Elucidation of the organization mechanism of dynamic higher-ordered structures in biological cells

本项目的题目是阐明生物细胞中动态高阶结构的组织机制。这里所说的“动态高级结构”主要指的是真核细胞中的膜结合的细胞器，而“组织机制的阐明”则是指对它的深入了解，以便在人工条件下重建细胞器。由于细胞内膜系统的动力学行为可以通过考虑它们与非膜高阶结构的相互作用来理解，因此本课题包括了许多类型的研究课题。除了细胞内膜系统(质膜、核膜、线粒体内膜、叶绿体类囊体膜、肌肉细胞的肌浆网、感光杆状细胞的盘膜、神经元的突触小泡)、非膜的高级结构(细胞囊、真核鞭毛、肌丝)、特殊的高级结构(病毒、细菌鞭毛马达、全息细菌的紫膜)和人造脂膜外，还研究了这些结构。我们举行了年度会议，项目的每个成员都被要求报告他的研究成果以及相关研究领域的当前主题。展示了如此多的发现，观众们对听到其他领域正在发生的事情感到满意。有人报道了重建一些特定的高序结构的试验，但很大一部分报告涉及在分子水平上阐明生物现象。指出在细胞水平上对生物现象进行卓有成效的讨论之前，应发展相关的物理化学方法来分析细胞内高阶结构的复杂耦合行为。我们希望，重建细胞内更高有序结构的挑战将导致未来更重要的发现的产生。

The title of this project is elucidation of the organization mechanism of dynamic higher-order structures in biological cells. Here the term "dynamic higher-ordered structures" means mainly membrane-bounded organella in eucaryotic cells, and "elucidation of the organization mechanism" means to understand it so deeply as to reconstitute the organella under artificial conditions. Since dynamic behaviors of intracellular membranous systems can be understood by taking account of their interactions with non-membranous higher-ordered structures, many types of research subject are included in this project. Besides intracellular membrane systems (plasma membrane, nuclear membranes, the inner membrane of mitochondria, the thylakoid membrane of chloroplasts, the sarcoplasmic reticulum of muscle cells, the disk membrane of photoreceptor rod cells, the synaptic vesicle of neurons), non-membrane higher-ordered structures (the cytoskelton, eucaryotic flagella, muscle filaments), special higher-ordered structures (virus, the bacterial flagella motor, the purple membrane of holobacteria) and artificial lipid membranes were studied. We held annual meetings, in which each member of the project was asked to report his research output as well as current topics in a related research field. So many discoveries were presented, and the audience were satisfied to hear what was going on in other fields. Trials to reconstitute some specific higher-ordered structures were reported, but a large fraction of the reports concerned elucidation of biological phenomena at the molecular level. It is pointed out that relevant physicochemical methods for analyzing complicatedly-coupled behaviors of intracellular higher-ordered structures should be developed before achieving fruitful discussion about biological phenomena at the cellular level. We hope that the challenge to reconstitute intracellular higher-ordered structures will lead to production of more important discoveries in future.