1
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Herrera A, Packer MM, Rosas-Lemus M, Minasov G, Chen J, Brumell JH, Satchell KJF. Vibrio MARTX toxin processing and degradation of cellular Rab GTPases by the cytotoxic effector Makes Caterpillars Floppy. Proc Natl Acad Sci U S A 2024; 121:e2316143121. [PMID: 38861595 PMCID: PMC11194500 DOI: 10.1073/pnas.2316143121] [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: 09/22/2023] [Accepted: 04/19/2024] [Indexed: 06/13/2024] Open
Abstract
Vibrio vulnificus causes life-threatening wound and gastrointestinal infections, mediated primarily by the production of a Multifunctional-Autoprocessing Repeats-In-Toxin (MARTX) toxin. The most commonly present MARTX effector domain, the Makes Caterpillars Floppy-like (MCF) toxin, is a cysteine protease stimulated by host adenosine diphosphate (ADP) ribosylation factors (ARFs) to autoprocess. Here, we show processed MCF then binds and cleaves host Ras-related proteins in brain (Rab) guanosine triphosphatases within their C-terminal tails resulting in Rab degradation. We demonstrate MCF binds Rabs at the same interface occupied by ARFs. Moreover, we show MCF preferentially binds to ARF1 prior to autoprocessing and is active to cleave Rabs only subsequent to autoprocessing. We then use structure prediction algorithms to demonstrate that structural composition, rather than sequence, determines Rab target specificity. We further determine a crystal structure of aMCF as a swapped dimer, revealing an alternative conformation we suggest represents the open, activated state of MCF with reorganized active site residues. The cleavage of Rabs results in Rab1B dispersal within cells and loss of Rab1B density in the intestinal tissue of infected mice. Collectively, our work describes an extracellular bacterial mechanism whereby MCF is activated by ARFs and subsequently induces the degradation of another small host guanosine triphosphatase (GTPase), Rabs, to drive organelle damage, cell death, and promote pathogenesis of these rapidly fatal infections.
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Affiliation(s)
- Alfa Herrera
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Megan M. Packer
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Monica Rosas-Lemus
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
- Center for Structural Biology of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - George Minasov
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
- Center for Structural Biology of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - Jiexi Chen
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
| | - John H. Brumell
- Cell Biology Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ONM5G 0A4, Canada
- Institute of Medical Science, University of Toronto, Toronto, ONM5S 1A8, Canada
- SickKids Inflammatory Bowel Disease Centre, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
| | - Karla J. F. Satchell
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
- Center for Structural Biology of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL60611
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2
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Escher TE, Yuk SA, Qian Y, Stubbs CK, Scott EA, Satchell KJF. Therapeutic expression of RAS Degrader RRSP in Pancreatic Cancer via Nanocarrier-mediated mRNA delivery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598439. [PMID: 38948803 PMCID: PMC11212117 DOI: 10.1101/2024.06.11.598439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
About one-third of all human cancers encode abnormal RAS proteins locked in a constitutively activated state to drive malignant transformation and uncontrolled tumor growth. Despite progress in development of small molecules for treatment of mutant KRAS cancers, there is a need for a pan-RAS inhibitor that is effective against all RAS isoforms and variants and that avoids drug resistance. We have previously shown that the naturally occurring bacterial enzyme RAS/RAP1-specific endopeptidase (RRSP) is a potent RAS degrader that can be re-engineered as a biologic therapy to induce regression of colorectal, breast, and pancreatic tumors. Here, we have developed a strategy for in vivo expression of this RAS degrader via mRNA delivery using a synthetic nonviral gene delivery platform composed of the poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-b-PPS) block copolymer conjugated to a dendritic cationic peptide (PPDP2). Using this strategy, PPDP2 is shown to deliver mRNA to both human and mouse pancreatic cells resulting in RRSP gene expression, activity, and loss of cell proliferation. Further, pancreatic tumors are reduced with residual tumors lacking detectable RAS and phosphorylated ERK. These data support that mRNA-loaded synthetic nanocarrier delivery of a RAS degrader can interrupt the RAS signaling system within pancreatic cancer cells while avoiding side effects during therapy.
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Affiliation(s)
- Taylor E Escher
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 United States
| | - Simseok A Yuk
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Yuan Qian
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Caleb K Stubbs
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 United States
| | - Evan A Scott
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Simpson Querrey Institute, Northwestern University, Chicago, IL 60611, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
- Robert H. Lurie Comprehensive Cancer Research Center, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 United States
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 United States
- Robert H. Lurie Comprehensive Cancer Research Center, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 United States
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3
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Shan T, Li X, Xie W, Wang S, Gao Y, Zheng Y, Su G, Li Y, Zhao Z. Rap1GAP exacerbates myocardial infarction by regulating the AMPK/SIRT1/NF-κB signaling pathway. Cell Signal 2024; 117:111080. [PMID: 38320624 DOI: 10.1016/j.cellsig.2024.111080] [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: 10/05/2023] [Revised: 01/11/2024] [Accepted: 02/02/2024] [Indexed: 02/08/2024]
Abstract
Rap1 GTPase-activating protein (Rap1GAP) is an important tumor suppressor. The purpose of this study was to investigate the role of Rap1GAP in myocardial infarction (MI) and its potential mechanism. Left anterior descending coronary artery ligation was performed on cardiac-specific Rap1GAP conditional knockout (Rap1GAP-CKO) mice and control mice with MI. Seven days after MI, Rap1GAP expression in the hearts of control mice peaked, the expression of proapoptotic markers (Bax and cleaved caspase-3) increased, the expression of antiapoptotic factors (Bcl-2) decreased, and the expression of the inflammatory factors IL-6 and TNF-α increased; thus, apoptosis occurred, inflammation, infarct size, and left ventricular dysfunction increased, while the heart changes caused by MI were alleviated in Rap1GAP-CKO mice. Mouse heart tissue was obtained for transcriptome sequencing, and gene set enrichment analysis (GSEA) was used to analyze Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We found that Rap1GAP was associated with the AMPK and NF-κB signaling pathways and that Rap1GAP inhibited AMPK/SIRT1 and activated the NF-κB signaling pathway in model animals. Similar results were observed in primary rat myocardial cells subjected to oxygen-glucose deprivation (OGD) to induce ischemia and hypoxia. Activating AMPK with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) reversed the damage caused by Rap1GAP overexpression in cardiomyocytes. In addition, the coimmunoprecipitation results showed that exogenous Rap1GAP interacted with AMPK. Rap1GAP was verified to regulate the AMPK SIRT1/NF-κB signaling pathway and exacerbate the damage to myocardial cells caused by ischemia and hypoxia. In conclusion, our results suggest that Rap1GAP promotes MI by modulating the AMPK/SIRT1/NF-κB signaling pathway and that Rap1GAP may be a therapeutic target for MI treatment in the future.
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Affiliation(s)
- Tiantian Shan
- Department of Cardiology, Jinan Central Hospital, Shandong University, Jinan 250013, China; Research Center of Translational Medicine, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Xiaoying Li
- Research Center of Translational Medicine, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China; Department of Emergency, Jinan Central Hospital, Jinan 250013, China; Department of Emergency, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Wenzhi Xie
- Department of Cardiology, Jinan Central Hospital, Shandong University, Jinan 250013, China; Department of Cardiology, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Shaoqin Wang
- Department of Emergency, Jinan Central Hospital, Jinan 250013, China; Department of Emergency, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Yan Gao
- Department of Cardiology, Qingdao Medical College, Qingdao University, Qingdao 266073, China
| | - Yan Zheng
- Research Center of Translational Medicine, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Guohai Su
- Department of Cardiology, Jinan Central Hospital, Shandong University, Jinan 250013, China; Department of Cardiology, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Ying Li
- Research Center of Translational Medicine, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China
| | - Zhuo Zhao
- Department of Cardiology, Jinan Central Hospital, Shandong University, Jinan 250013, China; Department of Cardiology, Central Hospital Affiliated Shandong First Medical University, Jinan 250013, China.
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4
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Lehman SS, Williamson CD, Tucholski T, Ellis NA, Bouchard S, Jarnik M, Allen M, Nita-Lazar A, Machner MP. The Legionella pneumophila effector DenR hijacks the host NRas proto-oncoprotein to downregulate MAPK signaling. Cell Rep 2024; 43:114033. [PMID: 38568811 PMCID: PMC11141579 DOI: 10.1016/j.celrep.2024.114033] [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: 05/18/2023] [Revised: 01/17/2024] [Accepted: 03/18/2024] [Indexed: 04/05/2024] Open
Abstract
Small GTPases of the Ras subfamily are best known for their role as proto-oncoproteins, while their function during microbial infection has remained elusive. Here, we show that Legionella pneumophila hijacks the small GTPase NRas to the Legionella-containing vacuole (LCV) surface. A CRISPR interference screen identifies a single L. pneumophila effector, DenR (Lpg1909), required for this process. Recruitment is specific for NRas, while its homologs KRas and HRas are excluded from LCVs. The C-terminal hypervariable tail of NRas is sufficient for recruitment, and interference with either NRas farnesylation or S-acylation sites abrogates recruitment. Intriguingly, we detect markers of active NRas signaling on the LCV, suggesting it acts as a signaling platform. Subsequent phosphoproteomics analyses show that DenR rewires the host NRas signaling landscape, including dampening of the canonical mitogen-activated protein kinase pathway. These results provide evidence for L. pneumophila targeting NRas and suggest a link between NRas GTPase signaling and microbial infection.
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Affiliation(s)
- Stephanie S Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chad D Williamson
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Trisha Tucholski
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole A Ellis
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sabrina Bouchard
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michal Jarnik
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Morgan Allen
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Aleksandra Nita-Lazar
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Matthias P Machner
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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5
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Zheng Q, Sheng J, Liu J, Chen X, Wang M. Histidine-Rich Protein Accelerates the Biomineralization of Zeolitic Imidazolate Frameworks for In Vivo Protein Delivery. Biomacromolecules 2023; 24:5132-5141. [PMID: 37859395 DOI: 10.1021/acs.biomac.3c00706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Biomineralization of metal-organic frameworks (MOFs) provides a powerful approach for intracellular protein delivery, enabling the study of biological function and therapeutic potential of proteins. However, the potency of this approach is largely challenged by the low efficiency of current strategies for interfacing proteins with MOFs for biomineralization and intracellular delivery. Here, we report a versatile and convenient biomineralization strategy for the rapid encapsulation and enhanced delivery of proteins using MOFs, accelerated by histidine-rich proteins. We demonstrate that the histidine-rich green fluorescent protein (H39GFP) can accelerate the biomineralization of MOFs by promoting the coordination between proteins and metal ions, leading to enhanced protein delivery efficiency up to 15-fold. Moreover, we show that the delivery of H39GFP-fused cytotoxic ribonuclease and bacterial-derived RAS protease can effectively inhibit tumor cell growth. The strategy of promoting the biomineralization of MOFs via histidine-rich proteins for enhanced intracellular delivery could be expanded to other biomacromolecules, advancing their therapeutic potential and the biomedical scope of MOFs.
