Schlosshauer B, Bauch H, Frank R
Naturwissenschaftliches und Medizinisches Institut, Universität Tübingen, Reutlingen/Germany.
Eur J Cell Biol. 1995 Oct;68(2):159-66.
Neurothelin is a cell surface protein of chicken endothelial cells at the blood-brain barrier and also of pigment epithelial cells forming the blood-eye barrier. Peptide sequencing of affinity-purified neurothelin revealed that it is likely to be identical with the protein called HT7. It belongs to the immunoglobulin superfamily having two extracellular C2-type domains, a membrane spanning region and a cytoplasmic tail. During development neurothelin cell surface localization changed on pigment epithelial cells. In early embryogenesis neurothelin was found preferentially at lateral sites of neighboring epithelial cells, but after hatching, predominantly on basal cell surfaces and on apical microvilli of epithelial cells that contact retinal photoreceptors. Disruption of cell-cell contacts induced a rapid change of neurothelin distribution on the cell surface in vitro as could be shown by confocal laser microscopy. Disintegration of microfilaments by cytochalasin D hampered this specific cell surface rearrangement of neurothelin, whereas depolymerization of microtubules by demecolcine had no effect. In double-labeling experiments neurothelin and F-actin were colocalized. The data suggest that the polarized cell surface distribution of neurothelin is influenced intracellularly by F-actin and extracellularly by cell-cell interactions.
神经腱蛋白是血脑屏障处鸡内皮细胞以及构成血眼屏障的色素上皮细胞的一种细胞表面蛋白。对亲和纯化的神经腱蛋白进行肽测序表明，它可能与名为HT7的蛋白质相同。它属于免疫球蛋白超家族，具有两个细胞外C2型结构域、一个跨膜区域和一个胞质尾巴。在发育过程中，神经腱蛋白在色素上皮细胞上的细胞表面定位发生了变化。在胚胎早期发育阶段，神经腱蛋白优先出现在相邻上皮细胞的侧面，但孵化后，主要出现在与视网膜光感受器接触的上皮细胞的基底细胞表面和顶端微绒毛上。共聚焦激光显微镜显示，体外细胞间接触的破坏会导致神经腱蛋白在细胞表面的分布迅速改变。用细胞松弛素D破坏微丝会阻碍神经腱蛋白这种特定的细胞表面重排，而用秋水仙胺使微管解聚则没有影响。在双重标记实验中，神经腱蛋白和F-肌动蛋白共定位。数据表明，神经腱蛋白的极化细胞表面分布在细胞内受F-肌动蛋白影响，在细胞外受细胞间相互作用影响。
