A surface-associated retinol- and fatty acid-binding protein (Gp-FAR-1) from the potato cyst nematode Globodera pallida:: lipid binding activities, structural analysis and expression pattern
A surface-associated retinol- and fatty acid-binding protein (Gp-FAR-1) from the potato cyst nematode Globodera pallida:: lipid binding activities, structural analysis and expression pattern
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DOI：
10.1042/0264-6021:3560387
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发表时间：
2001-06-01
影响因子：
4.1
通讯作者：
Kennedy, MW
中科院分区：
文献类型：
--
作者：
Prior, A;Jones, JT;Kennedy, MW
寄生线虫产生至少两类结构新颖的富含小螺旋的视黄醇和脂肪酸结合蛋白，它们在植物或动物宿主中没有对应物，因此代表了新杀线虫剂的潜在目标。在这里，我们描述了一种蛋白质（Gp-FAR-1）从植物寄生线虫Globodera苍白球，这是一个成员的线虫特异性脂肪酸和视黄醇结合（FAR）蛋白质家族，但本地化到这个物种的表面，将其放置在一个战略位置与主机的相互作用。发现重组Gp-FAR-1结合视黄醇、顺式-parinaric酸和荧光团标记的脂质11-（丹磺酰氨基）十一烷酸和丹磺酰-D，L-α-氨基-辛酸。丹磺酰化类似物的荧光发射特性表明整个配体进入结合腔。荧光竞争实验表明，Gp-FAR-1结合C-11至C-24范围内的脂肪酸，在C-15处具有最佳结合。固有荧光分析的突变体蛋白质中，色氨酸残基已被插入支持基于计算机的预测，该残基的位置在蛋白质的内部，也可能在结合位点。与植物防御系统直接相关的是观察到Gp-FAR-1结合两种脂质（亚麻酸和亚油酸），这两种脂质是植物防御化合物和茉莉酸信号传导途径的前体。此外，发现Gp-FAR-1在体外抑制脂氧合酶介导的这些底物的修饰。因此，不仅Gp-FAR-1作为一个广谱的视黄醇和脂肪酸结合蛋白的功能，结果是一致的想法，即Gp-FAR-1参与逃避主要宿主植物防御系统。
Parasitic nematodes produce at least two structurally novel classes of small helix-rich retinol- and fatty-acid-binding proteins that have no counterparts in their plant or animal hosts and thus represent potential targets for new nematicides. Here we describe a protein (Gp-FAR-1) from the plant-parasitic nematode Globodera pallida, which is a member of the nematode-specific fatty-acid- and retinol-binding (FAR) family of proteins but localizes to the surface of this species, placing it in a strategic position for interaction with the host. Recombinant Gp-FAR-1 was found to bind retinol, cis-parinaric acid and the fluorophore-tagged lipids 11-(dansylamino)undecanoic acid and dansyl-D,L-alpha -amino-octanoic acid. The fluorescence emission characteristics of the dansylated analogues indicated that the entire ligand enters the binding cavity. Fluorescence competition experiments showed that Gp-FAR-1 binds fatty acids in the range C-11 to C-24, with optimal binding at C-15. Intrinsic fluorescence analysis of a mutant protein into which a tryptophan residue had been inserted supported computer-based predictions of the position of this residue at the protein's interior and possibly also at the binding site. Of direct relevance to plant defence systems was the observation that Gp-FAR-1 binds two lipids (linolenic and linoleic acids) that are precursors of plant defence compounds and the jasmonic acid signalling pathway. Moreover, Gp-FAR-1 was found to inhibit the lipoxygenase-mediated modification of these substrates in vitro. Thus not only does Gp-FAR-1 function as a broad-spectrum retinol- and fatty-acid-binding protein, the results are consistent with the idea that Gp-FAR-1 is involved in the evasion of primary host plant defence systems.