14-3-3 binding sites in the snail protein are essential for snail-mediated transcriptional repression and epithelial-mesenchymal differentiation.
14-3-3 binding sites in the snail protein are essential for snail-mediated transcriptional repression and epithelial-mesenchymal differentiation.
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DOI：
10.1158/0008-5472.can-10-0070
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发表时间：
2010-06-01
期刊：
影响因子：
11.2
通讯作者：
Rauscher FJ 3rd
中科院分区：
文献类型：
--
作者：
Hou Z;Peng H;White DE;Wang P;Lieberman PM;Halazonetis T;Rauscher FJ 3rd
Snail转录因子是正常胚胎发育和肿瘤转移过程中上皮-间质转化事件（EMT）的抑制因子和主要调节因子。Snail直接调节影响细胞粘附、运动性和极性的基因。侵袭性肿瘤细胞表达高水平的Snail，它是侵袭性疾病和预后不良的标志物。Snail的转录抑制和EMT诱导需要与其专性辅阻遏物LIM蛋白Ajuba结合。目前还不清楚这种复合物是如何在Snail靶基因上组装和维持的。在这里，我们定义了蜗牛和筋骨草中选择性结合14 - 3 -3蛋白异构体的功能性14 - 3 -3结合基序。在Snail中，阻遏结构域中的NH 2-末端基序与COOH-末端高亲和力基序合作结合14-3-3蛋白。两个基序的协调突变废除14-3-3结合，并抑制蜗牛介导的基因阻遏和EMT分化。Snail、14-3-3蛋白和Ajuba形成三元复合物，其容易通过ChIP在内源性E-钙粘蛋白启动子处检测到。总的来说，这些数据表明，14-3-3蛋白是Snail转录抑制机制的新组分，并介导其重要的生物学功能。
The Snail transcription factor is a repressor and a master regulator of epithelial-mesenchymal transition events (EMT) in normal embryonic development and during tumor metastases. Snail directly regulates genes affecting cell adhesion, motility and polarity. Invasive tumor cells express high levels of Snail and it is a marker for aggressive disease and poor prognosis. Transcriptional repression and EMT induction by Snail requires binding to its obligate corepressor, the LIM protein Ajuba. It is unclear how this complex is assembled and maintained on Snail target genes. Here we define functional 14-3-3 binding motifs in Snail and Ajuba which selectively bind 14-3-3 protein isoforms. In Snail, a NH2-terminal motif in the repression domain cooperates with a COOH-terminal, high affinity motif for binding to 14-3-3 proteins. Coordinate mutation of both motifs abolishes 14-3-3 binding and inhibits Snail-mediated gene repression and EMT differentiation. Snail, 14-3-3 proteins, and Ajuba form a ternary complex which is readily detected via ChIP at the endogenous E-cadherin promoter. Collectively, these data show that 14-3-3 proteins are new components of the Snail transcriptional repression machinery and mediate its important biological functions.