Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA
<i>Filifactor alocis</i> is a Gram-positive asaccharolytic, obligate anaerobic rod that has been isolated from a variety of oral infections including periodontitis, peri-implantitis, and odontogenic abscesses. As a newly emerging pathogen, its type strain has been investigated for pathog...
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MDPI AG
2022-05-01
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| Series: | Pathogens |
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| Online Access: | https://www.mdpi.com/2076-0817/11/5/590 |
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| author | Kai Bao Rolf Claesson Peter Gehrig Jonas Grossmann Jan Oscarsson Georgios N. Belibasakis |
| author_facet | Kai Bao Rolf Claesson Peter Gehrig Jonas Grossmann Jan Oscarsson Georgios N. Belibasakis |
| author_sort | Kai Bao |
| collection | DOAJ |
| description | <i>Filifactor alocis</i> is a Gram-positive asaccharolytic, obligate anaerobic rod that has been isolated from a variety of oral infections including periodontitis, peri-implantitis, and odontogenic abscesses. As a newly emerging pathogen, its type strain has been investigated for pathogenic properties, yet little is known about its virulence variations among strains. We previously screened the whole genome of nine clinical oral isolates and a reference strain of <i>F. alocis</i>, and they expressed a novel RTX toxin, FtxA. In the present study, we aimed to use label-free quantification proteomics to characterize the full proteome of those ten <i>F. alocis</i> strains. A total of 872 proteins were quantified, and 97 among them were differentially expressed in FtxA-positive strains compared with the negative strains. In addition, 44 of these differentially expressed proteins formed 66 pairs of associations based on their predicted functions, which included clusters of proteins with DNA repair/mediated transformation and catalytic activity-related function, indicating different biosynthetic activities among strains. FtxA displayed specific interactions with another six intracellular proteins, forming a functional cluster that could discriminate between FtxA-producing and non-producing strains. Among them were FtxB and FtxD, predicted to be encoded by the same operon as FtxA. While revealing the broader qualitative and quantitative proteomic landscape of <i>F. alocis</i>, this study also sheds light on the deeper functional inter-relationships of FtxA, thus placing this RTX family member into context as a major virulence factor of this species. |
| first_indexed | 2024-03-10T03:11:28Z |
| format | Article |
| id | doaj.art-73b435c1162f4d2eb527fb3eaf2e4062 |
| institution | Directory Open Access Journal |
| issn | 2076-0817 |
| language | English |
| last_indexed | 2024-03-10T03:11:28Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Pathogens |
| spelling | doaj.art-73b435c1162f4d2eb527fb3eaf2e40622023-11-23T12:33:05ZengMDPI AGPathogens2076-08172022-05-0111559010.3390/pathogens11050590Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxAKai Bao0Rolf Claesson1Peter Gehrig2Jonas Grossmann3Jan Oscarsson4Georgios N. Belibasakis5Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, 14104 Huddinge, SwedenDivision of Oral Microbiology, Department of Odontology, Umeå University, 90187 Umeå, SwedenFunctional Genomics Center Zurich, ETH Zurich and University of Zurich, Winterthurerstrasse 190, 8057 Zurich, SwitzerlandFunctional Genomics Center Zurich, ETH Zurich and University of Zurich, Winterthurerstrasse 190, 8057 Zurich, SwitzerlandDivision of Oral Microbiology, Department of Odontology, Umeå University, 90187 Umeå, SwedenDivision of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, 14104 Huddinge, Sweden<i>Filifactor alocis</i> is a Gram-positive asaccharolytic, obligate anaerobic rod that has been isolated from a variety of oral infections including periodontitis, peri-implantitis, and odontogenic abscesses. As a newly emerging pathogen, its type strain has been investigated for pathogenic properties, yet little is known about its virulence variations among strains. We previously screened the whole genome of nine clinical oral isolates and a reference strain of <i>F. alocis</i>, and they expressed a novel RTX toxin, FtxA. In the present study, we aimed to use label-free quantification proteomics to characterize the full proteome of those ten <i>F. alocis</i> strains. A total of 872 proteins were quantified, and 97 among them were differentially expressed in FtxA-positive strains compared with the negative strains. In addition, 44 of these differentially expressed proteins formed 66 pairs of associations based on their predicted functions, which included clusters of proteins with DNA repair/mediated transformation and catalytic activity-related function, indicating different biosynthetic activities among strains. FtxA displayed specific interactions with another six intracellular proteins, forming a functional cluster that could discriminate between FtxA-producing and non-producing strains. Among them were FtxB and FtxD, predicted to be encoded by the same operon as FtxA. While revealing the broader qualitative and quantitative proteomic landscape of <i>F. alocis</i>, this study also sheds light on the deeper functional inter-relationships of FtxA, thus placing this RTX family member into context as a major virulence factor of this species.https://www.mdpi.com/2076-0817/11/5/590<i>Filifactor alocis</i>label-free quantification proteomicsFtxA |
| spellingShingle | Kai Bao Rolf Claesson Peter Gehrig Jonas Grossmann Jan Oscarsson Georgios N. Belibasakis Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA Pathogens <i>Filifactor alocis</i> label-free quantification proteomics FtxA |
| title | Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA |
| title_full | Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA |
| title_fullStr | Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA |
| title_full_unstemmed | Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA |
| title_short | Proteomic Characterization of the Oral Pathogen <i>Filifactor alocis</i> Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA |
| title_sort | proteomic characterization of the oral pathogen i filifactor alocis i reveals key inter protein interactions of its rtx toxin ftxa |
| topic | <i>Filifactor alocis</i> label-free quantification proteomics FtxA |
| url | https://www.mdpi.com/2076-0817/11/5/590 |
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