CHE-14, a protein with a sterol-sensing domain, is required for apical sorting in C-elegans ectodermal epithelial cells
CHE-14, a protein with a sterol-sensing domain, is required for apical sorting in C-elegans ectodermal epithelial cells
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DOI：
10.1016/s0960-9822(00)00695-3
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发表时间：
2000-09-21
期刊：
影响因子：
9.2
通讯作者：
Labouesse, M
中科院分区：
文献类型：
--
作者：
Michaux, G;Gansmuller, A;Labouesse, M
背景：蛋白质的极化运输对上皮细胞表型的正常表达至关重要，但其遗传控制尚不清楚。调控基因LIN-26对于线虫的正常上皮分化是必不可少的。为了确定LIN-26的潜在效应者，我们对导致LIN-26样表型的突变进行了表征。在这里，我们报道了一个这样的突变系CHE-14的表型和分子分析。结果：CHE-14的突变导致了几种部分穿透表型，影响了大多数外胚层上皮或上皮样细胞的功能，包括皮下组织、排泄道、外阴、直肠和几个支持细胞。这些缺陷通常与靠近根尖表面的囊泡或无定形物质的聚集有关，这表明分泌是有缺陷的。CHE-14蛋白与含有类固醇敏感结构域的蛋白具有相似性，包括Dispatted、Patted和NPC1。全长CHE-14和绿色荧光蛋白之间的融合蛋白定位于需要CHE-14功能的上皮细胞的顶端表面。ChE-14跨膜结构域或细胞外环的缺失取消了该蛋白的顶端定位和功能。结论：我们认为ChE-14参与了一种新的分泌途径，该途径致力于某些上皮细胞顶端表面脂质修饰蛋白的胞吐。我们的数据提出了含有类固醇敏感结构域的蛋白质的原始功能是控制囊泡运输的可能性：ChE-14，并在胞吐中被调度，Patch和NPC1在内吞中被调度。
Background: Polarised trafficking of proteins is critical for normal expression of the epithelial phenotype, but its genetic control is not understood. The regulatory gene lin-26 is essential for normal epithelial differentiation in the nematode Caenorhabditis elegans. To identify potential effecters of lin-26, we characterised mutations that result in lin-26-like phenotypes. Here, we report the phenotypic and molecular analysis of one such mutant line, che-14.Results: Mutations in che-14 resulted in several partially penetrant phenotypes affecting the function of most epithelial or epithelial-like cells of the ectoderm, including the hypodermis, excretory canal, vulva, rectum and several support cells. The defects were generally linked to the accumulation of vesicles or amorphous material near the apical surface, suggesting that secretion was defective. The CHE-14 protein showed similarity to proteins containing sterol-sensing domains, including Dispatched, Patched and NPC1. A fusion protein between full-length CHE-14 and the green fluorescent protein became localised to the apical surface of epithelial cells that require che-14 function. Deletions that removed the predicted transmembrane domains or extracellular loops of CHE-14 abolished apical localisation and function of the protein.Conclusions: We propose that CHE-14 is involved in a novel secretory pathway dedicated to the exocytosis of lipid-modified proteins at the apical surface of certain epithelial cells. Our data raise the possibility that the primordial function of proteins containing a sterol-sensing domain is to control vesicle trafficking: CHE-14 and Dispatched in exocytosis, Patched and NPC1 in endocytosis.