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Affiliation(s)
- Qizhen Zheng
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinhan Sheng
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ji Liu
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xianghan Chen
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming Wang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Palacio-Castañeda V, van de Crommert B, Verploegen E, Overeem M, van Oostrum J, Verdurmen WP. Potent and selective eradication of tumor cells by an EpCAM-targeted Ras-degrading enzyme. Mol Ther Oncolytics 2023; 30:16-26. [PMID: 37485031 PMCID: PMC10362089 DOI: 10.1016/j.omto.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 06/22/2023] [Indexed: 07/25/2023] Open
Abstract
Despite decades of efforts, an urgent need remains to develop tumor cell-selective rat sarcoma (Ras)-targeting therapies that can treat patients with Ras-driven tumors. Here we report modular engineered proteins that degrade Ras selectively in tumor cells that overexpress the tumor cell marker epithelial cell adhesion molecule (EpCAM) by fusing the Ras degrader Ras-Rap1-specific endopeptidase with the translocation domain of the Pseudomonas aeruginosa exotoxin A (ETA) or diphtheria toxin (DT). Redirection to EpCAM is achieved by a designed ankyrin repeat protein. In two-dimensional tumor cell cultures, complete degradation of Ras proteins after 24 h was observed with EpCAM-targeted Ras degraders fused to ETA or DT in EpCAM-overexpressing MCF7 and HCT116 cells, with median inhibition concentration values at sub-nanomolar levels. The viability of EpCAM-low non-cancerous fibroblasts remained unaffected. In a three-dimensional (3D) tumor-on-a-chip system that mimics the natural tumor microenvironment, effective Ras degradation and selective toxicity toward tumor cells, particularly with the ETA-fused constructs, was determined on-chip. To conclude, we demonstrate the potential of modular engineered proteins to kill tumor cells highly selectively by simultaneously exploiting EpCAM as a tumor-specific cell surface molecule as well as Ras as an intracellular oncotarget in a 3D system mimicking the natural tumor microenvironment.
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Affiliation(s)
- Valentina Palacio-Castañeda
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
| | - Bas van de Crommert
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
| | - Elke Verploegen
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
| | - Mike Overeem
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
| | - Jenny van Oostrum
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
| | - Wouter P.R. Verdurmen
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
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7
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Escher TE, Satchell KJF. RAS degraders: The new frontier for RAS-driven cancers. Mol Ther 2023; 31:1904-1919. [PMID: 36945775 PMCID: PMC10362401 DOI: 10.1016/j.ymthe.2023.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 01/20/2023] [Accepted: 03/16/2023] [Indexed: 03/23/2023] Open
Abstract
The function and significance of RAS proteins in cancer have been widely studied for decades. In 2013, the National Cancer Institute established the RAS Initiative to explore innovative approaches for attacking the proteins encoded by mutant forms of RAS genes and to create effective therapies for RAS-driven cancers. This initiative spurred researchers to develop novel approaches and to discover small molecules targeting this protein that was at one time termed "undruggable." More recently, advanced efforts in RAS degraders including PROTACs, linker-based degraders, and direct proteolysis degraders have been explored as novel strategies to target RAS for cancer treatment. These RAS degraders present new opportunities for RAS therapies and may prove fruitful in understanding basic cell biology. Novel delivery strategies will further enhance the efficacy of these therapeutics. In this review, we summarize recent efforts to develop RAS degraders, including PROTACs and E3 adaptor and ligase fusions as cancer therapies. This review also details the direct RAS protease degrader, RAS/RAP1-specific endopeptidase that directly and specifically cleaves RAS.
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Affiliation(s)
- Taylor E Escher
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Research Center, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Research Center, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.
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8
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Becker L, Plückthun A. DARPins bind their cytosolic targets after having been translocated through the protective antigen pore of anthrax toxin. Sci Rep 2023; 13:8048. [PMID: 37198284 DOI: 10.1038/s41598-023-34647-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 05/04/2023] [Indexed: 05/19/2023] Open
Abstract
Intracellular protein-protein interactions in aberrant signaling pathways have emerged as a prime target in several diseases, particularly cancer. Since many protein-protein interactions are mediated by rather flat surfaces, they can typically not be interrupted by small molecules as they require cavities for binding. Therefore, protein drugs might be developed to compete with undesired interactions. However, proteins in general are not able to translocate from the extracellular side to the cytosolic target site by themselves, and thus an efficient protein translocation system, ideally combining efficient translocation with receptor specificity, is in high demand. Anthrax toxin, the tripartite holotoxin of Bacillus anthracis, is one of the best studied bacterial protein toxins and has proven to be a suitable candidate for cell-specific translocation of cargoes in vitro and in vivo. Our group recently developed a retargeted protective antigen (PA) variant fused to different Designed Ankyrin Repeat Proteins (DARPins) to achieve receptor specificity, and we incorporated a receptor domain to stabilize the prepore and prevent cell lysis. This strategy had been shown to deliver high amounts of cargo DARPins fused behind the N-terminal 254 amino acids of Lethal Factor (LFN). Here, we established a cytosolic binding assay, demonstrating the ability of DARPins to refold in the cytosol and bind their target after been translocated by PA.
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Affiliation(s)
- Lukas Becker
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland.
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9
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Herrera A, Packer MM, Rosas-Lemus M, Minasov G, Brummel JH, Satchell KJF. Vibrio MARTX toxin processing and degradation of cellular Rab GTPases by the cytotoxic effector Makes Caterpillars Floppy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.19.537381. [PMID: 37131655 PMCID: PMC10153396 DOI: 10.1101/2023.04.19.537381] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Vibrio vulnificus causes life threatening infections dependent upon the effectors released from the Multifunctional-Autoprocessing Repeats-In-Toxin (MARTX) toxin. The Makes Caterpillars Floppy-like (MCF) cysteine protease effector is activated by host ADP ribosylation factors (ARFs), although the targets of processing activity were unknown. In this study we show MCF binds Ras-related proteins in brain (Rab) GTPases at the same interface occupied by ARFs and then cleaves and/or degrades 24 distinct members of the Rab GTPases family. The cleavage occurs in the C-terminal tails of Rabs. We determine the crystal structure of MCF as a swapped dimer revealing the open, activated state of MCF and then use structure prediction algorithms to show that structural composition, rather than sequence or localization, determine Rabs selected as MCF proteolytic targets. Once cleaved, Rabs become dispersed in cells to drive organelle damage and cell death to promote pathogenesis of these rapidly fatal infections.
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Affiliation(s)
- Alfa Herrera
- Department of Microbiology-Immunology and Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Megan M. Packer
- Department of Microbiology-Immunology and Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Monica Rosas-Lemus
- Department of Microbiology-Immunology and Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - George Minasov
- Department of Microbiology-Immunology and Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - John H. Brummel
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- SickKids IBD Centre, The Hospital for Sick Children, Toronto, ON, Canada
| | - Karla J. F. Satchell
- Department of Microbiology-Immunology and Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Center for Structural Biology of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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10
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Li W, Shao L, Liu J, Sheng J, Zheng Q, Wang M. Intracellular delivery of bacterial effectors for cancer therapy using biodegradable lipid nanoparticles. Biomater Sci 2023; 11:3172-3179. [PMID: 36919841 DOI: 10.1039/d3bm00008g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Bacterial effector proteins are virulence factors that are secreted and mediate orthogonal post-translational modifications of proteins that are not found naturally in mammalian systems. They hold great promise for developing biotherapeutics by regulating malignant cell signaling in a specific and targeted manner. However, delivering bacterial effectors into disease cells poses a significant challenge to their therapeutic potential. In this study, we report on the design of a combinatorial library of bioreducible lipid nanoparticles containing disulfide bonds for highly efficient bacterial effector delivery and potential cancer therapy. A leading lipid, PPPDA-O16B, identified from the library, can encapsulate and deliver DNA plasmids into cells. The gene cargo is released in response to the reductive cellular environment that is upregulated in cancer cells, leading to enhanced gene delivery and protein expression efficiency. Furthermore, we demonstrate that PPPDA-O16B can deliver the bacterial effector protein, DUF5, to degrade mutant RAS and inactivate downstream MAPK signaling cascades to suppress cancer cell growth in vitro and in tumor-bearing mouse xenografts. This strategy of delivering bacterial effectors using biodegradable lipid nanoparticles can be expanded for cancer cell signaling regulation and antitumor studies.
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Affiliation(s)
- Wenting Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Leihou Shao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ji Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinhan Sheng
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qizhen Zheng
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Oda K, Wlodawer A. Overview of the Properties of Glutamic Peptidases That Are Present in Plant and Bacterial Pathogens and Play a Role in Celiac Disease and Cancer. Biochemistry 2023; 62:672-694. [PMID: 36705990 DOI: 10.1021/acs.biochem.2c00622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Seven peptidase (proteinase) families─aspartic, cysteine, metallo, serine, glutamic, threonine, and asparagine─are in the peptidase database MEROPS, version 12.4 (https://www.ebi.ac.uk/merops/). The glutamic peptidase family is assigned two clans, GA and GB, and comprises six subfamilies. This perspective summarizes the unique features of their representatives. (1) G1, scytalidoglutamic peptidase, has a β-sandwich structure containing catalytic residues glutamic acid (E) and glutamine (Q), thus the name eqolisin. Most family members are pepstatin-insensitive and act as plant pathogens. (2) G2, preneck appendage protein, originates in phages, is a transmembrane protein, and its catalytic residues consist of glutamic and aspartic acids. (3) G3, strawberry mottle virus glutamic peptidase, originates in viruses and has a β-sandwich structure with catalytic residues E and Q. Neprosin has propyl endopeptidase activity, is associated with celiac disease, has a β-sandwich structure, and contains catalytic residues E-E and Q-tryptophan. (4) G4, Tiki peptidase, of the erythromycin esterase family, is a transmembrane protein, and its catalytic residues are E-histidine pairs. (5) G5, RCE1 peptidase, is associated with cancer, is a transmembrane protein, and its catalytic residues are E-histidine and asparagine-histidine. Microcystinase, a bacterial toxin, is a transmembrane protein with catalytic residues E-histidine and asparagine-histidine. (6) G6, Ras/Rap1-specific peptidase, is a bacterial pathogen, a transmembrane protein, and its catalytic residues are E-histidine pairs. This family's common features are that their catalytic residues consist of a glutamic acid and another (variable) amino acid and that they exhibit a diversity of biological functions─plant and bacterial pathogens and involvement in celiac disease and cancer─that suggests they are viable drug targets.
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Affiliation(s)
- Kohei Oda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-Ku, Kyoto 606-8585, Japan
| | - Alexander Wlodawer
- Center for Structural Biology, National Cancer Institute, Frederick, Maryland 21702, United States
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12
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Radiotherapy/Chemotherapy-Immunotherapy for Cancer Management: From Mechanisms to Clinical Implications. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2023; 2023:7530794. [PMID: 36778203 PMCID: PMC9911251 DOI: 10.1155/2023/7530794] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/03/2022] [Accepted: 11/24/2022] [Indexed: 02/05/2023]
Abstract
Cancer immunotherapy has drawn much attention because it can restart the recognition and killing function of the immune system to normalize the antitumor immune response. However, the role of radiotherapy and chemotherapy in cancer treatment cannot be ignored. Due to cancer heterogeneity, combined therapy has become a new trend, and its efficacy has been confirmed in many studies. This review discussed the clinical implications and the underlying mechanisms of cancer immunotherapy in combination with radiotherapy or chemotherapy, offering an outline for clinicians as well as inspiration for future research.
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13
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ERK and c-Myc signaling in host-derived tumor endothelial cells is essential for solid tumor growth. Proc Natl Acad Sci U S A 2023; 120:e2211927120. [PMID: 36574698 PMCID: PMC9910475 DOI: 10.1073/pnas.2211927120] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The limited efficacy of the current antitumor microenvironment strategies is due in part to the poor understanding of the roles and relative contributions of the various tumor stromal cells to tumor development. Here, we describe a versatile in vivo anthrax toxin protein delivery system allowing for the unambiguous genetic evaluation of individual tumor stromal elements in cancer. Our reengineered tumor-selective anthrax toxin exhibits potent antiproliferative activity by disrupting ERK signaling in sensitive cells. Since this activity requires the surface expression of the capillary morphogenesis protein-2 (CMG2) toxin receptor, genetic manipulation of CMG2 expression using our cell-type-specific CMG2 transgenic mice allows us to specifically define the role of individual tumor stromal cell types in tumor development. Here, we established mice with CMG2 only expressed in tumor endothelial cells (ECs) and determined the specific contribution of tumor stromal ECs to the toxin's antitumor activity. Our results demonstrate that disruption of ERK signaling only within tumor ECs is sufficient to halt tumor growth. We discovered that c-Myc is a downstream effector of ERK signaling and that the MEK-ERK-c-Myc central metabolic axis in tumor ECs is essential for tumor progression. As such, disruption of ERK-c-Myc signaling in host-derived tumor ECs by our tumor-selective anthrax toxins explains their high efficacy in solid tumor therapy.
