Manganese Peroxidase Gene Expression: Regulation by Mn

锰过氧化物酶基因表达：Mn 的调节

• 批准号: 9104610
• 负责人: Michael Gold
• 金额: --
• 依托单位: Oregon Graduate Institute of Science & Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1995-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9104610&HistoricalAwards=false
• 关键词: Manganese; Peroxidase; Gene; Expression; Regulation

The lignin degradative system (LDS) of the white rot basidiomycetous fungus Phanerochaete chrysosporium is capable of degrading the plant cell wall polymer, lignin, and a range of aromatic pollutants. The major components of this nonspecific oxidative system are two extracellular heme-containing peroxidases, manganese peroxidase (MnP) and lignin peroxidase (LiP). The LDS is expressed during secondary metabolic growth, the onset of which is triggered by limiting nutrient nitrogen. Recently, we discovered that MnP expression is also regulated at the level of gene transcription by Mn ion and heat shock and the primary goal of the proposed project is to elucidate on the molecular level the mechanisms of Mn regulation of mnp gene transcription. Isolation and analysis of mutants and titration with promoter copies will be utilized to determine the type of regulation. The promoter regions of P. chrysosporium mnp genes will be analyzed to determine the sequences responsible for Mn and heat shock regulation of transcription, using promoter-reporter constructs, deletion analysis and synthetic promoter elements. DNaseI footprinting and gel mobility shift assays will be used to assay putative DNA- binding transcription factors, and the factors will be isolated. A possible requirement for Mn in post-transcriptional events will be examined.

白色腐真菌黄孢原毛革菌的木质素降解系统（LDS）能够降解植物细胞壁聚合物、木质素和一系列芳香族污染物。这种非特异性氧化系统的主要成分是两种细胞外含血红素的过氧化物酶，锰过氧化物酶（MnP）和木质素过氧化物酶（LiP）。LDS在次级代谢生长期间表达，其起始由限制营养氮引发。最近，我们发现锰离子和热休克也在基因转录水平上调节MnP的表达，本项目的主要目标是在分子水平上阐明锰离子调节mnp基因转录的机制。将利用突变体的分离和分析以及启动子拷贝的滴定来确定调节的类型。将使用启动子-报告基因构建体、缺失分析和合成启动子元件分析黄孢原毛平革菌mnp基因的启动子区，以确定负责Mn和转录的热激调节的序列。DNA酶I足迹法和凝胶迁移率变动分析将用于分析推定的DNA结合转录因子，并分离这些因子。将检查转录后事件中对Mn的可能要求。