Son Yong Mi, Lee Jung Hwa, Kim Deok Ryong
Department of Biochemistry and MRCND and Institute of Health Sciences, Gyeongsang National University School of Medicine, 92 Chilam-dong, JinJu 660-751, Republic of Korea.
Biochem Biophys Res Commun. 2008 Jan 4;365(1):113-7. doi: 10.1016/j.bbrc.2007.10.132. Epub 2007 Oct 31.
V(D)J recombination, a site-specific gene rearrangement process, requires two RAG1 and RAG2 proteins specifically recognizing recombination signal sequences and forming DNA double-strand breaks. The broken DNA ends tightly bound to RAG proteins are joined by repair proteins. Here, we found that heat shock protein 70 was associated with RAG2 following two-step affinity chromatography purification. It was also co-immunoprecipitated with RAG2 in pro-B cells. Purified HSP70 protein disrupted RAG/DNA complexes assembled in vitro and also inhibited the V(D)J cleavage (both nick and hairpin formation) in a dose-dependent manner. This HSP70 action required ATP energy. These data suggest that HSP70 might play a crucial role in disassembling RAG/DNA complexes stably formed during V(D)J recombination.
V(D)J重组是一种位点特异性基因重排过程，需要两种RAG1和RAG2蛋白特异性识别重组信号序列并形成DNA双链断裂。与RAG蛋白紧密结合的断裂DNA末端由修复蛋白连接。在此，我们发现经过两步亲和层析纯化后，热休克蛋白70与RAG2相关联。在原B细胞中它也与RAG2进行了共免疫沉淀。纯化的HSP70蛋白破坏了体外组装的RAG/DNA复合物，并且还以剂量依赖性方式抑制V(D)J切割（切口和发夹形成）。这种HSP70作用需要ATP能量。这些数据表明，HSP70可能在拆解V(D)J重组过程中稳定形成的RAG/DNA复合物中起关键作用。
