Host factors LR1 and Sp1 regulate the Fp promoter of Epstein-Barr virus.
Host factors LR1 and Sp1 regulate the Fp promoter of Epstein-Barr virus.
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宿主因子 LR1 和 Sp1 调节 Epstein-Barr 病毒的 Fp 启动子。
DOI：
10.1073/pnas.92.18.8293
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发表时间：
1995
影响因子：
11.1
通讯作者：
Maizels,N
中科院分区：
文献类型：
--
作者：
Bulfone-Paus,S;Dempsey,LA;Maizels,N
V(D)J重组所涉及的调节元件的特征对于理解B和T细胞免疫谱系的发展至关重要。以前我们已经证明了鸡免疫球蛋白λ轻链基因(CLLCG)在转基因小鼠中经历了淋巴特性重排。该基因全长仅10kb，包含所有在系统发育上保守的重组和转录调控靶点。在这项研究中，我们将增强子元件定位在恒定(C)区下游4kb的区域。467个碱基序列可分为三个亚片段。先前在V-J插入序列上检测到的沉默元件被显示定位在500bp的片段上。部分消音器活性保留在一个250个碱基的片段上，其中包括一个八聚体基序。突变分析表明，该八聚体对B细胞是必需的，但对T细胞特异性沉默功能不是必需的。该沉默因子抑制由异源元件如SV 40启动子或Igκ3‘增强子引导的转录。我们认为，未重排和重排的免疫球蛋白基因的转录受启动子、增强子和沉默因子不同模块之间的复杂相互作用的调节，这种相互作用在B细胞发育过程中被重组消除
Characterization of the regulatory elements involved in V(D)J recombination is crucial for understanding development of the B and T cell immune repertoire. Previously we have shown that the chicken Immunoglobulin λ light chain gene (CLLCG) undergoes lymphoid-specffic rearrangement in transgenic mice. The whole gene is only 10 kb in length and contains all phylogenetically conserved target sites for recomblna-tional and transcriptlonal regulation. In this study we have localized an enhancer element In a region 4 kb downstream of the constant (C) region. The 467 bp element can be subdivided into three subfragments. The previously detected silencer element on the V-J Intervening sequence is shown to be localized on a 500 bp fragment. Partial silencer activity Is retained on a 250 bp fragment, which Includes an octamer motif. By mutatlonal analysis this octamer is shown to be essential for B cell- but not for T cell-specific silencer function. The silencer represses transcription directed by heterologous elements like the SV 40 promoter or the Ig κ 3′ enhancer. We propose that transcription of the unrearranged and rearranged Ig genes is regulated by complex interactions between different modules from the promoter, enhancer and silencer, which Is eliminated by recombination during B cell development