Molecular characterization of two ammonium transporters from the ectomycorrhizal fungus Hebeloma cylindrosporum

FEBS Letters

Rodrı́guez-Pastrana, Blanca-Rosa²  André, Bruno¹  Chalot, Michel²  Jacob, Christophe²  Marini, Anne-Marie¹  Brun, Annick²  Botton, Bernard²  Javelle, Arnaud² 

[1] Laboratoire de Physiologie Cellulaire, Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, 6041 Gosselies, Belgium;Université Henri Poincaré, Nancy I, UMR INRA/UHP 1136 Interactions Arbres Micro-organismes, P.O. Box 239, 54506 Vandoeuvre-les-Nancy, France

关键词: Ammonium transport;    Methylamine;    Nitrogen regulation;    Hebeloma cylindrosporum;    Saccharomyces cerevisiae;    MA;    methylammonium/methylamine;    YNB−N;    yeast nitrogen base without amino acids and ammonium sulfate;   

DOI  :  10.1016/S0014-5793(01)02802-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Heterologous expression of the yeast triple Mep mutant has enabled the first molecular characterization of AMT/MEP family members in an ectomycorrhizal fungus. External hyphae, which play a key role in nitrogen nutrition of trees, are considered as the absorbing structure of the ectomycorrhizal symbiosis and therefore molecular studies on ammonium transport in hyphae are urgently needed. The kinetic properties of AMT2 and AMT3 from Hebeloma cylindrosporum were studied in Saccharomyces cerevisiae. Expression of HcAmts in the yeast triple Mep mutant restored ammonium retention within cells. The HcAmts did not complement the ammonium sensing defect phenotype of Mep2Δ cells during pseudohyphal differentiation. Northern blot analysis in H. cylindrosporum showed that the HcAMTs were up-regulated upon nitrogen deprivation and down-regulated by ammonium.

【 授权许可】

Unknown