Analyzes of dynamic molecular organization of the membrane skeleton

1.Rous肉瘤病毒转化细胞的细胞/基质黏附结构：我们观察到Rous肉瘤病毒转化细胞在腹侧质膜中心区下方同时发育足体，并沿细胞周缘发生黏附。足体在几分钟的时间尺度上活动活跃，而外周粘连移动缓慢。收缩蛋白(肌动蛋白、肌球蛋白、钙调蛋白和原肌球蛋白)在足小体中丰富，这可能与足小体的主动运动有关。相比之下，蛋白质在外周粘连中没有聚集，而整合素在外周粘连中富含。这些发现提示，当细胞侵入组织时，这两种黏附结构可能参与了不同的功能：一是细胞通过外周黏附稳定地附着在组织上，二是足小体在主动运动和分泌蛋白质的同时侵入组织。脑内膜联蛋白VI的靶蛋白：阐明r…更多的膜联蛋白VI，我们在大鼠大脑中寻找与膜联蛋白VI相互作用的蛋白质。膜联蛋白VI以钙离子和磷脂依赖的方式与15种蛋白质结合。在这些蛋白质中，约有5种蛋白质富含在细胞骨架部分。其中一种蛋白被鉴定为钙调素。Annexin VI与钙粘附素结合，抑制钙粘附素的F-肌动蛋白交联活性。这些观察结果表明，Annexin VI可能参与了许多神经元功能，包括钙依赖的膜细胞骨架的调节、肌动蛋白和肌动蛋白结合蛋白以及神经细胞的运动性细胞/基质黏附结构：培养的神经元具有高度运动性的细胞/基质黏附结构，称为轴突顶端的生长锥体。生长锥内的肌动蛋白细丝、肌球蛋白、钙调蛋白、原肌球蛋白和明胶蛋白含量丰富，这可能是其主动运动和对钙离子敏感的原因之一。我们发现，培养的星形胶质细胞也沿着突起形成了高度能动的粘连结构，称为粘连褶皱接触。褶皱接触的运动与生长接触的运动相似。收缩蛋白和明胶蛋白也聚集在星形胶质细胞的粘连以及生长锥体和足体中。这些发现表明，收缩蛋白和明胶可能是这些运动性粘连主动运动的分子基础。较少

1. Cell/substratum adhesive structures of Rous sarcoma virus transformed cells : We observed that Rous sarcoma virus transformed-cells developed both podosomes under the center area of ventral plasma membrane and peripheral adhesion along the cell periphery. Podosomes moved actively on a time scale of minutes, while peripheral adhesions scarecely moved. Contractlie proteins (actin, myosin, caldesmon and tropomyosin) were enriched within the podosomes, which may be responsible for the active movement of podosomes. By contrast, the proteins were not acumulated in peripheral adhesions, where integrins, alternatively, were enriched. These findings suggest that the two adhesive structures may participate in different functions when the cells invade into tissues ; firstly, the cells attach stably on the tissue via peripheral adhesions, and secondly, the podosomes invade into the tissue while activly moving and secreting proteases.2. Target proteins of annexin VI in brain : To elucidate the r … More oles of annexin VI, we searched proteins interacting with annexin VI in the rat brains. Annexin VI bound to 15 spieces of proteins in a Ca^<2+> and phospholipid dependent manner. Of these proteins, about 5 proteins were enriched in the cytoskeletal fraction. One of these proteins was identified to be calspectin. Annexin VI bound to calspectin, inhibiting the F-actin crosslinking activity of calspectin. These observations sugget that annexin VI may be involved in many neuronal functions including Ca^<2+>-dependent regulation of the membrane cytoskeleton.Actin and actin binding proteins, and motile cell/substratum adhesive structures of neural cells : Cultured neurons possess highly motile cell/substratum adhesive structures called growth cones at tips of neurites. Actin filaments, myosin, caldesmon, tropomyosin and gelsolin were enriched within the growth cones, which may be responsible for the active movement and Ca^<2+> sensitivity of growth cones. We found out that cultured astrocytes also developed highly motile adhesive structures along the processes and termed the adhesion ruffling contact. The movement of ruffling contact was similar to that of growth one. The contractile proteins and gelsolin were also accumulated in the adhesions of astrocytes as well as in growth cones and the podosomes. These findings show that the contratile protein and gelsolin may be molecular bases for the active movement of these motile adhesion. Less