GATA2 and Sp1 Positively Regulate the c-kit Promoter in Mast Cells
GATA2 and Sp1 Positively Regulate the c-kit Promoter in Mast Cells
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DOI：
10.4049/jimmunol.1001228
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发表时间：
2010-10-01
影响因子：
4.4
通讯作者：
Okumura, Ko
中科院分区：
文献类型：
--
作者：
Maeda, Keiko;Nishiyama, Chiharu;Okumura, Ko
c-kit基因在造血干细胞和谱系祖细胞中表达，但在大多数谱系的细胞发育过程中下调，肥大细胞除外。在肥大细胞中，c-kit的高表达在发育期间维持，并且c-Kit信号传导对于肥大细胞发育是必不可少的。为了分析肥大细胞中c-kit基因表达的调节机制，我们研究了肥大细胞类型特异性的c-kit启动子区的调节。我们观察到，GC盒中的c-kit启动子的转录活性是至关重要的，并结合到转录因子Sp1使用报告分析和电泳迁移率测定评估。染色质免疫沉淀分析和共表达分析表明，转录因子GATA 2，这是招募到c-kit启动子在肥大细胞特异性的方式，除了Sp1，反式激活c-kit启动子通过GC盒。电泳迁移率分析和再染色质免疫沉淀分析表明GATA 2通过与Sp1形成复合物与GC盒结合。Sp1小干扰RNA的引入不仅显著降低了Sp1的量，而且还显著降低了肥大细胞中与c-kit启动子结合的GATA 2的量，导致c-kit转录的抑制。GATA 2的敲低抑制了GATA 2向c-kit启动子的募集，随后抑制了c-Kit的细胞表面表达。这些发现表明GATA 2和Sp1在肥大细胞中c-kit基因的表达中起关键作用。免疫学杂志，2010，185：4252-4260。
The c-kit gene is expressed in hematopoietic stem cells and lineage progenitor cells but is downregulated during cell development in most lineages, except for mast cells. In mast cells, high expression of c-kit is maintained during development, and c-Kit signaling is essential for mast cell development. To analyze the mechanisms by which c-kit gene expression are regulated in mast cells, we examined mast cell type-specific regulation of the c-kit promoter region. We observed that a GC-box in the c-kit promoter was critical for transcriptional activity and was bound to the transcription factor Sp1 as assessed using reporter assay and electrophoretic mobility assay. Chromatin immunoprecipitation assay and coexpression analyses showed that the transcription factor GATA2, which was recruited to the c-kit promoter in a mast cell-specific manner, in addition to Sp1, transactivated the c-kit promoter via the GC-box. Electrophoretic mobility assay and rechromatin immunoprecipitation assay indicated that GATA2 binds to the GC-box by forming a complex with Sp1. Introduction of Sp1 small interfering RNA significantly reduced the amount not only of Sp1 but also of GATA2 binding to the c-kit promoter in mast cells, resulting in suppression of c-kit transcription. Knockdown of GATA2 suppressed the recruitment of GATA2 toward the c-kit promoter, subsequently suppressing cell surface expression of c-Kit. These findings indicate that GATA2 and Sp1 play crucial roles in expression of the c-kit gene in mast cells. The Journal of Immunology, 2010, 185: 4252-4260.