Molecular evolution of glutamate receptors: A primitive signaling mechanism that existed before plants and animals diverged
Molecular evolution of glutamate receptors: A primitive signaling mechanism that existed before plants and animals diverged
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DOI：
10.1093/oxfordjournals.molbev.a026167
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发表时间：
1999-06-01
影响因子：
10.7
通讯作者：
Coruzzi, G
中科院分区：
文献类型：
--
作者：
Chiu, J;DeSalle, R;Coruzzi, G
我们对离子型谷氨酸受体（iGluR）基因家族进行了系谱分析，该家族包括动物iGluR和在拟南芥中发现的新分离的植物谷氨酸受体样基因（GLR）。距离措施坚定地将植物GLR基因内的iGluR分支，而不是其他离子通道分支，并表明iGluRs可能是一个原始的信号传导机制，早于动物和植物的分歧。此外，系统发育分析，使用简约和邻居加入表明，分歧的动物iGluRs和植物GLR基因早于分歧的iGluR亚型（NMDA与AMPA/KA）的动物。通过估计各种谷氨酸受体基因区域的一致性，我们发现，不同的功能结构域，包括两个配体结合结构域和跨膜区，共同进化，这表明它们组装在一起之前植物和动物的分歧。基于残基保守性和差异性以及残基相对于iGluR蛋白的功能结构域的位置，我们试图检查结构-功能关系。该分析将M3定义为最高度保守的跨膜结构域，并确定了潜在的功能重要的保守残基，其功能可以在未来的研究中进行检查。
We performed a genealogical analysis of the ionotropic glutamate receptor (iGluR) gene family, which includes the animal iGluRs and the newly isolated glutamate receptor-like genes (GLR) of plants discovered in Arabidopsis. Distance measures firmly placed the plant GLR genes within the iGluR clade as opposed to other ion channel clades and indicated that iGluRs may be a primitive signaling mechanism that predated the divergence of animals and plants. Moreover, phylogenetic analyses using both parsimony and neighbor joining indicated that the divergence of animal iGluRs and plant GLR genes predated the divergence of iGluR subtypes (NMDA vs. AMPA/KA) in animals. By estimating the congruence of the various glutamate receptor gene regions, we showed that the different functional domains, including the two ligand-binding domains and the transmembrane regions, have coevolved, suggesting that they assembled together before plants and animals diverged. Based on residue conservation and divergence as well as positions of residues with respect to functional domains of iGluR proteins, we attempted to examine structure-function relationships. This analysis defined M3 as the most highly conserved transmembrane domain and identified potential functionally important conserved residues whose function can be examined in future studies.