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14
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Zuo Z, Liu J, Sun Z, Silverstein R, Zou M, Finkel T, Bugge TH, Leppla SH, Liu S. A potent tumor-selective ERK pathway inactivator with high therapeutic index. PNAS NEXUS 2022; 1:pgac104. [PMID: 35899070 PMCID: PMC9308561 DOI: 10.1093/pnasnexus/pgac104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/28/2022] [Indexed: 02/05/2023]
Abstract
FDA-approved BRAF and MEK small molecule inhibitors have demonstrated some level of efficacy in patients with metastatic melanomas. However, these "targeted" therapeutics have a very low therapeutic index, since these agents affect normal cells, causing undesirable, even fatal, side effects. To address these significant drawbacks, here, we have reengineered the anthrax toxin-based protein delivery system to develop a potent, tumor-selective MEK inactivator. This toxin-based MEK inactivator exhibits potent activity against a wide range of solid tumors, with the highest activity seen when directed toward tumors containing the BRAFV600E mutation. We demonstrate that this reengineered MEK inactivator also exhibits an extremely high therapeutic index (>15), due to its in vitro and in vivo activity being strictly dependent on the expression of multiple tumor-associated factors including tumor-associated proteases matrix metalloproteinase, urokinase plasminogen activator, and anthrax toxin receptor capillary morphogenesis protein-2. Furthermore, we have improved the specificity of this MEK inactivator, restricting its enzymatic activity to only target the ERK pathway, thereby greatly diminishing off-target toxicity. Together, these data suggest that engineered bacterial toxins can be modified to have significant in vitro and in vivo therapeutic effects with high therapeutic index.
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Affiliation(s)
| | | | - Zhihao Sun
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Rachel Silverstein
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Meijuan Zou
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Toren Finkel
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA,Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Thomas H Bugge
- Proteases and Tissue Remodeling Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shihui Liu
- To whom correspondence should be addressed:
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15
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Vidimar V, Park M, Stubbs CK, Ingram NK, Qiang W, Zhang S, Gursel D, Melnyk RA, Satchell KJF. Proteolytic pan-RAS Cleavage Leads to Tumor Regression in Patient-derived Pancreatic Cancer Xenografts. Mol Cancer Ther 2022; 21:810-820. [PMID: 35247912 PMCID: PMC9933180 DOI: 10.1158/1535-7163.mct-21-0550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/12/2021] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
The lack of effective RAS inhibition represents a major unmet medical need in the treatment of pancreatic ductal adenocarcinoma (PDAC). Here, we investigate the anticancer activity of RRSP-DTB, an engineered biologic that cleaves the Switch I of all RAS isoforms, in KRAS-mutant PDAC cell lines and patient-derived xenografts (PDX). We first demonstrate that RRSP-DTB effectively engages RAS and impacts downstream ERK signaling in multiple KRAS-mutant PDAC cell lines inhibiting cell proliferation at picomolar concentrations. We next tested RRSP-DTB in immunodeficient mice bearing KRAS-mutant PDAC PDXs. Treatment with RRSP-DTB led to ≥95% tumor regression after 29 days. Residual tumors exhibited disrupted tissue architecture, increased fibrosis and fewer proliferating cells compared with controls. Intratumoral levels of phospho-ERK were also significantly lower, indicating in vivo target engagement. Importantly, tumors that started to regrow without RRSP-DTB shrank when treatment resumed, demonstrating resistance to RRSP-DTB had not developed. Tracking persistence of the toxin activity following intraperitoneal injection showed that RRSP-DTB is active in sera from immunocompetent mice for at least 1 hour, but absent after 16 hours, justifying use of daily dosing. Overall, we report that RRSP-DTB strongly regresses hard-to-treat KRAS-mutant PDX models of pancreatic cancer, warranting further development of this pan-RAS biologic for the management of RAS-addicted tumors.
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Affiliation(s)
- Vania Vidimar
- Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Minyoung Park
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Caleb K Stubbs
- Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Nana K Ingram
- Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Wenan Qiang
- Center for Developmental Therapeutics, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois
- Department of Obstetrics and Gynecology (Reproductive Science in Medicine), Feinberg School of Medicine, Northwestern University, Chicago, Illinois
- Pathology Core Facility, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Robert H. Lurie Comprehensive Cancer Research Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Shanshan Zhang
- Pathology Core Facility, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Demirkan Gursel
- Pathology Core Facility, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Roman A Melnyk
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Karla J F Satchell
- Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
- Robert H. Lurie Comprehensive Cancer Research Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
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Actin Cross-Linking Effector Domain of the Vibrio vulnificus F-Type MARTX Toxin Dominates Disease Progression During Intestinal Infection. Infect Immun 2022; 90:e0062721. [PMID: 35254094 DOI: 10.1128/iai.00627-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Vibrio vulnificus is an opportunistic pathogen that causes gastroenteritis and septicemia in humans. The V. vulnificus multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin is a pore-forming toxin that translocates multiple functionally independent effector domains into target cells and an essential virulence factor for fatal disease. The effector repertoire delivered and thus the mechanism of action of the toxin can differ dramatically across V. vulnificus isolates. Here, we utilize a strain of V. vulnificus that carries an F-type MARTX toxin that delivers an actin cross-linking domain (ACD) and four other effector domains. We demonstrate that ACD is the primary driver of virulence following intragastric infection and of bacterial dissemination to distal organs. We additionally show that ACD activates the transcription of intermediate early response genes in cultured intestinal epithelial cells (IECs). However, the genes activated by ACD are suppressed, at least in part, by the codelivered Ras/Rap1-specific endopeptidase (RRSP). The transcriptional response induced by strains translocating only RRSP results in a unique transcriptional profile, demonstrating that the transcriptional response to V. vulnificus is remodeled rather than simply suppressed by the MARTX toxin effector repertoire. Regardless, the transcriptional response in the intestinal tissue of infected mice is dominated by ACD-mediated induction of genes associated with response to tissue damage and is not impacted by RRSP or the three other effectors codelivered with ACD and RRSP. These data demonstrate that while other effectors do remodel early intestinal innate immune responses, ACD is the dominant driver of disease progression by ACD+ V. vulnificus during intestinal infection.
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17
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Woida PJ, Satchell KJF. Bacterial Toxin and Effector Regulation of Intestinal Immune Signaling. Front Cell Dev Biol 2022; 10:837691. [PMID: 35252199 PMCID: PMC8888934 DOI: 10.3389/fcell.2022.837691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
The host immune response is highly effective to detect and clear infecting bacterial pathogens. Given the elaborate surveillance systems of the host, it is evident that in order to productively infect a host, the bacteria often coordinate virulence factors to fine-tune the host response during infection. These coordinated events can include either suppressing or activating the signaling pathways that control the immune response and thereby promote bacterial colonization and infection. This review will cover the surveillance and signaling systems for detection of bacteria in the intestine and a sample of the toxins and effectors that have been characterized that cirumvent these signaling pathways. These factors that promote infection and disease progression have also been redirected as tools or therapeutics. Thus, these toxins are enemies deployed to enhance infection, but can also be redeployed as allies to enable research and protect against infection.
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18
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RAS specific protease induces irreversible growth arrest via p27 in several KRAS mutant colorectal cancer cell lines. Sci Rep 2021; 11:17925. [PMID: 34504197 PMCID: PMC8429734 DOI: 10.1038/s41598-021-97422-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023] Open
Abstract
Ras-specific proteases to degrade RAS within cancer cells are under active development as an innovative strategy to treat tumorigenesis. The naturally occurring biological toxin effector called RAS/RAP1-specific endopeptidase (RRSP) is known to cleave all RAS within a cell, including HRAS, KRAS, NRAS and mutant KRAS G13D. Yet, our understanding of the mechanisms by which RRSP drives growth inhibition are unknown. Here, we demonstrate, using isogenic mouse fibroblasts expressing a single isoform of RAS or mutant KRAS, that RRSP equally inactivates all isoforms of RAS as well as the major oncogenic KRAS mutants. To investigate how RAS processing might lead to varying outcomes in cell fate within cancer cells, we tested RRSP against four colorectal cancer cell lines with a range of cell fates. While cell lines highly susceptible to RRSP (HCT116 and SW1463) undergo apoptosis, RRSP treatment of GP5d and SW620 cells induces G1 cell cycle arrest. In some cell lines, growth effects were dictated by rescued expression of the tumor suppressor protein p27 (Kip1). The ability of RRSP to irreversibly inhibit cancer cell growth highlights the antitumor potential of RRSP, and further warrants investigation as a potential anti-tumor therapeutic.
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Abstract
RAS proteins represent critical drivers of tumor development and thus are the focus of intense efforts to pharmacologically inhibit these proteins in human cancer. Although recent success has been attained in developing clinically efficacious inhibitors to KRASG12C, there remains a critical need for developing approaches to inhibit additional mutant RAS proteins. A number of anti-RAS biologics have been developed which reveal novel and potentially therapeutically targetable vulnerabilities in oncogenic RAS. This review will discuss the growing field of anti-RAS biologics and potential development of these reagents into new anti-RAS therapies.
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Affiliation(s)
- Michael Whaby
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States.
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20
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Ras Isoforms from Lab Benches to Lives-What Are We Missing and How Far Are We? Int J Mol Sci 2021; 22:ijms22126508. [PMID: 34204435 PMCID: PMC8233758 DOI: 10.3390/ijms22126508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 11/21/2022] Open
Abstract
The central protein in the oncogenic circuitry is the Ras GTPase that has been under intense scrutiny for the last four decades. From its discovery as a viral oncogene and its non-oncogenic contribution to crucial cellular functioning, an elaborate genetic, structural, and functional map of Ras is being created for its therapeutic targeting. Despite decades of research, there still exist lacunae in our understanding of Ras. The complexity of the Ras functioning is further exemplified by the fact that the three canonical Ras genes encode for four protein isoforms (H-Ras, K-Ras4A, K-Ras4B, and N-Ras). Contrary to the initial assessment that the H-, K-, and N-Ras isoforms are functionally similar, emerging data are uncovering crucial differences between them. These Ras isoforms exhibit not only cell-type and context-dependent functions but also activator and effector specificities on activation by the same receptor. Preferential localization of H-, K-, and N-Ras in different microdomains of the plasma membrane and cellular organelles like Golgi, endoplasmic reticulum, mitochondria, and endosome adds a new dimension to isoform-specific signaling and diverse functions. Herein, we review isoform-specific properties of Ras GTPase and highlight the importance of considering these towards generating effective isoform-specific therapies in the future.
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21
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Lemichez E, Popoff MR, Satchell KJF. Cellular microbiology: Bacterial toxin interference drives understanding of eukaryotic cell function. Cell Microbiol 2021; 22:e13178. [PMID: 32185903 DOI: 10.1111/cmi.13178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/04/2019] [Accepted: 11/08/2019] [Indexed: 11/28/2022]
Abstract
Intimate interactions between the armament of pathogens and their host dictate tissue and host susceptibility to infection also forging specific pathophysiological outcomes. Studying these interactions at the molecular level has provided an invaluable source of knowledge on cellular processes, as ambitioned by the Cellular Microbiology discipline when it emerged in early 90s. Bacterial toxins act on key cell regulators or membranes to produce major diseases and therefore constitute a remarkable toolbox for dissecting basic biological processes. Here, we review selected examples of recent studies on bacterial toxins illustrating how fruitful the discipline of cellular microbiology is in shaping our understanding of eukaryote processes. This ever-renewing discipline unveils new virulence factor biochemical activities shared by eukaryotic enzymes and hidden rules of cell proteome homeostasis, a particularly promising field to interrogate the impact of proteostasis breaching in late onset human diseases. It is integrating new concepts from the physics of soft matter to capture biomechanical determinants forging cells and tissues architecture. The success of this discipline is also grounded by the development of therapeutic tools and new strategies to treat both infectious and noncommunicable human diseases.
