2017] [Indexed: 11/25/2022]
Abstract
Intracellular bacterial pathogens thrive within eukaryotic cells by interacting with a range of organelles to establish a replicative niche. In a new study in Cell Host and Microbe, Miller et al. identify a Brucella abortus effector that subverts membrane and protein transport to the Golgi apparatus to promote bacterial replication.
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Affiliation(s)
- Lee Dolat
- Department of Molecular Genetics and Microbiology and Center for Host-Microbe Interactions, Duke University School of Medicine, Durham, NC, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology and Center for Host-Microbe Interactions, Duke University School of Medicine, Durham, NC, USA.
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Miller CN, Smith EP, Cundiff JA, Knodler LA, Bailey Blackburn J, Lupashin V, Celli J. A Brucella Type IV Effector Targets the COG Tethering Complex to Remodel Host Secretory Traffic and Promote Intracellular Replication. Cell Host Microbe 2017; 22:317-329.e7. [PMID: 28844886 PMCID: PMC5599354 DOI: 10.1016/j.chom.2017.07.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 06/16/2017] [Accepted: 07/27/2017] [Indexed: 10/19/2022]
Abstract
Many intracellular pathogens exploit host secretory trafficking to support their intracellular cycle, but knowledge of these pathogenic processes is limited. The bacterium Brucella abortus uses a type IV secretion system (VirB T4SS) to generate a replication-permissive Brucella-containing vacuole (rBCV) derived from the host ER, a process that requires host early secretory trafficking. Here we show that the VirB T4SS effector BspB contributes to rBCV biogenesis and Brucella replication by interacting with the conserved oligomeric Golgi (COG) tethering complex, a major coordinator of Golgi vesicular trafficking, thus remodeling Golgi membrane traffic and redirecting Golgi-derived vesicles to the BCV. Altogether, these findings demonstrate that Brucella modulates COG-dependent trafficking via delivery of a T4SS effector to promote rBCV biogenesis and intracellular proliferation, providing mechanistic insight into how bacterial exploitation of host secretory functions promotes pathogenesis.
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Affiliation(s)
- Cheryl N Miller
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Erin P Smith
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Jennifer A Cundiff
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Leigh A Knodler
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Jessica Bailey Blackburn
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Vladimir Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jean Celli
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA.
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27
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Phosphorylation of Golgi Peripheral Membrane Protein Grasp65 Is an Integral Step in the Formation of the Human Cytomegalovirus Cytoplasmic Assembly Compartment. mBio 2016; 7:mBio.01554-16. [PMID: 27703074 PMCID: PMC5050342 DOI: 10.1128/mbio.01554-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Human cytomegalovirus (HCMV) is the largest member of the Herpesviridae and represents a significant cause of disease. During virus replication, HCMV alters cellular functions to facilitate its replication, including significant reorganization of the secretory and endocytic pathways of the infected cell. A defining morphologic change of the infected cell is the formation of a membranous structure in the cytoplasm that is designated the virion assembly compartment (AC), which consists of virion structural proteins surrounded by cellular membranes. The loss of normal Golgi compartment morphology and its relocalization from a juxtanuclear ribbonlike structure to a series of concentric rings on the periphery of the AC represents a readily recognized reorganization of cellular membranes in the HCMV-infected cell. Although trafficking of viral proteins to this compartment is required for the assembly of infectious virions, the functional significance of the reorganization of intracellular membranes like the Golgi membranes into the AC in the assembly of infectious virus remains understudied. In this study, we determined that Golgi membrane ribbon fragmentation increased during the early cytoplasmic phase of virion assembly and that Golgi membrane fragmentation in infected cells was dependent on the phosphorylation of an integral cis-Golgi protein, Grasp65. Inhibition of Golgi membrane fragmentation and of its reorganization into the AC resulted in decreased production of infectious particles and alteration of the incorporation of an essential protein into the envelope of the mature virion. These results demonstrated the complexity of the virus-host cell interactions required for efficient assembly of this large DNA virus. The human cytomegalovirus (HCMV)-induced reorganization of intracellular membranes that is required for the formation of the viral assembly compartment (AC) has been an area of study over the last 20 years. The significance of this virus-induced structure has been evinced by the results of several studies which showed that relocalization of viral proteins to the AC was required for efficient assembly of infectious virus. In this study, we have identified a mechanism for the fragmentation of the Golgi ribbon in the infected cell en route to AC morphogenesis. Identification of this fundamental process during HCMV replication allowed us to propose that the functional role of Golgi membrane reorganization during HCMV infection was the concentration of viral structural proteins and subviral structures into a single intracellular compartment in order to facilitate efficient protein-protein interactions and the virion protein trafficking required for the assembly of this large and structurally complex virus.
