Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1
The Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) is a heterotrimeric AB2 toxin capable of inducing lymphocytes, and other cell types, to undergo cell cycle arrest and apoptosis. Exposure to Cdt results in binding to the cell surface followed by internalization and transloc...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2017-11-01
|
| Series: | Frontiers in Cellular and Infection Microbiology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/article/10.3389/fcimb.2017.00469/full |
| _version_ | 1819087998034116608 |
|---|---|
| author | Kathleen Boesze-Battaglia Lisa P. Walker Anuradha Dhingra Konstantin Kandror Hsin-Yao Tang Bruce J. Shenker |
| author_facet | Kathleen Boesze-Battaglia Lisa P. Walker Anuradha Dhingra Konstantin Kandror Hsin-Yao Tang Bruce J. Shenker |
| author_sort | Kathleen Boesze-Battaglia |
| collection | DOAJ |
| description | The Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) is a heterotrimeric AB2 toxin capable of inducing lymphocytes, and other cell types, to undergo cell cycle arrest and apoptosis. Exposure to Cdt results in binding to the cell surface followed by internalization and translocation of the active subunit, CdtB, to intracellular compartments. These events are dependent upon toxin binding to cholesterol in the context of lipid rich membrane microdomains often referred to as lipid rafts. We now demonstrate that, in addition to binding to the plasma membrane of lymphocytes, another early and critical event initiated by Cdt is the translocation of the host cell protein, cellugyrin (synaptogyrin-2) to the same cholesterol-rich microdomains. Furthermore, we demonstrate that cellugyrin is an intracellular binding partner for CdtB as demonstrated by immunoprecipitation. Using CRISPR/cas9 gene editing we established a Jurkat cell line deficient in cellugyrin expression (JurkatCg−); these cells were capable of binding Cdt, but unable to internalize CdtB. Furthermore, JurkatCg− cells were not susceptible to Cdt-induced toxicity; these cells failed to exhibit blockade of the PI-3K signaling pathway, cell cycle arrest or cell death. We propose that cellugyrin plays a critical role in the internalization and translocation of CdtB to critical intracellular target sites. These studies provide critical new insight into the mechanism by which Cdt, and in particular, CdtB is able to induce toxicity. |
| first_indexed | 2024-12-21T21:45:02Z |
| format | Article |
| id | doaj.art-74da68f545e4450d9e22a0fe59218277 |
| institution | Directory Open Access Journal |
| issn | 2235-2988 |
| language | English |
| last_indexed | 2024-12-21T21:45:02Z |
| publishDate | 2017-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cellular and Infection Microbiology |
| spelling | doaj.art-74da68f545e4450d9e22a0fe592182772022-12-21T18:49:15ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882017-11-01710.3389/fcimb.2017.00469291094Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1Kathleen Boesze-Battaglia0Lisa P. Walker1Anuradha Dhingra2Konstantin Kandror3Hsin-Yao Tang4Bruce J. Shenker5Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Biochemistry, School of Medicine, Boston University, Boston, MA, United StatesWistar Proteomics and Metabolomics Core Facility, Wistar Institute, Philadelphia, PA, United StatesDepartment of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United StatesThe Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) is a heterotrimeric AB2 toxin capable of inducing lymphocytes, and other cell types, to undergo cell cycle arrest and apoptosis. Exposure to Cdt results in binding to the cell surface followed by internalization and translocation of the active subunit, CdtB, to intracellular compartments. These events are dependent upon toxin binding to cholesterol in the context of lipid rich membrane microdomains often referred to as lipid rafts. We now demonstrate that, in addition to binding to the plasma membrane of lymphocytes, another early and critical event initiated by Cdt is the translocation of the host cell protein, cellugyrin (synaptogyrin-2) to the same cholesterol-rich microdomains. Furthermore, we demonstrate that cellugyrin is an intracellular binding partner for CdtB as demonstrated by immunoprecipitation. Using CRISPR/cas9 gene editing we established a Jurkat cell line deficient in cellugyrin expression (JurkatCg−); these cells were capable of binding Cdt, but unable to internalize CdtB. Furthermore, JurkatCg− cells were not susceptible to Cdt-induced toxicity; these cells failed to exhibit blockade of the PI-3K signaling pathway, cell cycle arrest or cell death. We propose that cellugyrin plays a critical role in the internalization and translocation of CdtB to critical intracellular target sites. These studies provide critical new insight into the mechanism by which Cdt, and in particular, CdtB is able to induce toxicity.http://journal.frontiersin.org/article/10.3389/fcimb.2017.00469/fulllymphocytestoxincytolethal distending toxinAggregatibacter actinomycetemcomitanspathogenesiscell cycle arrest |
| spellingShingle | Kathleen Boesze-Battaglia Lisa P. Walker Anuradha Dhingra Konstantin Kandror Hsin-Yao Tang Bruce J. Shenker Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1 Frontiers in Cellular and Infection Microbiology lymphocytes toxin cytolethal distending toxin Aggregatibacter actinomycetemcomitans pathogenesis cell cycle arrest |
| title | Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1 |
| title_full | Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1 |
| title_fullStr | Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1 |
| title_full_unstemmed | Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1 |
| title_short | Internalization of the Active Subunit of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Is Dependent upon Cellugyrin (Synaptogyrin 2), a Host Cell Non-Neuronal Paralog of the Synaptic Vesicle Protein, Synaptogyrin 1 |
| title_sort | internalization of the active subunit of the aggregatibacter actinomycetemcomitans cytolethal distending toxin is dependent upon cellugyrin synaptogyrin 2 a host cell non neuronal paralog of the synaptic vesicle protein synaptogyrin 1 |
| topic | lymphocytes toxin cytolethal distending toxin Aggregatibacter actinomycetemcomitans pathogenesis cell cycle arrest |
| url | http://journal.frontiersin.org/article/10.3389/fcimb.2017.00469/full |
| work_keys_str_mv | AT kathleenboeszebattaglia internalizationoftheactivesubunitoftheaggregatibacteractinomycetemcomitanscytolethaldistendingtoxinisdependentuponcellugyrinsynaptogyrin2ahostcellnonneuronalparalogofthesynapticvesicleproteinsynaptogyrin1 AT lisapwalker internalizationoftheactivesubunitoftheaggregatibacteractinomycetemcomitanscytolethaldistendingtoxinisdependentuponcellugyrinsynaptogyrin2ahostcellnonneuronalparalogofthesynapticvesicleproteinsynaptogyrin1 AT anuradhadhingra internalizationoftheactivesubunitoftheaggregatibacteractinomycetemcomitanscytolethaldistendingtoxinisdependentuponcellugyrinsynaptogyrin2ahostcellnonneuronalparalogofthesynapticvesicleproteinsynaptogyrin1 AT konstantinkandror internalizationoftheactivesubunitoftheaggregatibacteractinomycetemcomitanscytolethaldistendingtoxinisdependentuponcellugyrinsynaptogyrin2ahostcellnonneuronalparalogofthesynapticvesicleproteinsynaptogyrin1 AT hsinyaotang internalizationoftheactivesubunitoftheaggregatibacteractinomycetemcomitanscytolethaldistendingtoxinisdependentuponcellugyrinsynaptogyrin2ahostcellnonneuronalparalogofthesynapticvesicleproteinsynaptogyrin1 AT brucejshenker internalizationoftheactivesubunitoftheaggregatibacteractinomycetemcomitanscytolethaldistendingtoxinisdependentuponcellugyrinsynaptogyrin2ahostcellnonneuronalparalogofthesynapticvesicleproteinsynaptogyrin1 |