High-resolution x-ray structure of human aquaporin 5
Journal article, 2008

Human aquaporin 5 (HsAQP5) facilitates the transport of water across plasma membranes and has been identified within cells of the stomach, duodenum, pancreas, airways, lungs, salivary glands, sweat glands, eyes, lacrimal glands, and the inner ear. AQP5, like AQP2, is subject to posttranslational regulation by phosphorylation, at which point it is trafficked between intracellular storage compartments and the plasma membrane. Details concerning the molecular mechanism of membrane trafficking are unknown. Here we report the x-ray structure of HsAQP5 to 2.0-Å resolution and highlight structural similarities and differences relative to other eukaryotic aquaporins. A lipid occludes the putative central pore, preventing the passage of gas or ions through the center of the tetramer. Multiple consensus phosphorylation sites are observed in the structure and their potential regulatory role is discussed. We postulate that a change in the conformation of the C terminus may arise from the phosphorylation of AQP5 and thereby signal trafficking.


Rob Horsefield

University of Gothenburg

Kristina Norden

Lund University

Maria Fellert

Lund University

Anna Backmark

Chalmers, Chemical and Biological Engineering

Susanna Törnroth-Horsefield

University of Gothenburg

Anke C. Terwisscha van Scheltinga

Max Planck Society

Jan Kvassman

Linnaeus University

P. Kjellbom

Lund University

Urban Johanson

Lund University

Richard Neutze

University of Gothenburg

Proceedings of the National Academy of Sciences of the United States of America

0027-8424 (ISSN) 1091-6490 (eISSN)

Vol. 105 36 13327-13332

Subject Categories

Chemical Sciences



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