Department of Chemistry - BMC, Uppsala University, Husargatan 3, 751 23 Uppsala, Sweden.
Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel.
Biochemistry. 2023 Jun 6;62(11):1594-1607. doi: 10.1021/acs.biochem.3c00096. Epub 2023 May 24.
The ERM (ezrin, radixin, and moesin) family of proteins and the related protein merlin participate in scaffolding and signaling events at the cell cortex. The proteins share an N-terminal FERM [band four-point-one (4.1) ERM] domain composed of three subdomains (F1, F2, and F3) with binding sites for short linear peptide motifs. By screening the FERM domains of the ERMs and merlin against a phage library that displays peptides representing the intrinsically disordered regions of the human proteome, we identified a large number of novel ligands. We determined the affinities for the ERM and merlin FERM domains interacting with 18 peptides and validated interactions with full-length proteins through pull-down experiments. The majority of the peptides contained an apparent Yx[FILV] motif; others show alternative motifs. We defined distinct binding sites for two types of similar but distinct binding motifs (YxV and FYDF) using a combination of Rosetta FlexPepDock computational peptide docking protocols and mutational analysis. We provide a detailed molecular understanding of how the two types of peptides with distinct motifs bind to different sites on the moesin FERM phosphotyrosine binding-like subdomain and uncover interdependencies between the different types of ligands. The study expands the motif-based interactomes of the ERMs and merlin and suggests that the FERM domain acts as a switchable interaction hub.
ERM（埃兹蛋白、根蛋白和膜突蛋白）家族蛋白和相关蛋白 Merlin 参与细胞皮质的支架和信号事件。这些蛋白质共享一个 N 端 FERM [四连接蛋白 4.1（4.1）ERM]结构域，由三个亚结构域（F1、F2 和 F3）组成，具有与短线性肽基序结合的位点。通过对 ERM 和 Merlin 的 FERM 结构域与展示人类蛋白质组中固有无序区域肽的噬菌体文库进行筛选，我们鉴定了大量新的配体。我们确定了 ERM 和 Merlin FERM 结构域与 18 个肽相互作用的亲和力，并通过下拉实验验证了与全长蛋白的相互作用。大多数肽含有明显的 Yx[FILV]基序；其他显示替代基序。我们使用 Rosetta FlexPepDock 计算肽对接协议和突变分析的组合，定义了两种类似但不同结合基序（YxV 和 FYDF）的不同结合位点。我们提供了关于两种具有不同基序的肽如何结合到 moesin FERM 磷酸酪氨酸结合样亚结构域上不同位点的详细分子理解，并揭示了不同类型配体之间的相互依赖性。该研究扩展了 ERM 和 Merlin 的基于基序的相互作用组，并表明 FERM 结构域充当可切换的相互作用中心。
