Tricellulin forms homomeric and heteromeric tight junctional complexes
Tricellulin forms homomeric and heteromeric tight junctional complexes
复制标题
DOI：
10.1007/s00018-010-0313-y
复制
发表时间：
2010-03
影响因子：
8
通讯作者：
J. Westphal;Max J. Dörfel;S. Krug;Jimmi Cording;J. Piontek;I. Blasig;R. Tauber;M. Fromm;O. Huber
中科院分区：
文献类型：
--
作者：
J. Westphal;Max J. Dörfel;S. Krug;Jimmi Cording;J. Piontek;I. Blasig;R. Tauber;M. Fromm;O. Huber
通过紧密连接封闭细胞旁间隙对于上皮细胞和内皮细胞作为细胞外空间和内环境之间的有效屏障起着至关重要的作用。封闭蛋白和密封蛋白代表了参与建立这种屏障功能的主要紧密连接组分。在三个细胞结合在一起的部位出现了一种特殊的情况。Tricellulin是最近发现的一种聚集在三细胞接触处的tetraspan蛋白，据报道其组织三细胞以及双细胞紧密连接。在这里，我们表明，在MDCK细胞中，三纤维素C-末端是重要的三纤维素的基底外侧易位，而N-末端结构域似乎参与指导三纤维素三细胞接触。在这方面，同聚的三纤维素-三纤维素和异聚的三纤维素-闭合蛋白复合物的鉴定扩展了先前发表的模型，并表明三纤维素和闭合蛋白一起被运输到伸长的双细胞连接的边缘，并在形成三细胞接触时分离。
Sealing of the paracellular cleft by tight junctions is of central importance for epithelia and endothelia to function as efficient barriers between the extracellular space and the inner milieu. Occludin and claudins represent the major tight junction components involved in establishing this barrier function. A special situation emerges at sites where three cells join together. Tricellulin, a recently identified tetraspan protein concentrated at tricellular contacts, was reported to organize tricellular as well as bicellular tight junctions. Here we show that in MDCK cells, the tricellulin C-terminus is important for the basolateral translocation of tricellulin, whereas the N-terminal domain appears to be involved in directing tricellulin to tricellular contacts. In this respect, identification of homomeric tricellulin-tricellulin and of heteromeric tricellulin-occludin complexes extends a previously published model and suggests that tricellulin and occludin are transported together to the edges of elongating bicellular junctions and get separated when tricellular contacts are formed.