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Affiliation(s)
- Emmanuel Lemichez
- Unité des Toxines Bactériennes, CNRS ERL6002, Institut Pasteur, Paris, France
| | | | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
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22
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Lu Z, Truex NL, Melo MB, Cheng Y, Li N, Irvine DJ, Pentelute BL. IgG-Engineered Protective Antigen for Cytosolic Delivery of Proteins into Cancer Cells. ACS CENTRAL SCIENCE 2021; 7:365-378. [PMID: 33655074 PMCID: PMC7908032 DOI: 10.1021/acscentsci.0c01670] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Indexed: 05/05/2023]
Abstract
Therapeutic immunotoxins composed of antibodies and bacterial toxins provide potent activity against malignant cells, but joining them with a defined covalent bond while maintaining the desired function is challenging. Here, we develop novel immunotoxins by dovetailing full-length immunoglobulin G (IgG) antibodies and nontoxic anthrax proteins, in which the C terminus of the IgG heavy chain is connected to the side chain of anthrax toxin protective antigen. This strategy enabled efficient conjugation of protective antigen variants to trastuzumab (Tmab) and cetuximab (Cmab) antibodies. The conjugates effectively perform intracellular delivery of edema factor and N terminus of lethal factor (LFN) fused with diphtheria toxin and Ras/Rap1-specific endopeptidase. Each conjugate shows high specificity for cells expressing human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), respectively, and potent activity across six Tmab- and Cmab-resistant cell lines. The conjugates also exhibit increased pharmacokinetics and pronounced in vivo safety, which shows promise for further therapeutic development.
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Affiliation(s)
- Zeyu Lu
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Nicholas L. Truex
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Mariane B. Melo
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Ragon
Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Yiran Cheng
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Na Li
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
| | - Darrell J. Irvine
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Ragon
Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department
of Materials Science and Engineering, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department
of Biological Engineering, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Howard Hughes
Medical Institute, 4000
Jones Bridge Road, Chevy Chase, Maryland 20815, United
States
| | - Bradley L. Pentelute
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Center
for Environmental Health Sciences, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Broad
Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
- E-mail:
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23
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Yu S, Zhang C, Xie KP. Therapeutic resistance of pancreatic cancer: Roadmap to its reversal. Biochim Biophys Acta Rev Cancer 2020; 1875:188461. [PMID: 33157162 DOI: 10.1016/j.bbcan.2020.188461] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/20/2020] [Accepted: 10/24/2020] [Indexed: 02/07/2023]
Abstract
Pancreatic cancer is a lethal disease with limited opportunity for resectable surgery as the first choice for cure due to its late diagnosis and early metastasis. The desmoplastic stroma and cellular genetic or epigenetic alterations of pancreatic cancer impose physical and biological barriers to effective therapies, including chemotherapy, radiotherapy, targeted therapy, and immunotherapy. Here, we review the current therapeutic options for pancreatic cancer, and underlying mechanisms and potential reversal of therapeutic resistance, a hallmark of this deadly disease.
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Affiliation(s)
- Sen Yu
- Department of Gastroenterology and Hepatology, Guangzhou First People's Hospital Affiliated to the South China University of Technology, School of Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Chunyu Zhang
- Department of Gastroenterology and Hepatology, Guangzhou First People's Hospital Affiliated to the South China University of Technology, School of Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Ke-Ping Xie
- Department of Gastroenterology and Hepatology, Guangzhou First People's Hospital Affiliated to the South China University of Technology, School of Medicine, Guangzhou, Guangdong, People's Republic of China.
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24
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Marshall CB, KleinJan F, Gebregiworgis T, Lee KY, Fang Z, Eves BJ, Liu NF, Gasmi-Seabrook GMC, Enomoto M, Ikura M. NMR in integrated biophysical drug discovery for RAS: past, present, and future. JOURNAL OF BIOMOLECULAR NMR 2020; 74:531-554. [PMID: 32804298 DOI: 10.1007/s10858-020-00338-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 07/16/2020] [Indexed: 06/11/2023]
Abstract
Mutations in RAS oncogenes occur in ~ 30% of human cancers, with KRAS being the most frequently altered isoform. RAS proteins comprise a conserved GTPase domain and a C-terminal lipid-modified tail that is unique to each isoform. The GTPase domain is a 'switch' that regulates multiple signaling cascades that drive cell growth and proliferation when activated by binding GTP, and the signal is terminated by GTP hydrolysis. Oncogenic RAS mutations disrupt the GTPase cycle, leading to accumulation of the activated GTP-bound state and promoting proliferation. RAS is a key target in oncology, however it lacks classic druggable pockets and has been extremely challenging to target. RAS signaling has thus been targeted indirectly, by harnessing key downstream effectors as well as upstream regulators, or disrupting the proper membrane localization required for signaling, by inhibiting either lipid modification or 'carrier' proteins. As a small (20 kDa) protein with multiple conformers in dynamic equilibrium, RAS is an excellent candidate for NMR-driven characterization and screening for direct inhibitors. Several molecules have been discovered that bind RAS and stabilize shallow pockets through conformational selection, and recent compounds have achieved substantial improvements in affinity. NMR-derived insight into targeting the RAS-membrane interface has revealed a new strategy to enhance the potency of small molecules, while another approach has been development of peptidyl inhibitors that bind through large interfaces rather than deep pockets. Remarkable progress has been made with mutation-specific covalent inhibitors that target the thiol of a G12C mutant, and these are now in clinical trials. Here we review the history of RAS inhibitor development and highlight the utility of NMR and integrated biophysical approaches in RAS drug discovery.
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Affiliation(s)
- Christopher B Marshall
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada.
| | - Fenneke KleinJan
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Teklab Gebregiworgis
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Ki-Young Lee
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Zhenhao Fang
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Ben J Eves
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Ningdi F Liu
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | | | - Masahiro Enomoto
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada.
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada.
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Loftis AR, Santos MS, Truex NL, Biancucci M, Satchell KJF, Pentelute BL. Anthrax Protective Antigen Retargeted with Single-Chain Variable Fragments Delivers Enzymes to Pancreatic Cancer Cells. Chembiochem 2020; 21:2772-2776. [PMID: 32369652 PMCID: PMC7541672 DOI: 10.1002/cbic.202000201] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/01/2020] [Indexed: 12/15/2022]
Abstract
The nontoxic, anthrax protective antigen/lethal factor N-terminal domain (PA/LFN ) complex is an effective platform for translocating proteins into the cytosol of cells. Mutant PA (mPA) was recently fused to epidermal growth factor (EGF) to retarget delivery of LFN to cells bearing EGF receptors (EGFR), but the requirement for a known cognate ligand limits the applicability of this approach. Here, we render practical protective antigen retargeting to a variety of receptors with mPA single-chain variable fragment (scFv) fusion constructs. Our design enables the targeting of two pancreatic cancer-relevant receptors, EGFR and carcinoembryonic antigen. We demonstrate that fusion to scFvs does not disturb the basic functions of mPA. Moreover, mPA-scFv fusions enable cell-specific delivery of diphtheria toxin catalytic domain and Ras/Rap1-specific endopeptidase to pancreatic cancer cells. Importantly, mPA-scFv fusion-based treatments display potent cell-specific toxicity in vitro, opening fundamentally new routes toward engineered immunotoxins and providing a potential solution to the challenge of targeted protein delivery to the cytosol of cancer cells.
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Affiliation(s)
- Alexander R Loftis
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Michael S Santos
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Nicholas L Truex
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Marco Biancucci
- Department of Microbiology-Immunology Feinberg School of Medicine, Northwestern University, 420 E Superior Street, Chicago, IL 60611, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology Feinberg School of Medicine, Northwestern University, 420 E Superior Street, Chicago, IL 60611, USA
| | - Bradley L Pentelute
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA 02142, USA
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142, USA
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26
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Delivering a RAS protease halts tumor growth. Oncotarget 2020; 11:3265-3266. [PMID: 32934771 PMCID: PMC7476736 DOI: 10.18632/oncotarget.27714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Indexed: 11/25/2022] Open
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Spatiotemporal Regulation of Vibrio Exotoxins by HlyU and Other Transcriptional Regulators. Toxins (Basel) 2020; 12:toxins12090544. [PMID: 32842612 PMCID: PMC7551375 DOI: 10.3390/toxins12090544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
After invading a host, bacterial pathogens secrete diverse protein toxins to disrupt host defense systems. To ensure successful infection, however, pathogens must precisely regulate the expression of those exotoxins because uncontrolled toxin production squanders energy. Furthermore, inappropriate toxin secretion can trigger host immune responses that are detrimental to the invading pathogens. Therefore, bacterial pathogens use diverse transcriptional regulators to accurately regulate multiple exotoxin genes based on spatiotemporal conditions. This review covers three major exotoxins in pathogenic Vibrio species and their transcriptional regulation systems. When Vibrio encounters a host, genes encoding cytolysin/hemolysin, multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin, and secreted phospholipases are coordinately regulated by the transcriptional regulator HlyU. At the same time, however, they are distinctly controlled by a variety of other transcriptional regulators. How this coordinated but distinct regulation of exotoxins makes Vibrio species successful pathogens? In addition, anti-virulence strategies that target the coordinating master regulator HlyU and related future research directions are discussed.
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Abstract
V. vulnificus is an opportunistic human pathogen that can cause life-threatening sepsis in immunocompromised patients via seafood poisoning or wound infection. Among the toxic substances produced by this pathogen, the MARTX toxin greatly contributes to disease progression by promoting the dysfunction and death of host cells, which allows the bacteria to disseminate and colonize the host. In response to this, host cells mount a counterattack against the invaders by upregulating various defense genes. In this study, the gene expression profiles of both host cells and V. vulnificus were analyzed by RNA sequencing to gain a comprehensive understanding of host-pathogen interactions. Our results suggest that V. vulnificus uses the MARTX toxin to subvert host cell immune responses as well as to oppose host counterattacks such as iron limitation. To understand toxin-stimulated host-pathogen interactions, we performed dual-transcriptome sequencing experiments using human epithelial (HT-29) and differentiated THP-1 (dTHP-1) immune cells infected with the sepsis-causing pathogen Vibrio vulnificus (either the wild-type [WT] pathogen or a multifunctional-autoprocessing repeats-in-toxin [MARTX] toxin-deficient strain). Gene set enrichment analyses revealed MARTX toxin-dependent responses, including negative regulation of extracellular related kinase 1 (ERK1) and ERK2 (ERK1/2) signaling and cell cycle regulation in HT-29 and dTHP-1 cells, respectively. Further analysis of the expression of immune-related genes suggested that the MARTX toxin dampens immune responses in gut epithelial cells but accelerates inflammation and nuclear factor κB (NF-κB) signaling in immune cells. With respect to the pathogen, siderophore biosynthesis genes were significantly more highly expressed in WT V. vulnificus than in the MARTX toxin-deficient mutant upon infection of dTHP-1 cells. Consistent with these results, iron homeostasis genes that limit iron levels for invading pathogens were overexpressed in WT V. vulnificus-infected dTHP-1 cells. Taken together, these results suggest that MARTX toxin regulates host inflammatory responses during V. vulnificus infection while also countering host defense mechanisms such as iron limitation. IMPORTANCEV. vulnificus is an opportunistic human pathogen that can cause life-threatening sepsis in immunocompromised patients via seafood poisoning or wound infection. Among the toxic substances produced by this pathogen, the MARTX toxin greatly contributes to disease progression by promoting the dysfunction and death of host cells, which allows the bacteria to disseminate and colonize the host. In response to this, host cells mount a counterattack against the invaders by upregulating various defense genes. In this study, the gene expression profiles of both host cells and V. vulnificus were analyzed by RNA sequencing to gain a comprehensive understanding of host-pathogen interactions. Our results suggest that V. vulnificus uses the MARTX toxin to subvert host cell immune responses as well as to oppose host counterattacks such as iron limitation.
