Modulation of the biological activity of a tobacco LTP1 by lipid complexation
Modulation of the biological activity of a tobacco LTP1 by lipid complexation
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DOI：
10.1091/mbc.e04-07-0575
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发表时间：
2004-11-01
影响因子：
3.3
通讯作者：
Blein, JP
中科院分区：
文献类型：
--
作者：
Buhot, N;Gomès, E;Blein, JP
植物脂质转移蛋白（LTP）是分泌到细胞外空间的富含半胱氨酸的小蛋白质。它们属于发病机制相关蛋白（PR-14）家族，被认为参与包括植物抗病性在内的多种生理过程，但其确切的生物学功能仍不清楚。在这里，我们证明重组烟草 LTP1 能够负载脂肪酸和茉莉酸。这种 LTP1 与特定的质膜位点（之前被称为激发素受体）结合，并被证明参与植物防御的激活。将该 LTP1 的生物学特性与 LTP1-亚麻酸和 LTP1-茉莉酸复合物的生物学特性进行了比较。 LTP1-亚麻酸复合物与纯化烟草质膜的结合曲线与用 LTP1 获得的曲线相当。相比之下，LTP1-茉莉酸复合物与质膜受体的相互作用显着增强。用 LTP1-茉莉酸处理烟草植物可增强对寄生疫霉的抗性。单独使用 LTP1 或茉莉酸治疗时，这些效果不存在。这项工作首次提供了 LTP1 生物活性的证据，并指出了蛋白质特异性亲脂配体相互作用在蛋白质活性调节中的关键作用。
Plant lipid transfer proteins (LTPs) are small, cysteine-rich proteins secreted into the extracellular space. They belong to the pathogenesis-related proteins (PR-14) family and are believed to be involved in several physiological processes including plant disease resistance, although their precise biological function is still unknown. Here, we show that a recombinant tobacco LTP1 is able to load fatty acids and jasmonic acid. This LTP1 binds to specific plasma membrane sites, previously characterized as elicitin receptors, and is shown to be involved in the activation of plant defense. The biological properties of this LTP1 were compared with those of LTP1-linolenic and LTP1-jasmonic acid complexes. The binding curve of the LTP1-linolenic acid complex to purified tobacco plasma membranes is comparable to the curve obtained with LTP1. In contrast, the LTP1-jasmonic acid complex shows a strongly increased interaction with the plasma membrane receptors. Treatment of tobacco plants with LTP1-jasmonic acid resulted in an enhancement of resistance toward Phytophthora parasitica. These effects were absent upon treatment with LTP1 or jasmonic acid alone. This work presents the first evidence for a biological activity of a LTP1 and points out the crucial role of protein-specific lipophilic ligand interaction in the modulation of the protein activity.