普通小麦TaTPR1基因的克隆及表达分析

Cloning and Expression Analysis of a Novel Tetratricopeptide Repeat Gene (TaTPR1) from Triticum aestivum L.

具有TPR基序的蛋白质被认为能够介导蛋白质间的相互作用,并且参与多种生物学过程,如细胞周期调控、转录调控、过氧化物酶等蛋白质的运输、信号传导和蛋白质折叠等。为了在小麦分子育种研究中获得更多有价值的候选基因,本研究采用电子克隆和RT-PCR方法从小麦中克隆得到1个TPR类基因,命名为TaTPR1。该基因ORF长度972bp,推测编码包含323个氨基酸残基的蛋白,相对分子质量34.9kD,理论等电点为5.89。氨基酸序列分析表明,该蛋白在142-207区和207-274区分别含有TPR类基因家族特有的保守结构域（TPR_16和TPR_11）。进化和聚类分析表明,小麦TaTPR1基因与粗山羊草AtTPR15基因、乌拉尔图小麦TuTPR15基因的亲缘关系较近,蛋白相似度分别为91.28%和91.55%。Real-time PCR表达特性分析显示,该基因为组成型表达,在根、茎、叶中均表达;幼苗期茎中表达量较高,随幼苗的生长,茎中表达量上调显著;该基因表达受高盐的强烈诱导,也受水分、低温和外源ABA胁迫诱导。

Proteins containing TPR have long been credited with mediateing protein protein interactions and are involved in a variety of biological processes, such as cell cycle regulation, transcriptional control, mitochondrial and peroxisomal protein transport, neurogenesis and protein folding. In this study, a new tetratricopeptide repeat gene （ TaTPR1） was assembled by searching wheat EST and genome databases. The TaTPR1 gene was cloned from common wheat seedling by RT PCR. TaTPR1 contains a 972 bp complete open reading frame （ORF） which encodes a peptide of 323 amino acids. The predicted molecular weight and isoelctric point of TaTPR1 are 34.9 kD and 5.89, respectively. The amino acids analysis indicated that the predicted protein sequence contained two typical TPR gene family domains （TPR_16 and TPR_11） in the 142 207 and 207 274 regions, respectively. Multiple sequences alignment revealed that TaTPR1 shared 91.28%, 91.55% and 87.46% sequence similarities with Aegilops tauschii （ AtTPR15）, Triticum urartu （ TuTPR15） and Hordeum vulgare （ HvTPR1）, respectively. The expression pattern analysis carried out by quantitative real time PCR indicated that TaTPR1 was constitutively expressed in various tissues of wheat seeding, and was strongly up regulated under high salinity, meanwhile, it was up regulated by drought, low temperature and exogenous application of abscisic acid （ABA） .