Channel-like NH3 flux by ammonium transporter AtAMT2.
Prokaryotes, plants and animals control ammonium fluxes by the regulated expression of ammonium transporters (AMTs) and/or the related Rhesus (Rh) proteins. Plant AMTs were previously reported to mediate electrogenic transport. Functional analysis of AtAMT2 from Arabidopsis in yeast and oocytes suggests that NH(4)(+) is the recruited substrate, but the uncharged form NH(3) is conducted. AtAMT2 partially co-localized with electrogenic AMTs and conducted methylamine with low affinity. This transport mechanism may apply to other plant ammonium transporters and explains the different capacities of AMTs to accumulate ammonium in the plant cell.
Neuhäuser
Benjamin
B
Zentrum für Molekularbiologie der Pflanzen (ZMBP), Pflanzenphysiologie, Universität Tübingen, Tübingen, Germany.
Dynowski
Marek
M
Ludewig
Uwe
U
D000818:Animals; D017360:Arabidopsis / Q000033:anatomy & histology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000378:metabolism*; D014982:Xenopus laevis
D029681:Arabidopsis Proteins; D027682:Cation Transport Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D000644:Quaternary Ammonium Compounds; C088952:ammonium transporters, plant