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Apostol AJ, Bragagnolo NJ, Rodriguez CS, Audette GF. Structural insights into the disulfide isomerase and chaperone activity of TrbB of the F plasmid type IV secretion system. Curr Res Struct Biol 2024; 8:100156. [PMID: 39131116 PMCID: PMC11315126 DOI: 10.1016/j.crstbi.2024.100156] [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: 12/21/2023] [Revised: 06/07/2024] [Accepted: 07/10/2024] [Indexed: 08/13/2024] Open
Abstract
Bacteria have evolved elaborate mechanisms to thrive in stressful environments. F-like plasmids in gram-negative bacteria encode for a multi-protein Type IV Secretion System (T4SSF) that is functional for bacterial proliferation and adaptation through the process of conjugation. The periplasmic protein TrbB is believed to have a stabilizing chaperone role in the T4SSF assembly, with TrbB exhibiting disulfide isomerase (DI) activity. In the current report, we demonstrate that the deletion of the disordered N-terminus of TrbBWT, resulting in a truncation construct TrbB37-161, does not affect its catalytic in vitro activity compared to the wild-type protein (p = 0.76). Residues W37-K161, which include the active thioredoxin motif, are sufficient for DI activity. The N-terminus of TrbBWT is disordered as indicated by a structural model of GST-TrbBWT based on ColabFold-AlphaFold2 and Small Angle X-Ray Scattering data and 1H-15N Heteronuclear Single Quantum Correlation (HSQC) spectroscopy of the untagged protein. This disordered region likely contributes to the protein's dynamicity; removal of this region results in a more stable protein based on 1H-15N HSQC and Circular Dichroism Spectroscopies. Lastly, size exclusion chromatography analysis of TrbBWT in the presence of TraW, a T4SSF assembly protein predicted to interact with TrbBWT, does not support the inference of a stable complex forming in vitro. This work advances our understanding of TrbB's structure and function, explores the role of structural disorder in protein dynamics in the context of a T4SSF accessory protein, and highlights the importance of redox-assisted protein folding in the T4SSF.
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Affiliation(s)
- Arnold J. Apostol
- Department of Chemistry, York University, 4700 Keele St, Toronto, ON, Canada, M3J 1P3
- Centre for Research on Biomolecular Interactions, York University, Canada
| | - Nicholas J. Bragagnolo
- Department of Chemistry, York University, 4700 Keele St, Toronto, ON, Canada, M3J 1P3
- Centre for Research on Biomolecular Interactions, York University, Canada
| | - Christina S. Rodriguez
- Department of Chemistry, York University, 4700 Keele St, Toronto, ON, Canada, M3J 1P3
- Centre for Research on Biomolecular Interactions, York University, Canada
| | - Gerald F. Audette
- Department of Chemistry, York University, 4700 Keele St, Toronto, ON, Canada, M3J 1P3
- Centre for Research on Biomolecular Interactions, York University, Canada
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Loh SN, Anthony IR, Gavor E, Lim XS, Kini RM, Mok YK, Sivaraman J. Recognition of Aedes aegypti Mosquito Saliva Protein LTRIN by the Human Receptor LTβR for Controlling the Immune Response. BIOLOGY 2024; 13:42. [PMID: 38248473 PMCID: PMC10813304 DOI: 10.3390/biology13010042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/23/2024]
Abstract
Salivary proteins from mosquitoes have received significant attention lately due to their potential to develop therapeutic treatments or vaccines for mosquito-borne diseases. Here, we report the characterization of LTRIN (lymphotoxin beta receptor inhibitor), a salivary protein known to enhance the pathogenicity of ZIKV by interrupting the LTβR-initiated NF-κB signaling pathway and, therefore, diminish the immune responses. We demonstrated that the truncated C-terminal LTRIN (ΔLTRIN) is a dimeric protein with a stable alpha helix-dominant secondary structure, which possibly aids in withstanding the temperature fluctuations during blood-feeding events. ΔLTRIN possesses two Ca2+ binding EF-hand domains, with the second EF-hand motif playing a more significant role in interacting with LTβR. Additionally, we mapped the primary binding regions of ΔLTRIN on LTβR using hydrogen-deuterium exchange mass spectrometry (HDX-MS) and identified that 91QEKAHIAEHMDVPIDTSKMSEQELQFHY118 from the N-terminal of ΔLTRIN is the major interacting region. Together, our studies provide insight into the recognition of LTRIN by LTβR. This finding may aid in a future therapeutic and transmission-blocking vaccine development against ZIKV.
