COGEME Proteomics Service Facility 1, School of Medical Sciences, University of Aberdeen, Institute of Medical Sciences, Aberdeen, UK.
Proteomics. 2010 Jan;10(2):212-23. doi: 10.1002/pmic.200800706.
Candida glabrata is a major fungal pathogen of humans, and the virulence of C. glabrata is increased by inactivation of the transcription factor, Ace2. Our previous examination of the effects of Ace2 inactivation upon the intracellular proteome suggested that the hypervirulence of C. glabrata ace2 mutants might be caused by differences in the secretome. Therefore in this study we have characterised the C. glabrata secretome and examined the effects of Ace2 inactivation upon this extracellular proteome. We have identified 31 distinct proteins in the secretome of wild-type C. glabrata cells by MS/MS of proteins that were precipitated from the growth medium and enriched by affinity chromatography on concanavalin A. Most of these proteins are predicted to be cell wall proteins, cell wall modifying enzymes and aspartyl proteinases. The endochitinase Cts1 and the endoglucanase Egt2 were not detected in the C. glabrata secretome following Ace2 inactivation. This can account for the cell separation defect of C. glabrata ace2 cells. Ace2 inactivation also resulted in the detection of new proteins in the C. glabrata secretome. The release of such proteins might contribute to the hypervirulence of ace2 cells.
光滑念珠菌是一种主要的人类真菌病原体，转录因子 Ace2 的失活会增加光滑念珠菌的毒力。我们之前对 Ace2 失活对细胞内蛋白质组的影响的研究表明，光滑念珠菌 ace2 突变体的高毒力可能是由于其分泌组的差异造成的。因此，在本研究中，我们对光滑念珠菌的分泌组进行了表征，并研究了 Ace2 失活对该细胞外蛋白质组的影响。通过对从生长培养基中沉淀并通过伴刀豆球蛋白 A 亲和层析富集的蛋白质进行 MS/MS，我们在野生型光滑念珠菌细胞的分泌组中鉴定出 31 种不同的蛋白质。这些蛋白质中的大多数被预测为细胞壁蛋白、细胞壁修饰酶和天冬氨酸蛋白酶。内切几丁质酶 Cts1 和内切葡聚糖酶 Egt2 在 Ace2 失活后未在光滑念珠菌的分泌组中检测到。这可以解释光滑念珠菌 ace2 细胞的细胞分离缺陷。Ace2 失活还导致在光滑念珠菌的分泌组中检测到新的蛋白质。这些蛋白质的释放可能有助于 ace2 细胞的高毒力。