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An engineered chimeric toxin that cleaves activated mutant and wild-type RAS inhibits tumor growth. Proc Natl Acad Sci U S A 2020; 117:16938-16948. [PMID: 32616570 DOI: 10.1073/pnas.2000312117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite nearly four decades of effort, broad inhibition of oncogenic RAS using small-molecule approaches has proven to be a major challenge. Here we describe the development of a pan-RAS biologic inhibitor composed of the RAS-RAP1-specific endopeptidase fused to the protein delivery machinery of diphtheria toxin. We show that this engineered chimeric toxin irreversibly cleaves and inactivates intracellular RAS at low picomolar concentrations terminating downstream signaling in receptor-bearing cells. Furthermore, we demonstrate in vivo target engagement and reduction of tumor burden in three mouse xenograft models driven by either wild-type or mutant RAS Intracellular delivery of a potent anti-RAS biologic through a receptor-mediated mechanism represents a promising approach to developing RAS therapeutics against a broad array of cancers.
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Wang X, Shen J, Jiang F, Jin Q. The Photorhabdus Virulence Cassettes RRSP-Like Effector Interacts With Cyclin-Dependent Kinase 1 and Causes Mitotic Defects in Mammalian Cells. Front Microbiol 2020; 11:366. [PMID: 32231646 PMCID: PMC7082817 DOI: 10.3389/fmicb.2020.00366] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/19/2020] [Indexed: 12/20/2022] Open
Abstract
The "Photorhabdus virulence cassettes" (PVCs) secreted by Photorhabdus are defined as "extracellular contractile injection systems" (eCISs) and can deliver effectors to eukaryotic hosts for cytotoxicity. Previously, we demonstrated the cryogenic electron microscopy (cryo-EM) structure and assembly process of an intact PVC particle from Photorhabdus asymbiotica. In this work, we characterized the biological functions of a PVC effector, which is defined as a homologous protein of Ras/Rap1-specific endopeptidase domain (RRSP) in the multifunctional autoprocessing repeats-in-toxin (MARTX) toxin from Vibrio vulnificus. In this work, we found that the RRSP homologous protein (RRSPPa) was associated with inhibition of cell proliferation and increased cell apoptosis and death of HeLa cells. Furthermore, we discovered that RRSPPa disturbed mitotic progression, including the induction of cell cycle alteration, retardation of cell abscission time, and regression of the cleavage furrow. In addition, we revealed that RRSPPa could target the cyclin-dependent kinase 1 (CDK1) protein and block activation of CDK1 through inhibition of Thr161 phosphorylation, which partially explained the crucial role of this effector in cell mitosis.
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Affiliation(s)
| | | | - Feng Jiang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qi Jin
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Herrera A, Muroski J, Sengupta R, Nguyen HH, Agarwal S, Ogorzalek Loo RR, Mattoo S, Loo JA, Satchell KJF. N-terminal autoprocessing and acetylation of multifunctional-autoprocessing repeats-in-toxins (MARTX) Makes Caterpillars Floppy-like effector is stimulated by adenosine diphosphate (ADP)-Ribosylation Factor 1 in advance of Golgi fragmentation. Cell Microbiol 2019; 22:e13133. [PMID: 31658406 DOI: 10.1111/cmi.13133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/26/2019] [Accepted: 10/11/2019] [Indexed: 12/17/2022]
Abstract
Studies have successfully elucidated the mechanism of action of several effector domains that comprise the multifunctional-autoprocessing repeats-in-toxins (MARTX) toxins of Vibrio vulnificus. However, the biochemical linkage between the cysteine proteolytic activity of Makes Caterpillars Floppy (MCF)-like effector and its cellular effects remains unknown. In this study, we identify the host cell factors that activate in vivo and in vitro MCF autoprocessing as adenosine diphosphate (ADP)-Ribosylation Factor 1 (ARF1) and ADP-Ribosylation Factor 3 (ARF3). Autoprocessing activity is enhanced when ARF1 is in its active [guanosine triphosphate (GTP)-bound] form compared to the inactive [guanosine diphosphate (GDP)-bound] form. Subsequent to auto-cleavage, MCF is acetylated on its exposed N-terminal glycine residue. Acetylation apparently does not dictate subcellular localization as MCF is found localized throughout the cell. However, the cleaved form of MCF gains the ability to bind to the specialized lipid phosphatidylinositol 5-phosphate enriched in Golgi and other membranes necessary for endocytic trafficking, suggesting that a fraction of MCF may be subcellularly localized. Traditional thin-section electron microscopy, high-resolution cryoAPEX localization, and fluorescent microscopy show that MCF causes Golgi dispersal resulting in extensive vesiculation. In addition, host mitochondria are disrupted and fragmented. Mass spectrometry analysis found no reproducible modifications of ARF1 suggesting that ARF1 is not post-translationally modified by MCF. Further, catalytically active MCF does not stably associate with ARF1. Our data indicate not only that ARF1 is a cross-kingdom activator of MCF, but also that MCF may mediate cytotoxicity by directly targeting another yet to be identified protein. This study begins to elucidate the biochemical activity of this important domain and gives insight into how it may promote disease progression.
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Affiliation(s)
- Alfa Herrera
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - John Muroski
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California
| | - Ranjan Sengupta
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana
| | - Hong Hanh Nguyen
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California
| | - Shivangi Agarwal
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rachel R Ogorzalek Loo
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California.,UCLA/DOE Institute of Genomics and Proteomics, University of California-Los Angeles, Los Angeles, California
| | - Seema Mattoo
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana.,Purdue Institute for Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, Indiana
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California.,Department of Biological Chemistry, David Geffen School of Medicine, UCLA Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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32
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Guo RH, Im YJ, Shin SI, Jeong K, Rhee JH, Kim YR. Vibrio vulnificus RtxA1 cytotoxin targets filamin A to regulate PAK1- and MAPK-dependent cytoskeleton reorganization and cell death. Emerg Microbes Infect 2019; 8:934-945. [PMID: 31237474 PMCID: PMC6598492 DOI: 10.1080/22221751.2019.1632153] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cytoskeletal rearrangement and acute cytotoxicity occur in Vibrio vulnificus-infected host cells. RtxA1 toxin, a multifunctional autoprocessing repeats-in-toxin (MARTX), is essential for the pathogenesis of V. vulnificus and the programmed necrotic cell death. In this study, HeLa cells expressing RtxA1 amino acids 1491–1971 fused to GFP were observed to be rounded. Through yeast two-hybrid screening and subsequent immunoprecipitation validation assays, we confirmed the specific binding of a RtxA11491–1971 fragment with host-cell filamin A, an actin cross-linking scaffold protein. Downregulation of filamin A expression decreased the cytotoxicity of RtxA1 toward host cells. Furthermore, the phosphorylation of JNK and p38 MAPKs was induced by the RtxA1-filamin A interaction during the toxin-mediated cell death. However, the phosphorylation of these MAPKs was not observed during the RtxA1 intoxication of filamin A-deficient M2 cells. In addition, the depletion of pak1, which appeared to be activated by the RtxA1-filamin A interaction, inhibited RtxA1-induced phosphorylation of JNK and p38, and the cells treated with a pak1 inhibitor exhibited decreased RtxA1-mediated cytoskeletal rearrangement and cytotoxicity. Thus, the binding of filamin A by the RtxA11491–1971 domain appears to be a requisite to pak1-mediated MAPK activation, which contributes to the cytoskeletal reorganization and host cell death.
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Affiliation(s)
- Rui Hong Guo
- a College of Pharmacy and Research Institute of Drug Development , Chonnam National University , Gwangju , Republic of Korea
| | - Young Jun Im
- a College of Pharmacy and Research Institute of Drug Development , Chonnam National University , Gwangju , Republic of Korea
| | - Soo Im Shin
- c Department of Bioengineering and Biotechnology, College of Engineering , Chonnam National University , Gwangju , Republic of Korea
| | - Kwangjoon Jeong
- b Clinical Vaccine R&D Center and Department of Microbiology , Chonnam National University Medical School , Hwasun , Republic of Korea
| | - Joon Haeng Rhee
- b Clinical Vaccine R&D Center and Department of Microbiology , Chonnam National University Medical School , Hwasun , Republic of Korea
| | - Young Ran Kim
- a College of Pharmacy and Research Institute of Drug Development , Chonnam National University , Gwangju , Republic of Korea
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33
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Liu D, Wu C, Wu R, Huang J, Liao B, Lei M, Zhang Y, He H. Comprehensive analysis of the phylogeny and extracellular proteases in genus Vibrio strain. Microb Pathog 2019; 131:1-8. [PMID: 30902730 DOI: 10.1016/j.micpath.2019.03.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 02/08/2023]
Abstract
As one of the dominant bacteria in the ocean, Vibrio play important roles in maintaining the aquatic ecosystem. In this study, we studied the phylogenetic relationships of 32 Vibrio based on the 16S rRNA genes sequences and utilized substrate immersing zymography method to detect the trend of protease production and components of multiprotease system of Vibrio extracellular proteases. The result showed that different extracellular proteolytic profiles among various Vibrio strains demonstrated a large interspecific variation, and for strains from the same environments, the closer the evolutionary relationship of them, the more similar their zymograms were. In addition, these proteases displayed very different hydrolysis abilities to casein and gelatin. Moreover, the results of the inhibitor-substrate immersing zymography indicated that the proteases secreted by marine Vibrio mostly belonged to serine proteases or metalloproteases. These results implied that combined taxonomic information of the Vibrios with their extracellular protease zymograms maybe contributed to the study of the classification, phylogeny and pathogenic mechanism of Vibrio, and can serve as a theoretical basis for controlling the pathogenic Vibrio disease as well as exploiting proteases. More importantly, we can also eliminate many similar strains by this way, thus can greatly reduce the workload of the experiments for us.
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Affiliation(s)
- Dan Liu
- School of Life Sciences, Central South University, Changsha, Hunan, 410013, China
| | - Cuiling Wu
- Department of Biochemistry, Changzhi Medical College, Changzhi, Shanxi, 046000, China
| | - Ribang Wu
- School of Life Sciences, Central South University, Changsha, Hunan, 410013, China
| | - Jiafeng Huang
- School of Life Sciences, Central South University, Changsha, Hunan, 410013, China
| | - Binqiang Liao
- School of Life Sciences, Central South University, Changsha, Hunan, 410013, China
| | - Ming Lei
- School of Life Sciences, Central South University, Changsha, Hunan, 410013, China
| | - Yanjiao Zhang
- Shandong Province Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, Qingdao, Shandong, 266109, China
| | - Hailun He
- School of Life Sciences, Central South University, Changsha, Hunan, 410013, China.
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Gavin HE, Satchell KJF. RRSP and RID Effector Domains Dominate the Virulence Impact of Vibrio vulnificus MARTX Toxin. J Infect Dis 2019; 219:889-897. [PMID: 30289477 PMCID: PMC6386806 DOI: 10.1093/infdis/jiy590] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 10/04/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The bacterial pathogen Vibrio vulnificus causes severe septic foodborne infections. The multifunctional autoprocessing repeats-in-toxins (MARTX) toxin is an important secreted virulence factor. The effector domain region is essential for lethal intestinal infection in mice, but the contribution of each of the 5 effector domains to infection has not been investigated. METHODS V. vulnificus mutants with varying effector domain content were inoculated intragastrically to mice, and the time to death was monitored to establish the contribution of each effector domain to overall virulence. Each strain was also tested for bacterial dissemination from the intestine to internal organs and for inhibition of phagocytosis. RESULTS The effector domain region was required for V. vulnificus to inhibit phagocytosis by J774 macrophages, but no single effector domain was required. No single MARTX effector domain was necessary for bacterial dissemination. Nonetheless, overall survival of infected mice differed with respect to the infecting V. vulnificus strain. Removal of rid or rrsp significantly reduced the virulence potential of V. vulnificus, while deletion of duf1 or abh accelerated the time to death. CONCLUSION Rho GTPases inactivation domain and Ras/Rap1-specific endopeptidase each exert greater effects on virulence than other MARTX domains, suggesting that modulation of the Rho/Ras family of GTPases is a critical function of the toxin during intestinal infection.
