MOLECULAR POLYMORPHISM OF A CELL-SURFACE PROTEOGLYCAN - DISTINCT STRUCTURES ON SIMPLE AND STRATIFIED EPITHELIA
MOLECULAR POLYMORPHISM OF A CELL-SURFACE PROTEOGLYCAN - DISTINCT STRUCTURES ON SIMPLE AND STRATIFIED EPITHELIA
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DOI：
10.1073/pnas.85.24.9562
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发表时间：
1988-12-01
影响因子：
11.1
通讯作者：
BERNFIELD, M
中科院分区：
文献类型：
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作者：
SANDERSON, RD;BERNFIELD, M
上皮细胞分为单层（单层上皮）或多层（复层上皮）。这些细胞组织的维持需要涉及许多细胞表面分子的独特粘附机制。其中一种分子是细胞表面蛋白多糖，称为多聚糖，它同时含有硫酸乙酰肝素和硫酸软骨素链。这种蛋白聚糖将细胞与纤维状胶原蛋白和纤连蛋白结合，从而充当间质基质的受体。蛋白多糖仅限于简单上皮细胞的基底外侧表面，但位于复层上皮细胞的整个表面上，甚至是那些不接触基质的表面。我们现在表明，简单和复层上皮细胞中的独特定位与独特的蛋白聚糖结构相关。来自单层上皮的蛋白多糖（模式分子大小，160 kDa）比来自复层上皮的蛋白多糖（模式分子大小，92 kDa）大，但它们的核心蛋白在大小和免疫反应性上相同。来自单层上皮的蛋白多糖比来自复层上皮的蛋白多糖具有更多且更大的硫酸乙酰肝素和硫酸软骨素链。因此，由于不同的翻译后修饰，细胞表面蛋白多糖显示出组织特异性的结构多态性。这种多态性可能反映了简单和复层上皮细胞中不同的蛋白多糖功能，可能满足这些不同组织中细胞的不同粘附要求。
Epithelial cells are organized into either a single layer (simple epithelia) or multiple layers (stratified epithelia). Maintenance of these cellular organizations requires distinct adhesive mechanisms involving many cell surface molecules. One such molecule is a cell surface proteoglycan, named syndecan, that contains both heparan sulfate and chondroitin sulfate chains. This proteoglycan binds cells to fibrillar collagens and fibronectin and thus acts as a receptor for interstitial matrix. The proteoglycan is restricted to the basolateral surface of simple epithelial cells, but is located over the entire surface of stratified epithelial cells, even those surfaces not contacting matrix. We now show that the distinct localization in simple and stratified epithelia correlates with a distinct proteoglycan structure. The proteoglycan from simple epithelia (modal molecular size, 160 kDa) is larger than that from stratified epithelia (modal molecular size, 92 kDa), but their core proteins are identical in size and immunoreactivity. The proteoglycan from simple epithelia has more and larger heparan sulfate and chondroitin sulfate chains than the proteoglycan from stratified epithelia. Thus, the cell surface proteoglycan shows a tissue-specific structural polymorphism due to distinct posttranslational modifications. This polymorphism likely reflects distinct proteoglycan functions in simple and stratified epithelia, potentially meeting the different adhesive requirements of the cells in these different organizations.