Role of deubiquitinating enzymes (DUBs) in Protein trafficking

去泛素化酶 (DUB) 在蛋白质运输中的作用

• 批准号: 71267618
• 负责人: Professor Dr. Ralf Kölling
• 金额: --
• 依托单位: Fachgebiet Hefegenetik und Gärungstechnologie (150f)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/71267618?language=en
• 关键词: Role; deubiquitinating; enzymes; DUBs; Protein

The fate of internalized cell surface proteins in eukaryotic cells is determined by their degree of ubiquitination. The mechanisms underlying ubiquitination-dependent sorting in the endocytic pathway will be examined more closely using the yeast ABC-transporter Ste6 as a model protein. At the level of early endosomes, ubiquitinated Ste6 is sorted into the lysosomal/vacuolar pathway for degradation, while non-ubiquitinated Ste6 is recycled back to the cell surface. In previous experiments, we found that recycling of non-ubiquitinated Ste6 is dependent on sorting nexin (Snx) 4 and on the monomeric clathrin adaptor Gga2. Our goal will be to examine how sorting nexins, clathrin adaptors and clathrin cooperate in ubiquitination-dependent sorting of Ste6. We will define recycling signals in Ste6 and look for proteins interacting with these signals. Of course, sorting nexins and clathrin adaptors are prime candidates for this analysis. The role of sorting nexins in tubular-based endosomal sorting is now becoming increasingly clear. At present, however, it is unclear how many distinct sorting pathways operate at the level of early endosomes and how cargo is specifically recognized. We established a working model that integrates most of the known data about the sorting of Ste6 and other yeast membrane proteins. This model will be tested by different experiments.

真核细胞中内化的细胞表面蛋白的命运由其泛素化程度决定。将使用酵母ABC转运蛋白Ste 6作为模型蛋白，更密切地研究内吞途径中的泛素化依赖性分选的机制。在早期内体水平，泛素化的Ste 6被分选到溶酶体/空泡途径中进行降解，而非泛素化的Ste 6被再循环回到细胞表面。在以前的实验中，我们发现，回收的非泛素化的Ste 6是依赖于分类连接蛋白（Snx）4和单体网格蛋白接头Gga 2。我们的目标将是研究如何排序连接蛋白，网格蛋白适配器和网格蛋白合作的Ste 6的泛素化依赖的排序。我们将在Ste 6中定义回收信号，并寻找与这些信号相互作用的蛋白质。当然，分选连接蛋白和网格蛋白衔接子是这种分析的主要候选者。分类连接蛋白在基于微管的内体分类中的作用现在变得越来越清楚。然而，目前还不清楚有多少不同的分选途径在早期内体水平上起作用，以及货物是如何被特异性识别的。我们建立了一个工作模型，该模型整合了大多数已知的关于Ste 6和其他酵母膜蛋白分选的数据。该模型将通过不同的实验进行检验。