FOG-1 represses GATA-1-dependent FCεRI β-chain transcription:: transcriptional mechanism of mast-cell-specific gene expression in mice
FOG-1 represses GATA-1-dependent FCεRI β-chain transcription:: transcriptional mechanism of mast-cell-specific gene expression in mice
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DOI：
10.1182/blood-2005-07-2878
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发表时间：
2006-07-01
期刊：
影响因子：
20.3
通讯作者：
Ogawa, Hideoki
中科院分区：
文献类型：
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作者：
Maeda, Keiko;Nishiyama, Chiharu;Ogawa, Hideoki
小鼠高亲和力IgE受体(Fc Epsilon RI)β链的细胞特异性转录受转录因子GATA-1的正调控。虽然GATA-1在红系细胞、巨核细胞和肥大细胞中表达，但小鼠Fc epsilon RIβ链的表达仅限于肥大细胞。在本研究中，我们研究了GATA相关辅因子FOG-1在Fc epsilon RIβ链启动子调控中的作用。逆转录-聚合酶链式反应(RT-PCR)和Western blotting分析各造血细胞系FOG-1、GATA-1和β链的表达水平。β链阴性的造血祖细胞系BA/F3中FOG-1的表达高于β链阳性的肥大细胞系PT18。相反，当比较两种细胞系时，GATA-1的表达相似。瞬时报告基因分析表明，β链启动子在PT18中起作用，而在BA/F3中不起作用；FOG-1的过表达明显抑制了PT18中β链启动子的转录活性。尽管在猴肾CV-1细胞(β链(-)、GATA-1(-)和FOG-1(-))中共表达FOG-1显著抑制了由GATA-1共表达上调的β链启动子的活性，但不能与FOG-1结合的突变体V205G对β链启动子的反式激活不受FOG-1共表达的影响。此外，在PT18中过表达FOG-1导致细胞表面Fc epsilon RI表达和β链转录减少。最后，使用siRNA方法抑制FOG-1的表达导致了BA/F3中β链启动子活性的增加。这些结果表明FOG-1的表达水平调节GATA-1依赖的Fc epsilon RIβ链启动子。
Cell-type-specific transcription of mouse high-affinity IgE receptor (Fc epsilon RI) beta-chain is positively regulated by the transcription factor GATA-1. Although GATA-1 is expressed in erythroid cells, megakaryocytes, and mast cells, the expression of mouse Fc epsilon RI beta-chain is restricted to mast cells. In the present study, we characterized the role of GATA-associated cofactor FOG-1 in the regulation of the FC epsilon RI beta-chain promoter. The expression levels of FOG-1, GATA-1, and beta-chain in each hematopoietic cell line were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. FOG-1 expression was higher in the beta-chain-negative hematopoietic progenitor cell line Ba/F3 than in the beta-chain-positive mast cell line PT18. By contrast, GATA-1 expression was similar when comparing the 2 cell lines. A transient reporter assay demonstrated that the beta-chain promoter functioned in PT18 but not in Ba/F3 and that the transcription activity of the beta-chain promoter in PT18 was markedly suppressed by overexpression of FOG-1. Although the activity of the beta-chain promoter, which was upregulated by coexpression of GATA-1, was significantly suppressed by coexpression of FOG-1 in the simian kidney CV-1 cells (beta-chain(-), GATA-1(-), and FOG-1(-)), the transactivation of the beta-chain promoter by the GATA-1 mutant V205G, which cannot bind FOG-1, was not affected by coexpression of FOG-1. Further, overexpression of FOG-1 in PT18 resulted in decreases in cell surface expression of Fc epsilon RI and beta-chain transcription. Finally, suppression of FOG-1 expression using an siRNA approach resulted in increased beta-chain promoter activity in Ba/F3. These results suggest that FOG-1 expression level regulates the GATA-1-dependent FC epsilon RI beta-chain promoter.