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Affiliation(s)
- Hannah E Gavin
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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35
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Kim BS. The Modes of Action of MARTX Toxin Effector Domains. Toxins (Basel) 2018; 10:toxins10120507. [PMID: 30513802 PMCID: PMC6315884 DOI: 10.3390/toxins10120507] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/20/2018] [Accepted: 11/27/2018] [Indexed: 12/26/2022] Open
Abstract
Many Gram-negative bacterial pathogens directly deliver numerous effector proteins from the bacterium to the host cell, thereby altering the target cell physiology. The already well-characterized effector delivery systems are type III, type IV, and type VI secretion systems. Multifunctional autoprocessing repeats-in-toxin (MARTX) toxins are another effector delivery platform employed by some genera of Gram-negative bacteria. These single polypeptide exotoxins possess up to five effector domains in a modular fashion in their central regions. Upon binding to the host cell plasma membrane, MARTX toxins form a pore using amino- and carboxyl-terminal repeat-containing arms and translocate the effector domains into the cells. Consequently, MARTX toxins affect the integrity of the host cells and often induce cell death. Thus, they have been characterized as crucial virulence factors of certain human pathogens. This review covers how each of the MARTX toxin effector domains exhibits cytopathic and/or cytotoxic activities in cells, with their structural features revealed recently. In addition, future directions for the comprehensive understanding of MARTX toxin-mediated pathogenesis are discussed.
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Affiliation(s)
- Byoung Sik Kim
- Department of Food Science and Engineering, ELTEC College of Engineering, Ewha Womans University, Seoul 03760, Korea.
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36
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Jang SY, Hwang J, Kim BS, Lee EY, Oh BH, Kim MH. Structural basis of inactivation of Ras and Rap1 small GTPases by Ras/Rap1-specific endopeptidase from the sepsis-causing pathogen Vibrio vulnificus. J Biol Chem 2018; 293:18110-18122. [PMID: 30282804 PMCID: PMC6254334 DOI: 10.1074/jbc.ra118.004857] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/25/2018] [Indexed: 12/15/2022] Open
Abstract
Multifunctional autoprocessing repeats-in-toxin (MARTX) toxins are secreted by Gram-negative bacteria and function as primary virulence-promoting macromolecules that deliver multiple cytopathic and cytotoxic effector domains into the host cytoplasm. Among these effectors, Ras/Rap1-specific endopeptidase (RRSP) catalyzes the sequence-specific cleavage of the Switch I region of the cellular substrates Ras and Rap1 that are crucial for host innate immune defenses during infection. To dissect the molecular basis underpinning RRSP-mediated substrate inactivation, we determined the crystal structure of an RRSP from the sepsis-causing bacterial pathogen Vibrio vulnificus (VvRRSP). Structural and biochemical analyses revealed that VvRRSP is a metal-independent TIKI family endopeptidase composed of an N-terminal membrane-localization and substrate-recruitment domain (N lobe) connected via an inter-lobe linker to the C-terminal active site-coordinating core β-sheet-containing domain (C lobe). Structure-based mutagenesis identified the 2His/2Glu catalytic residues in the core catalytic domain that are shared with other TIKI family enzymes and that are essential for Ras processing. In vitro KRas cleavage assays disclosed that deleting the N lobe in VvRRSP causes complete loss of enzymatic activity. Endogenous Ras cleavage assays combined with confocal microscopy analysis of HEK293T cells indicated that the N lobe functions both in membrane localization via the first α-helix and in substrate assimilation by altering the functional conformation of the C lobe to facilitate recruitment of cellular substrates. Collectively, these results indicate that RRSP is a critical virulence factor that robustly inactivates Ras and Rap1 and augments the pathogenicity of invading bacteria via the combined effects of its N and C lobes.
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Affiliation(s)
- Song Yee Jang
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141,; the Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, and
| | - Jungwon Hwang
- the Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, and.
| | - Byoung Sik Kim
- the Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, and; the Department of Food Science and Engineering, Ewha Womans University, Seoul 03760, Korea
| | - Eun-Young Lee
- the Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, and
| | - Byung-Ha Oh
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141,.
| | - Myung Hee Kim
- the Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, and.
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37
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Biancucci M, Minasov G, Banerjee A, Herrera A, Woida PJ, Kieffer MB, Bindu L, Abreu-Blanco M, Anderson WF, Gaponenko V, Stephen AG, Holderfield M, Satchell KJF. The bacterial Ras/Rap1 site-specific endopeptidase RRSP cleaves Ras through an atypical mechanism to disrupt Ras-ERK signaling. Sci Signal 2018; 11:eaat8335. [PMID: 30279169 PMCID: PMC6309442 DOI: 10.1126/scisignal.aat8335] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Ras-extracellular signal-regulated kinase pathway is critical for controlling cell proliferation, and its aberrant activation drives the growth of various cancers. Because many pathogens produce toxins that inhibit Ras activity, efforts to develop effective Ras inhibitors to treat cancer could be informed by studies of Ras inhibition by pathogens. Vibrio vulnificus causes fatal infections in a manner that depends on multifunctional autoprocessing repeats-in-toxin, a toxin that releases bacterial effector domains into host cells. One such domain is the Ras/Rap1-specific endopeptidase (RRSP), which site-specifically cleaves the Switch I domain of the small GTPases Ras and Rap1. We solved the crystal structure of RRSP and found that its backbone shares a structural fold with the EreA/ChaN-like superfamily of enzymes. Unlike other proteases in this family, RRSP is not a metalloprotease. Through nuclear magnetic resonance analysis and nucleotide exchange assays, we determined that the processing of KRAS by RRSP did not release any fragments or cause KRAS to dissociate from its bound nucleotide but instead only locally affected its structure. However, this structural alteration of KRAS was sufficient to disable guanine nucleotide exchange factor-mediated nucleotide exchange and prevent KRAS from binding to RAF. Thus, RRSP is a bacterial effector that represents a previously unrecognized class of protease that disconnects Ras from its signaling network while inducing limited structural disturbance in its target.
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Affiliation(s)
- Marco Biancucci
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - George Minasov
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Avik Banerjee
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alfa Herrera
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Patrick J Woida
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Matthew B Kieffer
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Lakshman Bindu
- National Cancer Institute-RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD 21702, USA
| | - Maria Abreu-Blanco
- National Cancer Institute-RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD 21702, USA
| | - Wayne F Anderson
- Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Andrew G Stephen
- National Cancer Institute-RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD 21702, USA
| | - Matthew Holderfield
- National Cancer Institute-RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, MD 21702, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
- Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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38
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Ancestral gene acquisition as the key to virulence potential in environmental Vibrio populations. ISME JOURNAL 2018; 12:2954-2966. [PMID: 30072747 PMCID: PMC6246604 DOI: 10.1038/s41396-018-0245-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 06/30/2018] [Accepted: 07/06/2018] [Indexed: 11/08/2022]
Abstract
Diseases of marine animals caused by bacteria of the genus Vibrio are on the rise worldwide. Understanding the eco-evolutionary dynamics of these infectious agents is important for predicting and managing these diseases. Yet, compared to Vibrio infecting humans, knowledge of their role as animal pathogens is scarce. Here we ask how widespread is virulence among ecologically differentiated Vibrio populations, and what is the nature and frequency of virulence genes within these populations? We use a combination of population genomics and molecular genetics to assay hundreds of Vibrio strains for their virulence in the oyster Crassostrea gigas, a unique animal model that allows high-throughput infection assays. We show that within the diverse Splendidus clade, virulence represents an ancestral trait but has been lost from several populations. Two loci are necessary for virulence, the first being widely distributed across the Splendidus clade and consisting of an exported conserved protein (R5.7). The second is a MARTX toxin cluster, which only occurs within V. splendidus and is for the first time associated with virulence in marine invertebrates. Varying frequencies of both loci among populations indicate different selective pressures and alternative ecological roles, based on which we suggest strategies for epidemiological surveys.
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Kam CY, Dubash AD, Magistrati E, Polo S, Satchell KJF, Sheikh F, Lampe PD, Green KJ. Desmoplakin maintains gap junctions by inhibiting Ras/MAPK and lysosomal degradation of connexin-43. J Cell Biol 2018; 217:3219-3235. [PMID: 29959233 PMCID: PMC6123000 DOI: 10.1083/jcb.201710161] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 04/26/2018] [Accepted: 06/11/2018] [Indexed: 12/13/2022] Open
Abstract
Desmosomal mutations result in potentially deadly cardiocutaneous disease caused by electrical conduction defects and disruption of gap junctions. Kam et al. demonstrate a mechanism whereby loss of the intermediate filament anchoring protein desmoplakin stimulates Cx43 turnover by increasing K-Ras expression, marking Cx43 for lysosomal degradation through ERK1/2 phosphorylation. Desmoplakin (DP) is an obligate component of desmosomes, intercellular adhesive junctions that maintain the integrity of the epidermis and myocardium. Mutations in DP can cause cardiac and cutaneous disease, including arrhythmogenic cardiomyopathy (ACM), an inherited disorder that frequently results in deadly arrhythmias. Conduction defects in ACM are linked to the remodeling and functional interference with Cx43-based gap junctions that electrically and chemically couple cells. How DP loss impairs gap junctions is poorly understood. We show that DP prevents lysosomal-mediated degradation of Cx43. DP loss triggered robust activation of ERK1/2–MAPK and increased phosphorylation of S279/282 of Cx43, which signals clathrin-mediated internalization and subsequent lysosomal degradation of Cx43. RNA sequencing revealed Ras-GTPases as candidates for the aberrant activation of ERK1/2 upon loss of DP. Using a novel Ras inhibitor, Ras/Rap1-specific peptidase (RRSP), or K-Ras knockdown, we demonstrate restoration of Cx43 in DP-deficient cardiomyocytes. Collectively, our results reveal a novel mechanism for the regulation of the Cx43 life cycle by DP in cardiocutaneous models.
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Affiliation(s)
- Chen Yuan Kam
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Adi D Dubash
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL
| | | | - Simona Polo
- Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy.,Dipartimento di Oncologia ed Emato-oncologia, Universita' degli Studi di Milano, Milan, Italy
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL
| | - Farah Sheikh
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Paul D Lampe
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Research Center, Seattle, WA
| | - Kathleen J Green
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL .,Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL
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40
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Burkholderia Lethal Factor 1, a Novel Anti-Cancer Toxin, Demonstrates Selective Cytotoxicity in MYCN-Amplified Neuroblastoma Cells. Toxins (Basel) 2018; 10:toxins10070261. [PMID: 29954071 PMCID: PMC6071135 DOI: 10.3390/toxins10070261] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/15/2018] [Accepted: 06/20/2018] [Indexed: 11/16/2022] Open
Abstract
Immunotoxins are being investigated as anti-cancer therapies and consist of a cytotoxic enzyme fused to a cancer targeting antibody. All currently used toxins function via the inhibition of protein synthesis, making them highly potent in both healthy and transformed cells. This non-specific cell killing mechanism causes dose-limiting side effects that can severely limit the potential of immunotoxin therapy. In this study, the recently characterised bacterial toxin Burkholderia lethal factor 1 (BLF1) is investigated as a possible alternative payload for targeted toxin therapy in the treatment of neuroblastoma. BLF1 inhibits translation initiation by inactivation of eukaryotic initiation translation factor 4A (eIF4A), a putative anti-cancer target that has been shown to regulate a number of oncogenic proteins at the translational level. We show that cellular delivery of BLF1 selectively induces apoptosis in neuroblastoma cells that display MYCN amplification but has little effect on non-transformed cells. Future immunotoxins based on this enzyme may therefore have higher specificity towards MYCN-amplified cancer cells than more conventional ribosome-inactivating proteins, leading to an increased therapeutic window and decreased side effects.
