Huber A H, Weis W I
Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Cell. 2001 May 4;105(3):391-402. doi: 10.1016/s0092-8674(01)00330-0.
As a component of adherens junctions and the Wnt signaling pathway, beta-catenin binds cadherins, Tcf family transcription factors, and the tumor suppressor APC. We have determined the crystal structures of both unphosphorylated and phosphorylated E-cadherin cytoplasmic domain complexed with the arm repeat region of beta-catenin. The interaction spans all 12 arm repeats, and features quasi-independent binding regions that include helices which interact with both ends of the arm repeat domain and an extended stretch of 14 residues which closely resembles a portion of XTcf-3. Phosphorylation of E-cadherin results in interactions with a hydrophobic patch of beta-catenin that mimics the binding of an amphipathic XTcf-3 helix. APC contains sequences homologous to the phosphorylated region of cadherin, and is likely to bind similarly.
作为黏着连接和Wnt信号通路的一个组成部分，β-连环蛋白可与钙黏着蛋白、Tcf家族转录因子以及肿瘤抑制因子APC结合。我们已经确定了未磷酸化和磷酸化的E-钙黏着蛋白细胞质结构域与β-连环蛋白的臂重复区域复合后的晶体结构。这种相互作用跨越了所有12个臂重复序列，其特征是具有准独立的结合区域，其中包括与臂重复结构域两端相互作用的螺旋以及一段14个残基的延伸序列，该序列与XTcf-3的一部分非常相似。E-钙黏着蛋白的磷酸化导致其与β-连环蛋白的一个疏水区域相互作用，该区域模拟了两亲性XTcf-3螺旋的结合。APC包含与钙黏着蛋白磷酸化区域同源的序列，并且可能以类似方式结合。
