In vivo regulation of murine granzyme B gene transcription in activated primary T cells
In vivo regulation of murine granzyme B gene transcription in activated primary T cells
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DOI：
10.1074/jbc.271.28.16485
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发表时间：
1996-07-12
影响因子：
4.8
通讯作者：
Bleackley, RC
中科院分区：
文献类型：
--
作者：
Babichuk, CK;Duggan, BL;Bleackley, RC
小鼠颗粒酶B启动子片段在转录起始位点上游延伸243个碱基对，在T细胞和小鼠L细胞成纤维细胞的瞬时转染试验中，该启动子片段包含转录因子AP-1、核心结合因子（CBF）、Ikaros和环AMP响应元件结合蛋白（CREB）的典型结合位点。含有颗粒酶B AP-1或CBF元素的寡核苷酸与活化的CD8（+）脾细胞、MTL细胞、EL4 T细胞和L细胞的核提取物中的蛋白质形成特异性复合物。活化的CD8(+) T细胞中存在与AP-1、CBF、Ikaros和CRE元素密切相关的强DNase1超敏位点，但在静止的T细胞或L细胞中不存在。在体外和体内，在活化的细胞毒性T细胞（CTL）中都观察到这些序列元件的足迹，而在静止的T细胞中则没有。内源性颗粒酶B基因是CTL特异性的，因为在EL4或L细胞中没有检测到mRNA。我们提出，颗粒酶B启动子上的浓缩染色质结构是导致转录因子不可接近和转录抑制的原因。
A murine granzyme B promoter fragment that extends 243 base pairs upstream of the transcription start site confers high levels of luciferase reporter gene activity in transient transfection assays into T cells and mouse L cell fibroblasts, This promoter fragment contains canonical binding sites for the transcription factors AP-1, core binding factor (CBF), Ikaros, and the cyclic AMP responsive element binding protein (CREB). Oligonucleotides containing the granzyme B AP-1 or CBF elements form specific complexes with proteins present in nuclear extracts from activated CD8(+) splenocytes, MTL cells, EL4 T cells, and L cells, A strong DNase1 hypersensitive site that coincides with the closely associated AP-1, CBF, Ikaros, and CRE elements is present in activated CD8(+) T cells but not in resting T cells or L cells, Both in vitro and in vivo footprints are observed at these sequence elements in activated cytotoxic T cells (CTL) but not in resting T cells, The endogenous granzyme B gene is CTL-specific as no mRNA is detectable in EL4 or L cells, We propose that a condensed chromatin structure at the granzyme B promoter is responsible for transcription factor inaccessibility and repression of transcription in non T cells.