In vitro characterization of the homogalacturonan-binding domain of the wall-associated kinase WAK1 using site-directed mutagenesis
In vitro characterization of the homogalacturonan-binding domain of the wall-associated kinase WAK1 using site-directed mutagenesis
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DOI：
10.1016/j.phytochem.2006.03.009
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发表时间：
2006-06-01
期刊：
影响因子：
3.8
通讯作者：
Messiaen, Johan
中科院分区：
文献类型：
--
作者：
Decreux, Annabelle;Thomas, Annick;Messiaen, Johan
WALL相关激酶1 -WAK 1是拟南芥（Arabidopsis thaliana（L.）嘿。在以前的论文[Decreux，A.，Messiaen，J.，2005.细胞壁相关激酶WAK 1在钙诱导的构象中与细胞壁果胶相互作用。Plant Cell Physiol.46，268-278]，我们表明在酵母中表达的对应于WAK 1胞外结构域的氨基酸67-254的重组肽与商业非甲基酯化的同型半乳糖醛酸、来自拟南芥的纯化同型半乳糖醛酸和钙诱导构象的寡聚半乳糖醛酸特异性相互作用。在这份报告中，我们使用了受体结合结构域序列为基础的预测方法，以确定四个推定的结合位点在细胞外结构域的WAK 1，其中阳离子氨基酸被选择取代定点突变。突变形式的WAK 1和homogalacturonans之间的相互作用研究使我们能够识别和确认至少五个特定的氨基酸参与与homogalacturonan二聚体和多聚体的相互作用。WAK 1的细胞外结构域内的这种同型半乳糖醛酸结合结构域的存在下进行了讨论的细胞壁结构和信号转导。(c)2006爱思唯尔有限公司保留所有权利。
Wall-associated kinase 1 - WAK1 is a transmembrane protein containing a cytoplasmic Ser/Thr kinase domain and an extracellular domain in contact with the pectin fraction of the plant cell wall in Arabidopsis thaliana (L.) HEYNH. In a previous paper [Decreux, A., Messiaen, J., 2005. Wall-associated kinase WAK1 interacts with cell wall pectins in a calcium-induced conformation. Plant Cell Physiol. 46, 268-278], we showed that a recombinant peptide expressed in yeast corresponding to amino acids 67-254 of the extracellular domain of WAK1 specifically interacts with commercial non-methylesterified homogalacturonic acid, purified homogalacturonans from Arabidopsis and oligogalacturonides in a calcium-induced conformation. In this report, we used a receptor binding domain sequence-based prediction method to identify four putative binding sites in the extracellular domain of WAK1, in which cationic amino acids were selected for substitution by site-directed mutagenesis. Interaction studies between mutated forms of WAK1 and homogalacturonans allowed us to identify and confirm at least five specific amino acids involved in the interaction with homogalacturonan dimers and multimers. The presence of this homogalacturonan-binding domain within the extracellular domain of WAK1 is discussed in terms of cell wall architecture and signal transduction. (c) 2006 Elsevier Ltd. All rights reserved.