STUDY ON THE STRUCTURE FUNCTION AND PHYSIOLOGICAL ROLES OF SA CHANNELS

SA通道的结构功能及生理作用研究

• 批准号: 13480216
• 负责人: SOKABE Masahiro
• 金额: $ 9.28万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480216/
• 关键词: SA channel; Structure-Function; Kca chahnel; Bacterial SA channel; Cytoskeleton; Integrin; Mechanical Stress; Cell Signaling; 心筋; NF-KB; ストレス; リン酸化; 接着斑; Mid1; シロイヌナズナ

The aim of this study was three fold : 1) elucidation of structure function of SA channels with known structure, 2) molecular identification of SA channels from higher order organisms, and 3) elucidation of roles of SA channels and cytoskeletons in mechano-induced cell signaling. Major results are as follows. (1) Identification of mechano-sensitive domain of the bacterial SA channel MscL : We found that hydrophobic amino-residues located at the peri-plasmic boundary of the lipid bilayer act as a mechanosensor of MscL. This site corresponds to the lipid glycerol backbone that is the most suitable structure for sensing tension in the membrane. (2)Molecular identification of the heart SA channel SAKCA : We cloned a gene encoding a stretch activated big Kca channel from chick heart and identified the 59 amino acids sequence called STREX at C-terminus as a mechanosensitive domain of this channel. We also isolated a 50 KDa protein acting as an accessory device that conveys tension in the membrane to STREX. (3) Role of cytosekelton in SA channel activation : We found that the stress fiber acts as a force transmitter in SA channel activation. (4) Role of SA channel in cell signaling : We analyzed the intracellular signaling leading to NF-kB activation in response to mechanical stimuli. It is suggested that cells can chose different mechano-signaling cascade depending on the time structure of mechanical stmuli. Mechano-signaling to cyclic or transient mechanical stimuli is mainly mediated by SA channels, while those to constant mechanical stimuli by integrin

这项研究的目的是三倍：1）阐明具有已知结构的SA通道的结构功能，2）来自高阶生物体的SA通道的分子鉴定，以及3）阐明机械诱导的细胞信号中SA通道和细胞骨架的作用。主要结果如下。 （1）鉴定细菌SA通道MSCL的机械敏感结构域：我们发现位于脂质双层的质质边界的疏水性氨基沉积物作为MSCL的机械传感器。该部位对应于脂质甘油主链，这是最适合感测膜张力的结构。 （2）sakca的心脏SA通道的分子鉴定：我们克隆了一个基因，该基因编码了小鸡心中激活的大型KCA通道，并确定了C-Terminus的59个氨基酸序列，称为strex是该通道的机械敏感域。我们还分离了50 kDa蛋白，该蛋白充当辅助装置，将膜中的张力传达到Strex中。 （3）细胞塞克尔顿在SA通道激活中的作用：我们发现应力纤维在SA通道激活中充当力。 （4）SA通道在细胞信号传导中的作用：我们分析了导致NF-KB激活的细胞内信号传导，以响应机械刺激。建议细胞可以根据机械stmuli的时间结构来选择不同的机械信号级联反应。机械信号对循环或瞬态机械刺激主要是由SA通道介导的，而这些刺激的机械信号是由整合素介导的。

项目成果

Kawakami K, Tatsumi H, Sokabe M.: "Dymanics of integrin at focal adhesion in endothelial cells detected by near field microscopy."J Cell Sci. 114・17. 3125-3135 (2001)

Kawakami K、Tatsumi H、Sokabe M.：“通过近场显微镜检测内皮细胞粘着斑处的整合素动力学。”J Cell Sci 114・17（2001）。

Kobayashi S, Nagino M, Komatsu S, Naruse K, Nimura Y, Nakanishi M, Sokabe M.: "Stretch-induced IL-6 secretion from endothelial cells requires NF-KB activation."Biochem.Bhiophys.Res.Com.. 308. 306-312 (2003)

Kobayashi S、Nagino M、Komatsu S、Naruse K、Nimura Y、Nakanishi M、Sokabe M.：“拉伸诱导内皮细胞分泌 IL-6 需要 NF-KB 激活。”Biochem.Bhiophys.Res.Com.. 308

曽我部正博, 郷信広(編): "生物物理学とはなにか"共立出版. 288 (2003)

Masahiro Sogabe、Nobuhiro Go（编辑）：“什么是生物物理学？” 288 (2003)

Hoshino T, Tatsumi H, Nakashima T, Sokabe M: "In vitro Reconstitution of Signal Transmission from a Hair Cell to the Growth Cone of a Chick Vestibular Ganglion Cell"Neurosci. 120. 993-1003 (2003)

Hoshino T、Tatsumi H、Nakashima T、Sokabe M：“体外重建从毛细胞到鸡前庭神经节细胞生长锥的信号传输”Neurosci。

曽我部正博, 河上敬介, 早川公英, 成瀬恵治, 辰巳仁史: "内皮細胞の伸展依存性リモデリング -分子から形へのインターフェースを見る-"血管医学. 4. 237-244 (2003)

Masahiro Sogabe、Keisuke Kawakami、Kimihide Hayakawa、Keiji Naruse、Hitoshi Tatsumi：“内皮细胞的拉伸依赖性重塑 - 从分子到形状的界面 -”血管医学。