CAJ | 학술논문

应用生物软件分析鸡和其他11种脊椎动物硒蛋白 T ( selenoprotein T ,SelT )的硒代半胱氨酸插入序列( selenocysteine insertion sequence , SECIS)元件、SelT核苷酸和氨基酸序列的同源性,并分析鸡SelT 的结构及功能；采用实时荧光定量PCR( fluorescent quantitative real-time PCR , fqRT-PCR)方法检测SelT基因在35日龄鸡体内30种组织中的表达谱.结果显示：脊椎动物 SelT的SECIS元件均属于Ⅱ型结构；鸡 SelT核苷酸序列与其他11种脊椎动物的同源性在48.0％～85.1％之间,而氨基酸序列与非洲爪蟾、斑马鱼的同源性低于90.0％,与其他9种动物的同源性在90.6％～94.9％之间；鸡 SelT 属于跨膜蛋白,存在信号肽,属于 RDx 家族,酶活性分类为EC 2.5.1.18,具有氧化还原功能,且存在Ca2＋结合位点.SelT在鸡各组织中广泛表达,在睾丸中含量极其丰富,提示鸡SelT在雄性生殖系统中可能发挥功能.
응용생물연건분석계화기타11충척추동물서단백 T ( selenoprotein T ,SelT )적서대반광안산삽입서렬( selenocysteine insertion sequence , SECIS)원건、SelT핵감산화안기산서렬적동원성,병분석계SelT 적결구급공능；채용실시형광정량PCR( fluorescent quantitative real-time PCR , fqRT-PCR)방법검측SelT기인재35일령계체내30충조직중적표체보.결과현시：척추동물 SelT적SECIS원건균속우Ⅱ형결구；계 SelT핵감산서렬여기타11충척추동물적동원성재48.0％～85.1％지간,이안기산서렬여비주조섬、반마어적동원성저우90.0％,여기타9충동물적동원성재90.6％～94.9％지간；계 SelT 속우과막단백,존재신호태,속우 RDx 가족,매활성분류위EC 2.5.1.18,구유양화환원공능,차존재Ca2＋결합위점.SelT재계각조직중엄범표체,재고환중함량겁기봉부,제시계SelT재웅성생식계통중가능발휘공능.
Selenium ( Se) was an important , biologically necessary trace element , which played an important biological roles in avian growth , reproduction , immune function and disease resistance . The biological significance of Se was attributed to its occurrence in selenoproteins in the form of selenocysteine ( Sec) with a 21 amino acid genetic code . Se uses the stop codon UGA as the coding codon encoding Sec . Selenoproteins involved in many life processes such as antioxidant defense , cell signal transduction , metabolic pathway , development , immune function , and hormone regulates , and it was related to the occurrence and mechanism of many diseases . Selenoprotein T (SelT) was originally identified through silico studies ,cloned and expressed in a mammalian cell line ,confirmed as a selenoprotein . Previous studies have proved that SelT mainly occurred in Golgi apparatus and endoplasmic reticulum , with important biological function . SelT can act on the Ca2+ homeostasis , involved in neuroendocrine secretion . SelT has also been showed in alter cell adhesion . Up to now , 25 selenoprotein-encoding genes were identified in birds , however , only about half have been functionally characterized , most of which were involved in redox reactions . SelT was a Se-containing protein whose cellular function has not been characterized . Research on the structure and function of SelT was still in its infancy , but reports in mammals about SelT and the information about avian SelT were not clear . The purpose of this study is to explore the selenocysteine insertion sequence ( SECIS) element , structures and functions of chicken SelT and the expression profiles of SelT in chicken tissues . The chicken SelT sequence was used in the experiment . The SECIS elements of 12 vertebrates were analyzed by the SECISearch 2.19 . The homologies of the molecule nucleotide and amino acid sequences on vertebrates were analyzed by DNAStar . The structure and functions of chicken SelT were predicted with the bioinformatics . The distribution of SelT in 30 tissues of 35-day-old chicken was analyzed by fluorescent quantitative real-time PCR ( qRT-PCR) . The results showed that SECIS element of vertebrates belonged to the type Ⅱ SECIS element . Compared with chicken and other 11 vertebrates , the nucleotide sequence homologies of SelT were 48.0% 85.1% . The homologies of amino acid sequences of chicken SelT with Xenopus laevis or Danio rerio were less than 90.0% and with other nine kinds of animals were among 90.6% 94.9% . The chicken SelT was a transmembrane protein and had a signal peptide . It belonged to the RDx families and its enzyme classification was EC 2.5.1.18 . SelT had binding sites with Ca2+ . The results of fqRT-PCR showed that the SelT was widely expressed in chicken tissues , and the expression level in testis was the highest . In summary , the SECIS element of vertebrate SelT belongs to the type Ⅱ and SelT is highly conserved in vertebrates . Avian SelT contains a CxxU motif in a thioredoxin-like fold , with glutathione S-transferase activity . SelT has binding sites with Ca2+ , it was predicted that avian SelT could regulate the Ca2+ homeostasis . Avian SelT is widely expressed in chicken tissues , and the testis has the highest expression level , suggesting that the chicken SelT has a special function in the male reproductive organs . This study provides a basis for further experimental analysis of the structure-function of avian SelT .