CO2 transport by PIP2 aquaporins of barley

CO2 permeability of plasma membrane intrinsic protein 2 (PIP2) aquaporins of Hordeum vulgare L. was investigated. Five PIP2 members were heterologously expressed in Xenopus laevis oocytes. CO2 permeability was determined by decrease of cytosolic pH in CO2-enriched buffer using a hydrogen ion-selecti...

Full description

Saved in:
Bibliographic Details
Published in:Plant and cell physiology 2014-02, Vol.55 (2), p.251-257
Main Authors: Mori, Izumi C, Rhee, Jiye, Shibasaka, Mineo, Sasano, Shizuka, Kaneko, Toshiyuki, Horie, Tomoaki, Katsuhara, Maki
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Animals
Aquaporins - genetics
Aquaporins - metabolism
Biological Transport
Carbon Dioxide - metabolism
Cell Membrane - metabolism
Cell Membrane Permeability
Cytosol - metabolism
Gene Expression
Gene Expression Regulation, Plant
Hordeum - genetics
Hordeum - metabolism
Hydrogen-Ion Concentration
Isoleucine
Models, Molecular
Molecular Sequence Data
Oocytes
Plant Proteins - genetics
Plant Proteins - metabolism
Plant Roots - genetics
Plant Roots - metabolism
Sequence Alignment
Special Focus Issue – Regular Papers
Water - metabolism
Xenopus
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:CO2 permeability of plasma membrane intrinsic protein 2 (PIP2) aquaporins of Hordeum vulgare L. was investigated. Five PIP2 members were heterologously expressed in Xenopus laevis oocytes. CO2 permeability was determined by decrease of cytosolic pH in CO2-enriched buffer using a hydrogen ion-selective microelectrode. HvPIP2;1, HvPIP2;2, HvPIP2;3 and HvPIP2;5 facilitated CO2 transport across the oocyte cell membrane. However, HvPIP2;4 that is highly homologous to HvPIP2;3 did not. The isoleucine residue at position 254 of HvPIP2;3 was conserved in PIP2 aquaporins of barley, except HvPIP2;4, which possesses methionine instead. CO2 permeability was lost by the substitution of the Ile254 of HvPIP2;3 by methionine, while water permeability was not affected. These results suggest that PIP2 aquaporins are permeable to CO2. and the conserved isoleucine at the end of the E-loop is crucial for CO2 selectivity.
ISSN:0032-0781
1471-9053
DOI:10.1093/pcp/pcu003