NF-E2p18/mafK is required in DMSO-induced differentiation of Friend erythroleukemia cells by enhancing NF-E2 activity
NF-E2p18/mafK is required in DMSO-induced differentiation of Friend erythroleukemia cells by enhancing NF-E2 activity
复制标题
DMSO 通过增强 NF-E2 活性诱导 Friend 红白血病细胞分化，需要 NF-E2p18/mafK
作者：
C. Francastel;V. Poindessous;Y. Augery;J. Robert
当 Friend 鼠红白血病 (F-MEL) 细胞被二甲基亚砜 (DMSO) 诱导分化时，红系特异性基因被转录激活。红系转录因子 NF-E2 对于珠蛋白基因座控制区域的增强子活性至关重要。 NF-E2 作为由 45 kDa 亚基 (NF-E2p45) 和 18 kDa 亚基 (NF-E2p18) 组成的异质复合物发挥作用。较大的亚基 NF-E2p45 是组织限制性的，并且被认为在 F-MEL 细胞中的珠蛋白基因表达中发挥作用。较小亚基 NF-E2p18 是 Maf 家族成员 (MafK)，其表达具有细胞类型和发育阶段特异性。我们通过将正义和反义 p18 构建体稳定转染到分化敏感的 745A 和部分分化缺陷的 TFP10 细胞系中，研究了 NF-E2p18 在 Friend 红细胞分化中的可能作用。 NF-E2p18 的过度表达诱导两种细胞系中珠蛋白转录物的表达，并在暴露于 DMSO 时增加它们对红细胞分化的敏感性。相反，反义转录物抑制 p18 表达会抑制 DMSO 诱导的两种细胞系的分化。这些结果表明 NF-E2p18 对于 F-MEL 细胞中珠蛋白表达是必需的，并且它是参与 DMSO 诱导的红系分化的 Maf 家族的主要基因。此外，过表达NF-E2p18的F-MEL克隆显示出特异性NF-E2 DNA结合活性的增加，而在表达反义p18的克隆中该活性降低。最后，使用瞬时转染测定的研究表明，p18 激活 F-MEL 细胞中 NF-E2 位点依赖性转录。这些数据表明NF-E2p18可以通过增强NF-E2活性来参与DMSO诱导的F-MEL细胞的红系分化。
When Friend murine erythroleukemia (F-MEL) cells are induced to differentiate by dimethylsulfoxide (DMSO), erythroid-specific genes are transcriptionally activated. The erythroid transcription factor NF-E2 is essential for enhancer activity of the globin locus control regions. NF-E2 functions as a heterocomplex consisting of a 45-kDa subunit (NF-E2p45) and a 18-kDa subunit (NF-E2p18). The larger subunit NF-E2p45 is tissue-restricted and is believed to play a role in globin gene expression in F-MEL cells. The expression of the smaller subunit NF-E2p18, which is a Maf family member (MafK), is cell type- and developmental stage-specific. We have investigated the possible role of NF-E2p18 in Friend erythroid differentiation by stably transfecting either sense and antisense p18 constructs into differentiation-sensitive 745A and partially defective-differentiation TFP10 cell lines. Overexpression of NF-E2p18 induced expression of globin transcripts in both cell lines and increased their sensitivity to erythroid differentiation when exposed to DMSO. Conversely, inhibition of p18 expression by antisense transcripts resulted in the inhibition of DMSO-induced differentiation in both cell lines. These results indicate that NF-E2p18 is necessary for globin expression in F-MEL cells and that it is the predominant gene of the Maf family involved in DMSO-induced erythroid differentiation. Moreover F-MEL clones overexpressing NF-E2p18 showed an increase in specific NF-E2 DNA-binding activity whereas this activity was decreased in clones expressing antisense p18. Finally, studies using transient transfection assays showed that p18 activated NF-E2 site-dependent transcription in F-MEL cells. These data suggest that NF-E2p18 can participate in DMSO-induced erythroid differentiation of F-MEL cells by enhancing NF-E2 activity.