Aquaporin homologues in plants and mammals transport ammonia
- 12 August 2004
- journal article
- Published by Wiley in FEBS Letters
- Vol. 574 (1-3) , 31-36
- https://doi.org/10.1016/j.febslet.2004.08.004
Abstract
Using functional complementation and a yeast mutant deficient in ammonium (NH4 +) transport (Δmep1–3), three wheat (Triticum aestivum) TIP2 aquaporin homologues were isolated that restored the ability of the mutant to grow when 2 mM NH4 + was supplied as the sole nitrogen source. When expressed in Xenopus oocytes, TaTIP2;1 increased the uptake of NH4 + analogues methylammonium and formamide. Furthermore, expression of TaTIP2;1 increased acidification of the oocyte‐bathing medium containing NH4 + in accordance with NH3 diffusion through the aquaporin. Homology modeling of TaTIP2;1 in combination with site directed mutagenesis suggested a new subgroup of NH3‐transporting aquaporins here called aquaammoniaporins. Mammalian AQP8 sharing the aquaammoniaporin signature also complemented NH4 + transport deficiency in yeast.Keywords
This publication has 34 references indexed in Scilit:
- Architecture and Selectivity in Aquaporins: 2.5 Å X-Ray Structure of Aquaporin ZPLoS Biology, 2003
- Structural clues in the sequences of the aquaporinsJournal of Molecular Biology, 2000
- Three Functional Transporters for Constitutive, Diurnally Regulated, and Starvation-Induced Uptake of Ammonium into Arabidopsis RootsPlant Cell, 1999
- Cloning and Functional Expression of a New Aquaporin (AQP9) Abundantly Expressed in the Peripheral Leukocytes Permeable to Water and Urea, but Not to GlycerolBiochemical and Biophysical Research Communications, 1998
- Structure and transport mechanism of a high-affinity potassium uptake transporter from higher plantsNature, 1994
- Water channels in the plant plasma membrane cloned by immunoselection from a mammalian expression systemThe Plant Journal, 1994
- Effects of ammonium on intracellular pH in rat medullary thick ascending limb: mechanisms of apical membrane NH4+ transport.The Journal of general physiology, 1994
- Comparative Protein Modelling by Satisfaction of Spatial RestraintsJournal of Molecular Biology, 1993
- Appearance of Water Channels in Xenopus Oocytes Expressing Red Cell CHIP28 ProteinScience, 1992
- The stimulus-secretion coupling of glucose-induced insulin release. Metabolic and functional effects of NH4+ in rat islets.Journal of Clinical Investigation, 1978