Jockusch B M, Wiegand C, Temm-Grove C J, Nikolai G
Cell Biology Group, University of Bielefeld, Germany.
Symp Soc Exp Biol. 1993;47:253-66.
Microfilament-membrane attachment sites are complex structures that are essential for tissue differentiation in animals. In this article, we focus on the assembly and dynamics of such contact sites as seen in two cell types differentiating in cultures of the embryonic chicken heart, cardiocytes and fibroblasts. Concentrating on the cytoplasmic domain, we refer to previous biochemical, light, and electron microscopic studies on the structure and dynamics of these regions and supplement them with our own recent data. Although many details are still to be elucidated, we would like to propose the following model. Actin, alpha-actinin and vinculin are the major structural components of all microfilament-membrane contacts. Various subtypes of junctions are characterised by additional structural components or by specific isoforms. Temporal regulation of contact sites is linked to assembly and disassembly of microfilaments and might be controlled by special regulatory proteins. Finally, the cytoplasmic domains of junctional complexes may serve as structural matrices for the positioning of proteins involved in signal transduction pathways.
微丝-膜附着位点是复杂的结构，对动物组织分化至关重要。在本文中，我们聚焦于在鸡胚心脏培养物中分化的两种细胞类型，即心肌细胞和成纤维细胞中所观察到的此类接触位点的组装和动态变化。专注于细胞质区域，我们参考了以往关于这些区域结构和动态变化的生化、光学及电子显微镜研究，并以我们自己最近的数据加以补充。尽管许多细节仍有待阐明，但我们想提出以下模型。肌动蛋白、α-辅肌动蛋白和纽蛋白是所有微丝-膜接触的主要结构成分。各种连接亚型的特征在于额外的结构成分或特定的同工型。接触位点的时间调控与微丝的组装和解聚相关，可能由特殊的调节蛋白控制。最后，连接复合体的细胞质区域可能作为参与信号转导途径的蛋白质定位的结构基质。
