Schäfer S, Troyanovsky S M, Heid H W, Eshkind L G, Koch P J, Franke W W
Division of Cell Biology, German Cancer Research Center, Heidelberg.
C R Acad Sci III. 1993 Nov;316(11):1316-23.
Desmosomes are morphologically well defined junctions between epithelial cells and also some other cells such as myocardiocytes, meningeal cells and dendritic reticulum cells of lymphatic follicles. Besides their function in cell coupling, desmosomes anchor components of the cytoskeleton, i.e. intermediate-sized filaments (IFs), through their cytoplasmic plaques, thereby contributing to cytoskeletal and tissue architecture. In molecular terms, desmosomes are specific assemblies of transmembrane glycoproteins of the cadherin family, desmoglein(s) and desmocollin(s), that contribute to cell adhesion via their extracellular, aminoterminal domains and to plaque formation and IF coupling through their cytoplasmic, carboxyterminal "tails". Using transfection assays, we analyzed the function of different tail domains in plaque assembly and IF anchorage. Furthermore, we present evidence that both desmogleins and desmocollins represent multigene subfamilies showing cell type specific expression and that a desmosomal plaque protein occurring in stratified and complex epithelia, the "band 6 protein", is related to the plakoglobin family.
桥粒是上皮细胞以及其他一些细胞（如心肌细胞、脑膜细胞和淋巴滤泡的树突状网状细胞）之间形态学上定义明确的连接结构。除了在细胞连接中的功能外，桥粒还通过其细胞质斑锚定细胞骨架成分，即中间丝（IFs），从而有助于细胞骨架和组织结构的形成。从分子角度来看，桥粒是钙黏蛋白家族跨膜糖蛋白（桥粒芯糖蛋白和桥粒胶蛋白）的特定组装体，它们通过其细胞外氨基末端结构域促进细胞黏附，并通过其细胞质羧基末端“尾巴”促进斑的形成和IF连接。我们利用转染实验分析了不同尾巴结构域在斑组装和IF锚定中的功能。此外，我们提供的证据表明，桥粒芯糖蛋白和桥粒胶蛋白均代表多基因亚家族，表现出细胞类型特异性表达，并且在复层和复杂上皮中出现的一种桥粒斑蛋白“6带蛋白”与桥粒斑珠蛋白家族相关。
