MOLECULAR BIOLOGY OF CRYPTOCOCCUS NEOFORMANS

描述：（改编自申请人摘要）。隐球菌 新生儿仍然是发病率和死亡率的重要原因， 患有艾滋病和其他免疫抑制状态的患者。 尽管取得了进展 在隐球菌性脑膜炎的治疗中， 艾滋病患者的治疗。 在过去的五年里， C.分子生物学的重大进展。新人类 通过 已经克隆和鉴定了十几个基因，转化系统 已经开发出来，并且对毒性相关基因的开创性研究 已经描述了 总的来说，这些研究表明， 这种生物体是一个重要的研究领域，因为它与 人类健康，但它提供了一个理想的模式系统的真菌 发病机制 埃德曼实验室的重点，这一直是一个 了解C.新形式主义者 交配型基因座的表征，以及MAT α的作用 基因座在促进毒力，将继续通过研究描述 在这个应用中。埃德曼博士最近的观察表明， 在C.新型野生型， 单倍体，MAT α细胞。 对这种过渡的控制将是 其特征在于分离该途径中的突变体，克隆 由这些突变体定义的基因，以及菌丝的形态学评估 在突变型和野生型菌株中产生。交配型位点的分析表明，C. 通过转录分析，DNA序列， 和基因破坏。 虽然这些基因中有十几个基因 复杂的基因座，两个MAT α基因已经被分离出来， 信息素基因和S.酿酒酵母PRT1基因，将 接受初步审查。 成熟信息素的特征是 从过表达细胞中纯化，并通过 质谱分析法来顺式和反式作用因子 信息素基因调控将被鉴定、分离和表征。 这些研究将通过继续分离C. 在交配后不能形成丝状体的新形式突变体。 MAT α缺失和MAT α：：MAT α置换菌株将被 构建了一个正式的测试假设， MATalpha基因座内的决定因素。 这些菌株将提供新的 对C.新人类

DESCRIPTION: (Adapted from Applicant's Abstract). Cryptococcus neoformans remains a significant cause of morbidity and mortality in patients with AIDS and other immunosuppressive states. Despite advances in the treatment of cryptococcal meningitis, there is still no curative treatment in AIDS patients. In the past five years, there has been significant advances in the molecular biology of C. neoformans. Over a dozen genes have been cloned and characterized, transformation systems have been developed, and pioneering studies on virulence-related genes have been described. Overall, these studies have shown that not only is this organism an important field of study because of its relevance to human health, but it provides an ideal model system of fungal pathogenesis. The focus of the Edman laboratory, which has been an understanding of the mechanisms of dimorphism in C. neoformans, the characterization of the mating type loci, and the role of the MAT alpha locus in promoting virulence, will be continued through studies described in this application. Recent observations by Dr. Edman have demonstrated a true yeast to hyphae dimorphic transition in C. neoformans wild type, haploid, MAT alpha cells. The control of this transition will be characterized by the isolation of mutants in this pathway, cloning the genes defined by these mutants, and morphologic assessment of the hyphae produced in mutant and wild type strains. The mating type loci of C. neoformans will be characterized by transcript analysis, DNA sequence, and gene disruption. While there are over a dozen genes within these complex loci, two MATalpha genes that have already been isolated, the pheromone gene and a homologue of the S. cerevisiae PRT1 gene, will receive initial scrutiny. The mature pheromone will be characterized by purification from overexpressing cells and its structure determined by mass spectrometry. Cis- and trans-acting factors responsible for pheromone gene regulation will be identified, isolated and characterized. These studies will be complemented by the continuing isolation of C. neoformans mutants that are unable to form filaments after mating. MATalpha deletion and MATalpha::MATalpha replacement strains will be constructed to formally test the hypothesis that there are virulence determinants within the MATalpha locus. These strains should provide new insights into the mechanisms of pathogenesis of C. neoformans.