Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.

The gram-negative bacterium Kingella kingae is a leading cause of osteoarticular infections in young children and initiates infection by colonizing the oropharynx. Adherence to respiratory epithelial cells represents an initial step in the process of K. kingae colonization and is mediated in part by...

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Main Authors: Alexandra L Sacharok, Eric A Porsch, Taylor A Yount, Orlaith Keenan, Joseph W St Geme
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-03-01
Series:PLoS Pathogens
Online Access:https://doi.org/10.1371/journal.ppat.1010440
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author Alexandra L Sacharok
Eric A Porsch
Taylor A Yount
Orlaith Keenan
Joseph W St Geme
author_facet Alexandra L Sacharok
Eric A Porsch
Taylor A Yount
Orlaith Keenan
Joseph W St Geme
author_sort Alexandra L Sacharok
collection DOAJ
description The gram-negative bacterium Kingella kingae is a leading cause of osteoarticular infections in young children and initiates infection by colonizing the oropharynx. Adherence to respiratory epithelial cells represents an initial step in the process of K. kingae colonization and is mediated in part by type IV pili. In previous work, we observed that elimination of the K. kingae PilC1 and PilC2 pilus-associated proteins resulted in non-piliated organisms that were non-adherent, suggesting that PilC1 and PilC2 have a role in pilus biogenesis. To further define the functions of PilC1 and PilC2, in this study we eliminated the PilT retraction ATPase in the ΔpilC1ΔpilC2 mutant, thereby blocking pilus retraction and restoring piliation. The resulting strain was non-adherent in assays with cultured epithelial cells, supporting the possibility that PilC1 and PilC2 have adhesive activity. Consistent with this conclusion, purified PilC1 and PilC2 were capable of saturable binding to epithelial cells. Additional analysis revealed that PilC1 but not PilC2 also mediated adherence to selected extracellular matrix proteins, underscoring the differential binding specificity of these adhesins. Examination of deletion constructs and purified PilC1 and PilC2 fragments localized adhesive activity to the N-terminal region of both PilC1 and PilC2. The deletion constructs also localized the twitching motility property to the N-terminal region of these proteins. In contrast, the deletion constructs established that the pilus biogenesis function of PilC1 and PilC2 resides in the C-terminal region of these proteins. Taken together, these results provide definitive evidence that PilC1 and PilC2 are adhesins and localize adhesive activity and twitching motility to the N-terminal domain and biogenesis to the C-terminal domain.
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spelling doaj.art-209e7c83bb884bc78c30130c9c1ecc6c2022-12-22T00:38:42ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742022-03-01183e101044010.1371/journal.ppat.1010440Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.Alexandra L SacharokEric A PorschTaylor A YountOrlaith KeenanJoseph W St GemeThe gram-negative bacterium Kingella kingae is a leading cause of osteoarticular infections in young children and initiates infection by colonizing the oropharynx. Adherence to respiratory epithelial cells represents an initial step in the process of K. kingae colonization and is mediated in part by type IV pili. In previous work, we observed that elimination of the K. kingae PilC1 and PilC2 pilus-associated proteins resulted in non-piliated organisms that were non-adherent, suggesting that PilC1 and PilC2 have a role in pilus biogenesis. To further define the functions of PilC1 and PilC2, in this study we eliminated the PilT retraction ATPase in the ΔpilC1ΔpilC2 mutant, thereby blocking pilus retraction and restoring piliation. The resulting strain was non-adherent in assays with cultured epithelial cells, supporting the possibility that PilC1 and PilC2 have adhesive activity. Consistent with this conclusion, purified PilC1 and PilC2 were capable of saturable binding to epithelial cells. Additional analysis revealed that PilC1 but not PilC2 also mediated adherence to selected extracellular matrix proteins, underscoring the differential binding specificity of these adhesins. Examination of deletion constructs and purified PilC1 and PilC2 fragments localized adhesive activity to the N-terminal region of both PilC1 and PilC2. The deletion constructs also localized the twitching motility property to the N-terminal region of these proteins. In contrast, the deletion constructs established that the pilus biogenesis function of PilC1 and PilC2 resides in the C-terminal region of these proteins. Taken together, these results provide definitive evidence that PilC1 and PilC2 are adhesins and localize adhesive activity and twitching motility to the N-terminal domain and biogenesis to the C-terminal domain.https://doi.org/10.1371/journal.ppat.1010440
spellingShingle Alexandra L Sacharok
Eric A Porsch
Taylor A Yount
Orlaith Keenan
Joseph W St Geme
Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.
PLoS Pathogens
title Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.
title_full Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.
title_fullStr Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.
title_full_unstemmed Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.
title_short Kingella kingae PilC1 and PilC2 are adhesive multifunctional proteins that promote bacterial adherence, twitching motility, DNA transformation, and pilus biogenesis.
title_sort kingella kingae pilc1 and pilc2 are adhesive multifunctional proteins that promote bacterial adherence twitching motility dna transformation and pilus biogenesis
url https://doi.org/10.1371/journal.ppat.1010440
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