Neuhäuser Benjamin, Dynowski Marek, Ludewig Uwe
Zentrum für Molekularbiologie der Pflanzen (ZMBP), Pflanzenphysiologie, Universität Tübingen, Tübingen, Germany.
FEBS Lett. 2009 Sep 3;583(17):2833-8. doi: 10.1016/j.febslet.2009.07.039. Epub 2009 Jul 25.
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.
原核生物、植物和动物通过铵转运蛋白（AMTs）和/或相关的恒河猴（Rh）蛋白的表达调控来控制铵通量。此前有报道称植物AMTs介导生电转运。对拟南芥AtAMT2在酵母和卵母细胞中的功能分析表明，NH(4)(+)是被招募的底物，但传导的是不带电荷的NH(3)形式。AtAMT2与生电AMTs部分共定位，并以低亲和力传导甲胺。这种转运机制可能适用于其他植物铵转运蛋白，并解释了AMTs在植物细胞中积累铵的不同能力。
