BINDING OF TENASCIN-C TO SOLUBLE FIBRONECTIN AND MATRIX FIBRILS
BINDING OF TENASCIN-C TO SOLUBLE FIBRONECTIN AND MATRIX FIBRILS
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DOI：
10.1074/jbc.270.48.29012
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发表时间：
1995-12-01
影响因子：
4.8
通讯作者：
ERICKSON, HP
中科院分区：
文献类型：
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作者：
CHUNG, CY;ZARDI, L;ERICKSON, HP
tenascin-C （TN）的小剪接变体具有8个纤维连接蛋白III型（FN3）结构域。主要的大剪接变体在第5和第6结构域之间插入了3个（鸡）或7个（人）额外的FN3结构域，Chiquet- ehrismann等人(Chiquet- ehrismann， R, Matsuoka， Y, Hofer， U, Spring， J, Bernasconi， C，和Chiquet， M, （1991, Cell Regul, 2,927 -938）证明，在酶联免疫吸附试验中，小变体优先结合纤维连接蛋白，只有小变体通过培养的鸡成纤维细胞结合到基质中。在这里，我们研究了人类TN，并证实了小变异优先结合纯化的纤维连接蛋白和含有纤维连接蛋白的细胞外基质。利用细菌表达蛋白，我们将主要结合位点定位到TN的第三个FN3结构域，与此定位一致的是，针对该结构域表位的单克隆抗体没有染色与细胞培养基质原纤维结合的TN片段，小TN变体的增强结合表明可能在FN3结构域6-8中存在另一个弱结合位点。它只在小剪接变体中与纤维连接蛋白结合。结构域6-8的结合可能涉及到存在于基质原纤维中的第三个分子，因为小TN与基质原纤维的结合比纯化纤维连接蛋白的结合更为突出。
The small splice variant of tenascin-C (TN) has eight fibronectin type III (FN3) domains. The major large splice variant has three (in chicken) or seven (in human) additional FN3 domains inserted between domains five and six, Chiquet-Ehrismann et al, (Chiquet-Ehrismann, R,, Matsuoka, Y,, Hofer, U,, Spring, J,, Bernasconi, C,, and Chiquet, M, (1991, Cell Regul. 2, 927-938) demonstrated that the small variant bound preferentially to fibronectin in enzyme-linked immunosorbent assay, and only the small variant was incorporated into the matrix by cultures of chicken fibroblasts. Here we have studied human TN, and confirmed that the small variant binds preferentially to purified fibronectin and to fibronectin-containing extracellular matrix. Thus this differential binding appears to be conserved across vertebrate species, Using bacterial expression proteins, we mapped the major binding site to the third FN3 domain of TN, Consistent with this mapping, a monoclonal antibody against an epitope in this domain did not stain TN segments bound to cell culture matrix fibrils, The enhanced binding of the small TN variant suggests the existence of another, weak binding site probably in FN3 domains 6-8, which is only positioned to bind fibronectin in the small splice variant. This binding of domains 6-8 may involve a third molecule present in matrix fibrils, as the enhanced binding of small TN was much more prominent to matrix fibrils than to purified fibronectin.