The origin and evolution of vertebrate glycine transporters.
The origin and evolution of vertebrate glycine transporters.
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脊椎动物甘氨酸转运蛋白的起源和进化。
DOI：
10.1007/s00239-014-9615-2
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发表时间：
2014
影响因子：
3.9
通讯作者：
Miranda,Manuel
中科院分区：
文献类型：
--
作者：
Shpak,Max;Gentil,LucianaGirotto;Miranda,Manuel
在脊椎动物中枢神经系统中，甘氨酸神经传递受甘氨酸转运蛋白1和2 （GlyT1和GlyT2）的作用调节，甘氨酸转运蛋白是溶质载体家族6 （SLC6）的成员。一些无脊椎后口动物有两个旁系的甘氨酸载体基因，其中一个基因与GlyT1具有更高的序列同一性和比对得分，另一个与GlyT2具有更高的相似性。在系统发育树中，来自无脊椎动物后口动物的GlyT2样序列与脊椎动物GlyT2形成单系亚枝，而无脊椎动物GlyT1样蛋白构成GlyT2样蛋白和脊椎动物GlyT1序列的外群。这些结果与脊椎动物GlyT1和GlyT2分别来源于无脊椎动物后口动物GlyT1-和GlyT2样基因的假设一致。这意味着导致这些相似现象的基因复制发生在脊椎动物起源之前。作为功能特化的结果，GlyT2随后与其无脊椎同源基因显著分化（即通过获得独特的终端），主要在中枢神经系统下部表达；而GlyT1在中枢神经系统下部和前脑的几个区域都有活动。
In the vertebrate central nervous system, glycinergic neurotransmission is regulated by the action of the glycine transporters 1 and 2 (GlyT1 and GlyT2)—members of the solute carrier family 6 (SLC6). Several invertebrate deuterostomes have two paralogous glycine carrier genes, with one gene in the pair having greater sequence identity and higher alignment scores with respect to GlyT1 and the other paralog showing greater similarity to GlyT2. In phylogenetic trees, GlyT2-like sequences from invertebrate deuterostomes form a monophyletic subclade with vertebrate GlyT2, while invertebrate GlyT1-like proteins constitute an outgroup to both the GlyT2-like proteins and to vertebrate GlyT1 sequences. These results are consistent with the hypothesis that vertebrate GlyT1 and GlyT2 are, respectively, derived from GlyT1- and GlyT2-like genes in invertebrate deuterostomes. This implies that the gene duplication which gave rise to these paralogs occurred prior to the origin of vertebrates. GlyT2 subsequently diverged significantly from its invertebrate orthologs (i.e., through the acquisition of a uniqueN-terminus) as a consequence of functional specialization, being expressed principally in the lower CNS; while GlyT1 has activity in both the lower CNS and several regions of the forebrain.