Die Rolle des MATE-Proteins für die Ektomykorrhizasymbiose mit Pilzen der Gattung Tricholoma

MATE（“多药和毒性排出”）家族的转运蛋白是能够从细胞中分泌多种化合物的应激保护机制的一部分。在外生菌根共生中，真菌伴侣可以通过不将这些有毒物质传递给植物来保护其宿主树免受环境胁迫。MATE编码基因mte1从菌根真菌口蘑的鉴定，使我们能够使用酵母系统的蛋白质的功能特征。我们可以显示外源物质，植物次生代谢产物和重金属的运输。随着新开发的，稳定的转化系统，转运蛋白基因现在可以在口蘑中过表达，允许在菌根条件下的表征，包括在体外诱变序列的转化。由于在自然界中，真菌将与其他土传微生物相互作用，我们希望确定Mte1蛋白运输的其他通信分子。这项工作将通过在另一种相关真菌Schizophyllum commune中进行的调查来补充。对于这种真菌，基因组序列允许鉴定两个MATE编码基因，其中一个显示了掺入硒代半胱氨酸的证据，这将改变蛋白质的活性。因此，我们希望对MATE家族的这一新成员进行表征，并特别关注这种不寻常氨基酸的功能。

The transporters of the MATE („multidrug and toxic extrusion“) family are part of the stress protection machinery able to excrete a broad variety of compounds from the cell. In the ectomycorrhizal symbiosis, the fungal partner can protect its host tree from environmental stressors by not delivering such toxic agents to the plant. The identification of the MATE encoding gene mte1 from the mycorrhizal basidiomycete Tricholoma vaccinum allowed us to functionally characterize the protein using a yeast system. We could show transport of xenobiotics, plant secondary metabolites and heavy metals. With a newly developed, stable transformation system, the transporter gene can now be over-expressed in Tricholoma, allowing a characterization also under mycorrhizal conditions including transformation of in vitro mutagenized sequences. Since in nature, the fungi will interact with other soil-borne microbes, we would like to identify additional communication molecules for their transport by the Mte1 protein. This work is to be supplemented by investigations performed in another, related fungus, Schizophyllum commune. For this fungus, the genome sequence allowed the identification of two MATE encoding genes, one of which shows evidence for incorporation of selenocysteine, which would modify the activity of the protein. Hence, we want to characterize this new member of the MATE family with special respect to the function of this unusual amino acid.