Evolutionarily conserved non-AUG translation initiation in NAT1/p97/DAP5 (EIF4G2)
Evolutionarily conserved non-AUG translation initiation in NAT1/p97/DAP5 (EIF4G2)
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DOI：
10.1016/j.ygeno.2004.11.012
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发表时间：
2005-03-01
期刊：
影响因子：
4.4
通讯作者：
Yamanaka, S
中科院分区：
文献类型：
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作者：
Takahashi, K;Maruyama, M;Yamanaka, S
非aug密码子的排他性翻译起始只有少数报道。我们最近证明，由EIF4G2编码的哺乳动物NAT1 mRNA使用GUG作为其唯一的翻译起始密码子。在本研究中，我们从鸡、爪蟾和斑马鱼中鉴定了NAT1同源物，发现在所有物种中，GUG密码子也作为起始密码子。在所有物种中，GUG密码子都满足了报道的非aug起始条件：一个最优的Kozak基序和一个下游发夹结构。定点突变表明-3和+4位点的核苷酸对gug介导的翻译起始至关重要。我们发现黑腹果蝇（Drosophila melanogaster）和罗氏盐蝉（Halocynthia roretzi）的NAT1同源基因也使用非aug起始密码子，证明了非规范翻译起始的进化保守性。(c) 2004 Elsevier Inc.版权所有。
Only a few cases of exclusive translation initiation at non-AUG codons have been reported. We recently demonstrated that mammalian NAT1 mRNA, encoded by EIF4G2, uses GUG as its only translation initiation codon. In this study, we identified NAT1 orthologs from chicken, Xenopus, and zebrafish and found that in all species, the GUG codon also serves as the initiation codon. In all species, the GUG codon fulfilled the reported requirements for non-AUG initiation: an optimal Kozak motif and a downstream hairpin structure. Site-directed mutagenesis showed that nucleotides at positions -3 and +4 are critical for the GUG-mediated translation initiation in vitro. We found that NAT1 orthologs in Drosophila melanogaster and Halocynthia roretzi also use non-AUG start codons, demonstrating evolutionary conservation of the noncanonical translation initiation. (c) 2004 Elsevier Inc. All rights reserved.