Identification of the region of α-catenin that plays an essential role in cadherin-mediated cell adhesion

鉴定在钙粘蛋白介导的细胞粘附中起重要作用的 α-连环蛋白区域

基本信息

批准号：
10680586
负责人：
OZAWA Masayuki
金额：
$ 2.43万
依托单位：
Kagoshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680586/
关键词：
cell adhesion molecule cadherin cytoplasmic domain α-catenin actin α-actinin vinculin chimera カテニン細胞接着

项目摘要

α-Catenin is an intrinsic component of the cadherin adhesion complex and is a 102 kDa protein with multiple interaction sites, including homodimerization sites, and binding sites for β- and γ-catenin (plakoglobin), α-actinin, and actin. Besides the binding to β- or γ-catenin, it is unknown, however, which interaction is critical for the function of cadherins. By expressing a series of E-cadherin-α-catenin chimeric molecules on leukemia cells (K562), we have identified the region of α-catenin that confers aggregation-inducing activity to nonfunctional tail-less E-cadherin. The region has been mapped to the carboxy-terminal 295 amino acids of α-catenin. The region contains a binding site for F-actin. Consistent with this result, expression in α-catenin deficient cells ( DLD-1/Δα) of a mutant α-catenin molecule consisting of the amino-terminal β-/γ-catenin-binding site and the carboxy-terminal cell adhesion region identified in the above experiments induced E-cadherin-mediated cell aggregation and compaction. Cells expressing E-cadherin chimeric molecules with the homologous carboxy-terminal region of vinculin, which contains the actin-binding site of vinculin, did not, however, aggregate as strongly as ones expressing E-cadherin-α-catenin chimeric molecules.

α-连环蛋白是钙粘蛋白粘附复合物的内在成分，是一种 102 kDa 的蛋白质，具有多个相互作用位点，包括同源二聚化位点以及 β- 和 γ-连环蛋白（斑珠蛋白）、α-肌动蛋白和肌动蛋白的结合位点。通过表达一系列 E-钙粘蛋白-α-连环蛋白，与 β- 或 γ-连环蛋白结合，但哪种相互作用对于钙粘蛋白的功能至关重要。通过在白血病细胞 (K562) 上的嵌合分子，我们鉴定了 α-连环蛋白的区域，该区域赋予非功能性无尾 E-钙粘蛋白聚集诱导活性，该区域已被定位到 α-连环蛋白的羧基末端 295 个氨基酸。该区域包含 F-肌动蛋白的结合位点，与突变 α-连环蛋白分子在 α-连环蛋白缺陷细胞 (DLD-1/Δα) 中的表达一致。由上述实验中鉴定的氨基末端β-/γ-连环蛋白结合位点和羧基末端细胞粘附区域组成，诱导E-钙粘蛋白介导的细胞聚集和压缩，表达具有同源羧基的E-钙粘蛋白嵌合分子。然而，纽蛋白的β-末端区域包含纽蛋白的肌动蛋白结合位点，其聚集不如表达E-钙粘蛋白-α-连环蛋白嵌合分子的区域那样强烈。