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P. aeruginosa ExoY Disrupts Microtubules and Induces Endothelial Cell Gap Formation
Author(s) -
Prasain Nutan,
Stevens Troy
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.964.10
Subject(s) - microtubule , microbiology and biotechnology , cytosol , endothelial stem cell , biology , type three secretion system , cell , chemistry , biochemistry , in vitro , virulence , gene , enzyme
Microtubule architecture controls endothelial cell barrier function, as acute microtubule disruption leads to inter‐endothelial gap formation. The P. aeruginosa toxin, ExoY, is injected through a type III secretion system (TTSS) into the cytosol of endothelial cells, where it associates with microtubules, and produces a cytosolic cAMP pool that disrupts the endothelial barrier. However, it is unclear whether cytosolic cAMP reorganizes microtubules as a necessary prerequisite. To test this idea, confluent pulmonary microvascular endothelial cell monolayers were infected with two strains of P. aeruginosa that possess a: (1) functional TTSS, and only injects ExoY (ExoY + ), and (2) functional TTSS, but injects a catalytically inactive ExoY (ExoY K81M ) due to a single point mutation at the ATP binding site. After 4 hours of incubation, cells were stained for microtubule organization. Although microtubules were disrupted and inter‐endothelial gaps were formed in ExoY + ‐treated cells, neither microtubules nor inter‐endothelial gaps were formed in ExoY K81M or vehicle control‐treated cells. However, stabilizing microtubules prior to infection prevented ExoY + ‐induced microtubule disruption and inter‐endothelial gap formation. Collectively, these data suggest that ExoY generates a cytosolic cAMP pool that reorganizes microtubules and causes endothelial barrier disruption. [HL‐60024 & HL‐66299]