Single amino acid substitutions in proteins of the armadillo gene family abolish their binding to alpha-catenin
Single amino acid substitutions in proteins of the armadillo gene family abolish their binding to alpha-catenin
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DOI：
10.1074/jbc.271.3.1520
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发表时间：
1996-01-19
影响因子：
4.8
通讯作者：
Kemler, R
中科院分区：
文献类型：
--
作者：
Aberle, H;Schwartz, H;Kemler, R
对钙依赖性细胞粘附分子 E-钙粘蛋白的分析导致了对钙粘蛋白功能所必需的连环蛋白的鉴定。越来越多的证据表明钙粘蛋白和连环蛋白在致癌过程中受到遗传改变的影响，这使得了解钙粘蛋白-连环蛋白复合物内蛋白质-蛋白质相互作用变得尤为重要。在此，我们报告了斑珠蛋白（γ-连环蛋白）中α-连环蛋白结合位点的鉴定和分析。使用斑球蛋白的 N 端和 C 端截短，我们鉴定了结合 α-连环蛋白所必需且充分的 29 个氨基酸结构域。 α-连环蛋白结合位点完全编码在斑球蛋白的外显子 3 内，但仅部分代表在犰狳重复序列 1 中。这表明外显子而不是单个 Arm 重复序列编码斑球蛋白的功能域。定点诱变鉴定了α-连环蛋白结合位点中对于体外结合必不可少的残基，β-连环蛋白和犰狳中的类似突变具有相同的效果。我们的结果表明，犰狳同源物的α-连环蛋白结合位点中的单个氨基酸突变可以阻止与α-连环蛋白的稳定结合，从而影响钙粘蛋白介导的粘附。
Analysis of the calcium-dependent cell adhesion molecule E-cadherin has led to the identification of catenins, which are necessary for cadherin function. Growing evidence that cadherins and catenins are subjected to genetic alterations in carcinogenesis makes it especially important to understand protein-protein interactions within the cadherin-catenin complex, Here we report the identification and analysis of the alpha-catenin binding site in plakoglobin (gamma-catenin). Using N- and C-terminal truncations of plakoglobin, we identified a domain of 29 amino acids necessary and sufficient for binding alpha-catenin. The alpha-catenin binding site is fully encoded within exon 3 of plakoglobin but only partially represented in Armadillo repeat 1. This suggests that exons rather than individual Arm repeats encode functional domains of plakoglobin. Site-directed mutagene sis identified residues in the alpha-catenin binding site indispensable for binding in vitro, Analogous mutations in beta-catenin and Armadillo had identical effects, Our re suits indicate that single amino acid mutations in the alpha-catenin binding site of homologs of Armadillo could prevent a stable association with alpha-catenin, thus affecting cadherin-mediated adhesion.