@ARTICLE{Xiao_Feng_Zhu_NH4+-mediated_2015,
 author={Xiao Feng Zhu and Wan Hui Cai and Jin Hee Jung and Yuan Hu Xuan},
 volume={vol. 57},
 number={No 2},
 journal={Acta Biologica Cracoviensia s. Botanica},
 howpublished={online},
 year={2015},
 publisher={Biological Commission of the Polish Academy of Sciences – Cracow Branch},
 abstract={Abstract NH4+ is an important N-source which regulates plant growth and development. However, the underlying mechanism of NH4+ uptake and its-mediated signaling is poorly understood. Here, we performed phosphoproteomic studies using the titanium dioxide (TiO2)-mediated phosphopeptides collection method together with LC-MS analysis. The results indicated that phosphorylation levels of 23 and 43 peptides/proteins involved in diverse aspects, including metabolism, transport and signaling pathway, were decreased and increased respectively after NH4+ treatment in rice roots. Among 23 proteins detected, IDD10, a key transcription factor in ammonium signaling, was identified to reduce phosphorylation level of S313 residue. Further biochemical analysis using IDD10-GFP transgenic plants and immunoprecipitation assay confirmed that NH4+ supply reduces IDD10 phosphorylation level. Phosphorylation of ammonium transporter 1;1 (AMT1;1) was increased upon NH4+ treatment. Interestingly, phosphorylation of T446, a rice specific residue against Arabidopsis was identified. It was also established that phosphorylation of T452 is conserved with T460 of Arabidopsis AMT1;1. Yeast complementation assay with transformation of phosphomimic forms of AMT1;1 (T446/D and T452/D) into 31019b strain revealed that phosphorylation at T446 and T452 residues abolished AMT1;1 activity, while their plasma membrane localization was not changed. Our analyses show that many proteins were phosphorylated or dephosphorylated by NH4+ that may provide important evidence for studying ammonium uptake and its mediated signaling by which rice growth and development are regulated.},
 title={NH4+-mediated Protein Phosphorylation in Rice Roots},
 URL={http://czasopisma.pan.pl/Content/81858/PDF/03_zhu.pdf},
 doi={10.1515/abcsb-2015-0022},
}