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41
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Schorch B, Heni H, Zahaf NI, Brummer T, Mione M, Schmidt G, Papatheodorou P, Aktories K. Targeting oncogenic Ras by the Clostridium perfringens toxin TpeL. Oncotarget 2018; 9:16489-16500. [PMID: 29662661 PMCID: PMC5893256 DOI: 10.18632/oncotarget.24740] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 03/02/2018] [Indexed: 12/18/2022] Open
Abstract
Clostridium perfringens toxin TpeL belongs to the family of large clostridial glycosylating toxins. The toxin causes N-acetylglucosaminylation of Ras proteins at threonine35 thereby inactivating the small GTPases. Here, we show that all main types of oncogenic Ras proteins (H-Ras, K-Ras and N-Ras) are modified by the toxin in vitro and in vivo. Toxin-catalyzed modification of Ras was accompanied by inhibition of the MAP kinase pathway. Importantly, TpeL inhibited the paradoxical activation of the MAP kinase pathway induced by the BRAF inhibitor Vemurafenib in the human melanoma cell line SBCL2. The toxin also blocked Ras signaling in a zebrafish embryo model expressing oncogenic H-RasG12V, resulting in a reduction of melanocyte number. By using the binding and translocation component of anthrax toxin (protective antigen), the glucosyltransferase domain of TpeL was effectively introduced into target cells that were not sensitive to native TpeL toxin. To reach a higher specificity towards cancer cells, a chimeric TpeL toxin was engineered that possessed the knob region of adenovirus serotype 35 fiber, which interacts with CD46 of target cells frequently overexpressed in cancer cells. The chimeric TpeL fusion toxin efficiently inhibited Ras and MAP kinases in human pancreatic cancer Capan-2 cells, which were insensitive to the wild-type toxin. The data reveal that TpeL and TpeL-related immunotoxins provide a new toolset as Ras-inactivating agents.
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Affiliation(s)
- Björn Schorch
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Hannah Heni
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Nour-Imene Zahaf
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Tilman Brummer
- Institut für Molekulare Medizin und Zellforschung, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK), Partner Site Freiburg, Germany, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Marina Mione
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggestein-Leopoldshafen, Germany.,Present Address: Center for Integrative Biology, University of Trento, Trento, Italy
| | - Gudula Schmidt
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Panagiotis Papatheodorou
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.,Present Address: Institute of Pharmaceutical Biotechnology, University of Ulm, Ulm, Germany.,Present Address: Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.,Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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42
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Woida PJ, Satchell KJF. Coordinated delivery and function of bacterial MARTX toxin effectors. Mol Microbiol 2017; 107:133-141. [PMID: 29114985 DOI: 10.1111/mmi.13875] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2017] [Indexed: 12/22/2022]
Abstract
Bacteria often coordinate virulence factors to fine-tune the host response during infection. These coordinated events can include toxins counteracting or amplifying effects of another toxin or though regulating the stability of virulence factors to remove their function once it is no longer needed. Multifunctional autoprocessing repeats-in toxin (MARTX) toxins are effector delivery toxins that form a pore into the plasma membrane of a eukaryotic cell to deliver multiple effector proteins into the cytosol of the target cell. The function of these proteins includes manipulating actin cytoskeletal dynamics, regulating signal transduction pathways and inhibiting host secretory pathways. Investigations into the molecular mechanisms of these effector domains are providing insight into how the function of some effectors overlap and regulate one another during infection. Coordinated crosstalk of effector function suggests that MARTX toxins are not simply a sum of all their parts. Instead, modulation of cell function by effector domains may depend on which other effector domain are co-delivered. Future studies will elucidate how these effectors interact with each other to modulate the bacterial host interaction.
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Affiliation(s)
- Patrick J Woida
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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43
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Kim IH, Aryal SK, Aghai DT, Casanova-Torres ÁM, Hillman K, Kozuch MP, Mans EJ, Mauer TJ, Ogier JC, Ensign JC, Gaudriault S, Goodman WG, Goodrich-Blair H, Dillman AR. The insect pathogenic bacterium Xenorhabdus innexi has attenuated virulence in multiple insect model hosts yet encodes a potent mosquitocidal toxin. BMC Genomics 2017; 18:927. [PMID: 29191166 PMCID: PMC5709968 DOI: 10.1186/s12864-017-4311-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/16/2017] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Xenorhabdus innexi is a bacterial symbiont of Steinernema scapterisci nematodes, which is a cricket-specialist parasite and together the nematode and bacteria infect and kill crickets. Curiously, X. innexi expresses a potent extracellular mosquitocidal toxin activity in culture supernatants. We sequenced a draft genome of X. innexi and compared it to the genomes of related pathogens to elucidate the nature of specialization. RESULTS Using green fluorescent protein-expressing X. innexi we confirm previous reports using culture-dependent techniques that X. innexi colonizes its nematode host at low levels (~3-8 cells per nematode), relative to other Xenorhabdus-Steinernema associations. We found that compared to the well-characterized entomopathogenic nematode symbiont X. nematophila, X. innexi fails to suppress the insect phenoloxidase immune pathway and is attenuated for virulence and reproduction in the Lepidoptera Galleria mellonella and Manduca sexta, as well as the dipteran Drosophila melanogaster. To assess if, compared to other Xenorhabdus spp., X. innexi has a reduced capacity to synthesize virulence determinants, we obtained and analyzed a draft genome sequence. We found no evidence for several hallmarks of Xenorhabdus spp. toxicity, including Tc and Mcf toxins. Similar to other Xenorhabdus genomes, we found numerous loci predicted to encode non-ribosomal peptide/polyketide synthetases. Anti-SMASH predictions of these loci revealed one, related to the fcl locus that encodes fabclavines and zmn locus that encodes zeamines, as a likely candidate to encode the X. innexi mosquitocidal toxin biosynthetic machinery, which we designated Xlt. In support of this hypothesis, two mutants each with an insertion in an Xlt biosynthesis gene cluster lacked the mosquitocidal compound based on HPLC/MS analysis and neither produced toxin to the levels of the wild type parent. CONCLUSIONS The X. innexi genome will be a valuable resource in identifying loci encoding new metabolites of interest, but also in future comparative studies of nematode-bacterial symbiosis and niche partitioning among bacterial pathogens.
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Affiliation(s)
- Il-Hwan Kim
- Department of Entomology, University of Wisconsin-Madison, Madison, WI USA
- Present address: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD USA
| | | | - Dariush T. Aghai
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
| | | | - Kai Hillman
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
| | - Michael P. Kozuch
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
| | - Erin J. Mans
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
- Department of Microbiology, University of Tennessee-Knoxville, Knoxville, TN USA
| | - Terra J. Mauer
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
- Department of Microbiology, University of Tennessee-Knoxville, Knoxville, TN USA
| | | | - Jerald C. Ensign
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
| | | | - Walter G. Goodman
- Department of Entomology, University of Wisconsin-Madison, Madison, WI USA
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
- Department of Microbiology, University of Tennessee-Knoxville, Knoxville, TN USA
| | - Adler R. Dillman
- Department of Nematology, University of California, Riverside, CA USA
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44
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Chen CL, Chien SC, Leu TH, Harn HIC, Tang MJ, Hor LI. Vibrio vulnificus MARTX cytotoxin causes inactivation of phagocytosis-related signaling molecules in macrophages. J Biomed Sci 2017; 24:58. [PMID: 28822352 PMCID: PMC5563386 DOI: 10.1186/s12929-017-0368-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/13/2017] [Indexed: 01/22/2023] Open
Abstract
Background Vibrio vulnificus is a marine bacterial species that causes opportunistic infections manifested by serious skin lesions and fulminant septicemia in humans. We have previously shown that the multifunctional autoprocessing repeats in toxin (MARTXVv1) of a biotype 1 V. vulnificus strain promotes survival of this organism in the host by preventing it from engulfment by the phagocytes. The purpose of this study was to further explore how MARTXVv1 inhibits phagocytosis of this microorganism by the macrophage. Methods We compared between a wild-type V. vulnificus strain and its MARTXVv1-deficient mutant for a variety of phagocytosis-related responses, including morphological change and activation of signaling molecules, they induced in the macrophage. We also characterized a set of MARTXVv1 domain-deletion mutants to define the regions associated with antiphagocytosis activity. Results The RAW 264.7 cells and mouse peritoneal exudate macrophages underwent cell rounding accompanied by F-actin disorganization in the presence of MARTXVv1. In addition, phosphorylation of some F-actin rearrangement-associated signaling molecules, including Lyn, Fgr and Hck of the Src family kinases (SFKs), focal adhesion kinase (FAK), proline-rich tyrosine kinase 2 (Pyk2), phosphoinositide 3-kinase (PI3K) and Akt, but not p38, was decreased. By using specific inhibitors, we found that these kinases were all involved in the phagocytosis of MARTXVv1-deficient mutant in an order of SFKs-FAK/Pyk2-PI3K-Akt. Deletion of the effector domains in the central region of MARTXVv1 could lead to reduced cytotoxicity, depending on the region and size of deletion, but did not affect the antiphagocytosis activity and ability to cause rounding of macrophage. Reduced phosphorylation of Akt was closely associated with inhibition of phagocytosis by the wild-type strain and MARTXVv1 domain-deletion mutants, and expression of the constitutively active Akt, myr-Akt, enhanced the engulfment of these strains by macrophage. Conclusions MARTXVv1 could inactivate the SFKs-FAK/Pyk2-PI3K-Akt signaling pathway in the macrophages. This might lead to impaired phagocytosis of the V. vulnificus-infected macrophage. The majority of the central region of MARTXVv1 is not associated with the antiphagocytosis activity. Electronic supplementary material The online version of this article (doi:10.1186/s12929-017-0368-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chun-Liang Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Shu-Chun Chien
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Tzeng-Horng Leu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.,Department of Pharmacology College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Hans I-Chen Harn
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Ming-Jer Tang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.,Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Lien-I Hor
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan. .,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.
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Lee SJ, Jung YH, Kim JS, Lee HJ, Lee SH, Lee KH, Jang KK, Choi SH, Han HJ. A Vibrio vulnificus VvpM Induces IL-1β Production Coupled with Necrotic Macrophage Death via Distinct Spatial Targeting by ANXA2. Front Cell Infect Microbiol 2017; 7:352. [PMID: 28848713 PMCID: PMC5554522 DOI: 10.3389/fcimb.2017.00352] [Citation(s) in RCA: 14] [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: 04/27/2017] [Accepted: 07/21/2017] [Indexed: 12/23/2022] Open
Abstract
An inflammatory form of phagocyte death evoked by the Gram-negative bacterium Vibrio (V.) vulnificus (WT) is one of hallmarks to promote their colonization, but the virulence factor and infectious mechanism involved in this process remain largely unknown. Here, we identified extracellular metalloprotease VvpM as a new virulence factor and investigated the molecular mechanism of VvpM which acts during the regulation of the inflammatory form of macrophage death and bacterial colonization. Mutation of the vvpM gene appeared to play major role in the prevention of IL-1β production due to V. vulnificus infection in macrophage. However, the recombinant protein (r) VvpM caused IL-1β production coupled with necrotic cell death, which is highly susceptible to the knockdown of annexin A2 (ANXA2) located in both membrane lipid and non-lipid rafts. In lipid rafts, rVvpM recruited NOX enzymes coupled with ANXA2 to facilitate the production of ROS responsible for the epigenetic and transcriptional regulation of NF-κB in the IL-1β promoter. rVvpM acting on non-lipid rafts increased LC3 puncta formation and autophagic flux, which are required for the mRNA expression of Atg5 involved in the autophagosome formation process. The autophagy activation caused by rVvpM induced NLRP3 inflammasome-dependent caspase-1 activation in the promoting of IL-1β production. In mouse models of V. vulnificus infection, the VvpM mutant failed to elevate the level of pro-inflammatory responses closely related to IL-1β production and prevented bacterial colonization. These findings delineate VvpM efficiently regulates two pathogenic pathways that stimulate NF-κB-dependent IL-1β production and autophagy-mediated NLRP3 inflammasome via distinct spatial targeting by ANXA2.
