烟草铜伴侣蛋白NtATX1基因的克隆、生物信息学及表达分析

Cloning,Bioinformatics and Expression Analysis of NtATX1 Gene from Tobacco Copper Chaperone

铜伴侣蛋白ATX(Antioxidant)在维持生命体内铜离子浓度平衡中发挥着重要作用,并且具有一定的镉螯合功能。本研究采用RT-PCR方法从普通烟草中克隆到1个铜离子伴侣蛋白基因,命名为NtATX1。序列分析表明,烟草NtATX1基因的CDS全长354 bp,编码117个氨基酸,包含1个保守的MxCxxC铜离子结合基序,属于HMA亚家族,亚细胞定位于细胞核和叶绿体中,不含跨膜结构域。进化分析显示其与番茄亲缘关系最近。定量PCR结果显示,NtATX1基因在烟草不同组织中均有表达,且在叶片中相对表达量最高,并可受到铜和镉的胁迫诱导,处理后4 d的相对表达量达到最高值,表明其可能在烟草铜离子平衡和镉积累中发挥重要作用。上述结果为后续NtATX1基因的功能研究及利用提供帮助。

Copper chaperone proteins play an important role in regulating copper homeostasis in organisms,and may contribute to chelating Cadmium.We cloned an ATX(Antioxidant)gene,named NtATX1,from Nicotiana tabacum using RT-PCR technology.Sequence analysis of NtATX1 gene showed the full length of the CDS is 354 bp,encoding 117 amino acids.The deduced protein contained a conserved MxCxxC Cu-binding motif,belonging to HMA sup-family.This protein,which is not found in transmembrane domains,localized in nucleus and chloroplastid.Evolutionary analysis revealed NtATX1 was highly closely related to SlATX1 in Solanum lycopersicum.Quantitative PCR results showed that NtATX1 gene was expressed in different tissues of tobacco,and the relative expression level was the highest in leaves,and could be induced by the stress of copper and cadmium.The relative expression level reached the peak at four days after treatment,suggesting that it might play an important role in the balance of copper ions and cadmium accumulation in tobacco.The results provide help for the subsequent functional research and utilization of NtATX1 gene.