Recombination signal sequences restrict chromosomal V(D)J recombination beyond the 12/23 rule
Recombination signal sequences restrict chromosomal V(D)J recombination beyond the 12/23 rule
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DOI：
10.1038/35014635
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发表时间：
2000-06-01
期刊：
影响因子：
64.8
通讯作者：
Sleckman, BP
中科院分区：
文献类型：
--
作者：
Bassing, CH;Alt, FW;Sleckman, BP
编码淋巴细胞抗原受体可变区的基因由可变(V)、多样性(D)和连接(J)基因片段组装而成(1)，V(D)J重组由重组酶激活基因(RAG)-1和-2蛋白启动，在V、D和J片段及其侧翼重组信号序列(RSS)之间引入DNA双链断裂，一般表达DNA修复蛋白，然后进行连接反应(2,3)，保守的RSS 的七聚体和九聚体序列被 12 或 23 个碱基对的非保守间隔区分开（形成 12-RSS 和 23-RSS）。 12/23 规则在 RAG-1/2 识别和切割水平上介导 (4,5)，指定 V(D)J 重组仅发生在侧翼为 12-RSS 的基因片段和侧翼为 23-RSS1 的基因片段之间，V beta 片段被附加到 DJ beta 重排，几乎没有或没有直接 V beta 与 J beta 连接，尽管 V beta 23-RSS 和 J 具有 12/23 兼容性β 12-RSS(6,7)。在这里，我们使用胚胎干细胞和具有仅包含一个 D beta (D beta 1) 基因片段和一个 J beta (J beta 1) 基因簇的修饰 T 细胞受体 (TCR)beta 基因座的小鼠来表明 5' D beta 1 12-RSS 而不是 J beta 1 12-RSS，其目标是多种 V beta 库的重排，这种目标是精确的且与位置无关。这种对 V(D)J 重组的额外限制对于可变区基因组装和库开发的调节具有重要意义。
The genes encoding the variable regions of lymphocyte antigen receptors are assembled from variable (V), diversity (D) and joining (J) gene segments(1), V(D)J recombination is initiated by the recombinase activating gene (RAG)-1 and -2 proteins, which introduce DNA double-strand breaks between the V, D and J segments and their flanking recombination signal sequences (RSSs), Generally expressed DNA repair proteins then carry out the joining reaction(2,3), The conserved heptamer and nonamer sequences of the RSSs are separated by non-conserved spacers of 12 or 23 base pairs (forming 12-RSSs and 23-RSSs). The 12/23 rule, which is mediated at the level of RAG-1/2 recognition and cutting(4,5), specifies that V(D)J recombination occurs only between a gene segment flanked by a 12-RSS and one flanked by a 23-RSS1, V beta segments are appended to DJ beta rearrangements, with little or no direct V beta to J beta joining, despite 12/23 compatibility of V beta 23-RSSs and J beta 12-RSSs(6,7). Here we use embryonic stem cells and mice with a modified T-cell receptor (TCR)beta locus containing only one D beta (D beta 1) gene segment and one J beta (J beta 1) gene cluster to show that the 5' D beta 1 12-RSS, but not the J beta 1 12-RSSs, targets rearrangement of a diverse V beta repertoire, This targeting is precise and position-independent. This additional restriction on V(D)J recombination has important implications for the regulation of variable region gene assembly and repertoire development.