ORGANIZATION AND SEQUENCES OF THE DIVERSITY, JOINING, AND CONSTANT REGION GENES OF THE HUMAN T-CELL RECEPTOR BETA-CHAIN
ORGANIZATION AND SEQUENCES OF THE DIVERSITY, JOINING, AND CONSTANT REGION GENES OF THE HUMAN T-CELL RECEPTOR BETA-CHAIN
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DOI：
10.1073/pnas.82.24.8624
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发表时间：
1985-12-01
影响因子：
11.1
通讯作者：
MAK, TW
中科院分区：
文献类型：
--
作者：
TOYONAGA, B;YOSHIKAI, Y;MAK, TW
人类β的组织和序列-链T细胞受体的多样性，连接，和恒定区片段进行了描述。的β人T细胞受体的链类似于小鼠的对应物，由两个不同的恒定区基因组成。相隔10英里。两个恒定区基因C β 1和C β 2不仅在序列上而且在基因组结构上都非常相似。这些C β的每一个的编码序列恒定区基因分为四个外显子。前两个外显子编码大部分细胞外恒定结构域。第三个外显子编码推测的跨膜部分的主要部分，最后一个外显子包含胞质编码序列以及3“非翻译序列。除了一段. apprxeq。95个高度保守的核苷酸延伸C区基因的第一外显子的3“，在C β 1和C β 2的内含子序列之间几乎没有发现同源性。连接区（J β）的小簇基因片段位于在这两个恒定区的上游。第一个簇J β 1含有六个功能性J基因片段，而第二个簇J β 2含有七个功能性J基因片段。此外，多样性区域（D β.）基因片段位于每个J β上游600个碱基对。发现含有由12或23个碱基分隔的高度保守的七聚体和九聚体序列的互补信号与所有这些D β相邻。和J β。基因片段这些信号序列被认为参与体细胞重组过程。这些结果表明，似乎是一个基因复制事件引起这两个不同的区域必须出现在很久以前，在这个基因位点的进化。
The organization and sequences of the human .beta.-chain T-cell receptor diversity, joining, and constant region segments are described. The .beta. chain of the human T-cell receptor, analogous to the mouse counterpart, consists of two distinct constant region genes .apprxeq. 10 kilobases apart. The two constant region genes, C.beta.1 and C.beta.2, are very similar not only in sequence but also in genomic organization. The coding sequences of each of these C.beta. constant region genes are divided into four exons. The first two exons encode most of the extracellular constant domain. The third exon encodes a major part of the presumed transmembrane portion, and the last exon contains the cytoplasmic coding sequence as well as 3'' untranslated sequences. Except for a stretch of .apprxeq. 95 highly conserved nucleotides extending 3'' of the first exon of the C region genes, little homology can be found between the intron sequences of C.beta.1 and C.beta.2. A small cluster of joining region (J.beta.) gene segments is located .apprxeq. kilobases upstream of each of these two constant regions. The first cluster, J.beta.1, contains six functional J gene segments while the second, J.beta.2, contains seven functional J gene segments. In addition, diversity region (D.beta.) gene segments are located .apprxeq. 600 base pairs upstream of each J.beta.. Recombinational signals containing highly conserved heptamer and nonamer sequences separated by 12 or 23 bases are found adjacent to all of these D.beta. and J.beta. gene segments. These signal sequences are though to be involved in the somatic recombination processes. These results indicate that what appears to be a gene duplication event giving rise to these two distinct regions must have arisen a long time ago in the evolution of this gene locus.