AIDS Opportunistic Pathogens/Fungal Cell Wall Drug Targets

描述（由申请人提供）：口腔念珠菌病是HIV感染的标志。三分之一的艾滋病毒血清阳性和90%的艾滋病患者将出现口咽念珠菌病。很少有抗真菌剂可用于治疗，并且使问题复杂化，一些念珠菌属物种，特别是光滑念珠菌，对重要的三唑类抗真菌剂具有先天性抗性。这项资助旨在确定酵母细胞壁生物发生中的潜在靶点，以开发新型抗真菌药物。念珠菌细胞壁是一个被证实的药物靶点：棘白菌素类药物（默克公司的Cancidas是其中一员）靶向β 1，3葡聚糖合酶，可以成功地用于对抗多种念珠菌，包括白色念珠菌和念珠菌。光滑的细胞壁中的另一种主要葡聚糖是β 1 -6葡聚糖。尽管β 1 -6生物合成通常对细胞的生存力至关重要，但在生化水平上对β 1 -6生物合成的了解较少。β 1 -6葡聚糖的基本功能之一是将蛋白质共价交联到细胞壁中：S. cerevisiae和C.白色念珠菌和C. glabrata是所谓的GPI-细胞壁蛋白（或GPI-CWP），并通过GPI锚的残余物共价连接到β 1 -6葡聚糖。 GPI蛋白质附着在细胞壁上的过程根本没有被详细了解。我们已经建立了用于分析GPI蛋白交联到细胞壁的试剂，并建议使用这些试剂来鉴定和分析S.酿酒酵母，其中GPI-CWP加工和与β 1 -6葡聚糖的交联受到损害。具体来说，我们正在产生一系列已知或预测参与GPI-CWP生物发生的基因的温度敏感等位基因。我们将使用这些温度敏感的突变菌株来分析GPI-CWP交联途径中的中间体，以更精确地定义这些基因在GPI-CWP成熟和交联中的作用。 酵母细胞壁对于酵母活力是必不可少的，并且GPI-CWP功能对于细胞壁完整性是必不可少的。鉴定负责GPI-CWP交联的酶将允许化疗靶向真菌特异性的、必需的和经证实的靶标，用于开发新的抗真菌治疗。

DESCRIPTION (provided by applicant): Oral candidiasis is a hallmark of HIV infection. A third of HIV sero-positive and 90% of AIDS patients will present with oropharyngeal candidiasis. Few antifungal agents are available for treatment and to compound the problem, some species of Candida, notably Candida glabrata, are innately resistant to the important triazole class of antifungals. This grant proposes to identify potential targets in yeast cell wall biogenesis for development of novel antifungal agents. The Candida cell wall is a proven drug target: the echinocandin class of drugs (of which Merck's Cancidas is a member) target beta1,3 glucan synthase and can be successfully used against multiple species of Candida including Candida albicans and C. glabrata. The other major glucan in the cell wall is beta1-6 glucan. Less is understood at a biochemical level about beta1-6 biosynthesis, although it is normally essential for the viability of the cell. One of beta1-6 glucan's essential functions is to covalently crosslink proteins into the cell wall: the vast majority of cell wall proteins in S. cerevisiae and in C. albicans and C. glabrata are so called GPI-cell wall proteins (or GPI-CWPs) and are covalently attached through the remnant of the GPI anchor to beta1-6 glucan. The process by which GPI-proteins are attached to the cell wall is not understood in detail at all. We have established reagents for analyzing GPI-protein crosslinking to the cell wall and propose using these to identify and analyze mutants of S. cerevisiae in which GPI-CWP processing and crosslinking to beta1-6 glucan is compromised. Specifically, we are generating a series of temperature sensitive alleles of genes known or predicted to be involved in GPI-CWP biogenesis. We will use these temperature sensitive mutant strains to analyze intermediates in the GPI-CWP crosslinking pathway to more precisely define the role of these genes in the maturation and crosslinking of GPI-CWPs. The yeast cell wall is essential for yeast viability, and GPI-CWP function is essential to cell wall integrity. Identification of the enzymes responsible for GPI-CWP crosslinking will allow chemotherapeutic targeting of a fungal specific, essential and proven target for development of new antifungal therapy.