ALS GENE FAMILY OF CANDIDA ALBICANS

描述：(改编自申请者摘要)主要目的 这项建议是为了描述白色念珠菌ALS基因家族的特征并进行测试 ALS蛋白与白色念珠菌有关的假说 粘附力。第一个肌萎缩侧索硬化症基因，als1在一个差异中被发现 杂交筛选。预测的ALS1蛋白具有显著的相似性 与酿酒酵母细胞表面黏附的同源性 糖蛋白α-凝集素(AGalpha1)。预测的构造特征 提示它也将定位于细胞表面，是 高度糖基化，可起粘连作用。ALS1包含一个 重复序列的中心结构域在AGalpha1中不存在。 Southern杂交表明该序列与几种白色念珠菌杂交 基因组片段；所有这些都被认为属于ALS基因 一家人。这种重复序列具有一些特征，表明它将高度 N-和O-糖基化。修饰到这个程度的蛋白质将会是大多数 可能定位在细胞表面，这表明所有ALS蛋白都有 发挥粘合剂作用的潜力。中使用的基本方法 这些研究包括克隆所有肌萎缩侧索硬化症基因并完成DNA 每一项的顺序。将对这些序列进行比较，并针对特定的区域 识别出的每一种ALS基因。这些特定的探头将用于 研究肌萎缩侧索硬化症基因的样本菌株变异性并确定 基因表达的条件。唯一的序列将 也可用于制备针对ALS蛋白的抗血清。本土化 和修正数据将与在C. 白念珠菌和ALS基因异源表达时的观察 在酿酒酵母中。假设每一个都有相似的数据，这些酿酒酵母 将对菌株进行检测，以确定ALS蛋白是否具有粘附性 属性。肌萎缩侧索硬化症的大小和数量有很大的变异性 白念珠菌菌株之间的基因可能是第一个基因 白念珠菌细胞表面变异与应变相关的解释。 来自ALS家族研究的数据也将进一步定义 蛋白质定位和信号传递的异同 白色念珠菌和酿酒酵母之间的修饰。这些数据将 说明酿酒酵母在什么情况下，其发育良好 基因系统，可以用来促进分析，否则将 在二倍体、无性的白色念珠菌中是复杂的。

DESCRIPTION: (Adapted from Applicant's Abstract) The main objective of this proposal is to characterize the C. albicans ALS gene family and test the hypothesis that the ALS proteins are involved in C. albicans adhesion. The first ALS gene, ALS1 was identified in a differential hybridization screen. The predicted ALS1 protein shares significant identity with the Saccharomyces cerevisiae cell-surface adhesion glycoprotein alpha-agglutinin (AGalpha1). Predicted structural features of ALS1 suggest that it too will be localized on the cell surface, be highly glycosylated and may function in adhesion. ALS1 contains a central domain of tandemly repeated sequence not present in AGalpha1. Southern blots indicated this sequence hybridizes to several C. albicans genomic fragments; all of these are considered to belong to the ALS gene family. This repeated sequence has features suggesting it will be highly N- and O- glycosylated. Proteins modified to this extent will most likely be localized on the cell surface suggesting all ALS proteins have the potential to function in adhesive roles. The basic approach used in these studies involves cloning all ALS genes and completing the DNA sequence of each. These sequences will be compared and regions specific for each ALS gene identified. These specific probes will be used to study the sample strain variability of the ALS genes and define conditions under which the genes are expressed. Unique sequences will also be used to raise antisera specific for ALS proteins. Localization and modification data will be compared between what is observed in C. albicans and what is observed when ALS genes are heterologously expressed in S. cerevisiae. Assuming similar data for each, these S. cerevisiae strains will be assayed to determine if ALS proteins have adhesive properties. The large degree of variability in size and numbers of ALS genes between C. albicans strains may be the first example of a genetic explanation for strain-dependent cell-surface variation in C. albicans. Data derived from studies of the ALS family will also further define the similarities and differences in signals for protein localization and modification between C. albicans and S. cerevisiae. These data will indicate circumstances under which S. cerevisiae, with its well-developed genetic system, can be used to facilitate analyses that would otherwise be complicated in the diploid, asexual C. albicans.