Is H95 a pH-dependent gate in aquaporin 4?

TY - JOUR

T1 - Is H95 a pH-dependent gate in aquaporin 4?

AU - Kaptan, Shreyas

AU - Assentoft, Mette

AU - Schneider, Hans Peter

AU - Fenton, Robert A.

AU - Deitmer, Joachim

AU - MacAulay, Nanna

AU - de Groot, Bert L

PY - 2015/12/1

Y1 - 2015/12/1

N2 - Aquaporin 4 (AQP4) is a transmembrane protein from the aquaporin family and is the predominant water channel in the mammalian brain. The regulation of permeability of this protein could be of potential therapeutic use to treat various forms of damage to the nervous tissue. In this work, based on data obtained from in silico and in vitro studies, a pH sensitivity that regulates the osmotic water permeability of AQP4 is demonstrated. The results indicate that AQP4 has increased water permeability at conditions of low pH in atomistic computer simulations and experiments carried out on Xenopus oocytes expressing AQP4. With molecular dynamics simulations, this effect was traced to a histidine residue (H95) located in the cytoplasmic lumen of AQP4. A mutant form of AQP4, in which H95 was replaced with an alanine (H95A), loses sensitivity to cytoplasmic pH changes in in vitro osmotic water permeability, thereby substantiating the in silico work

AB - Aquaporin 4 (AQP4) is a transmembrane protein from the aquaporin family and is the predominant water channel in the mammalian brain. The regulation of permeability of this protein could be of potential therapeutic use to treat various forms of damage to the nervous tissue. In this work, based on data obtained from in silico and in vitro studies, a pH sensitivity that regulates the osmotic water permeability of AQP4 is demonstrated. The results indicate that AQP4 has increased water permeability at conditions of low pH in atomistic computer simulations and experiments carried out on Xenopus oocytes expressing AQP4. With molecular dynamics simulations, this effect was traced to a histidine residue (H95) located in the cytoplasmic lumen of AQP4. A mutant form of AQP4, in which H95 was replaced with an alanine (H95A), loses sensitivity to cytoplasmic pH changes in in vitro osmotic water permeability, thereby substantiating the in silico work

U2 - 10.1016/j.str.2015.08.020

DO - 10.1016/j.str.2015.08.020

M3 - Journal article

C2 - 26585511

SN - 0969-2126

VL - 23

SP - 2309

EP - 2318

JO - Structure

JF - Structure

IS - 12

ER -