Molecular mechanism of cellular response induced by dynamic metabolism of membrane phospholipid

膜磷脂动态代谢诱导细胞反应的分子机制

基本信息

批准号：
17390065
负责人：
SAITO Naoaki
金额：
$ 9.34万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

Recent technical development has enabled us to monitor the production, movement and signaling of lipid messengers in living cells using probes for specific lipids. In this project, we performed the spatio-temporal analysis using various probes for lipid messengers to elucidate when and where the lipid signaling occurs within the cells in physiological cellular responses. As a result, we obtained the results below.1) Live imaging of signaling molecules (Protein kinase C (PKC) subtypes, Rac subtypes, p47^<Phox>, p40^<Phox>) in phagocytosis. Each molecule having different lipid binding ability translocated to the specific intracellular compartment in different time course. The finely tuned control of targeting mechanism of signaling molecules to lipid regulate the superoxide production in phagocytosis.2) Functional and molecular interaction of Diacylglycerol (DG)-PKC-DG kinase (DGK) pathway. Direct binding between PKC and DGK and the regulation of each enzymatic activity by the binding were demonstrated using live-imaging techniques. PKC binds to DGK on the plasma membrane and phosphorylates DGK at S776and S779. The phosphorylated DGK is then activated and terminates PKC pathway by convert DG to PA on the plasma membrane.3) Nuclear translocation of DGKgamma requires its Cl domain but not the kinase activity. Nuclear DGKgamma controls cell cycle.4) Aggregation of mutant PKCgamma within cells may cause Spinocerebellar ataxia type 14 (SCA14).

最近的技术开发使我们能够使用特定脂质的探针来监测活细胞中脂质使者的产生，运动和信号。在这个项目中，我们使用脂质使者的各种探针进行了时空分析，以阐明生理细胞反应中细胞内脂质信号的何时何地发生。结果，我们获得了以下结果。1）吞噬作用中信号分子的实时成像（蛋白激酶C（PKC）亚型，RAC亚型，p47^<phox>，p40^<phox>）。每个具有不同脂质结合能力的分子在不同的时间过程中转移到特定的细胞内室。信号分子对脂质的靶向机理的细胞调节控制脂肪细胞中的超氧化物的产生。2）二酰基甘油（DG）-PKC-DG激酶（DGK）途径的功能和分子相互作用。 PKC和DGK之间的直接结合以及使用实影技术证明了通过结合对每种酶活性的调节。 PKC与质膜上的DGK结合，并在S776和S779处磷酸化DGK。然后将磷酸化的DGK激活，并通过将DG转换为质膜上的DG终止PKC途径。3）DGKGAMMA的核易位需要其CL结构域，而不是激酶活性。核dgkgamma控制细胞周期。4）细胞内突变体PKCGAMMA的聚集可能会导致14型脊髓脑性共济失调（SCA14）。