CO2 Transport by PIP2 Aquaporins of Barley
| Autor: | Toshiyuki Kaneko, Maki Katsuhara, Tomoaki Horie, Shizuka Sasano, Mineo Shibasaka, Jiye Rhee, Izumi C. Mori |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Models
Molecular Cell Membrane Permeability Physiology Xenopus Molecular Sequence Data Aquaporin Gene Expression Plant Science Aquaporins Plant Roots Cell membrane chemistry.chemical_compound Cytosol Gene Expression Regulation Plant Barley medicine Animals Amino Acid Sequence Special Focus Issue – Regular Papers Isoleucine Plant Proteins Methionine biology Cell Membrane Water Biological Transport Hordeum Cell Biology General Medicine Carbon Dioxide Hydrogen-Ion Concentration biology.organism_classification Plasma membrane intrinsic protein 2 medicine.anatomical_structure Biochemistry chemistry Permeability (electromagnetism) Oocytes lipids (amino acids peptides and proteins) Hordeum vulgare Sequence Alignment |
| Zdroj: | Plant and Cell Physiology |
| ISSN: | 1471-9053 0032-0781 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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