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Affiliation(s)
- Sei-Jung Lee
- Department of Pharmaceutical Engineering, Daegu Haany UniversityGyeongsan, South Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Jun Sung Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Hyun Jik Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Sang Hun Lee
- Medical Science Research Institute, Soonchunhyang University Seoul HospitalSeoul, South Korea
- Departments of Biochemistry, Soonchunhyang University College of MedicineCheonan, South Korea
| | - Kyu-Ho Lee
- Department of Life Science, Sogang UniversitySeoul, South Korea
| | - Kyung Ku Jang
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National UniversitySeoul, South Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National UniversitySeoul, South Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
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Murciano C, Lee CT, Fernández-Bravo A, Hsieh TH, Fouz B, Hor LI, Amaro C. MARTX Toxin in the Zoonotic Serovar of Vibrio vulnificus Triggers an Early Cytokine Storm in Mice. Front Cell Infect Microbiol 2017; 7:332. [PMID: 28775962 PMCID: PMC5517466 DOI: 10.3389/fcimb.2017.00332] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/05/2017] [Indexed: 12/18/2022] Open
Abstract
Vibrio vulnificus biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTXVv (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA13), which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing in vitro, ex vivo, and in vivo assays. First, we demonstrated that the ACD domain, present exclusively in this toxin variant, effectively has an actin-cross-linking activity. Second, we determined that the whole toxin caused death of human endotheliocytes and monocytes by lysis and apoptosis, respectively. Finally, we tested the hypothesis that RtxA13 contributes to human death caused by this zoonotic serovar by triggering an early cytokine storm in blood. To this end, we used a Bt2-SerE strain (R99) together with its rtxA13 deficient mutant, and a Bt1 strain (YJ016) producing RtxA11 (the most studied MARTXVv) together with its rtxA11 deficient mutant, as controls. Our results showed that RtxA13 was essential for virulence, as R99ΔΔrtxA13 was completely avirulent in our murine model of infection, and that R99, but not strain YJ016, induced an early, strong and dysregulated immune response involving the up-regulation of a high number of genes. This dysregulated immune response was directly linked to RtxA13. Based on these results and those obtained ex vivo (human blood), we propose a model of infection for the zoonotic serovar of V. vulnificus, in which RtxA13 would act as a sepsis-inducing toxin.
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Affiliation(s)
- Celia Murciano
- Departamento de Microbiología y Ecología & Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina, Universitat de ValènciaValencia, Spain
| | - Chung-Te Lee
- Department of Microbiology & Immunology & College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Ana Fernández-Bravo
- Departamento de Microbiología y Ecología & Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina, Universitat de ValènciaValencia, Spain
| | - Tsung-Han Hsieh
- Department of Microbiology & Immunology & College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Belén Fouz
- Departamento de Microbiología y Ecología & Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina, Universitat de ValènciaValencia, Spain
| | - Lien-I Hor
- Department of Microbiology & Immunology & College of Medicine, National Cheng Kung UniversityTainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Carmen Amaro
- Departamento de Microbiología y Ecología & Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina, Universitat de ValènciaValencia, Spain
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47
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Biancucci M, Rabideau AE, Lu Z, Loftis AR, Pentelute BL, Satchell KJF. Substrate Recognition of MARTX Ras/Rap1-Specific Endopeptidase. Biochemistry 2017; 56:2747-2757. [PMID: 28459538 DOI: 10.1021/acs.biochem.7b00246] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ras/Rap1-specific endopeptidase (RRSP) is a cytotoxic effector domain of the multifunctional autoprocessing repeats-in-toxin (MARTX) toxin of highly virulent strains of Vibrio vulnificus. RRSP blocks RAS-MAPK kinase signaling by cleaving Ras and Rap1 within the switch I region between Y32 and D33. Although the RRSP processing site is highly conserved among small GTPases, only Ras and Rap1 have been identified as proteolytic substrates. Here we report that residues Y32 and D33 at the scissile bond play an important role in RRSP substrate recognition, while the nucleotide state of Ras has an only minimal effect. In addition, substrate specificity is generated by residues across the entire switch I region. Indeed, swapping the Ras switch I region into either RalA or RhoA, GTPases that are not recognized by RRSP, generated chimeras that are substrates of RRSP. However, a difference in the processing efficiency of Ras switch I in the context of Ras, RalA, or RhoA indicates that protein regions outside Ras switch I also contribute to efficient RRSP substrate recognition. Moreover, we show that synthetic peptides corresponding to the Ras and Rap1, but not RalA, switch I regions are cleaved by RRSP, demonstrating sequence-specific substrate recognition. In conclusion, this work demonstrates that the GTPase recognition of RRSP is independent of the nucleotide state and is mainly driven by the Ras and Rap1 switch I loop and also influenced by additional protein-protein interactions, increasing the substrate specificity of RRSP.
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Affiliation(s)
- Marco Biancucci
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine , Chicago, Illinois 60611, United States
| | - Amy E Rabideau
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Zeyu Lu
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Alex R Loftis
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Bradley L Pentelute
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine , Chicago, Illinois 60611, United States
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Hisao GS, Brothers MC, Ho M, Wilson BA, Rienstra CM. The membrane localization domains of two distinct bacterial toxins form a 4-helix-bundle in solution. Protein Sci 2017; 26:497-504. [PMID: 27977897 PMCID: PMC5326565 DOI: 10.1002/pro.3097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 11/12/2022]
Abstract
Membrane localization domain (MLD) was first proposed for a 4-helix-bundle motif in the crystal structure of the C1 domain of Pasteurella multocida toxin (PMT). This structure motif is also found in the crystal structures of several clostridial glycosylating toxins (TcdA, TcdB, TcsL, and TcnA). The Ras/Rap1-specific endopeptidase (RRSP) module of the multifunctional autoprocessing repeats-in-toxins (MARTX) toxin produced by Vibrio vulnificus has sequence homology to the C1-C2 domains of PMT, including a putative MLD. We have determined the solution structure for the MLDs in PMT and in RRSP using solution state NMR. We conclude that the MLDs in these two toxins assume a 4-helix-bundle structure in solution.
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Affiliation(s)
- Grant S. Hisao
- Department of ChemistryUniversity of Illinois at Urbana‐ChampaignIllinois
| | | | - Mengfei Ho
- Department of MicrobiologyUniversity of Illinois at Urbana‐ChampaignIllinois
| | - Brenda A. Wilson
- Department of MicrobiologyUniversity of Illinois at Urbana‐ChampaignIllinois
| | - Chad M. Rienstra
- Department of ChemistryUniversity of Illinois at Urbana‐ChampaignIllinois
- Department of BiochemistryUniversity of Illinois at Urbana‐ChampaignIllinois
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana‐ChampaignIllinois
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Biancucci M, Dolores JS, Wong J, Grimshaw S, Anderson WF, Satchell KJF, Kwon K. New ligation independent cloning vectors for expression of recombinant proteins with a self-cleaving CPD/6xHis-tag. BMC Biotechnol 2017; 17:1. [PMID: 28056928 PMCID: PMC5216533 DOI: 10.1186/s12896-016-0323-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 12/09/2016] [Indexed: 12/30/2022] Open
Abstract
Background Recombinant protein purification is a crucial step for biochemistry and structural biology fields. Rapid robust purification methods utilize various peptide or protein tags fused to the target protein for affinity purification using corresponding matrices and to enhance solubility. However, affinity/solubility-tags often need to be removed in order to conduct functional and structural studies, adding complexities to purification protocols. Results In this work, the Vibrio cholerae MARTX toxin Cysteine Protease Domain (CPD) was inserted in a ligation-independent cloning (LIC) vector to create a C-terminal 6xHis-tagged inducible autoprocessing enzyme tag, called “the CPD-tag”. The pCPD and alternative pCPD/ccdB cloning vectors allow for easy insertion of DNA and expression of the target protein fused to the CPD-tag, which is removed at the end of the purification step by addition of the inexpensive small molecule inositol hexakisphosphate to induce CPD autoprocessing. This process is demonstrated using a small bacterial membrane localization domain and for high yield purification of the eukaryotic small GTPase KRas. Subsequently, pCPD was tested with 40 proteins or sub-domains selected from a high throughput crystallization pipeline. Conclusion pCPD vectors are easily used LIC compatible vectors for expression of recombinant proteins with a C-terminal CPD/6xHis-tag. Although intended only as a strategy for rapid tag removal, this pilot study revealed the CPD-tag may also increase expression and solubility of some recombinant proteins. Electronic supplementary material The online version of this article (doi:10.1186/s12896-016-0323-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marco Biancucci
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Ward 6-205, Chicago, IL, 60611, USA
| | - Jazel S Dolores
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Ward 6-205, Chicago, IL, 60611, USA.,Present address: Northwestern Memorial Hospital, Chicago, IL, USA
| | - Jennifer Wong
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Ward 6-205, Chicago, IL, 60611, USA.,Present address: Indiana University, Bloomington, IN, USA
| | - Sarah Grimshaw
- Infectious Diseases Group, J. Craig Venter Institute, 9714 Medical Center Drive, Rockville, MD, 20850, USA.,Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Wayne F Anderson
- Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Ward 6-205, Chicago, IL, 60611, USA. .,Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Keehwan Kwon
- Infectious Diseases Group, J. Craig Venter Institute, 9714 Medical Center Drive, Rockville, MD, 20850, USA. .,Center for Structural Genomics of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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50
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Gavin HE, Beubier NT, Satchell KJF. The Effector Domain Region of the Vibrio vulnificus MARTX Toxin Confers Biphasic Epithelial Barrier Disruption and Is Essential for Systemic Spread from the Intestine. PLoS Pathog 2017; 13:e1006119. [PMID: 28060924 PMCID: PMC5218395 DOI: 10.1371/journal.ppat.1006119] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/12/2016] [Indexed: 12/14/2022] Open
Abstract
Vibrio vulnificus causes highly lethal bacterial infections in which the Multifunctional Autoprocessing Repeats-in-Toxins (MARTX) toxin product of the rtxA1 gene is a key virulence factor. MARTX toxins are secreted proteins up to 5208 amino acids in size. Conserved MARTX N- and C-terminal repeat regions work in concert to form pores in eukaryotic cell membranes, through which the toxin's central region of modular effector domains is translocated. Upon inositol hexakisphosphate-induced activation of the of the MARTX cysteine protease domain (CPD) in the eukaryotic cytosol, effector domains are released from the holotoxin by autoproteolytic activity. We previously reported that the native MARTX toxin effector domain repertoire is dispensable for epithelial cellular necrosis in vitro, but essential for cell rounding and apoptosis prior to necrotic cell death. Here we use an intragastric mouse model to demonstrate that the effector domain region is required for bacterial virulence during intragastric infection. The MARTX effector domain region is essential for bacterial dissemination from the intestine, but dissemination occurs in the absence of overt intestinal tissue pathology. We employ an in vitro model of V. vulnificus interaction with polarized colonic epithelial cells to show that the MARTX effector domain region induces rapid intestinal barrier dysfunction and increased paracellular permeability prior to onset of cell lysis. Together, these results negate the inherent assumption that observations of necrosis in vitro directly predict bacterial virulence, and indicate a paradigm shift in our conceptual understanding of MARTX toxin function during intestinal infection. Results implicate the MARTX effector domain region in mediating early bacterial dissemination from the intestine to distal organs-a key step in V. vulnificus foodborne pathogenesis-even before onset of overt intestinal pathology.
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Affiliation(s)
- Hannah E. Gavin
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - Nike T. Beubier
- Department of Pathology, Northwestern University Feinberg School of Medicine and Northwestern Memorial Hospital, Chicago, IL, United States of America
| | - Karla J. F. Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
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