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Structural mechanism of plant aquaporin gating

Tornroth-Horsefield, S LU ; Wang, Y; Hedfalk, K; Johanson, Urban LU ; Karlsson, Maria LU ; Tajkhorshid, E; Neutze, R and Kjellbom, Per LU (2006) In Nature 439(7077). p.688-694
Abstract
Plants counteract fluctuations in water supply by regulating all aquaporins in the cell plasma membrane. Channel closure results either from the dephosphorylation of two conserved serine residues under conditions of drought stress, or from the protonation of a conserved histidine residue following a drop in cytoplasmic pH due to anoxia during flooding. Here we report the X-ray structure of the spinach plasma membrane aquaporin SoPIP2; 1 in its closed conformation at 2.1 angstrom resolution and in its open conformation at 3.9 angstrom resolution, and molecular dynamics simulations of the initial events governing gating. In the closed conformation loop D caps the channel from the cytoplasm and thereby occludes the pore. In the open... (More)
Plants counteract fluctuations in water supply by regulating all aquaporins in the cell plasma membrane. Channel closure results either from the dephosphorylation of two conserved serine residues under conditions of drought stress, or from the protonation of a conserved histidine residue following a drop in cytoplasmic pH due to anoxia during flooding. Here we report the X-ray structure of the spinach plasma membrane aquaporin SoPIP2; 1 in its closed conformation at 2.1 angstrom resolution and in its open conformation at 3.9 angstrom resolution, and molecular dynamics simulations of the initial events governing gating. In the closed conformation loop D caps the channel from the cytoplasm and thereby occludes the pore. In the open conformation loop D is displaced up to 16 angstrom and this movement opens a hydrophobic gate blocking the channel entrance from the cytoplasm. These results reveal a molecular gating mechanism which appears conserved throughout all plant plasma membrane aquaporins. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nature
volume
439
issue
7077
pages
688 - 694
publisher
Nature Publishing Group
external identifiers
  • pmid:16340961
  • wos:000235193100036
  • scopus:32544450674
ISSN
0028-0836
DOI
10.1038/nature04316
language
English
LU publication?
yes
id
4d8ff816-8541-47fc-bf23-16ed0c6c8201 (old id 418074)
alternative location
http://www.nature.com/nature/journal/v439/n7077/full/nature04316.html
date added to LUP
2007-08-20 09:53:53
date last changed
2019-10-13 03:30:52
@article{4d8ff816-8541-47fc-bf23-16ed0c6c8201,
  abstract     = {Plants counteract fluctuations in water supply by regulating all aquaporins in the cell plasma membrane. Channel closure results either from the dephosphorylation of two conserved serine residues under conditions of drought stress, or from the protonation of a conserved histidine residue following a drop in cytoplasmic pH due to anoxia during flooding. Here we report the X-ray structure of the spinach plasma membrane aquaporin SoPIP2; 1 in its closed conformation at 2.1 angstrom resolution and in its open conformation at 3.9 angstrom resolution, and molecular dynamics simulations of the initial events governing gating. In the closed conformation loop D caps the channel from the cytoplasm and thereby occludes the pore. In the open conformation loop D is displaced up to 16 angstrom and this movement opens a hydrophobic gate blocking the channel entrance from the cytoplasm. These results reveal a molecular gating mechanism which appears conserved throughout all plant plasma membrane aquaporins.},
  author       = {Tornroth-Horsefield, S and Wang, Y and Hedfalk, K and Johanson, Urban and Karlsson, Maria and Tajkhorshid, E and Neutze, R and Kjellbom, Per},
  issn         = {0028-0836},
  language     = {eng},
  number       = {7077},
  pages        = {688--694},
  publisher    = {Nature Publishing Group},
  series       = {Nature},
  title        = {Structural mechanism of plant aquaporin gating},
  url          = {http://dx.doi.org/10.1038/nature04316},
  volume       = {439},
  year         = {2006},
}