Plasma membrane protein sorting in polarized epithelial cells.
Plasma membrane protein sorting in polarized epithelial cells.
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DOI：
10.1083/jcb.116.3.577
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发表时间：
1992-02
期刊：
影响因子：
--
通讯作者：
Okamoto C
中科院分区：
文献类型：
--
作者：
Mostov K;Apodaca G;Aroeti B;Okamoto C
空间不对称是大多数真核细胞结构和功能的基础。这种极性的一个基本方面是，细胞的质膜被分成不同的区域。例如，神经元中的轴突和树突的膜，酵母中生长的芽和交配突起，以及成纤维细胞中的片状脂肪。然而，研究最深入的是上皮细胞，这是动物中最常见的组织类型(52，56)。在单纯上皮细胞中，细胞形成单层，细胞的一个表面--顶端--面对外部世界或拓扑上相等的空间，如肠腔。这是由与基底外侧表面的紧密连接隔开的，该表面接触相邻的细胞和下面的结缔组织。根尖和基底外侧表面的蛋白质和脂肪成分非常不同(4，10，57)。例如，基底外侧表面含有黏附其他细胞和基底膜的受体，以及从循环中吸收营养物质的受体。顶端表面含有与外界交换小分子的转运体。当上皮细胞分裂和分化时，它们必须将蛋白质送到正确的表面以确定它们的极性(25)。此外，在分化的上皮细胞中，尽管膜组件来往于每个表面的流量巨大，但极性仍保持不变。
PATIAL asymmetry is fundamental to the structure and function ofmost eukaryotic cells. A basic aspect of this polarity is that the cell's plasma membrane is divided into discrete domains. Examples include the membranes of axons and dendrites in neurons, the growing bud and mating projection in the yeast Saccharomyces cerevisiae, and lamellipodia in fibroblasts. However, the best-studied type of polarity is found in epithelia, which is the most common type of tissue in animals (52, 56). In simple epithelia the cells form a monolayer where one surface of the cell-the apical-faces the outside world or a topologically equivalent space, such as the lumen of the intestines. This is separated by tight junctions from the basolateral surface, which contacts adjacent cells and the underlying connective tissue. Apical and basolateral surfaces have very different protein and lipid compositions (4, 10, 57). For example, the basolateral surface contains receptors for adhering to other cells and the basement membrane, and for uptake of nutrients from the circulation. The apical surface contains transporters for exchanging small molecules with the outside world. As epithelial cells divide and differentiate they must send proteins to the correct surface to establish their polarity (25). Moreover, in a differentiated epithelial cell, polarity is maintained despite an enormous flux of membrane components traveling to and from each surface.