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Affiliation(s)
- Su Ning Loh
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
| | - Ian Russell Anthony
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
| | - Edem Gavor
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
| | - Xin Shan Lim
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
| | - R. Manjunatha Kini
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
| | - Yu Keung Mok
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
| | - J. Sivaraman
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; (S.N.L.)
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The dynamic nature of the Coronavirus receptor, angiotensin-converting enzyme 2 (ACE2) in differentiating airway epithelia. BBA ADVANCES 2022; 2:100044. [PMID: 35187520 PMCID: PMC8840828 DOI: 10.1016/j.bbadva.2022.100044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 01/13/2022] [Accepted: 02/06/2022] [Indexed: 01/10/2023] Open
Abstract
Once inhaled, SARS-CoV-2 particles enter respiratory ciliated cells by interacting with angiotensin converting enzyme 2 (ACE2). Understanding the nature of ACE2 within airway tissue has become a recent focus particularly in light of the COVID-19 pandemic. Airway mucociliary tissue was generated in-vitro using primary human nasal epithelial cells and the air-liquid interface (ALI) model of differentiation. Using ALI tissue, three distinct transcript variants of ACE2 were identified. One transcript encodes the documented full-length ACE2 protein. The other two transcripts are unique truncated isoforms, that until recently had only been predicted to exist via sequence analysis software. Quantitative PCR revealed that all three transcript variants are expressed throughout differentiation of airway mucociliary epithelia. Immunofluorescence analysis of individual ACE2 protein isoforms exogenously expressed in cell-lines revealed similar abilities to localize in the plasma membrane and interact with the SARS CoV 2 spike receptor binding domain. Immunohistochemistry on differentiated ALI tissue using antibodies to either the N-term or C-term of ACE2 revealed both overlapping and distinct signals in cells, most notably only the ACE2 C-term antibody displayed plasma-membrane localization. We also demonstrate that ACE2 protein shedding is different in ALI Tissue compared to ACE2-transfected cell lines, and that ACE2 is released from both the apical and basal surfaces of ALI tissue. Together, our data highlights various facets of ACE2 transcripts and protein in airway mucociliary tissue that may represent variables which impact an individual's susceptibility to SARS-CoV-2 infection, or the severity of Covid-19.
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Szabó JE, Nyíri K, Andrási D, Matejka J, Ozohanics O, Vértessy B. Redox status of cysteines does not alter functional properties of human dUTPase but the Y54C mutation involved in monogenic diabetes decreases protein stability. Sci Rep 2021; 11:19197. [PMID: 34584184 PMCID: PMC8478915 DOI: 10.1038/s41598-021-98790-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/13/2021] [Indexed: 02/08/2023] Open
Abstract
Recently it was proposed that the redox status of cysteines acts as a redox switch to regulate both the oligomeric status and the activity of human dUTPase. In a separate report, a human dUTPase point mutation, resulting in a tyrosine to cysteine substitution (Y54C) was identified as the monogenic cause of a rare syndrome associated with diabetes and bone marrow failure. These issues prompt a critical investigation about the potential regulatory role of cysteines in the enzyme. Here we show on the one hand that independently of the redox status of wild-type cysteines, human dUTPase retains its characteristic trimeric assembly and its catalytic activity. On the other hand, the Y54C mutation did not compromise the substrate binding and the catalytic properties of the enzyme at room temperature. The thermal stability of the mutant protein was found to be decreased, which resulted in the loss of 67% of its activity after 90 min incubation at the physiological temperature in contrast to the wild-type enzyme. In addition, the presence or absence of reducing agents had no effect on hDUTY54C activity and stability, although it was confirmed that the introduced cysteine contains a solvent accessible thiol group.
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Affiliation(s)
- Judit Eszter Szabó
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, Budapest, Hungary.
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, Hungary.
| | - Kinga Nyíri
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, Budapest, Hungary
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, Hungary
| | - Dániel Andrási
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, Hungary
| | - Judit Matejka
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, Budapest, Hungary
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, Hungary
| | - Olivér Ozohanics
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Beáta Vértessy
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, Budapest, Hungary.
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest, Hungary.
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Maternal cysteine intake influenced oxidative status and lipid-related gut microbiota and plasma metabolomics in male suckling piglets. Anim Feed Sci Technol 2021. [DOI: 10.1016/j.anifeedsci.2021.114947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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