Gene structure and molecular analysis of the laccase-like multicopper oxidase (LMCO) gene family in Arabidopsis thaliana
Gene structure and molecular analysis of the laccase-like multicopper oxidase (LMCO) gene family in Arabidopsis thaliana
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DOI：
10.1007/s00425-004-1472-6
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发表时间：
2005-07-01
期刊：
影响因子：
4.3
通讯作者：
Dean, JFD
中科院分区：
文献类型：
--
作者：
McCaig, BC;Meagher, RB;Dean, JFD
已完成的基因组测序表明，与漆酶相关的多铜氧化酶在高等植物中以多基因家族的形式广泛分布。从GenBank和拟南芥基因组中挑选的漆酶样多铜氧化酶（LMCO）序列，以及从几个新克隆的基因，被用来构建一个基因同源性，清楚地划分植物LMCO为6个不同的类，至少其中3个早于被子植物和裸子植物的进化分歧。预测的氨基酸序列的比对突出了可变序列侧翼的高度保守的铜结合结构域，表征该酶家族的成员的区域。所有预测的蛋白质含有明显的信号序列。17个LMCO基因中的13个在A.使用RT-PCR在不同发育阶段的不同组织中评估拟南芥。表达模式的多样性被证明与一些基因被表达在一个组成型的方式，而其他人只在特定的组织中表达在特定的发展阶段。只有少数的LMCO基因表达的模式，可以被认为是一致的主要作用，这些酶在木质素沉积。这些结果在植物LMCO的其他潜在生理功能的背景下进行了讨论，如铁代谢和伤口愈合。
Completed genome sequences have made it clear that multicopper oxidases related to laccase are widely distributed as multigene families in higher plants. Laccase-like multicopper oxidase (LMCO) sequences culled from GenBank and the Arabidopsis thaliana genome, as well as those from several newly cloned genes, were used to construct a gene phylogeny that clearly divided plant LMCOs into six distinct classes, at least three of which predate the evolutionary divergence of angiosperms and gymnosperms. Alignments of the predicted amino acid sequences highlighted regions of variable sequence flanked by the highly conserved copper-binding domains that characterize members of this enzyme family. All of the predicted proteins contained apparent signal sequences. The expression of 13 of the 17 LMCO genes in A. thaliana was assessed in different tissues at various stages of development using RT-PCR. A diversity of expression patterns was demonstrated with some genes being expressed in a constitutive fashion, while others were only expressed in specific tissues at a particular stage of development. Only a few of the LMCO genes were expressed in a pattern that could be considered consistent with a major role for these enzymes in lignin deposition. These results are discussed in the context of other potential physiological functions for plant LMCOs, such as iron metabolism and wound healing.