Referenced in: none

Automatically associated channels: Kir2.3

Title: A molecular modeling approach defines a new group of Nodulin 26-like aquaporins in plants.

Authors: Pierre Rougé, Annick Barre

Journal, date & volume: Biochem. Biophys. Res. Commun., 2008 Feb 29 , 367, 60-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/18155659

Abstract
The three-dimensional models built for the Nod26-like aquaporins all exhibit the typical alpha-helical fold of other aquaporins containing the two ar/R and NPA constriction filters along the central water channel. Besides these structural homologies, they readily differ with respect to the amino acid residues forming the ar/R selective filter. According to these discrepancies in both the hydrophilicity and pore size of the ar/R filter, Nod26-like aquaporins can be distributed in three subgroups corresponding to NIP-1, NIP-II and a third subgroup of Nod26-like aquaporins exhibiting a highly hydrophilic and widely open filter. However, all Nod26-like aquaporins display a bipartite distribution of electrostatic charges along the water channel with an electropositive extracellular vestibular portion followed by an electronegative cytosolic vestibular portion. The specific transport of water, non-ionic solutes (glycerol, urea, ammoniac), ions (NH4+) and gas (NH(3)) across the Nod26-like obviously depends on the electrostatic and conformational properties of their central water channel.