A binding motif for Siah ubiquitin ligase
A binding motif for Siah ubiquitin ligase
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DOI：
10.1073/pnas.0534783100
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发表时间：
2003-03-18
影响因子：
11.1
通讯作者：
Bowtell, DDL
中科院分区：
文献类型：
--
作者：
House, CM;Frew, IJ;Bowtell, DDL
果蝇SINA（seven in absentia）蛋白及其哺乳动物直系同源物（Siah，seven in absentia homolog）是RING结构域蛋白，其在E3泛素连接酶复合物中起作用，并促进广泛的细胞蛋白（包括β-连环蛋白）的泛素化和降解。尽管有这些不同的目标，SINA/Siah识别底物或结合蛋白的方法仍然未知。在这里，我们确定了一个肽基序（RPVAxispPxxR），介导的Siah蛋白与一系列蛋白质的合作伙伴的相互作用。序列比对和诱变扫描揭示了这种相互作用的重要残基。该共有序列正确地预测了与肽的高亲和力相互作用。来自细胞骨架蛋白质plectin-1（残基95-117）。与23个残基的肽（K-Dapp = 29 nM与SINA）获得的异常高的亲和力结合表明，它可以作为一个有用的显性负性试剂SINA/Siah蛋白。
The Drosophila SINA (seven in absentia) protein and its mammalian orthologs (Siah, seven in absentia homolog) are RING domain proteins that function in E3 ubiquitin ligase complexes and facilitate ubiquitination and degradation of a wide range of cellular proteins, including beta-catenin. Despite these diverse targets, the means by which SINA/Siah recognize substrates or binding proteins has remained unknown. Here we identify a peptide motif (RPVAxVxPxxR) that mediates the interaction of Siah protein with a range of protein partners. Sequence alignment and mutagenesis scanning revealed residues that are important to this interaction. This consensus sequence correctly predicted a high-affinity interaction with a peptide. from the cytoskeletal protein plectin-1 (residues 95-117). The unusually high-affinity binding obtained with a 23-residue peptide (K-Dapp = 29 nM with SINA) suggests that it may serve as a useful dominant negative reagent for SINA/Siah proteins.