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.

我们从酵母核仁中分离出了一个大的蛋白质复合物（SNOS 为亚核仁结构）。已鉴定的蛋白质包括 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 Nop1p、Cbf5p、Nhp2p 和 Rrp5p。该复合物支持 rRNA 的精确转录、终止和修饰，表明存在生产成熟 rRNA 的合作网络。由于大型分离复合物中的大多数成分 (?30) 仍有待确定，MALDI 质谱法应作为鉴定其他（新型）核仁蛋白的工具。我们已经在亚核仁结构中鉴定出两种新的蛋白质，它们是真核蛋白质家族的成员，基于它们对某些子结构域的惊人保守性。由于保守结构域之一预测与 DNA 的选择性结合，因此将分析蛋白质与 DNA 的相互作用，特别是与 rDNA 单元的结构域的相互作用。亚核仁结构的两个进一步鉴定的因素显然与 rDNA 单位的转录有关。它们最初被描述为有效转录 mRNA 所必需的。我们将结合使用生化、遗传和细胞生物学方法来分析已识别的（新）蛋白质在 rRNA 合成和加工中的作用以及它们在构建核仁结构中的可能参与。