权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular Genetic Mining of the Aspergillus Nidulans Secondary Metabolome

构巢曲霉次生代谢组的分子遗传学挖掘

基本信息

批准号：
8314132
负责人：
BERL Ray OAKLEY
金额：
$ 33.79万
依托单位：
UNIVERSITY OF KANSAS LAWRENCE
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

项目摘要

Secondary metabolites are a remarkably rich source of medically useful compounds. It is, consequently, of great value to identify new secondary metabolites and to develop methods to increase secondary metabolite production. In fungi, the genes of particular secondary metabolite biosynthetic pathways are usually clustered together, and sequencing of the genomes of several species of the filamentous fungus Aspergillus has revealed that there are many secondary metabolism gene clusters (approximately 46 in Aspergillus nidulans alone, a much larger number than would have been predicted prior to the sequencing of the genome). The products of the great majority of these pathways are unknown and A. nidulans is, thus, a potentially rich source of useful secondary metabolites as well as an excellent model organism for developing procedures to mine the secondary metabolomes of fungi. This proposal takes advantage of recent progress in gene targeting in A. nidulans to create a set of molecular genetic tools and strains that will allow the efficient exploitation of the A. nidulans secondary metabolome. Our first specific aim is to create a set of transformants that will allow the products of all A. nidulans secondary metabolism gene clusters to be identified. We will pursue two approaches. Approximately 15 unexplored gene clusters contain transcription factor genes that are predicted to control expression of the other genes in the cluster. We will replace the promoters of these transcription factor genes with inducible promoters. This will allow overexpression of the genes of target clusters and increased synthesis of the product(s) of the cluster. This will, in turn, allow our collaborator, Dr. Clay Wang, to identify and purify the products of particular clusters. Our second aim will be to delete genes of selected secondary metabolism pathways to allow the steps of the pathways to be clarified and shunt products isolated. In some cases, the shunt products may be as useful as, or more useful than, the normal products of the pathway. Our third aim will be to develop promoter replacement strains that will allow increased expression of secondary metabolism pathways. This will be particularly important in gene clusters that do not contain transcription factor genes. A portion of this aim will be to develop a serial promoter replacement procedure that will allow the promoters of all the genes in target pathways to be replaced. For all of these aims we will work closely with our collaborators, Dr. Wang and Dr. Nancy Keller.

次生代谢物是一种非常丰富的医学有用化合物来源。因此，它是发现新的次生代谢物和开发增加次生代谢物的方法具有重要价值制作。在真菌中，特定次生代谢物生物合成途径的基因通常是几种丝状真菌曲霉菌的基因组序列分析已发现有许多次生代谢基因簇(曲霉中约有46个仅尼杜罗一种，比在测序之前预测的数字要大得多基因组)。这些途径中的绝大多数产物都是未知的，因此，根结线虫是一种潜在丰富的有用次生代谢物的来源，以及一个优秀的模式生物开发挖掘真菌次生代谢物的程序。这项建议充分利用了利用根瘤拟青霉基因打靶建立一套分子遗传学工具和菌株的最新进展允许有效利用根瘤拟青霉的次生代谢组。我们的第一个具体目标是创建一个一组转化子，将允许所有根瘤拟青霉次级代谢基因簇的产物确认身份。我们将采取两种方法。大约有15个未被探索的基因簇包含转录被预测为控制簇中其他基因表达的因子基因。我们将替换这些转录因子基因的启动子带有可诱导的启动子。这将允许过度表达靶基因簇和增加合成的产物(S)的簇。这将反过来允许我们的合作者，Clay Wang博士，鉴定和提纯特定集群的产品。我们的第二个目标是删除选定的次生代谢途径的基因，以允许这些途径的步骤隔离澄清和分流产品。在某些情况下，分流产品可能与分流产品一样有用，甚至更有用而不是该途径的正常产物。我们的第三个目标将是开发启动子替代菌株将允许增加次级代谢途径的表达。这将在以下方面尤为重要不包含转录因子基因的基因簇。这一目标的一部分将是开发一系列启动子替换程序，将允许靶途径中所有基因的启动子被替换了。为了实现所有这些目标，我们将与我们的合作者王博士和南希·凯勒博士密切合作。