ANALYSIS OF PHYSIOLOGICAL FUNCTION OF LIPID SIGNALLING SYSTEM

脂质信号系统的生理功能分析

• 批准号: 18370053
• 负责人: KANAHO Yasunori
• 金额: $ 10.99万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18370053/
• 关键词: single transduction; lipid kinase; synaptic vesicle; ARF6; knockout mice; endocytosis; AP-2 complex; PIP5K; 低分子量G蛋白質; アレルギー; 神経; PIP5Kγ661; シナプス小胞

The lipid kinase phosphatidylinositol 4-phosphate 5-kinase (PIP5K) phosphorylates phosphatidylinositol 4-phosphate to produce phosphatidylinositol 4,5-bisphosphate (PIP2), which functions as a lipid signaling molecule. Three isozymes for mammalian PIP5K, α β and γ, and three splicing variants of γ type of PIP5K, γ635, γ661 and γ687, have been identified. We have been investigating activation mechanisms and physiological functions of each PIP5K isozyme to understand the molecular multiplicity of PIP5K. During 2 years of this project, we obtained the results described below.1. Specific partner protein of PIP5K γ661PIP5K γ661 of PIP5K isozymes and splicing variants, was found to specifically interact with and is activated by the adaptor complex AP-2 in mouse hippocampal neurons. Furthermore, it was found that the interaction of these molecules is absolutely required for the clathrin-dependent synaptic vesicle endocytosis induced by depolarization, in mouse hippocampal neurons.2. Specific partner protein of PIP5KβPIP5Kβ of PIP5K isozymes specifically interact with KIF2A. The interaction stimulated PIP5Kβ kinase activity and microtubule depolymerizing activity of KIF2A. Finally, the interaction of these two molecules was found to negatively regulate axonal outgrowth of mouse hippocampal neurons.3. PIP5K binding site for its activator ARF6The small G protein ARF6 activates PIP5K. We identified that ARF6 binds to the kinase core domain of PIP5K, which is highly conserved among PIP5K isozymes.4. Preparation and analysis of PIP5K α knockout miceWe prepared PIP5K α knockout mice, which have not yet been reported. These mice were apparently healthy and any defects were not observe.

磷脂酰肌醇-4-磷酸-5-激酶(PIP5K)通过磷酸化磷脂酰肌醇-4-磷酸生成磷脂酰肌醇-4，5-二磷酸(PIP2)，作为脂质信号分子发挥作用。已鉴定出哺乳动物PIP5K的三种同工酶αβ和γ，以及γ类型PIP5K的三种剪接变异体γ635、γ661和γ687。我们一直在研究每种PIP5K同工酶的激活机制和生理功能，以了解PIP5K的分子多样性。在这个项目的两年时间里，我们取得了如下结果：1.在小鼠海马神经元中，PIP5Kγ661PIP5Kγ661的特异性配对蛋白PIP5K同工酶和剪接变异体被发现与适配器复合体AP-2特异地相互作用并被激活。此外，研究还发现这些分子之间的相互作用是去极化诱导小鼠海马神经元中依赖于笼蛋白的突触囊泡内吞所必需的。PIP5Kβ的特定伴侣蛋白PIP5K同工酶的PIP5Kβ与KIF2a特异地相互作用。这种相互作用刺激了PIP5Kβ激酶活性和KIF2a微管解聚活性。最后，发现这两种分子的相互作用对小鼠海马神经元的轴突生长具有负性调节作用。其激活剂ARF6的PIP5K结合部位小G蛋白ARF6激活PIP5K。我们发现ARF6与PIP5K的激酶核心区结合，该结构域在PIP5K同工酶中高度保守。PIP5Kα基因敲除小鼠的制备与分析我们制备了尚未见报道的PIP5Kα基因敲除小鼠。这些小鼠显然是健康的，没有观察到任何缺陷。

项目成果

Crucial role of the small GTPase ARF6 in hepatic cord formation during liver developent

小GTP酶ARF6在肝脏发育过程中肝索形成中的关键作用

• 发表时间: 2006
• 期刊: Mol. Cell. Biol 26(peer review)
• 作者: Suzu T;Kanai Y;Hara T;Sasaki T;Khara M;Maehama T;Taya C;Shitara H;Yonekawa H;Frohaman M. A.;Yokozeki T. and Kanaho Y
• 通讯作者: Yokozeki T. and Kanaho Y

Function of the small G protein ARF6 in angiogenesis

小G蛋白ARF6在血管生成中的功能

• 发表时间: 2007
• 作者: T. Hongu;T. Suzuki;T. Yokozeki;and Y. Kanaho
• 通讯作者: and Y. Kanaho

Novel activation mechanism and physiological function of PIP 5-kinase γ661

PIP 5-激酶γ661的新激活机制和生理功能

• 发表时间: 2007
• 作者: Tateishi;Y.;Ariyoshi;M.;Igarashi;R.;Hara;H.;Mizuguchi;K;Seto;A.;Nakai;A.;Kokubo;T.;Tochio;H.;Shirakawa;M.;Y. Kanaho
• 通讯作者: Y. Kanaho

Role of phospholipase D in membrane ruffle formation

磷脂酶 D 在膜皱褶形成中的作用

• 发表时间: 2006
• 作者: T. Yokozeki;A. Hara;and Y. Kanaho
• 通讯作者: and Y. Kanaho

Novel activation mechanism and physiological function of PIP 5-kinase γ661.

PIP 5-激酶γ661的新激活机制和生理功能。

• 发表时间: 2007
• 作者: H.;Shimizu;Y. Kanaho
• 通讯作者: Y. Kanaho