Ren Chunhua, Chen Ting, Jiang Xiao, Wang Yanhong, Hu Chaoqun
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, PR China.
Fish Shellfish Immunol. 2014 Dec;41(2):137-46. doi: 10.1016/j.fsi.2014.08.030. Epub 2014 Sep 2.
Translationally controlled tumor protein (TCTP) is a multifunctional protein that existed ubiquitously in different eukaryote species and distributed widely in various tissues and cell types. In this study, the gene structure and biological function of TCTP were first characterized in echinoderm. An echinoderm TCTP named StmTCTP was identified from sea cucumber (Stichopus monotuberculatus) by expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach. The StmTCTP cDNA is 1219 bp in length, containing a 5'-untranslated region (UTR) of 77 bp, a 3'-UTR of 623 bp and an open reading frame (ORF) of 519 bp that encoding a protein of 172 amino acids with a deduced molecular weight of 19.80 kDa and a predicted isolectric point of 4.66. Two deduced signal signatures termed TCTP1 and TCTP2, a microtubule binding domain, a Ca(2+) binding domain and the conserved residues forming Rab GTPase binding surface were found in the StmTCTP amino acid sequence. For the gene structure, StmTCTP contains four exons separated by three introns. The anti-oxidation and heat shock protein activities of recombinant TCTP protein were also demonstrated in this study. In addition, the expression of StmTCTP was found to be significantly upregulated by polyriboinosinic polyribocytidylic acid [poly (I:C)], lipopolysaccharides (LPS) or inactivated bacteria challenge in in vitro primary culture experiments of coelomocytes, suggested that the sea cucumber TCTP might play critical roles not only in the defense against oxidative and thermal stresses, but also in the innate immune defense against bacterial and viral infections.
翻译调控肿瘤蛋白（TCTP）是一种多功能蛋白，广泛存在于不同的真核生物物种中，在各种组织和细胞类型中均有分布。在本研究中，首次在棘皮动物中对TCTP的基因结构和生物学功能进行了表征。通过表达序列标签（EST）分析和cDNA末端快速扩增（RACE）方法，从海参（单环刺螠）中鉴定出一种棘皮动物TCTP，命名为StmTCTP。StmTCTP cDNA长度为1219 bp，包含一个77 bp的5'-非翻译区（UTR）、一个623 bp的3'-UTR和一个519 bp的开放阅读框（ORF），该开放阅读框编码一个由172个氨基酸组成的蛋白质，推导分子量为19.80 kDa，预测等电点为4.66。在StmTCTP氨基酸序列中发现了两个推导的信号特征，称为TCTP1和TCTP2，一个微管结合结构域、一个Ca(2+)结合结构域以及形成Rab GTPase结合表面的保守残基。就基因结构而言，StmTCTP包含四个外显子，由三个内含子隔开。本研究还证实了重组TCTP蛋白的抗氧化和热休克蛋白活性。此外，在体腔细胞的体外原代培养实验中发现，poly（I:C）、脂多糖（LPS）或灭活细菌刺激可显著上调StmTCTP的表达，这表明海参TCTP不仅可能在抵抗氧化和热应激中起关键作用，还可能在针对细菌和病毒感染的先天免疫防御中起关键作用。
