Molecular characterisation and function of nucleolar and nuclear protein complexes involved in sequential maturation steps of ribosomal precursor particles

参与核糖体前体颗粒连续成熟步骤的核仁和核蛋白复合物的分子特征和功能

• 批准号: 5238848
• 负责人: Professor Dr. Herbert Tschochner
• 金额: --
• 依托单位: Lehrstuhl für Biochemie III
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2000
• 资助国家: 德国
• 起止时间: 1999-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5238848?language=en
• 关键词: Molecular; characterisation; function; nucleolar; nuclear

We have isolated a large protein complex from the yeast nucleolus (SNOS for subnucelolar structure). Among the identified proteins were RNA polymerase I (pol I), pol I transcription factors TBP, Rrn3p, Rrn10p and Reb1p and rRNA processing factors Nop1p, Cbf5p, Nhp2p and Rrp5p. The complex supports accurate transcription, termination and modification of rRNA suggesting the existence of a cooperative network to produce mature rRNA. Since most of the compontents (?30) within the large isolated complex remain to be determined, MALDI mass spectrometry should serve as a tool to identify other (novel) nucleolar proteins. Among the components that we have already identified within the subnucleolar structure are two novel proteins which are members of a eukaryotic protein family based on their striking conservation of certain subdomains. Since one of the conserved domain predicts selective binding to DNA the interaction of the proteins with DNA, especially with domains of the rDNA unit will be analysed. Two further identified factors ot the subnucleolar structure are obviously involved in transcribing the rDNA unit. They were both originally described to be required to transcribe efficiently mRNA. We will use a combination of biochemical, genetic and cell biological methods to analyse the roles of the identified (novel) proteins in synthesis and processing of rRNA and their possible involvement in building up the nucleolar structure.

我们已经从酵母核仁中分离出一个大的蛋白质复合物（SNOS为亚核仁结构）。在所鉴定的蛋白质中有RNA聚合酶I（pol I）、pol I转录因子TBP、Rrn3p、Rrn10p和Reb1p以及rRNA加工因子Nop 1p、Cbf 5p、Nhp 2p和Rrp5p。该复合物支持rRNA的精确转录、终止和修饰，表明存在产生成熟rRNA的合作网络。由于大多数组件（？30)在大的分离的复合物仍有待确定，MALDI质谱应作为一种工具，以确定其他（新的）核仁蛋白。在我们已经确定的亚核仁结构中的组分中，有两种新的蛋白质是真核蛋白质家族的成员，它们基于某些亚结构域的惊人保守性。由于其中一个保守结构域预测与DNA的选择性结合，因此将分析蛋白质与DNA，特别是与rDNA单元的结构域的相互作用。进一步确定的亚核仁结构的两个因子明显参与rDNA单位的转录。它们最初都被描述为有效转录mRNA所需的。我们将使用生物化学，遗传学和细胞生物学方法的组合来分析所识别的（新）蛋白质在rRNA合成和加工中的作用，以及它们可能参与构建核仁结构。