Liang Hong-Erh, Hsu Lih-Yun, Cado Dragana, Cowell Lindsay G, Kelsoe Garnett, Schlissel Mark S
Department of Molecular & Cell Biology, Division of Immunology, University of California, Berkeley 94720, USA.
Immunity. 2002 Nov;17(5):639-51. doi: 10.1016/s1074-7613(02)00448-x.
Previous in vitro studies defined the minimal regions of RAG1 and RAG2 essential for V(D)J recombination. In order to characterize the role of the C-terminal "dispensable" portion of RAG2, we generated core-RAG2 knock-in mice. We found that the core-RAG2-containing recombinase complex is selectively defective in catalyzing V-to-DJ rearrangement at the IgH and TCRbeta loci, resulting in partial developmental blocks in B and T lymphopoiesis. Analysis of recombination intermediates showed defects at the cleavage phase of the reaction. We also observed a reduction in overall recombinase activity in core-RAG2-expressing thymocytes, leading us to suggest that the interaction of a defective recombinase with RSS sequences unique to VH and Vbeta gene segments may underlie the specific V-to-DJ rearrangement defect in core-RAG2 mice.
先前的体外研究确定了RAG1和RAG2中对于V(D)J重组必不可少的最小区域。为了表征RAG2 C末端“非必需”部分的作用，我们构建了核心RAG2基因敲入小鼠。我们发现，含有核心RAG2的重组酶复合物在催化IgH和TCRβ基因座处的V到DJ重排时存在选择性缺陷，导致B和T淋巴细胞生成出现部分发育阻滞。重组中间体分析显示反应的切割阶段存在缺陷。我们还观察到表达核心RAG2的胸腺细胞中总体重组酶活性降低，这使我们推测有缺陷的重组酶与VH和Vβ基因片段特有的重组信号序列（RSS）之间的相互作用可能是核心RAG2小鼠中特定V到DJ重排缺陷的基础。
