Münsterkötter Martin, Steinberg Gero
Munich Information Center for Protein Sequences/Institute of Bioinformatics and Systems Biology, Helmholz Zentrum München, Germany.
BMC Genomics. 2007 Dec 20;8:473. doi: 10.1186/1471-2164-8-473.
The corn smut fungus Ustilago maydis is a well-established model system for molecular phytopathology. In addition, it recently became evident that U. maydis and humans share proteins and cellular processes that are not found in the standard fungal model Saccharomyces cerevisiae. This prompted us to do a comparative analysis of the predicted proteome of U. maydis, S. cerevisiae and humans.
At a cut off at 20% identity over protein length, all three organisms share 1738 proteins, whereas both fungi share only 541 conserved proteins. Despite the evolutionary distance between U. maydis and humans, 777 proteins were shared. When applying a more stringent criterion (> or = 20% identity with a homologue in one organism over at least 50 amino acids and > or = 10% less in the other organism), we found 681 proteins for the comparison of U. maydis and humans, whereas the both fungi share only 622 fungal specific proteins. Finally, we found that S. cerevisiae and humans shared 312 proteins. In the U. maydis to H. sapiens homology set 454 proteins are functionally classified and 42 proteins are related to serious human diseases. However, a large portion of 222 proteins are of unknown function.
The fungus U. maydis has a long history of being a model system for understanding DNA recombination and repair, as well as molecular plant pathology. The identification of functionally un-characterized genes that are conserved in humans and U. maydis opens the door for experimental work, which promises new insight in the cell biology of the mammalian cell.
玉米黑粉菌是分子植物病理学中一个成熟的模型系统。此外，最近有证据表明，玉米黑粉菌与人类共享一些在标准真菌模型酿酒酵母中不存在的蛋白质和细胞过程。这促使我们对玉米黑粉菌、酿酒酵母和人类的预测蛋白质组进行比较分析。
在蛋白质长度上同一性为20%的截断值下，所有三种生物共享1738种蛋白质，而两种真菌仅共享541种保守蛋白质。尽管玉米黑粉菌与人类在进化上距离较远，但仍有777种蛋白质是共享的。当应用更严格的标准（与一种生物中的同源物至少50个氨基酸的同一性≥20%，且在另一种生物中少≥10%）时，我们发现玉米黑粉菌与人类比较时有681种蛋白质，而两种真菌仅共享622种真菌特异性蛋白质。最后，我们发现酿酒酵母和人类共享312种蛋白质。在玉米黑粉菌与智人的同源组中，454种蛋白质进行了功能分类，42种蛋白质与严重人类疾病相关。然而，222种蛋白质中有很大一部分功能未知。
玉米黑粉菌长期以来一直是理解DNA重组与修复以及分子植物病理学的模型系统。鉴定在人类和玉米黑粉菌中保守但功能未表征的基因，为实验工作打开了大门，有望为哺乳动物细胞的细胞生物学带来新的见解。
