ジャーナル: Dev Cell / 年: 2011 タイトル: Structural and functional studies of LRP6 ectodomain reveal a platform for Wnt signaling. 著者: Shuo Chen / Doryen Bubeck / Bryan T MacDonald / Wen-Xue Liang / Jian-Hua Mao / Tomas Malinauskas / Oscar Llorca / A Radu Aricescu / Christian Siebold / Xi He / E Yvonne Jones / 要旨: LDL-receptor-related protein 6 (LRP6), alongside Frizzled receptors, transduces Wnt signaling across the plasma membrane. The LRP6 ectodomain comprises four tandem β-propeller-EGF-like domain (PE) ...LDL-receptor-related protein 6 (LRP6), alongside Frizzled receptors, transduces Wnt signaling across the plasma membrane. The LRP6 ectodomain comprises four tandem β-propeller-EGF-like domain (PE) pairs that harbor binding sites for Wnt morphogens and their antagonists including Dickkopf 1 (Dkk1). To understand how these multiple interactions are integrated, we combined crystallographic analysis of the third and fourth PE pairs with electron microscopy (EM) to determine the complete ectodomain structure. An extensive inter-pair interface, conserved for the first-to-second and third-to-fourth PE interactions, contributes to a compact platform-like architecture, which is disrupted by mutations implicated in developmental diseases. EM reconstruction of the LRP6 platform bound to chaperone Mesd exemplifies a binding mode spanning PE pairs. Cellular and binding assays identify overlapping Wnt3a- and Dkk1-binding surfaces on the third PE pair, consistent with steric competition, but also suggest a model in which the platform structure supports an interplay of ligands through multiple interaction sites.
全体 : Ectodomain of LRP6 residues 20 to 1361 and chaperone Mesd
全体
名称: Ectodomain of LRP6 residues 20 to 1361 and chaperone Mesd
要素
試料: Ectodomain of LRP6 residues 20 to 1361 and chaperone Mesd
タンパク質・ペプチド: LDL-receptor-related protein 6
タンパク質・ペプチド: Mesoderm development protein
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超分子 #1000: Ectodomain of LRP6 residues 20 to 1361 and chaperone Mesd
超分子
名称: Ectodomain of LRP6 residues 20 to 1361 and chaperone Mesd タイプ: sample / ID: 1000 / 詳細: The sample was monodisperse / 集合状態: one LRP6 binds to one Mesd / Number unique components: 2