A novel role for aquaporin-5 in enhancing microtubule organization and stability.
Aquaporin-5 (AQP5) is a water-specific channel located on the apical surface of airway epithelial cells. In addition to regulating transcellular water permeability, AQP5 can regulate paracellular permeability, though the mechanisms by which this occurs have not been determined. Microtubules also regulate paracellular permeability. Here, we report that AQP5 promotes microtubule assembly and helps maintain the assembled microtubule steady state levels with slower turnover dynamics in cells. Specifically, reduced levels of AQP5 correlated with lower levels of assembled microtubules and decreased paracellular permeability. In contrast, overexpression of AQP5 increased assembly of microtubules, with evidence of increased MT stability, and promoted the formation of long straight microtubules in the apical domain of the epithelial cells. These findings indicate that AQP5-mediated regulation of microtubule dynamics modulates airway epithelial barrier properties and epithelial function.
Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America. vsidhay1@jhmi.edu
Venkataramana K
VK
Sidhaye
Eric
E
Chau
Vasudha
V
Srivastava
Srinivas
S
Sirimalle
Chinmayee
C
Balabhadrapatruni
Neil R
NR
Aggarwal
Franco R
FR
D'Alessio
Douglas N
DN
Robinson
Landon S
LS
King
D051402:Aquaporin 5 / Q000235:genetics / Q000378:metabolism*; D002461:Cell Line, Transformed; D002463:Cell Membrane Permeability / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*
C496036:AQP5 protein, human; D051402:Aquaporin 5