Uncoupling of XB/U-cadherin-catenin complex formation from its function in cell-cell adhesion
Uncoupling of XB/U-cadherin-catenin complex formation from its function in cell-cell adhesion
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DOI：
10.1074/jbc.272.18.11856
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发表时间：
1997-05-02
影响因子：
4.8
通讯作者：
Wedlich, D
中科院分区：
文献类型：
--
作者：
Finnemann, S;Mitrik, I;Wedlich, D
当在鼠L-TK成纤维细胞中表达时，爪蟾XB/U-钙粘蛋白与小鼠α-和β-连环蛋白以及p120（cas）形成功能性复合物。这些细胞稳定转染的cDNA编码不同的细胞质XB/U-钙粘蛋白突变体，每个部分删除的38个最羧基末端氨基酸的不同部分。p120（cas）的结合不受羧基末端缺失的影响，证实了它与一个更氨基末端的区域结合，并且与连环蛋白不同。如果存在钙粘蛋白38个氨基酸尾部的19个氨基酸的一半，则α-和β-连环蛋白与截短的XB/U-钙粘蛋白结合，这表明连环蛋白相互作用的位点在缺失的上游。然而，对于XB/U钙粘蛋白构建体的粘附功能，最羧基末端的19个氨基酸是必需的;如果这些氨基酸缺失，则形成不能介导细胞-细胞粘附的钙粘蛋白-连环蛋白复合物。非粘性复合物可被温和的洗涤剂溶解，而功能性复合物则稳定。如果钙粘蛋白-连环蛋白复合物的去污剂稳定性作为衡量其细胞骨架关联的指标，我们的研究结果首次证明了细胞骨架稳定化的发生与钙粘蛋白-连环蛋白复合物的形成无关，并且需要19个氨基酸的钙粘蛋白羧基末端。
Xenopus XB/U-cadherin forms functional complexes with mouse alpha- and beta-catenins and p120(cas) when expressed in murine L-TK- fibroblasts. These cells were stably transfected with cDNAs encoding different cytoplasmic XB/U-cadherin mutants, each partially deleted in the different parts of the 38 most carboxyl-terminal amino acids. The binding of p120(cas) was not affected by carboxyl-terminal deletions, confirming its binding to a region more amino-terminal and distinct from the catenins. alpha- and beta-catenins associate with truncated XB/U-cadherins if either 19 amino acid half of the cadherin 38 amino acid tail is present, indicating that the site of catenin interaction is upstream of the deletions. However, for adhesive function of XB/U cadherin constructs, the most carboxyl-terminal 19 amino acids are essential; if these amino acids are deleted, cadherin-catenin complexes unable to mediate cell-cell adhesion are formed. Nonadhesive complexes are solubilized by mild detergent, whereas functional complexes are stable. Provided that detergent stability of cadherin-catenin complexes is taken as a measure of their cytoskeletal association, our results give first evidence that cytoskeletal stabilization occurs independent of cadherin-catenin complex formation and requires the 19-amino acid cadherin carboxyl terminus.