To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

Characterization of aquap… - University of Gothenburg, Sweden Till startsida
Sitemap
To content Read more about how we use cookies on gu.se

Characterization of aquaporin-driven hydrogen peroxide transport.

Journal article
Authors Hao Wang
Stefan Schoebel
Florian Schmitz
Hansong Dong
Kristina Hedfalk
Published in Biochimica et biophysica acta. Biomembranes
Pages 183065
ISSN 1879-2642
Publication year 2019
Published at Department of Chemistry and Molecular Biology
Pages 183065
Language en
Links dx.doi.org/10.1016/j.bbamem.2019.18...
www.ncbi.nlm.nih.gov/entrez/query.f...
Subject categories Biochemistry

Abstract

Aquaporins are membrane-intrinsic proteins initially defined as water (H2O) channels in all organisms and subsequently found to have multiple substrate specificities, such as hydrogen peroxide (H2O2). H2O2 is a signaling molecule that partakes in immune responses where its transport is mediated by aquaporins. To shed further light on the molecular basis of the aquaporin function in H2O2 transport, we have characterized an Arabidopsis thaliana aquaporin, AtPIP2;4, recombinantly produced to high yields in Pichia pastoris. Here, we present a newly established assay that allows detection of H2O2 transport by purified aquaporins reconstituted into liposomes, enabling us to compare aquaporin homologues with respect to substrate specificity. To get additional insight into the structural determinants for aquaporin-mediated H2O2 transport, we solved the 3D-structure of AtPIP2;4 to 3.7 Å resolution and found structural identity to the water channel from spinach (SoPIP2;1), with the difference that Cd2+ cation is not required to retain the closed conformation. The transport specificities of the two plant aquaporins were compared to a human homologue, AQP1. Overall, we conclude that AtPIP2;4, SoPIP2;1 and hAQP1 are all transporters of both H2O and H2O2, but have different efficiencies for various specificities. Notably, all three homologues expedite H2O transport equally well while the plant aquaporins are more permeable to H2O2 than hAQP1. Comparison of the structures indicates that the observed variations in H2O and H2O2 transport cannot be explained by differences in the monomeric pore. Possibly, the determinants for transport specificities reside in the flexible domains outside the membrane core of these channels.

Page Manager: Webmaster|Last update: 9/11/2012
Share:

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?