Kang C J, Oh U, Koshland M E
Sensory Research Group, Creative Research Initiatives, College of Pharmacy, Seoul National University, Korea.
Mol Cells. 2000 Feb 29;10(1):32-7. doi: 10.1007/s10059-000-0032-6.
Dynamic chromatin remodeling during B cell differentiation was identified in the vicinity of J chain gene. In pre-B cells, the enhancer-containing DNase I hypersensitive sites (HSSs) 3-4 were open. However, these HSSs 3-4 turned out to be unassociated with J chain gene expression, as the J chain promoter-containing HSS1 remained in a closed state. The open enhancer HSSs 3-4 in the pre-B cells might be related to the expression of a pre-B cell-specific gene upstream of the HSSs 3-4, which was identified in our Northern blot analyses. The HSSs 3-4 are then closed in the next immature and mature B cell stages until the IL-2 opens the HSSs 3-4 again as well as HSS1 to express J chain gene in the primary immune responses. The dynamic regulation of chromatin structure during B cell differentiation for the expression of two stage-specific genes will provide a good model system for the study of B cell differentiation and gene expression.
在J链基因附近发现了B细胞分化过程中的动态染色质重塑。在前B细胞中，含有增强子的DNase I超敏位点（HSSs）3 - 4是开放的。然而，这些HSSs 3 - 4与J链基因表达无关，因为含有J链启动子的HSS1仍处于关闭状态。前B细胞中开放的增强子HSSs 3 - 4可能与HSSs 3 - 4上游的一个前B细胞特异性基因的表达有关，这是我们通过Northern印迹分析确定的。然后，在接下来的未成熟和成熟B细胞阶段，HSSs 3 - 4关闭，直到白细胞介素-2再次打开HSSs 3 - 4以及HSS1，以便在初次免疫反应中表达J链基因。B细胞分化过程中染色质结构的动态调节以表达两个阶段特异性基因，将为研究B细胞分化和基因表达提供一个良好的模型系统。
