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Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579

Pseudomonas aeruginosa is a Gram negative, opportunistic pathogen that uses the overproduction of alginate, a surface polysaccharide, to form biofilms in vivo. Overproduction of alginate, also known as mucoidy, affords the bacterium protection from the host's defenses and facilitates the establ...

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Autores principales: Ryan Withers, T, Heath Damron, F, Yin, Yeshi, Yu, Hongwei D
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Blackwell Publishing Ltd 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684759/
https://www.ncbi.nlm.nih.gov/pubmed/23533140
http://dx.doi.org/10.1002/mbo3.86
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author Ryan Withers, T
Heath Damron, F
Yin, Yeshi
Yu, Hongwei D
author_facet Ryan Withers, T
Heath Damron, F
Yin, Yeshi
Yu, Hongwei D
author_sort Ryan Withers, T
collection PubMed
description Pseudomonas aeruginosa is a Gram negative, opportunistic pathogen that uses the overproduction of alginate, a surface polysaccharide, to form biofilms in vivo. Overproduction of alginate, also known as mucoidy, affords the bacterium protection from the host's defenses and facilitates the establishment of chronic lung infections in individuals with cystic fibrosis. Expression of the alginate biosynthetic operon is primarily controlled by the alternative sigma factor AlgU (AlgT/σ(22)). In a nonmucoid strain, AlgU is sequestered by the transmembrane antisigma factor MucA to the cytoplasmic membrane. AlgU can be released from MucA via regulated intramembrane proteolysis by proteases AlgW and MucP causing the conversion to mucoidy. Pseudomonas aeruginosa strain PAO579, a derivative of the nonmucoid strain PAO1, is mucoid due to an unidentified mutation (muc-23). Using whole genome sequencing, we identified 16 nonsynonymous and 15 synonymous single nucleotide polymorphisms (SNP). We then identified three tandem single point mutations in the pilA gene (PA4525), as the cause of mucoidy in PAO579. These tandem mutations generate a premature stop codon resulting in a truncated version of PilA (PilA(108)), with a C-terminal motif of phenylalanine-threonine-phenylalanine (FTF). Inactivation of pilA(108) confirmed it was required for mucoidy. Additionally, algW and algU were also required for mucoidy of PAO579. Western blot analysis indicated that MucA was less stable in PAO579 than nonmucoid PAO1 or PAO381. The mucoid phenotype and high P(algU) and P(algD) promoter activities of PAO579 require pilA(108), algW, algU, and rpoN encoding the alternative sigma factor σ(54). We also observed that RpoN regulates expression of algW and pilA in PAO579. Together, these results suggest that truncation in type IV pilin in P. aeruginosa strain PAO579 can induce mucoidy through an AlgW/AlgU-dependent pathway.
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spelling pubmed-36847592013-06-20 Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579 Ryan Withers, T Heath Damron, F Yin, Yeshi Yu, Hongwei D Microbiologyopen Original Research Pseudomonas aeruginosa is a Gram negative, opportunistic pathogen that uses the overproduction of alginate, a surface polysaccharide, to form biofilms in vivo. Overproduction of alginate, also known as mucoidy, affords the bacterium protection from the host's defenses and facilitates the establishment of chronic lung infections in individuals with cystic fibrosis. Expression of the alginate biosynthetic operon is primarily controlled by the alternative sigma factor AlgU (AlgT/σ(22)). In a nonmucoid strain, AlgU is sequestered by the transmembrane antisigma factor MucA to the cytoplasmic membrane. AlgU can be released from MucA via regulated intramembrane proteolysis by proteases AlgW and MucP causing the conversion to mucoidy. Pseudomonas aeruginosa strain PAO579, a derivative of the nonmucoid strain PAO1, is mucoid due to an unidentified mutation (muc-23). Using whole genome sequencing, we identified 16 nonsynonymous and 15 synonymous single nucleotide polymorphisms (SNP). We then identified three tandem single point mutations in the pilA gene (PA4525), as the cause of mucoidy in PAO579. These tandem mutations generate a premature stop codon resulting in a truncated version of PilA (PilA(108)), with a C-terminal motif of phenylalanine-threonine-phenylalanine (FTF). Inactivation of pilA(108) confirmed it was required for mucoidy. Additionally, algW and algU were also required for mucoidy of PAO579. Western blot analysis indicated that MucA was less stable in PAO579 than nonmucoid PAO1 or PAO381. The mucoid phenotype and high P(algU) and P(algD) promoter activities of PAO579 require pilA(108), algW, algU, and rpoN encoding the alternative sigma factor σ(54). We also observed that RpoN regulates expression of algW and pilA in PAO579. Together, these results suggest that truncation in type IV pilin in P. aeruginosa strain PAO579 can induce mucoidy through an AlgW/AlgU-dependent pathway. Blackwell Publishing Ltd 2013-06 2013-03-27 /pmc/articles/PMC3684759/ /pubmed/23533140 http://dx.doi.org/10.1002/mbo3.86 Text en © 2013 Published by John Wiley & Sons Ltd. http://creativecommons.org/licenses/by/2.5/ Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.
spellingShingle Original Research
Ryan Withers, T
Heath Damron, F
Yin, Yeshi
Yu, Hongwei D
Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579
title Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579
title_full Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579
title_fullStr Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579
title_full_unstemmed Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579
title_short Truncation of type IV pilin induces mucoidy in Pseudomonas aeruginosa strain PAO579
title_sort truncation of type iv pilin induces mucoidy in pseudomonas aeruginosa strain pao579
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684759/
https://www.ncbi.nlm.nih.gov/pubmed/23533140
http://dx.doi.org/10.1002/mbo3.86
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