Structural analysis of mouse tenascin-X: evolutionary aspects of reduplication of FNIII repeats in the tenascin gene family
Structural analysis of mouse tenascin-X: evolutionary aspects of reduplication of FNIII repeats in the tenascin gene family
复制标题
DOI：
10.1016/s0378-1119(98)00355-2
复制
发表时间：
1998-09-14
期刊：
影响因子：
3.5
通讯作者：
Matsumoto, K
中科院分区：
文献类型：
--
作者：
Ikuta, T;Sogawa, N;Matsumoto, K
Tenascin-X(TnX)是一种细胞外基质糖蛋白，参与多细胞生物体的主要结构功能和调节细胞活动。我们测定了小鼠Tnx基因全长67977个碱基的核苷酸序列，其中还包括CrEB-RP和Cyp21的最后一个外显子。我们将其与直系人的基因轨迹进行了比较。这三个功能无关的基因在这个位置上的位置和方向都是保守的。比较还发现，Tnx基因内含子1、4和6在物种间高度保守。测序结果表明，小鼠Tnx基因包含43个外显子，由42个内含子隔开。推测的氨基酸序列(4114个残基)表明，小鼠Tnx具有Tenascins的一级结构特征，它由一个信号肽和4个七肽重复组成，然后是18.5个表皮生长因子(EGF)重复，31个纤维连接蛋白III型(FNIII)重复，以及一个与纤维蛋白原同源的区域。通过8个连续的FNIII重复序列(M15-M22)的交替剪接以及近端的FNIII重复序列(M3)的选择性剪接产生的cDNA克隆也被鉴定出来。经过选择性剪接的FNIII基序被分配到最近重复的FNIII重复组，因为它们具有很高的氨基酸序列相似性。我们还分析了TnX中FNIII重复序列的进化。(C)1998 Elsevier Science B.V.保留所有权利。
Tenascin-X (TNX) is an extracellular matrix glycoprotein involved in both primary structural functions and modulating cellular activities in multicellular organisms. We determined the 67977 bp nucleotide sequence of the entire mouse tenascin-X (Tnx) gene, which also includes the last exon of Cr eb-rp and Cyp21. We compared it with the orthologous human locus. Conservation of both position and orientation of the three functionally unrelated genes at this position was found. Comparison also revealed that introns 1, 4 and 6 of Tnx are highly conserved between species. The sequence showed that mouse Tnx contains 43 exons separated by 42 introns. The deduced amino-acid sequence (4114 residues) revealed that mouse Tnx has a primary structure characteristic of tenascins, which consists of a signal peptide and four heptad repeats followed by 18.5 epidermal growth factor-like (EGF) repeats, 31 fibronectin type III-like (FNIII) repeats, and a region homologous to fibrinogen. cDNA clones generated by alternative splicing of eight consecutive FNIII repeats (M15-M22) as well as a proximal FNIII repeat (M3) were also identified. The FNIII motifs that were subject to alternative splicing were assigned to the group of recently reduplicated FNIII repeats because they have a high level of amino-acid sequence similarity. We also analyzed the evolution of FNIII repeats in TNX. (C) 1998 Elsevier Science B.V. All rights reserved.