Reconsidering the evolution of eukaryotic selenoproteins:: a novel nonmammalian family with scattered phylogenetic distribution
Reconsidering the evolution of eukaryotic selenoproteins:: a novel nonmammalian family with scattered phylogenetic distribution
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DOI：
10.1038/sj.embor.7400036
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发表时间：
2004-01-01
期刊：
影响因子：
7.7
通讯作者：
Guigó, R
中科院分区：
文献类型：
--
作者：
Castellano, S;Novoselov, SV;Guigó, R
虽然基因组序列和基因内容可用于越来越多的生物体，真核硒蛋白仍然很差的特点。UGA密码子的双重作用使新的硒蛋白基因的鉴定变得困难。在这里，我们描述了一个比较基因组学的方法，依赖于全基因组的预测与框内TGA密码子的基因，和随后的比较从不同的基因组的预测，其中保护区侧翼的TGA密码子表明硒代半胱氨酸编码功能。将该方法应用于人类和河豚的基因组中，在河豚中发现了一个新的硒蛋白家族，命名为SelU。其他鱼类、鸡、海胆、绿色藻类和硅藻中也含有硒代半胱氨酸。相比之下，哺乳动物，蠕虫和陆地植物含有半胱氨酸同系物。我们证明了硒掺入鸡SelU和特征的SelU在斑马鱼胚胎中的表达模式。我们的数据表明，在真核生物中的硒蛋白的分散的进化分布，并建议，相反的图片出现的数据到目前为止，其他类群特异性硒蛋白可能存在。
While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. Them dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteine-containing form also occurred in other fish, chicken, sea urchin, green algae and diatoms. In contrast, mammals, worms and land plants contained cysteine homologues. We demonstrated selenium incorporation into chicken SelU and characterized the SelU expression pattern in zebrafish embryos. Our data indicate a scattered evolutionary distribution of selenoproteins in eukaryotes, and suggest that, contrary to the picture emerging from data available so far, other taxa-specific selenoproteins probably exist.