Study on the buildup principle of the plasma membrane signaling domains.

质膜信号结构域构建原理的研究。

基本信息

批准号：
11680658
负责人：
SATO Satoshi
金额：
$ 2.18万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

The plasma membrane contains various forms of invaginations with apparently different physical building principles. To specify the mechanisms of domain formation, particularly those for clathrin-coated pits and caveolae, the dynamical characterization of the lattice assembly should be an important approach. We addressed the effects of poly (ethylene glycol) cholesteryl ether (PEG-Chol) on the structure/function of clathrin-coated pit and caveolae. Addition of the compound to cultured cells induced progressive smoothening of the surface. In these cells were accumulated opened clathrin-coated pits, which ultimately became flat on occasion of the cell rupture by slightly more PEG-Chol. These results strongly suggested that coated-pit elastically differentiates from the bulk membrane phase and also from caveolae. Next, we analyzed the effect of accumulated membrane stress. Whereas simple incubation of PEG-Chol gave no morphological effect, we found numerous plasma membrane tubules decorate … More d with biotinylated PEG-Chol (bPEG-Chol) and SA were introduced. The tubules were homogeneous in diameter (d【approximately equal】100 nm) and contained actin filaments. Biochemically, bPEG-Chol induced tyrosinephosphorylation of proteins. The analysis suggested that local accumulation of lipid-packing defects evoked signaling reaction (s) that mobilize actin to reduce the stress from the main cell body. Next, we describe the responses of K562 human leukemia cells that were treated with okadaic acid, an inhibitor of type 1 and 2A protein dephosphatases, to physical stress on the plasma membrane. While OKA alone induced patchy accumulation of cortical F-actin, application of mechanical stresses induced budding of membrane-bound body containing the whole cell F-actin. The formation of this actin-rich body was prevented by modification of F-actin and also by protein kinase-inhibitors. Moreover, when a non-receptor tyrosine kinase Fyn was knocked-out, such change did not occur. In this project, we suggest the presence of the specific mechanical linkage between actin microfilaments and a defined set of membrane organelles or surfaces proteins in OKA-treated cells. Less

质膜包含各种形式的内知，具有不同的物理建筑原理。为了指定域形成的机制，尤其是那些用于网格蛋白涂层坑和小窝的机制，晶格组装的动态表征应该是一种重要方法。我们解决了聚（乙二醇）胆固醇（PEG-CHOL）对网格蛋白涂层坑和小窝的结构/功能的影响。将化合物添加到培养的细胞中诱导表面进行性平滑。在这些细胞中，积累了开放的网格蛋白涂层的坑，最终在细胞破裂的情况下通过稍微稍微peg-chol变为平坦。这些结果强烈表明，涂层的凹坑弹性地与大块膜相区分开，也与小窝区分开。接下来，我们分析了累积的膜应激的影响。虽然简单的PEG-CHOL孵育没有形态学效应，但我们发现了许多质膜管的装饰……更多的D与生物素化的PEG-Chol（BPEG-CHOL）和SA引入了更多的D。管的直径均匀（D [大约等于] 100 nm），并包含肌动蛋白丝。在生化上，BPEG-Chol诱导蛋白质的酪氨酸磷酸化。分析表明，脂质包装缺陷的局部积累诱发信号反应，动员肌动蛋白减少主细胞体的应力。接下来，我们描述了用冈田酸治疗的K562人白血病细胞的反应，后者是1型和2A蛋白去磷酸酶的抑制剂，对质膜上的物理胁迫。虽然单独使用OKA会诱导皮质F-肌动蛋白的斑驳积累，但机械应力引起的膜结合体的出现含有整个细胞F-肌动蛋白。通过修饰F-肌动蛋白以及蛋白激酶抑制剂来预防这种富含肌动蛋白的身体的形成。此外，当将非受体酪氨酸激酶FYN击倒时，就不会发生这种变化。在这个项目中，我们建议在OKA处理的细胞中肌动蛋白微丝和一组定义的膜细胞器或表面蛋白之间存在特定的机械连接。较少的