Open AccessCharacterization of a developmentally regulated amino acid transporter (AAT1p) of the rust fungus Uromyces fabae
Author(s) -
Struck Christine,
Ernst Michael,
Hahn Matthias
Publication year - 2002
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1046/j.1464-6722.2001.00091.x
Subject(s) - biology , rust (programming language) , fungus , microbiology and biotechnology , botany , computer science , programming language
summary In the rust fungus Uromyces fabae , invasion of the host plant and haustorium formation are accompanied by the activation of many genes ( PIG s = in planta induced genes). In addition to the previously described AAT2 ( PIG2 ), AAT1 ( PIG27 ) was found to encode a protein with a high similarity to fungal amino acid permeases. AAT1 transcripts are present in germinated hyphae and throughout the mycelium later in the infection process, but occur at the highest levels in haustoria. Expression of AAT1p in a histidine uptake‐defective yeast mutant revealed energy‐dependent transport of 14 C‐histidine, with a K M value of 25.8 µ m . In addition, complementation analysis revealed AAT1 ‐dependent transport for lysine. Using Xenopus oocytes as expression system, AAT1p‐dependent symport of protons with a broad spectrum of amino acids was observed, with the highest activities obtained with histidine and lysine. These results confirm that in rust fungi, the expression of amino acid transporters is developmentally regulated and occurs preferentially in the parasitic phase of development.