Li Fang, Palecek Sean P
Department of Chemical & Biological Engineering, University of Wisconsin-Madison, 53706, USA.
Biotechnol Prog. 2005 Nov-Dec;21(6):1601-9. doi: 10.1021/bp050236c.
Morphogenesis and adhesion to host tissues and medical devices contribute to the virulence of Candida albicans, the most common fungal pathogen isolated from humans. However, identification of molecular mechanisms of C. albicans adhesion and morphogenesis has been impaired by the lack of effective molecular and genetic tools available for this organism. Saccharomyces cerevisiae provides an attractive model system for studying C. albicans adhesion and morphogenesis because of its well-characterized genetics and gene expression systems. To gain insight into the genetic mechanisms of C. albicans adhesion and morphogenesis, we used a parallel plate flow chamber to screen and quantitatively characterize attachment to polystyrene of an adhesion-deficient nonfilamentous flo8Delta S. cerevisiae strain expressing a C. albicans genomic library. We identified six C. albicans genes that are capable of promoting cell adhesion and pseudohyphal development in S. cerevisiae. We also analyzed the ability of these adhesion-promoting genes to regulate the expression of FLO11, which encodes an endogenous S. cerevisiae adhesin. One C. albicans gene, EAP1, appears to directly mediate adhesion and morphogenesis while the remaining five (EAP2, SWI1, MSB1, AAF1, and TEC1) upregulate expression of endogenous S. cerevisiae adhesins. These results suggest that S. cerevisiae is a useful system for molecular characterization of factors that regulate C. albicans adhesion and morphogenesis and that parallel plate flow chamber-based adhesion assays can be used in conjunction with genetic screens to identify molecular mechanisms regulating fungal cell adhesion.
形态发生以及对宿主组织和医疗设备的黏附作用有助于白色念珠菌（从人类分离出的最常见真菌病原体）的毒力。然而，由于缺乏适用于该生物体的有效分子和遗传工具，白色念珠菌黏附和形态发生的分子机制的鉴定受到了阻碍。酿酒酵母因其具有特征明确的遗传学和基因表达系统，为研究白色念珠菌的黏附和形态发生提供了一个有吸引力的模型系统。为了深入了解白色念珠菌黏附和形态发生的遗传机制，我们使用平行平板流动腔来筛选并定量表征表达白色念珠菌基因组文库的黏附缺陷型非丝状flo8Δ酿酒酵母菌株对聚苯乙烯的附着情况。我们鉴定出六个能够促进酿酒酵母细胞黏附和假菌丝发育的白色念珠菌基因。我们还分析了这些促进黏附的基因调节FLO11表达的能力，FLO11编码一种内源性酿酒酵母黏附素。一个白色念珠菌基因EAP1似乎直接介导黏附和形态发生，而其余五个基因（EAP2、SWI1、MSB1、AAF1和TEC1）上调内源性酿酒酵母黏附素的表达。这些结果表明，酿酒酵母是用于分子表征调节白色念珠菌黏附和形态发生的因子的有用系统，并且基于平行平板流动腔的黏附测定可与遗传筛选结合使用，以鉴定调节真菌细胞黏附的分子机制。
