Enzymology of Golgi Stack Formation

高尔基体堆栈形成的酶学

• 批准号: 6603909
• 负责人: VIVEK MALHOTRA
• 金额: $ 34.2万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6603909
• 关键词: Golgi apparatus; SDS polyacrylamide gel electrophoresis; adenosinetriphosphatase; cell component structure /function; electron microscopy; guanosine triphosphate; intracellular membranes; laboratory mouse; laboratory rabbit; membrane biogenesis; membrane fusion; protein binding; protein degradation; protein kinase; protein purification; protein sequence; protein transport; protein tyrosine kinase; tissue /cell culture; yeast two hybrid system

DESCRIPTION (provided by applicant): We have identified a serine threonine kinase called protein kinase D (PKD) as an essential component in the reactions leading to the fission of transport carriers from the TGN. When the kinase activity of PKD is compromised the transport carriers form from the TGN but fail to undergo fission. The cargo containing carriers grow as a result into large tubes. PKD is recruited to specific regions of the Trans Golgi Network (TGN) via the first cysteine rich domain (C1a). Cia binds to the TGN via Diacyiglycerol (DAG). Reducing the cellular levels of DAG inhibit PKD recruitment to the TGN and protein transport to the cell surface is blocked. Our aim is understand the mechanism by which PKD cycles on and off the TGN. We will identify components involved in the binding and the release of PKD from the TGN. We will reconstitute the generation of PKD containing tubes from the TGN in permeabilized cells. This is aimed towards the purification of components that are involved in the formation of the TGN derived transport carriers. We have generated a cell line, in which we can accumulate the PKD containing tubes and then cause their dissociation by shifting to a permissible temperature. This approach will be used to isolate the PKD containing TGN derived transport carriers. This will help reveal the molecular composition of the TGN derived transport carriers. In addition, we will provide a function for another isoform of PKD3, which we propose, is involved in transport from Golgi to the ER. We will formally test the hypothesis that the organization of the Golgi stacks is regulated through TGN. Vesiculation of the TGN causes vesiculation of the early Golgi cisternae by uncontrolled generation of COPI vesicle. Our studies will reveal novel insights into the process by which transport carriers form from the TON and how a regulated production of these carriers is essential for maintaining the overall Golgi organization.

Please try later.