Structural basis for pH gating of plant aquaporins.

Abstract

Plants have evolved to cope with fluctuations in water supply by gating their water channels known as aquaporins. During flooding, a rapid drop of cytosolic pH due to anoxia leads to a simultaneous closure of the aquaporins in the plasma membrane. The closing mechanism has been suggested to involve a conserved histidine on cytosolic loop D. Here we report the crystal structure of a spinach aquaporin at low pH, revealing for the first time the structural basis for how this pH-sensitive histidine helps to keep the aquaporin in a closed state.

• Authors: Anna Frick, Michael Järvå, Susanna Törnroth-Horsefield
• Journal: FEBS letters (FEBS Lett) Vol. 587 Issue 7 Pg. 989-93 (Apr 02 2013) ISSN: 1873-3468 [Electronic] England
• PMID: 23454640 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Chemical References

• Aquaporins
• Plant Proteins
• Recombinant Proteins
• Water
• Histidine

Topics

• Aquaporins (chemistry, genetics, metabolism)
• Binding Sites (genetics)
• Biological Transport
• Cell Membrane (metabolism)
• Crystallography, X-Ray
• Cytosol (chemistry, metabolism)
• Histidine (chemistry, genetics, metabolism)
• Hydrogen-Ion Concentration
• Models, Molecular
• Mutation
• Plant Proteins (chemistry, genetics, metabolism)
• Protein Conformation
• Protein Structure, Secondary
• Recombinant Proteins (chemistry, metabolism)
• Spinacia oleracea (genetics, metabolism)
• Water (metabolism)