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Abstract
Chlamydia spp. are important causes of human disease for which no effective vaccine exists. These obligate intracellular pathogens replicate in a specialized membrane compartment and use a large arsenal of secreted effectors to survive in the hostile intracellular environment of the host. In this Review, we summarize the progress in decoding the interactions between Chlamydia spp. and their hosts that has been made possible by recent technological advances in chlamydial proteomics and genetics. The field is now poised to decipher the molecular mechanisms that underlie the intimate interactions between Chlamydia spp. and their hosts, which will open up many exciting avenues of research for these medically important pathogens.
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Bailey Blackburn J, Pokrovskaya I, Fisher P, Ungar D, Lupashin VV. COG Complex Complexities: Detailed Characterization of a Complete Set of HEK293T Cells Lacking Individual COG Subunits. Front Cell Dev Biol 2016; 4:23. [PMID: 27066481 PMCID: PMC4813393 DOI: 10.3389/fcell.2016.00023] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/11/2016] [Indexed: 01/05/2023] Open
Abstract
The Conserved Oligomeric Golgi complex is an evolutionarily conserved multisubunit tethering complex (MTC) that is crucial for intracellular membrane trafficking and Golgi homeostasis. The COG complex interacts with core vesicle docking and fusion machinery at the Golgi; however, its exact mechanism of action is still an enigma. Previous studies of COG complex were limited to the use of CDGII (Congenital disorders of glycosylation type II)-COG patient fibroblasts, siRNA mediated knockdowns, or protein relocalization approaches. In this study we have used the CRISPR approach to generate HEK293T knock-out (KO) cell lines missing individual COG subunits. These cell lines were characterized for glycosylation and trafficking defects, cell proliferation rates, stability of COG subunits, localization of Golgi markers, changes in Golgi structure, and N-glycan profiling. We found that all KO cell lines were uniformly deficient in cis/medial-Golgi glycosylation and each had nearly abolished binding of Cholera toxin. In addition, all cell lines showed defects in Golgi morphology, retrograde trafficking and sorting, sialylation and fucosylation, but severities varied according to the affected subunit. Lobe A and Cog6 subunit KOs displayed a more severely distorted Golgi structure, while Cog2, 3, 4, 5, and 7 knock outs had the most hypo glycosylated form of Lamp2. These results led us to conclude that every subunit is essential for COG complex function in Golgi trafficking, though to varying extents. We believe that this study and further analyses of these cells will help further elucidate the roles of individual COG subunits and bring a greater understanding to the class of MTCs as a whole.
