Genome-wide search identifies Ccnd2 as a direct transcriptional target of Elf5 in mouse mammary gland.
Genome-wide search identifies Ccnd2 as a direct transcriptional target of Elf5 in mouse mammary gland.
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DOI：
10.1186/1471-2199-11-68
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发表时间：
2010-09-10
影响因子：
--
通讯作者：
Sinha S
中科院分区：
文献类型：
--
作者：
Escamilla-Hernandez R;Chakrabarti R;Romano RA;Smalley K;Zhu Q;Lai W;Halfon MS;Buck MJ;Sinha S
Ets转录因子ELF5(又称ESE-2)在乳腺中高表达，在乳腺的发育和分化中起重要作用。事实上，在小鼠身上的研究表明，ELF5在指导怀孕期间肺泡形成方面发挥了重要作用。虽然ELF5缺失乳腺发育受阻的分子机制开始被揭开，但ELF5靶基因的识别信息有限阻碍了这项研究。为了解决这一缺点，在本研究中，我们进行了芯片克隆实验，以确定ELF5在怀孕小鼠乳腺中占据的特定基因组片段。体内ELF5结合的顺式调控区的测序和基因组定位已经确定了几个潜在的靶基因，涵盖了广泛的功能类别。这些靶基因的一个子集在ELF5缺失的乳腺中表现出较高的表达水平，表明该转录因子具有抑制功能。在这里，我们重点关注ELF5的一个假定靶点，即出现在我们屏幕上的CCND2基因。我们发现了CCND2基因上游一个新的ELF5结合片段，并证明ELF5可以通过直接结合近端的启动子区域来转录抑制CCND2。最后，使用ELF5缺失的乳腺上皮细胞和乳腺，我们发现ELF5在体内的缺失导致CCND2的上调和腔细胞表达模式的改变。识别ELF5靶标是阐明由这一重要调控因子塑造的转录图景的重要第一步。我们的研究为研究ELF5在乳腺发育和分化中的生物学作用提供了新的工具箱。
The ETS transcription factor Elf5 (also known as ESE-2) is highly expressed in the mammary gland and plays an important role in its development and differentiation. Indeed studies in mice have illustrated an essential role for Elf5 in directing alveologenesis during pregnancy. Although the molecular mechanisms that underlie the developmental block in Elf5 null mammary glands are beginning to be unraveled, this investigation has been hampered by limited information about the identity of Elf5-target genes. To address this shortcoming, in this study we have performed ChIP-cloning experiments to identify the specific genomic segments that are occupied by Elf5 in pregnant mouse mammary glands. Sequencing and genomic localization of cis-regulatory regions bound by Elf5 in vivo has identified several potential target genes covering broad functional categories. A subset of these target genes demonstrates higher expression levels in Elf5-null mammary glands suggesting a repressive functional role for this transcription factor. Here we focus on one putative target of Elf5, the Ccnd2 gene that appeared in our screen. We identify a novel Elf5-binding segment upstream of the Ccnd2 gene and demonstrate that Elf5 can transcriptionally repress Ccnd2 by directly binding to the proximal promoter region. Finally, using Elf5-null mammary epithelial cells and mammary glands, we show that loss of Elf5 in vivo leads to up regulation of Ccnd2 and an altered expression pattern in luminal cells. Identification of Elf5-targets is an essential first step in elucidating the transcriptional landscape that is shaped by this important regulator. Our studies offer new toolbox in examining the biological role of Elf5 in mammary gland development and differentiation.
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影响因子：
16
作者：
Fujiwara T;O'Geen H;Keles S;Blahnik K;Linnemann AK;Kang YA;Choi K;Farnham PJ;Bresnick EH
通讯作者：
Bresnick EH
影响因子：
6.5
作者：
Romano, Rose-Anne;Birkaya, Barbara;Sinha, Satrajit
通讯作者：
Sinha, Satrajit
影响因子：
10.5
作者：
Bouchard, C;Dittrich, O;Lüscher, B
通讯作者：
Lüscher, B
影响因子：
5.3
作者：
Sripathy, Smitha P.;Stevens, Jessica;Schultz, David C.
通讯作者：
Schultz, David C.
影响因子：
5.2
作者：
Cho, Robert W.;Wang, Xinhao;Clarke, Michael F.
通讯作者：
Clarke, Michael F.