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GCN2是目前所有测序植物中唯一的eIF2α激酶,它可以通过磷酸化真核翻译起始因子eIF2α来调节蛋白的合成,从而对氨基酸的缺乏和各种胁迫做出响应。本研究采用RACE PCR技术从烟草K326中获得了GCN2的末端序列,通过RT-PCR方法获得了部分cDNA序列,经过拼接得到了GCN2的全长cDNA序列,将其命名为NtGCN2(Gen Bank登录号KJ706220)。分析发现,NtGCN2基因的cDNA全长为4 196 bp,ORF全长为3 759 bp,编码1 252个氨基酸残基,分子量为141.4 kDa,等电点为5.58。BLASTP分析结果表明,NtGCN2与土豆和番茄的同源性分别达到90%和88%。对其蛋白质结构域进行预测发现,NtGCN2包含了典型的GCN2激酶功能域。荧光定量PCR分析表明,该基因在根、茎、叶和花中均有表达,在叶片中表达最强,根中的表达最弱。
GCN2, the only eIF2α kinase present in all sequenced plants, regulates protein synthesis by phosphorylating the eIF2α eukaryotic translation initiation factor, thus responding to the lack of amino acids and various stresses. In this study, we obtained the end sequence of GCN2 from tobacco K326 by RACE PCR. Partial cDNA sequence was obtained by RT-PCR. The full-length cDNA sequence of GCN2 was obtained by splicing and named as NtGCN2 (Gen Bank Accession No. KJ706220 ). The full-length cDNA of NtGCN2 gene was 4 196 bp in length and 3 759 bp in ORF encoding a polypeptide of 1 252 amino acid residues with a molecular weight of 141.4 kDa and an isoelectric point of 5.58. BLASTP analysis showed that the homology between NtGCN2 and potato and tomato were 90% and 88% respectively. Prediction of its protein domain found that NtGCN2 contains a typical GCN2 kinase domain. Fluorescent quantitative PCR analysis showed that the gene was expressed in roots, stems, leaves and flowers, the strongest expression in the leaves, and the weakest in the roots.