麻疯树Jc-Tctp1基因的同源性分析及时空表达模式鉴定

从麻疯树胚乳cDNA文库中获得了翻译调节肿瘤蛋白（translationally controlled tumor protein, TCTP）cDNA序列，命名为Jc-Tctp1（GenBank登录号为EF091818）.该序列全长1 410 bp，开放阅读框由507个碱基组成.Jc-Tctp1编码的推测蛋白产物含有168个氨基酸残基，该蛋白具有典型的TCTP蛋白特点：由3个α螺旋组成α螺旋核心、4个β片层结构构成β片层核心，及微管结合结构域（MTB）和钙结合结构域（CaB）.其推测氨基酸序列与巴西橡胶树（Hevea brasiliensis）、油棕（Elaeis guineensis）、大豆（Glycine max）、水稻（Oryza sativa,japonica cultivar-group）、黑杨（Populus trichocarpa）、番茄（Lycopersicon esculentum）、西加云杉（Picea sitchensis）、拟南芥（Arabidopsis thaliana）以及玉米（Zea may）的TCTP同源性依次为93 %、90 %、85 %、84 %、85 %、84 %、77 %、80 %和77 %.经构建含Jc-TCTP1在内的植物TCTP蛋白分子进化树分析，发现单子叶植物并未按照其生物学分类的地位出现聚合.用半定量RT-PCR研究Jc-Tctp1基因的表达模式，结果显示,其表达在转录水平上具有一定的组织和时间特异性，茎、Ⅰ期胚乳、胚中最为丰富，而在Ⅱ期胚乳和花中表达最弱.

Sequencing and Expression of Translationally Controlled Tumor Protein (TCTP) of Jatropha curcas L.

The full-length cDNA encoding a translationally controlled tumor protein (TCTP) has been isolated from cDNA library of Jatropha curcas L, denoted as Jc-Tctp1with GenBank accession number EF091818. The Jc-Tctp1 is 1 410 bp in length that contains a 507 bp open reading frame (ORF) encoding a putative protein of 168 amino acid residures. The predicted structure of Jc-TCTP1 appeared to be consist of an α-helical core and a β-sheet core, which are composed of 3 major α-helices and 4 major β-sheets , respectively. A homologous microtubule binding (MTB) domain as well as a calcium binding (CaB) domain. can also be identified from the predictions. The Jc-TCTP1 amino acid sequence is highly homologous to other TCTPs, such as from Hevea brasiliensis (93 %), Elaeis guineensis (90 %), Glycine max (85 %), Oryza sativa (84 %), Populus trichocarpa (85 %), Lycopersicon esculentum (84 %), Picea sitchensis (77 %), Arabidopsis thaliana (80 %) and Zea may (77%). The semi-quantitative RT-PCR results have shown that Jc-Tctp1 expression was the highest in the stem, endosperm atⅠstage and embryo of Jatropha curcas tissues, and the lowest in the endosperm at stage Ⅱ and flower, demonstrating a pattern of temporal and spatial specific expression. This might related to certain divergence in the phylogenic analysis of plant TCTP sequences where the selected monocots were not forming a separate cluster.