摘要
从缢蛏(Sinonovacula constricta)cDNA文库中筛选出一条铁蛋白同源序列,直接扩增质粒获得全长cDNA序列,共1 106 bp,包括128 bp的5'非翻译区和309 bp的3'非翻译区,以及669 bp的开放阅读框。阅读框共编码222个氨基酸,N端含有17个氨基酸的信号肽序列,推算的分子量约为25.47 ku,理论等电点为5.48。氨基酸序列分析结果表明,该基因含有保守的铁氧化酶活性中心的7个氨基酸残基,但是不具有糖基化位点(NQS)和5'非编码区铁蛋白的铁反应元件(iron response element,IRE),属于H型铁蛋白基因,该基因被命名为ScFERs。系统进化显示,基本上同一个物种的不同亚型铁蛋白首先聚在一起,然后和其他物种的铁蛋白聚在一起。缢蛏ScFERs首先与日本花棘石鳖(Liolophura japonica)LjFERs聚在一起,然后与缢蛏另一种ScFER以及文蛤(Meretrix meretrix)MmFERs聚在一起。荧光定量PCR检测结果显示ScFERs基因在肝胰腺中高度表达,肝胰腺与其它组织间的表达量存在着极显著差异。经鳗弧菌(Vibrioanguillarum)和副溶血弧菌(Vibrio parahaemolyticus)诱导后,ScFERs基因表达水平呈显著上调。为进一步研究缢蛏铁蛋白基因的结构和功能奠定了基础。
One EST sequence with high homology with ferritin gene of other species was found from the cDNA library of Sinonovacula constricta and then the complete expression sequence was obtained by PCR.The cDNA of this gene was 1 106 bp,which consists of a 128 bp 5′untranslated region（UTR）,a 669 bp open reading frame（ORF） and a 309 bp 3′ UTR.The translated protein is composed of 222 amino acids,containing a signal peptide of 17 amino acids,with 25.47 ku molecular weight,and its calculated isoelectric point was 5.48.Sequence analysis of the protein revealed that the protein contained a highly conserved motif for the ferroxidase center,which consisted of seven residues of a typical vertebrate heavy-chain ferritin,but lacking a N-glycosylattion site and an iron-responsive element（IRE） with a typical stem-loop structure in the 5′UTR position.This gene is H subunit ferritin gene and designated as ScFERs.Phylogenetic analysis suggested that the same species of different subsets of ferritin first gathered together,and then clustered with other marine animals.ScFERs of S.constricta clustered with LjFERs of L.japonica firstly,and then clustered with ScFER of S.constricta and MmFERs of M.meretrix.The quantitative reverse transcriptase（qRT-PCR） analyses showed that the expression level of ScFERs gene was highest in liver,significantly higher than other tissues.The expression of ScFERs gene in liver tissue was up-regulated following the challenge with Vibrio anguillarum and Vibrio parahaemolyticu,respectively.This study will be helpful for further understanding the structure and function of ferritin from S.constricta.
出处
《上海海洋大学学报》
CAS
CSCD
北大核心
2012年第5期641-649,共9页
Journal of Shanghai Ocean University
基金
国家高技术研究发展计划项目(2012AA10A400-3)
国家自然科学基金(31101897)
关键词
缢蛏
铁蛋白基因
序列分析
基因表达
Sinonovacula constricta； ferritin gene； sequence analysis； gene expression
