Pseudomonas aeruginosa Exotoxin Y-Mediated Tau Hyperphosphorylation Impairs Microtubule Assembly in Pulmonary Microvascular Endothelial Cells

PLoS One

Nutan Prasain¹  Jason Prater¹  Dara W. Frank¹  Mikhail Alexeyev¹  Ron Balczon²  Sarah Sayner³  Cristhiaan Ochoa⁴  Troy Stevens⁵  Bing Zhu⁵ 

[1] Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America;Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama, United States of America;Department of Medicine, University of South Alabama, Mobile, Alabama, United States of America;Department of Pediatrics, University of Indiana School of Medicine, Indianapolis, Indiana, United States of America;Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America

关键词: Microtubules;    Pseudomonas aeruginosa;    Tubulins;    Phosphorylation;    Endothelial cells;    Centrosomes;    Pseudomonas infections;    Cell membranes;   

DOI  :  10.1371/journal.pone.0074343

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

Pseudomonas aeruginosa uses a type III secretion system to introduce the adenylyl and guanylyl cyclase exotoxin Y (ExoY) into the cytoplasm of endothelial cells. ExoY induces Tau hyperphosphorylation and insolubility, microtubule breakdown, barrier disruption and edema, although the mechanism(s) responsible for microtubule breakdown remain poorly understood. Here we investigated both microtubule behavior and centrosome activity to test the hypothesis that ExoY disrupts microtubule dynamics. Fluorescence microscopy determined that infected pulmonary microvascular endothelial cells contained fewer microtubules than control cells, and further studies demonstrated that the microtubule-associated protein Tau was hyperphosphorylated following infection and dissociated from microtubules. Disassembly/reassembly studies determined that microtubule assembly was disrupted in infected cells, with no detectable effects on either microtubule disassembly or microtubule nucleation by centrosomes. This effect of ExoY on microtubules was abolished when the cAMP-dependent kinase phosphorylation site (Ser-214) on Tau was mutated to a non-phosphorylatable form. These studies identify Tau in microvascular endothelial cells as the target of ExoY in control of microtubule architecture following pulmonary infection by Pseudomonas aeruginosa and demonstrate that phosphorylation of tau following infection decreases microtubule assembly.

【 授权许可】

CC BY