Structural determinants of oligomerization of the aquaporin-4 channel
Abstract
©2016 by The American Society for Biochemistry and Molecular Biology, Inc. The aquaporin (AQP) family of integral membrane protein channels mediate cellular water and solute flow. Although qualitative and quantitative differences in channel permeability, selectivity, subcellular localization, and trafficking responses have been observed for different members of the AQP family, the signature homotetrameric quaternary structure is conserved. Using a variety of biophysical techniques, we show that mutations to an intracellular loop (loop D) of human AQP4 reduce oligomerization. Non-tetrameric AQP4 mutants are unable to relocalize to the plasma membrane in response to changes in extracellular tonicity, despite equivalent constitutive surface expression levels and water permeability to wild-type AQP4. A network of AQP4 loop D hydrogen bonding interactions, identified using molecular dynamics simulations and based on a comparative mutagenic analysis of AQPs 1, 3, and 4, suggest that loop D interactions may provide a general structural framework for tetrameric assembly within theAQPfamily.Citation
Kitchen, P., Conner, M. T., Bill, R. M. and Conner, A. C. (2016) Structural determinants of oligomerization of the aquaporin-4 channel, Journal of Biological Chemistry, 29(13), pp. 6858-6871.Journal
Journal of Biological ChemistryPubMed ID
26786101Additional Links
http://www.jbc.org/content/291/13/6858Type
Journal articleLanguage
enISSN
0021-9258EISSN
1083-351XSponsors
Supported by Biotechnology and Biological Sciences Research Council Grants BB/I019960/1, BB/K013319/1, and BB/L502194/1 and Innovative Medicines Joint Undertaking under Grant Agreement 115583 to the ND4BB ENABLE Consortium.ae974a485f413a2113503eed53cd6c53
10.1074/jbc.M115.694729
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Except where otherwise noted, this item's license is described as Licence for published version: Creative Commons Attribution 4.0 International
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