Döbbeling U, Hobi R, Berchtold M W, Kuenzle C C
Institut für Veterinärbiochemie, Universität Zürich, Switzerland.
J Mol Biol. 1996 Aug 23;261(3):309-14. doi: 10.1006/jmbi.1996.0462.
Here we compare the regulation of V(D)J recombination in the fibroblast cell line L4 and the pre-B cell line 38B9. The former has been rendered recombination-competent by stable transfection of a genomic fragment comprising the recombination activating genes, RAG-1 and RAG-2, along with some of their flanking sequences. We show that V(D)J recombination is similarly regulated in these two cell lines. Activating signals are transmitted through the protein kinase A (PKA) pathway, and inhibitory signals through the protein kinase C (PKC) and the calcium signalling pathways. In both cell lines, recombinational activity reflects steady state levels of mRNA transcribed from the RAG-1 and RAG-2 genes. This suggests that transcription of the RAG genes is a major determinant regulating V(D)J recombination. A comparison of RAG-1 and RAG-2 mRNA levels within each cell line reveals almost identical response patterns indicating that RAG-1 and RAG-2 transcription is coordinately regulated. Together, these results imply that the RAG-containing fragment in L4 fibroblasts carries most, if not all, control regions regulating the transcription of the RAG-1 and RAG-2 genes.
在此，我们比较了成纤维细胞系L4和前B细胞系38B9中V(D)J重组的调控情况。通过稳定转染包含重组激活基因RAG-1和RAG-2及其一些侧翼序列的基因组片段，前者已具备重组能力。我们发现这两种细胞系中V(D)J重组的调控方式相似。激活信号通过蛋白激酶A（PKA）途径传递，抑制信号则通过蛋白激酶C（PKC）和钙信号途径传递。在这两种细胞系中，重组活性反映了从RAG-1和RAG-2基因转录的mRNA的稳态水平。这表明RAG基因的转录是调控V(D)J重组的主要决定因素。对每个细胞系中RAG-1和RAG-2 mRNA水平的比较揭示了几乎相同的反应模式，表明RAG-1和RAG-2的转录是协同调控的。这些结果共同表明，L4成纤维细胞中含RAG的片段携带了大部分（如果不是全部）调控RAG-1和RAG-2基因转录的控制区域。