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Affiliation(s)
- Jessica Bailey Blackburn
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
| | - Irina Pokrovskaya
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
| | - Peter Fisher
- Department of Biology, University of York York, UK
| | - Daniel Ungar
- Department of Biology, University of York York, UK
| | - Vladimir V Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences Little Rock, AR, USA
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Truchan HK, Cockburn CL, Hebert KS, Magunda F, Noh SM, Carlyon JA. The Pathogen-Occupied Vacuoles of Anaplasma phagocytophilum and Anaplasma marginale Interact with the Endoplasmic Reticulum. Front Cell Infect Microbiol 2016; 6:22. [PMID: 26973816 PMCID: PMC4771727 DOI: 10.3389/fcimb.2016.00022] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 02/08/2016] [Indexed: 11/13/2022] Open
Abstract
The genus Anaplasma consists of tick-transmitted obligate intracellular bacteria that invade white or red blood cells to cause debilitating and potentially fatal infections. A. phagocytophilum, a human and veterinary pathogen, infects neutrophils to cause granulocytic anaplasmosis. A. marginale invades bovine erythrocytes. Evidence suggests that both species may also infect endothelial cells in vivo. In mammalian and arthropod host cells, A. phagocytophilum and A. marginale reside in host cell derived pathogen-occupied vacuoles (POVs). While it was recently demonstrated that the A. phagocytophilum-occupied vacuole (ApV) intercepts membrane traffic from the trans-Golgi network, it is unclear if it or the A. marginale-occupied vacuole (AmV) interacts with other secretory organelles. Here, we demonstrate that the ApV and AmV extensively interact with the host endoplasmic reticulum (ER) in endothelial, myeloid, and/or tick cells. ER lumen markers, calreticulin, and protein disulfide isomerase, and the ER membrane marker, derlin-1, were pronouncedly recruited to the peripheries of both POVs. ApV association with the ER initiated early and continued throughout the infection cycle. Both the ApV and AmV interacted with the rough ER and smooth ER. However, only derlin-1-positive rough ER derived vesicles were delivered into the ApV lumen where they localized with intravacuolar bacteria. Transmission electron microscopy identified multiple ER-POV membrane contact sites on the cytosolic faces of both species' vacuoles that corresponded to areas on the vacuoles' lumenal faces where intravacuolar Anaplasma organisms closely associated. A. phagocytophilum is known to hijack Rab10, a GTPase that regulates ER dynamics and morphology. Yet, ApV-ER interactions were unhindered in cells in which Rab10 had been knocked down, demonstrating that the GTPase is dispensable for the bacterium to parasitize the ER. These data establish the ApV and AmV as pathogen-host interfaces that directly engage the ER in vertebrate and invertebrate host cells and evidence the conservation of ER parasitism between two Anaplasma species.
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Affiliation(s)
- Hilary K Truchan
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine Richmond, VA, USA
| | - Chelsea L Cockburn
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine Richmond, VA, USA
| | - Kathryn S Hebert
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine Richmond, VA, USA
| | - Forgivemore Magunda
- Program in Vector Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State UniversityPullman, WA, USA; The Paul G. Allen School for Global Animal Health, Washington State UniversityPullman, WA, USA
| | - Susan M Noh
- Program in Vector Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State UniversityPullman, WA, USA; Animal Disease Research Unit, Agricultural Research Service, U. S. Department of AgriculturePullman, WA, USA
| | - Jason A Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine Richmond, VA, USA
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Personnic N, Bärlocher K, Finsel I, Hilbi H. Subversion of Retrograde Trafficking by Translocated Pathogen Effectors. Trends Microbiol 2016; 24:450-462. [PMID: 26924068 DOI: 10.1016/j.tim.2016.02.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/22/2016] [Accepted: 02/01/2016] [Indexed: 12/22/2022]
Abstract
Intracellular bacterial pathogens subvert the endocytic bactericidal pathway to form specific replication-permissive compartments termed pathogen vacuoles or inclusions. To this end, the pathogens employ type III or type IV secretion systems, which translocate dozens, if not hundreds, of different effector proteins into their host cells, where they manipulate vesicle trafficking and signaling pathways in favor of the intruders. While the distinct cocktail of effectors defines the specific processes by which a pathogen vacuole is formed, the different pathogens commonly target certain vesicle trafficking routes, including the endocytic or secretory pathway. Recently, the retrograde transport pathway from endosomal compartments to the trans-Golgi network emerged as an important route affecting pathogen vacuole formation. Here, we review current insight into the host cell's retrograde trafficking pathway and how vacuolar pathogens of the genera Legionella, Coxiella, Salmonella, Chlamydia, and Simkania employ mechanistically distinct strategies to subvert this pathway, thus promoting intracellular survival and replication.
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Affiliation(s)
- Nicolas Personnic
- Institute of Medical Microbiology, Department of Medicine, University of Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland
| | - Kevin Bärlocher
- Institute of Medical Microbiology, Department of Medicine, University of Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland
| | - Ivo Finsel
- Max von Pettenkofer Institute, Ludwig-Maximilians University Munich, Pettenkoferstrasse 9a, 80336 Munich, Germany
| | - Hubert Hilbi
- Institute of Medical Microbiology, Department of Medicine, University of Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland; Max von Pettenkofer Institute, Ludwig-Maximilians University Munich, Pettenkoferstrasse 9a, 80336 Munich, Germany.
