水稻TFⅢA型锌指蛋白基因ZFP207的克隆和表达分析

Cloning and expression analysis of ZFP207 encoding a TFⅢA-type zinc finger protein in rice

锌指蛋白是一类重要的转录因子,广泛参与植物的生长发育和胁迫应答过程。文章使用生物信息学方法从水稻中预测并克隆了一个TFⅢA型锌指蛋白基因ZFP207(GenBank登陆号:AK063147.1),该基因包含一个567bp的开放阅读框,编码一条188个氨基酸组成的多肽,其编码产物的预测分子量为20.72kDa,等电点为9.67。锌指蛋白ZFP207含有一个典型的TFⅢA型锌指结构,并且在C端含有一个可能具有转录抑制功能的EAR-motif,但不具有任何已知的核定位信号。系统发生分析结果表明,ZFP207与植物中已经发现的单锌指蛋白亲缘关系较近。通过RT-PCR方法分析了ZFP207基因在成株期水稻不同组织中的表达,发现ZFP207在茎和叶中表达量较高,而在穗和根中表达量较低。在酵母中的转录激活实验结果显示,ZFP207在酵母中不具有转录激活功能。

The zinc finer proteins consist of a large transcription factor family involved in plant development and responses to environmental stresses.In this paper,a TFⅢA-type zinc finger protein gene ZFP207（GenBank assession number AK063147.1）was cloned from rice variety Jiucaiqing by RT-PCR approach.This gene contains an open reading frame （ORF）of 567 bp,which encodes a peptide of 188 amino acid residues.The isoelectric point（pI）of the protein is 9.67,and its molecular weight is 20.72 kDa.Bioinformatic analysis showed that the ZFP207 protein comprises a typical TF ⅢA-type zinc finger domain and an EAR-motif at its C-terminus.However,nuclear localization signals（NLS）commonly existing in TFⅢA-type zinc finger proteins was not found in the ZFP207 amino acid sequence.In addition,based on the alignments of the whole amino acid sequences of some known TFⅢA-type zinc finger proteins in plants,a phylogenetic tree was constructed by the neighbour joining method.The phylogenetic tree showed that ZFP207 and other TFⅢA-type zinc finger proteins with single zinc finger domain were grouped into the same branch.The expression pattern of ZFP207 gene was also investigated in various rice tissues at adult stage by RT-PCR and the results showed that ZFP207 was expressed with high levels in culms and leaves,but lower in roots and spikes.Finally,the trans-activation assay in yeast cells revealed that ZFP207 lacked the trans-activation activity.