拟南芥AtTERT基因特性分析及其对盐与过氧化氢胁迫的响应  

Characterization Analysis and Responses to NaCl and H_2O_2 Stress of AtTERT in Arabidopsis thaliana

作　　者：王杨[1] 孙玉萍 董琦 杨颖[1] 刘颖 于婷乔 吴晓飞 卢存福[1] WANG Yang;SUN Yu-Ping;DONG Qi;YANG Ying;LIU Ying;YU Ting-Qiao;WU Xiao-Fei;LU Cun-Fu(Beijing Advanced Innovation Center for Tree Breeding by Molecular Design/National Engineering Laboratory for Tree Breeding/College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China;School of Life Sciences, Peking University,Beijing 100871, China)

机构地区：[1]北京林业大学生物科学与技术学院/林木分子设计育种高精尖创新中心/林木育种国家工程中心,北京100083 [2]北京大学生命科学学院,北京100871

出　　处：《农业生物技术学报》2019年第4期581-592,共12页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(No.31270737);高等学校学科创新引智计划(No.B13007);长江学者和创新团队发展计划(No.IRT13047);北京市自然科学基金(No.6112016)

摘　　要：端粒酶逆转录酶(telomerase reverse transcriptase, TERT)是真核细胞中具有逆转录酶活性的核糖核蛋白复合物—端粒酶(telomerase)的主要组成成分。拟南芥(Arabidopsis thaliana)AtTERT是第1个被克隆的植物端粒酶逆转录酶基因。为了明确AtTERT的结构和功能特点,本研究利用生物信息学和软件对AtTERT的理化性质和蛋白质结构等进行了系统分析,探讨了不同物种间TERT的亲缘关系;同时对盐和氧化胁迫下端粒酶活性和AtTERT基因表达模式进行分析。结果表明:AtTERT属于不具有信号肽的亲水性蛋白,未发现明显的跨膜结构域。AtTERT磷酸化位点有125个,其中丝氨酸、苏氨酸和酪氨酸位点分别为87、28和10个。无规则卷曲和α-螺旋是AtTERT二级结构的主要结构元件。保守结构域为端粒酶RNA结合功能域(telomerase RNA binding motif, TRBD)和逆转录酶功能域(telomerase reverse transcriptase motifs, RT)。端粒酶活性变化与AtTERT表达对盐与过氧化氢胁迫反应一致,均呈现先升高后降低的趋势。该研究结果为研究植物TERT的结构功能积累了新的资料。Telomerase is a ribonucleoprotein complex with reverse transcriptase activity in eukaryotic cells,telomerase reverse transcriptase(TERT) is the major component of telomerase. AtTERT is the first plant telomerase reverse transcriptase TERT gene cloned from Arabidopsis thaliana. In order to clarify the structure and function of AtTERT, bioinformatics tools and software were used to analyze the physicochemical properties, protein structure and functional domain of AtTERT, and the genetic relationship of TERT genes among different species. Moreover, the telomerase activity and AtTERT gene expression patterns under salt and oxidative stress were analyzed. The results showed that the AtTERT belonged to a hydrophilic protein without a signal peptide, and had no obvious transmembrane domain. There were 125 phosphorylation sites, of which 87, 28 and 10 were serine, threonine and tyrosine sites, respectively. Irregular crimps and α-helices were the major structural elements of secondary structure of AtTERT. Conserved domains were the TRBD(telomerase RNA binding motif) domain and the RT(telomerase reverse transcriptase motifs) domain. Threedimensional structure modeling analysis revealed a 74% similarity of the main-chain conformation between AtTERT and the Tetrahymena thermophila telomerase reverse transcriptase c6 d6 vA. Phylogenetic analysis using the TERT protein sequences of Gramineae, Leguminosae, Liliaceae, Rosaceae, etc, revealed that TERT was highly conserved in the same plant group. For example, TERT was highly conserved in the branches of Prunus mume and P. persica(bootstrap>99), and they had a confidence index cluster of 100, and all of the above belonged to Rosaceae. The phylogentic tree constructed by TERT conforms the right phylogenetic relationships of the plant species. Leguminous plants such as Glycine max, Phaseolus vulgaris and Solanaceae plants such as Solanum lycopersicum, S. tuberosum, Nicotiana tabacum also reflected a similar situation.Furthermore, intron and exon sequence analysis was carried out

关 键 词：拟南芥 端粒酶逆转录酶(TERT) 生物信息学 非生物胁迫 端粒酶活性 

分 类 号：S188[农业科学—农业基础科学]