5-Lipoxygenase contains a functional Src homology 3-binding motif that interacts with the Src homology 3 domain of Grb2 and cytoskeletal proteins.
5-Lipoxygenase contains a functional Src homology 3-binding motif that interacts with the Src homology 3 domain of Grb2 and cytoskeletal proteins.
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DOI：
10.1016/s0021-9258(19)51063-8
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发表时间：
1994-09
期刊：
影响因子：
--
通讯作者：
R. Lepley;F. Fitzpatrick
中科院分区：
文献类型：
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作者：
R. Lepley;F. Fitzpatrick
人5-脂氧合酶的566-577位氨基酸残基是生长因子受体结合蛋白2(Grb2)的Src同源3(SH3)结构域的结合部位，Grb2是酪氨酸激酶介导的细胞信号转导的“接头”蛋白。纯化的与Grb2的谷胱甘肽S转移酶结合的5-脂氧合酶与含有其SH3结构域的截短型Grb2的融合产物。一种与富含脯氨酸的SH3结合基序相对应的肽在体外抑制5-脂氧合酶Grb2复合体的形成。在钙离子载体A23187激活的完整或通透性中性粒细胞中，该肽还抑制5-脂氧合酶从胞浆到膜的重新分布。5-脂氧合酶不与GTP酶激活蛋白、磷脂酶C-γ等其他信号蛋白的SH3结构域结合，但与细胞骨架蛋白包括α-肌动蛋白和肌动蛋白结合。5-脂氧合酶在296-299位含有一个共同的鸟嘌呤核苷酸结合部位，鸟嘌呤核苷酸在体外抑制5-脂氧合酶的活性。我们的结果表明，5-脂氧合酶在酪氨酸激酶信号转导中可能具有以前未知的作用，不同于其对脂质介体形成的催化作用。我们的结果也阐明了5-脂氧合酶在髓系细胞中区隔和移位的分子基础，这意味着它与其他蛋白质结合，而不是它的激活蛋白。
A short, proline-rich region spanning residues 566-577 in human 5-lipoxygenase is a binding site for the Src homology 3 (SH3) domain of growth factor receptor-bound protein 2 (Grb2), an “adaptor” protein for tyrosine kinase-mediated cell signaling. Purified 5-lipoxygenase bound to glutathione S-transferase fusion products of Grb2 and a truncated version of Grb2 containing its SH3 domain. A peptide corresponding to the proline-rich, SH3-binding motif inhibited formation of the 5-lipoxygenase.Grb2 complex in vitro. The peptide also inhibited the redistribution of 5-lipoxygenase from the cytosol to the membrane in intact or permeabilized neutrophils activated by calcium ionophore A23187. 5-Lipoxygenase did not bind to the SH3 domains of other signaling proteins, such as GTPase-activating protein and phospholipase C gamma; however, it bound to certain cytoskeletal proteins including alpha-actinin and actin. 5-Lipoxygenase contains a consensus guanine nucleotide-binding site at residues 296-299, and guanine nucleotides inhibit 5-lipoxygenase activity in vitro. Our results suggest that 5-lipoxygenase may have a previously unrecognized role in tyrosine kinase signaling, distinct from its catalysis of lipid mediator formation. Our results also clarify the molecular basis for compartmentalization and translocation of 5-lipoxygenase in myeloid cells, implying that it binds to proteins other than its activating protein.