Ammonium and nitrate regulate NH4+ uptake activity of Arabidopsis ammonium transporter AtAMT1;3 via phosphorylation at multiple C-terminal sites.

ABSTRACT: In plants, nutrient transporters require tight regulation to ensure optimal uptake in complex environments. The activities of many nutrient transporters are post-translationally regulated by reversible phosphorylation, allowing rapid adaptation to variable environmental conditions. Here, we show that the Arabidopsis root epidermis-expressed ammonium transporter AtAMT1;3 was dynamically (de-)phosphorylated at multiple sites in the cytosolic C-terminal region (CTR) responding to ammonium and nitrate signals. Under ammonium resupply rapid phosphorylation of a Thr residue (T464) in the conserved part of the CTR (CTRC) effectively inhibited AtAMT1;3-dependent NH4+ uptake. Moreover, phosphorylation of Thr (T494), one of three phosphorylation sites in the non-conserved part of the CTR (CRTNC), mo

SUBMITTER: Wu X 

PROVIDER: S-EPMC6760267 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature