Böhmer Maik, Colby Thomas, Böhmer Christian, Bräutigam Anne, Schmidt Jürgen, Bölker Michael
Max-Planck Institute for Plant Breeding Research, Köln, Germany.
Proteomics. 2007 Mar;7(5):675-85. doi: 10.1002/pmic.200600900.
In the corn smut fungus Ustilago maydis, the dimorphic transition from budding to filamentous growth is intrinsically associated with the switch from a saprophytic to a pathogenic lifestyle. Both pathogenicity and filament formation are triggered by a heterodimeric homeodomain transcription factor encoded by the b mating type locus. Here, we present a reference map of the proteome of this dimorphic phytopathogenic fungus. Using 2-DE in combination with MALDI-TOF-MS and ESI-MS/MS, we were able to identify 250 distinct proteins obtained from soluble protein samples. In addition, we determined the abundance of cytosolic proteins in filamentous U. maydis cells and compared it with that of budding cells. Filamentous growth was induced by two independent regimes, either by overexpression of the bW2/bE1-heterodimer or by overexpression of the small GTP binding protein Rac1. By comparison of expression profiles, we have identified 13 protein spots that were significantly enhanced during filamentous growth induced by bW2/bE1. Rac1 only up-regulates a subset of four of these protein spots. None of these proteins have previously been associated with filamentous growth. Comparison of Rac1- and b-regulated protein sets supports the hypothesis that filament formation during pathogenic development occurs via stimulation of a Rac1-containing signalling module.
在玉米黑粉菌（Ustilago maydis）中，从出芽生长到丝状生长的双态转变与从腐生生活方式到致病生活方式的转变内在相关。致病性和菌丝形成均由b交配型位点编码的异源二聚体同源结构域转录因子触发。在此，我们展示了这种双态植物病原真菌的蛋白质组参考图谱。使用二维电泳（2-DE）结合基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）和电喷雾串联质谱（ESI-MS/MS），我们能够从可溶性蛋白质样品中鉴定出250种不同的蛋白质。此外，我们测定了丝状玉米黑粉菌细胞中胞质蛋白的丰度，并将其与出芽细胞的进行比较。通过两种独立的方式诱导丝状生长，即通过bW2/bE1异源二聚体的过表达或小GTP结合蛋白Rac1的过表达。通过比较表达谱，我们鉴定出13个在bW2/bE1诱导的丝状生长过程中显著增强的蛋白质斑点。Rac1仅上调其中四个蛋白质斑点的一个子集。这些蛋白质以前均未与丝状生长相关联。对Rac1和b调节的蛋白质组的比较支持了这样的假设，即致病发育过程中的菌丝形成是通过刺激含Rac1的信号模块发生的。
