| 1. |
- Curtis, Michael W., et al.
(författare)
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Identification of amino acid domains of Borrelia burgdorferi P66 that are surface exposed and important for localization, oligomerization, and porin function of the protein
- 2022
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Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media S.A.. - 2235-2988. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- P66, a bifunctional integral outer membrane protein, is necessary for Borrelia burgdorferi to establish initial infection and to disseminate in mice. The integrin binding function of P66 facilitates extravasation and dissemination, but the role of its porin function during murine infection has not been investigated. A limitation to studying P66 porin function during mammalian infection has been the lack of structural information for P66. In this study, we experimentally characterized specific domains of P66 with regard to structure and function. First, we aligned the amino acid sequences of P66 from Lyme disease-causing Borrelia and relapsing fever-causing Borrelia to identify conserved and unique domains between these disease-causing clades. Then, we examined whether specific domains of P66 are exposed on the surface of the bacteria by introducing c-Myc epitope tags into each domain of interest. The c-Myc epitope tag inserted C-terminally to E33 (highly conserved domain), to T187 (integrin binding region domain and a non-conserved domain), and to E334 (non-conserved domain) were all detected on the surface of Borrelia burgdorferi. The c-Myc epitope tag inserted C-terminally to E33 and D303 in conserved domains disrupted P66 oligomerization and porin function. In a murine model of infection, the E33 and D303 mutants exhibited decreased infectivity and dissemination. Taken together, these results suggest the importance of these conserved domains, and potentially P66 porin function, in vivo.
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| 2. |
- Pinne, Marija, et al.
(författare)
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Elimination of chanel-forming activity by insertional inactivation of the p66 gene in Borrelia burgdorferi.
- 2007
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Ingår i: FEMS Microbiol Lett. - : Oxford University Press (OUP). - 0378-1097 .- 1574-6968. ; 266, s. 241-249
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Tidskriftsartikel (refereegranskat)abstract
- Abstract P66 is a chromosomally encoded 66-kDa integral outer membrane protein of the Lyme disease agent Borrelia burgdorferi exhibiting channel-forming activity. Herein, we inactivated and subsequently complemented the p66 gene in the B31-A (WT) strain. The P66 protein was also inactivated in two other channel-forming protein mutant strains, P13-18 (Deltap13) and Deltabba01, and then compared with the channel-forming activities of wild-type and various p66 mutant strains. We further investigated the ion-selectivity of native, purified P66. In conclusion, we show that the porin activity of P66 is eliminated by insertional inactivation and that this activity can be rescued by gene complementation.
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| 3. |
- Ristow, Laura, et al.
(författare)
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Integrin binding by Borrelia burgdorferi P66 facilitates dissemination but is not required for infectivity
- 2015
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Ingår i: Cellular Microbiology. - : Hindawi Limited. - 1462-5814 .- 1462-5822. ; 17:7, s. 1021-1036
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Tidskriftsartikel (refereegranskat)abstract
- P66, a Borrelia burgdorferi surface protein with porin and integrin-binding activities, is essential for murine infection. The role of P66 integrin-binding activity in B. burgdorferi infection was investigated and found to affect transendothelial migration. The role of integrin binding, specifically, was tested by mutation of two amino acids (D205A,D207A) or deletion of seven amino acids (Del202–208). Neither change affected surface localization or channel-forming activity of P66, but both significantly reduced binding to αvβ3. Integrin-binding deficient B. burgdorferi strains caused disseminated infection in mice at 4 weeks post-subcutaneous inoculation, but bacterial burdens were significantly reduced in some tissues. Following intravenous inoculation, the Del202–208 bacteria were below the limit of detection in all tissues assessed at 2 weeks post-inoculation, but bacterial burdens recovered to wild-type levels at 4 weeks post-inoculation. The delay in tissue colonization correlated with reduced migration of the Del202–208 strains across microvascular endothelial cells, similar to Δp66bacteria. These results indicate that integrin binding by P66 is important to efficient dissemination of B. burgdorferi, which is critical to its ability to cause disease manifestations in incidental hosts and to its maintenance in the enzootic cycle.
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