Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany.
Mol Plant Pathol. 2002 Jan 1;3(1):23-30. doi: 10.1046/j.1464-6722.2001.00091.x.
summary In the rust fungus Uromyces fabae, invasion of the host plant and haustorium formation are accompanied by the activation of many genes (PIGs =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 microm. 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.
总结 在锈菌 Uromyces fabae 中，宿主植物的侵染和吸器的形成伴随着许多基因的激活（PIGs = 植物体内诱导基因）。除了先前描述的 AAT2（PIG2）外，还发现 AAT1（PIG27）编码的蛋白质与真菌氨基酸转运蛋白具有高度相似性。AAT1 转录本存在于发芽的菌丝体中，并且在侵染过程的后期在整个菌丝体中存在，但在吸器中存在最高水平。在组氨酸摄取缺陷型酵母突变体中表达 AAT1p 揭示了能量依赖性的（14）C-组氨酸运输，其 K（M）值为 25.8 µm。此外，互补分析表明赖氨酸的转运依赖 AAT1。使用非洲爪蟾卵母细胞作为表达系统，观察到 AAT1p 依赖的质子与多种氨基酸的协同运输，其中以组氨酸和赖氨酸获得的活性最高。这些结果证实，在锈菌中，氨基酸转运蛋白的表达是发育调控的，并优先发生在寄生发育阶段。
