Chen Z, Loiseau P, Bories J C, Bensussan A, Sigaux F
INSERM U 301, Hôpital Saint Louis, Paris, France.
Eur J Immunol. 1989 Apr;19(4):637-42. doi: 10.1002/eji.1830190410.
Human T cell rearranging gamma genes encode membrane proteins which are expressed by a minor subset of T cells. Extensive studies have shown that TcR gamma gene rearrangements result from V gamma-J gamma recombinations. Here we analyze an unusual rearrangement involving a non-translatable sequence flanked by heptamer and nonamer signals in a Ti alpha/beta-positive T cell clone (JF1). This sequence, designated here as I gamma RS, is distinct from V, D or J elements. It is located in the first intron of the first constant region (C gamma 1) and homologous sequences are conserved in C gamma 2 introns. In JF1 cells the I gamma RS is juxtaposed to the J gamma 2 segment downstream to a V gamma 10-J gamma 1 rearrangement. The use of a cryptic splicing site induced JF1 cells to produce an aberrant large-sized transcript containing the I gamma RS 3' to the first exon of C gamma 1. Such a rearrangement occurring downstream to an inframe V gamma-J gamma junction may induce premature arrest of translation and lack of the C-terminal part of C gamma involved in gamma-protein assembly.
人类T细胞重排γ基因编码的膜蛋白由一小部分T细胞表达。大量研究表明，TcRγ基因重排是由Vγ-Jγ重组导致的。在此，我们分析了在一个Tiα/β阳性T细胞克隆（JF1）中涉及一个由七聚体和九聚体信号侧翼的不可翻译序列的异常重排。这个序列在此被命名为IγRS，与V、D或J元件不同。它位于第一个恒定区（Cγ1）的第一个内含子中，并且同源序列在Cγ2内含子中保守。在JF1细胞中，IγRS与Vγ10-Jγ1重排下游的Jγ2片段并列。一个隐蔽剪接位点的使用促使JF1细胞产生一个异常的大尺寸转录本，该转录本在Cγ1的第一个外显子3'端包含IγRS。这种发生在框内Vγ-Jγ连接下游的重排可能会诱导翻译过早终止，并缺失参与γ蛋白组装的Cγ的C末端部分。