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32
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The Cytolytic Amphipathic β(2,2)-Amino Acid LTX-401 Induces DAMP Release in Melanoma Cells and Causes Complete Regression of B16 Melanoma. PLoS One 2016; 11:e0148980. [PMID: 26881822 PMCID: PMC4755540 DOI: 10.1371/journal.pone.0148980] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/26/2016] [Indexed: 01/23/2023] Open
Abstract
In the present study we examined the ability of the amino acid derivative LTX-401 to induce cell death in cancer cell lines, as well as the capacity to induce regression in a murine melanoma model. Mode of action studies in vitro revealed lytic cell death and release of danger-associated molecular pattern molecules, preceded by massive cytoplasmic vacuolization and compromised lysosomes in treated cells. The use of a murine melanoma model demonstrated that the majority of animals treated with intratumoural injections of LTX-401 showed complete and long-lasting remission. Taken together, these results demonstrate the potential of LTX-401 as an immunotherapeutic agent for the treatment of solid tumors.
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33
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Creating Knockouts of Conserved Oligomeric Golgi Complex Subunits Using CRISPR-Mediated Gene Editing Paired with a Selection Strategy Based on Glycosylation Defects Associated with Impaired COG Complex Function. Methods Mol Biol 2016; 1496:145-61. [PMID: 27632008 DOI: 10.1007/978-1-4939-6463-5_12] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The conserved oligomeric Golgi (COG) complex is a key evolutionally conserved multisubunit protein machinery that regulates tethering and fusion of intra-Golgi transport vesicles. The Golgi apparatus specifically promotes sorting and complex glycosylation of glycoconjugates. Without proper glycosylation and processing, proteins and lipids will be mislocalized and/or have impaired function. The Golgi glycosylation machinery is kept in homeostasis by a careful balance of anterograde and retrograde trafficking to ensure proper localization of the glycosylation enzymes and their substrates. This balance, like other steps of membrane trafficking, is maintained by vesicle trafficking machinery that includes COPI vesicular coat proteins, SNAREs, Rabs, and both coiled-coil and multi-subunit vesicular tethers. The COG complex interacts with other membrane trafficking components and is essential for proper localization of Golgi glycosylation machinery. Here we describe using CRISPR-mediated gene editing coupled with a phenotype-based selection strategy directly linked to the COG complex's role in glycosylation homeostasis to obtain COG complex subunit knockouts (KOs). This has resulted in clonal KOs for each COG subunit in HEK293T cells and gives the ability to further probe the role of the COG complex in Golgi homeostasis.
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34
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Abstract
The ability to create and maintain a specialized organelle that supports bacterial replication is an important virulence property for many intracellular pathogens. Living in a membrane-bound vacuole presents inherent challenges, including the need to remodel a plasma membrane-derived organelle into a novel structure that will expand and provide essential nutrients to support replication, while also having the vacuole avoid membrane transport pathways that target bacteria for destruction in lysosomes. It is clear that pathogenic bacteria use different strategies to accomplish these tasks. The dynamics by which host Rab GTPases associate with pathogen-occupied vacuoles provide insight into the mechanisms used by different bacteria to manipulate host membrane transport. In this review we highlight some of the strategies bacteria use to maintain a pathogen-occupied vacuole by focusing on the Rab proteins involved in biogenesis and maintenance of these novel organelles.
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Affiliation(s)
- Racquel Kim Sherwood
- Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA
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35
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Mehlitz A, Rudel T. Modulation of host signaling and cellular responses by Chlamydia. Cell Commun Signal 2013; 11:90. [PMID: 24267514 PMCID: PMC4222901 DOI: 10.1186/1478-811x-11-90] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 11/19/2013] [Indexed: 01/24/2023] Open
Abstract
Modulation of host cell signaling and cellular functions is key to intracellular survival of pathogenic bacteria. Intracellular growth has several advantages e.g. escape from the humoral immune response and access to a stable nutrient rich environment. Growth in such a preferred niche comes at the price of an ongoing competition between the bacteria and the host as well as other microbes that compete for the very same host resources. This requires specialization and constant evolution of dedicated systems for adhesion, invasion and accommodation. Interestingly, obligate intracellular bacteria of the order Chlamydiales have evolved an impressive degree of control over several important host cell functions. In this review we summarize how Chlamydia controls its host cell with a special focus on signal transduction and cellular modulation.
