Phenotypic complementation establishes requirements for specific POU domain and generic transactivation function of Oct-3/4 in embryonic stem cells
Phenotypic complementation establishes requirements for specific POU domain and generic transactivation function of Oct-3/4 in embryonic stem cells
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DOI：
10.1128/mcb.22.5.1526-1536.2002
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发表时间：
2002-03-01
影响因子：
5.3
通讯作者：
Miyazaki, J
中科院分区：
文献类型：
--
作者：
Niwa, H;Masui, S;Miyazaki, J
POU家族的转录因子通过与辅活化子和辅抑制子的组合作用来控制细胞的命运。POU因子Oct-3/4可以以敏感的、剂量依赖的方式定义多能胚胎干细胞的分化、去分化或自我更新(H.Niwa，J.-I.Miyazalli和A.G.Smith，NAT)。吉内。2000年24：372-376)。在这里，我们开发了一种基于Oct-3/4转基因拯救条件性缺失ES细胞自我更新的能力的互补试验，并利用该方法来确定Oct-3/4的哪些结构域是维持未分化干细胞表型所必需的。令人惊讶的是，我们发现，缺乏N端或C端反式激活结构域的分子，虽然不是两者都缺乏，但可以有效地取代全长Oct-3/4。此外，异源OCT-2的反式激活结构域与Oct-3/4 POU结构域的融合也可以维持自我更新。因此，Oct-3/4在ES细胞增殖中的独特功能存在于特定的POU结构域和通用的富含Pro的反式激活结构域的组合中。然而，有趣的是，由N端和C端反式激活结构域引发的Oct-3/4靶基因表达并不相同，这表明至少一类由Oct-3/4激活的基因不是ES细胞增殖所必需的。
Transcription factors of the POU family govern cell fate through combinatorial interactions with coactivators and corepressors. The POU factor Oct-3/4 can define differentiation, dedifferentation, or self-renewal of pluripotent embryonic stem (ES) cells in a sensitive, dose-dependent manner (H. Niwa, J.-I. Miyazalli, and A. G. Smith, Nat. Genet. 24:372-376, 2000). Here we have developed a complementation assay based on the ability of Oct-3/4 transgenes to rescue self-renewal in conditionally null ES cells and used this to define which domains of Oct-3/4 are required to sustain the undifferentiated stem cell phenotype. Surprisingly, we found that molecules lacking either the N-terminal or C-terminal transactivation domain, though not both, can effectively replace full-length Oct-3/4. Furthermore, a fusion of the heterologous transactivation domain of Oct-2 to the Oct-3/4 POU domain can also sustain self-renewal. Thus, the unique function of Oct-3/4 in ES cell propagation resides in combination of the specific POU domain with a generic proline-rich transactivation domain. Interestingly, however, Oct-3/4 target gene expression elicited by the N- and C-terminal transactivation domains is not identical, indicating that at least one class of genes activated by Oct-3/4 is not required for ES cell propagation.