The pH sensitivity of Aqp0 channels in tetraploid and diploid teleosts
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Author
Zapater, Cinta
Stavang, Jon Anders
Taranger, Geir Lasse
Finn, Roderick Nigel
Publication date
2015-02-09ISSN
0892-6638
Abstract
Water homeostasis and the structural integrity of the vertebrate lens is partially mediated by AQP0
channels. Emerging evidence indicates that external pH may be involved in channel gating. Here we show that a tetraploid teleost, the Atlantic salmon, retains 4 aqp0 genes (aqp0a1, -0a2, -0b1, and -0b2), which are highly, but not exclusively, expressed in the lens. Functional characterization reveals that,although each paralog permeateswater efficiently, the permeability is respectively shifted to the
neutral, alkaline, or acidic pH in Aqp0a1, -0a2, and -0b1, whereas that of Aqp0b2 is not regulated by external pH. Mutagenesis studies demonstrate that Ser38, His39, and His40 residues in the extracellular transmembrane domain of a-helix 2 facing the water pore are critical for the pH modulation of water transport. To validate these findings, we show that both zebrafish Aqp0a and -0b are functional water channels with respective pH sensitivities toward alkaline or acid pH ranges and that an N-terminal allelic
variant (Ser19) of Aqp0b exists that abolishes water transport in Xenopus laevis oocytes. The data suggest that the alkaline pH sensitivity is a conserved trait in teleost Aqp0 a-type channels, whereas mammalian AQP0 and some teleost Aqp0 b-type channels display an acidic pH permeation preference.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
639 - Hunting. Fishing. Fish breeding
Pages
13
Publisher
Wiley Open Access
Is part of
FASEB Journal
Citation
Chauvigne, François, Cinta Zapater, Jon Anders Stavang, Geir Lasse Taranger, Joan Cerda, and Roderick Nigel Finn. 2015. “The pH sensitivity of Aqp0 channels in tetraploid and diploid teleosts”. FASEB Journal 29(5). doi:10.1096/fj.14-267625
Grant agreement number
MICINN/Programa Nacional de Proyectos de Investigación Fundamental/AGL2010-15597/ES/AQUAPORINAS TESTICULARES DURANTE LA ESPERMATOGENESIS DE PECES MARINOS Y LA ACTIVACION Y PERMEABILIDAD ESPERMATICA/
Program
Aqüicultura
This item appears in the following Collection(s)
- ARTICLES CIENTÍFICS [2647]
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc/4.0/