Function of a separate NH3-pore in Aquaporin TIP2;2 from wheat.
Functional analysis of heterologously expressed TaTIP2;2 by means of stopped-flow spectrometric studies provide evidence for water and ammonia conductivity. A series of experiments under increasing pH indicate that the gaseous NH(3), rather than the ammonium ion NH(4)(+) was transported. Results from inhibitor studies strongly suggest that NH(3) is not transported in file with water, but through a separate pathway, which could be supplied by the 5th central pore in a tetramer conformation.
Bertl
Adam
A
Institute of Botany, Applied Plant Science, Darmstadt University of Technology, Schnittspahnstrasse 10, D-64287 Darmstadt, Germany.
Kaldenhoff
Ralf
R
D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D006863:Hydrogen-Ion Concentration; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000378:metabolism*; D014867:Water / Q000378:metabolism
D020346:Aquaporins; D000644:Quaternary Ammonium Compounds; D014867:Water