The Cell Wall of the Human Pathogen Candida glabrata: Differential Incorporation of Novel Adhesin-Like Wall Proteins
The Cell Wall of the Human Pathogen Candida glabrata: Differential Incorporation of Novel Adhesin-Like Wall Proteins
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DOI：
10.1128/ec.00284-08
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发表时间：
2008-11-01
期刊：
影响因子：
--
通讯作者：
Weig, Michael
中科院分区：
文献类型：
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作者：
de Groot, Piet W. J.;Kraneveld, Eefje A.;Weig, Michael
人类病原体光滑念珠菌的细胞壁控制着最初的宿主-病原体相互作用，这是真菌感染建立的基础。为了鉴定可能与其毒力直接相关的种特异性特征，我们研究了C. glabrata使用多学科的方法，结合显微镜成像，生物化学研究，生物信息学和串联质谱。电子显微镜显示双层壁结构，其中外层挤满了甘露糖蛋白。生化研究表明，C. glabrata壁比酿酒酵母壁多掺入50%的蛋白质，并且与此一致，具有更高的甘露糖/葡萄糖比率。证据表明C. glabrata壁含有共价结合到壁1，6-β-葡聚糖上的糖基磷脂酰肌醇（GPI）蛋白，以及通过温和的碱敏感性键连接到1，3-β-葡聚糖上的蛋白。一项全面的全基因组计算机检测表明，与其他真菌相比，C。glabrata含有异常大量的67个编码粘附素样GPI蛋白的基因。系统发生这些粘附素样蛋白形成不同的簇，其中之一是凝集素样EPA家族。质谱分析鉴定了23种细胞壁蛋白，包括4种新的粘附素样蛋白，Awp 1/2/3/4和Epa 6，其参与粘附于人类上皮细胞和生物膜形成。重要的是，在壁中的粘附素样蛋白的存在取决于生长阶段和所使用的遗传背景，这反映在粘附能力和细胞表面疏水性的改变。我们认为，C.光叶藓的适应性和毒力都很强。
The cell wall of the human pathogen Candida glabrata governs initial host-pathogen interactions that underlie the establishment of fungal infections. With the aim of identifying species-specific features that may directly relate to its virulence, we have investigated the cell wall of C. glabrata using a multidisciplinary approach that combines microscopy imaging, biochemical studies, bioinformatics, and tandem mass spectrometry. Electron microscopy revealed a bilayered wall structure in which the outer layer is packed with mannoproteins. Biochemical studies showed that C. glabrata walls incorporate 50% more protein than Saccharomyces cerevisiae walls and, consistent with this, have a higher mannose/glucose ratio. Evidence is presented that C. glabrata walls contain glycosylphosphatidylinositol (GPI) proteins, covalently bound to the wall 1,6-beta-glucan, as well as proteins linked through a mild-alkali-sensitive linkage to 1,3-beta-glucan. A comprehensive genome-wide in silico inspection showed that in comparison to other fungi, C. glabrata contains an exceptionally large number, 67, of genes encoding adhesin-like GPI proteins. Phylogenetically these adhesin-like proteins form different clusters, one of which is the lectin-like EPA family. Mass spectrometric analysis identified 23 cell wall proteins, including 4 novel adhesin-like proteins, Awp1/2/3/4, and Epa6, which is involved in adherence to human epithelia and biofilm formation. Importantly, the presence of adhesin-like proteins in the wall depended on the growth stage and on the genetic background used, and this was reflected in alterations in adhesion capacity and cell surface hydrophobicity. We propose that the large repertoire of adhesin(-like) genes of C. glabrata contributes to its adaptability and virulence.