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Affiliation(s)
- Adrian Mehlitz
- University of Wuerzburg, Biocenter, Department of Microbiology, Am Hubland, D-97074, Wuerzburg, Germany.
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36
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Romano JD, Coppens I. Host Organelle Hijackers: a similar modus operandi for Toxoplasma gondii and Chlamydia trachomatis: co-infection model as a tool to investigate pathogenesis. Pathog Dis 2013; 69:72-86. [PMID: 23821471 DOI: 10.1111/2049-632x.12057] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 06/11/2013] [Accepted: 06/11/2013] [Indexed: 12/27/2022] Open
Abstract
The bacterium Chlamydia trachomatis and the protozoan parasite Toxoplasma gondii are the causative agents of chlamydiosis and toxoplasmosis in humans, respectively. Both microorganisms are obligate intracellular pathogens and notorious for extensively modifying the cytoskeletal architecture and the endomembrane system of their host cells to establish productive infections. This review highlights the similar tactics developed by these two pathogens to manipulate their host cell despite their genetic unrelatedness. Using an in vitro cell culture model whereby single fibroblasts are infected by C. trachomatis and T. gondii simultaneously, thus setting up an intracellular competition, we demonstrate that the solutions to the problem of intracellular survival deployed by the parasite and the bacterium may represent an example of convergent evolution, driven by the necessity to acquire nutrients in a hostile environment.
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Affiliation(s)
- Julia D Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
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37
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Vesicle-associated membrane protein 4 and syntaxin 6 interactions at the chlamydial inclusion. Infect Immun 2013; 81:3326-37. [PMID: 23798538 DOI: 10.1128/iai.00584-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The predominant players in membrane fusion events are the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family of proteins. We hypothesize that SNARE proteins mediate fusion events at the chlamydial inclusion and are important for chlamydial lipid acquisition. We have previously demonstrated that trans-Golgi SNARE syntaxin 6 localizes to the chlamydial inclusion. To investigate the role of syntaxin 6 at the chlamydial inclusion, we examined the localization and function of another trans-Golgi SNARE and syntaxin 6-binding partner, vesicle-associated membrane protein 4 (VAMP4), at the chlamydial inclusion. In this study, we demonstrate that syntaxin 6 and VAMP4 colocalize to the chlamydial inclusion and interact at the chlamydial inclusion. Furthermore, in the absence of VAMP4, syntaxin 6 is not retained at the chlamydial inclusion. Small interfering RNA (siRNA) knockdown of VAMP4 inhibited chlamydial sphingomyelin acquisition, correlating with a log decrease in infectious progeny. VAMP4 retention at the inclusion was shown to be dependent on de novo chlamydial protein synthesis, but unlike syntaxin 6, VAMP4 recruitment is observed in a species-dependent manner. Notably, VAMP4 knockdown inhibits sphingomyelin trafficking only to inclusions in which it localizes. These data support the hypothesis that VAMP proteins play a central role in mediating eukaryotic vesicular interactions at the chlamydial inclusion and, thus, support chlamydial lipid acquisition and chlamydial development.
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38
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Bastidas RJ, Elwell CA, Engel JN, Valdivia RH. Chlamydial intracellular survival strategies. Cold Spring Harb Perspect Med 2013; 3:a010256. [PMID: 23637308 DOI: 10.1101/cshperspect.a010256] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen and the causative agent of blinding trachoma. Although Chlamydia is protected from humoral immune responses by residing within remodeled intracellular vacuoles, it still must contend with multilayered intracellular innate immune defenses deployed by its host while scavenging for nutrients. Here we provide an overview of Chlamydia biology and highlight recent findings detailing how this vacuole-bound pathogen manipulates host-cellular functions to invade host cells and maintain a replicative niche.
