Topology, regulation and function of acid sphingomyelinase in death receptor signaling

死亡受体信号传导中酸性鞘磷脂酶的拓扑、调节和功能

• 批准号: 39297910
• 负责人: Professor Dr. Stefan Schütze
• 金额: --
• 依托单位: Institut für Immunologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/39297910?language=en
• 关键词: Topology; regulation; function; acid; sphingomyelinase

In this project we aim to evaluate the molecular mechanisms of acid sphingomyelinase (A-SMase) activation by the death receptors TNF-R1, CD95, TRAIL receptor 1 and -2 using our patented method to isolate intact subcellular membrane compartments by immunomagnetic sorting. First, the mechanism of the fusion of trans-Golgi vesicles with internalized TNF-receptosomes leading to A-SMase activation in late endosomal/multivesicular compartments will be analyzed. Next we want to investigate the contribution of reactive oxygen species (ROS) mediated by TNF-R1 associated riboflavin kinase within TNF receptosomes to A-SMase activation. In the second part, we will identify the CD95- and TRAIL- responsive A-SMase-containing compartment, identify the signal initiating translocation of these vesicles, study the regulation of trafficking of A-SMase-bearing secretory vesicles to the plasma-membrane, and the mechanisms of A-SMase activation during exocytosis / after exposure of the enzyme at the cell surface. Here we will focus on post-transcriptional modifications of A-SMase. In the third part, we want to follow internalization and trafficking of CD95- and TRAIL-receptosomes and ask for activation of endo-lysosomal A-SMase and possible intracellular effector molecules downstream of ceramide in this compartment. Finally, we aim to investigate the compartmentalization and regulation of ceramide metabolism including sphingosine and sphingosine-1-phospate production in isolated TNF-R1, CD95 and TRAIL receptosomes.

在这个项目中，我们的目标是用我们的专利方法通过免疫磁选分离完整的亚细胞膜隔膜，评估死亡受体TNF-R1、CD95、TRAIL受体1和-2激活酸性鞘磷脂酶(A-sMase)的分子机制。首先，我们将分析跨高尔基体小泡与内化的肿瘤坏死因子受体小体融合导致A-sMase在晚期内体/多囊体室激活的机制。接下来，我们想要研究肿瘤坏死因子受体1相关的核黄素激酶介导的活性氧物种(ROS)在肿瘤坏死因子受体体内对A-sMase激活的作用。在第二部分中，我们将鉴定CD95和TRAIL反应的A-sMase，鉴定这些小泡的信号转位，研究含A-sMase的分泌小泡转运到质膜的调节，以及A-sMase在胞吐过程中/酶暴露在细胞表面后的激活机制。在这里，我们将重点介绍A-sMase的转录后修饰。在第三部分中，我们想要跟踪CD95-和TRAIL-受体的内化和运输，并要求激活内切溶酶体A-sMase和神经酰胺下游可能的细胞内效应分子。最后，我们的目标是研究神经酰胺代谢的区划和调节，包括神经鞘氨醇和神经鞘氨醇-1-磷酸的产生在分离的肿瘤坏死因子-R1、CD95和TRAIL受体体内。