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Affiliation(s)
- Robert J Bastidas
- Department of Molecular Genetics and Microbiology, Center for Microbial Pathogenesis, Duke University Medical Center, Durham, NC 27710, USA
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39
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Ostertag M, Stammler J, Douchkov D, Eichmann R, Hückelhoven R. The conserved oligomeric Golgi complex is involved in penetration resistance of barley to the barley powdery mildew fungus. MOLECULAR PLANT PATHOLOGY 2013; 14:230-40. [PMID: 23145810 PMCID: PMC6638642 DOI: 10.1111/j.1364-3703.2012.00846.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Membrane trafficking is vital to plant development and adaptation to the environment. It is suggested that post-Golgi vesicles and multivesicular bodies are essential for plant defence against directly penetrating fungal parasites at the cell wall. However, the actual plant proteins involved in membrane transport for defence are largely unidentified. We applied a candidate gene approach and single cell transient-induced gene silencing for the identification of membrane trafficking proteins of barley involved in the response to the fungal pathogen Blumeria graminis f.sp. hordei. This revealed potential components of vesicle tethering complexes [putative exocyst subunit HvEXO70F-like and subunits of the conserved oligomeric Golgi (COG) complex] and Golgi membrane trafficking (COPIγ coatomer and HvYPT1-like RAB GTPase) as essential for resistance to fungal penetration into the host cell.
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Affiliation(s)
- Maya Ostertag
- Lehrstuhl für Phytopathologie, Technische Universität München, Freising-Weihenstephan, Germany
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40
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Isolation of Chlamydia trachomatis and membrane vesicles derived from host and bacteria. J Microbiol Methods 2012; 91:222-30. [PMID: 22960504 DOI: 10.1016/j.mimet.2012.08.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/21/2012] [Accepted: 08/24/2012] [Indexed: 02/06/2023]
Abstract
The study of intracellular bacteria and nanometer-size membrane vesicles within infected host cells poses an important challenge as it is difficult to identify each distinct population in the context of the complex populations generated from active host-pathogen interactions. Here, suspension cultures of L929 cells infected with the prevalent obligate intracellular bacterium Chlamydia trachomatis strain F/Cal-IC-13 are utilized for the large scale preparation and isolation of natural membrane vesicles and bacterial forms. Cell lysis with nitrogen cavitation in combination with differential centrifugation, OptiPrep™ density gradient separation, and immunoenrichment using anti-chlamydial lipopolysaccharide antibodies and MagnaBind beads allows for the isolation of both productive and persistent bacterial forms, as well as membrane vesicles derived from the host and pathogen. We have evaluated these populations by electron microscopy and Western blot analysis for identification of biomarkers. In addition, purified persistent forms of C. trachomatis induced by ampicillin display adenosine-5'-triphosphate (ATP) transport activity, suggesting that ampicillin-induced persistent C. trachomatis organisms, at least in part, rely upon host ATP as an energy source. Importantly, several chlamydial cytotoxic and/or secreted proteins are demonstrated to be associated with these vesicles, supporting the idea that membrane vesicles are generated by Chlamydia as a means of carrying and delivering virulence factors necessary for pathogenesis. The ability to produce large-scale infections and generate distinct bacteria and host-derived populations for biochemical analysis, while reducing the burdens of time and cost have implications in all areas of chlamydiology. These protocols can be applied to other strains of C. trachomatis or other intracellular bacteria.
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41
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Abstract
Chlamydia species are obligate intracellular pathogens that are important causes of human genital tract, ocular and respiratory infections. The bacteria replicate within a specialized membrane-bound compartment termed the inclusion and require host-derived lipids for intracellular growth and development. Emerging evidence indicates that Chlamydia has evolved clever strategies to fulfil its lipid needs by interacting with multiple host cell compartments and redirecting trafficking pathways to its intracellular niche. In this review, we highlight recent findings that have significantly expanded our understanding of how Chlamydia exploit lipid trafficking pathways to ensure the survival of this important human pathogen.
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Affiliation(s)
- Cherilyn A Elwell
- Departments of Medicine, University of California, San Francisco, CA, USA.
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