Thanatos-Associated Protein 11 (Thap11) in Human Embryonic Stem Cells

我们在hES细胞中发现了一种新的蛋白质，命名为Thap 11（死亡相关蛋白11）。Thap 11是 胚胎干细胞分化的抑制剂。与大多数其他因素相比，Thap 11似乎直接 涉及转录控制和表观遗传修饰。Thapl 1具有推定的DMA结合功能， 与果蝇P元件的DMA结合结构域（DMA）显示出显著相似性的结构域 转座子）。这表明，与P元件一样，Thapl 1可能是一个位点特异性转录因子， 调制器，我们随后证实了这一可能性。有趣的是，其中一个最引人注目的基因 在ES细胞中由Thap 11上调的是Suz 12（Zeste 12的抑制因子，抑制 在hES细胞中的分化）。此外，Thapl 1与DMA甲基转移酶样蛋白3相互作用， （DnmtSL），并具有自身的NAD+依赖性组蛋白去乙酰化酶（HDAC）活性，使其成为一种新型的HDAC 在它自己的权利。 我们的总体假设是Thapl 1在控制hES细胞的自我更新中起关键作用， 阻断分化。为了检验这一假设，将（a）分析Thapl 1如何控制 Suz 12并鉴定Thapll的另外的靶基因;了解这些基因（包括Suz 12）是有益的。 关键是因为它们是控制未分化状态的转录网络的一部分， （B）剖析Thapl 1和DnmtSL之间的关系;我们将研究如何在体外培养人胚胎干细胞（hES细胞）; Thapll与DnmtSL相互作用，并且如果这调节基因的位点特异性DMA甲基化（Suz 12和Suz 14），则Thapll与DnmtSL相互作用。 其他）;（c）分析Thapll的NAD+依赖性HDAC活性。这些信息将使我们能够 调节Thap 11的HDAC活性，如果我们的研究发现， 第一假设是正确的。 由于Thapl 1作为转录因子起作用并且还参与至少两种表观遗传机制， DNA甲基化和组蛋白去乙酰化，它可能代表了转录调控之间的重要联系。 hES细胞中的对照和表观遗传学。针对Thapl 1的特定遗传和药理学干预 功能可以允许控制hES细胞的自我更新和分化。

We identified a novel protein, designated Thap11 (Thanatos-associated protein 11) in hES cells. Thap11 is an inhibitor of differentiation in ES cells. In contrast to most other factors, Thap11 seems to be directly involved with both, transcriptional control and epigenetic modification. Thapl 1 has a putative DMA-binding domain that shows significant similarity to the DMA-binding domain of the Drosophila P element (a DMA transposon). This suggested that, like the P element, Thapl 1 might act as a site-specific transcriptional modulator, a possibility we subsequently confirmed. Interestingly, one of the genes most strikingly upregulated by Thapl 1 in ES cells is Suz12 (Suppressor of Zeste 12, epigenetic modifier that suppresses differentiation in hES cells). In addition Thapl 1 interacts with DMA methyltransferase like protein 3 (DnmtSL), and has its own NAD+-dependent histone deacetylase (HDAC) activity, making it a novel HDAC in its own right. Our overall hypothesis is that Thapl 1 plays a critical role in controlling self-renewal of hES cells by blocking differentiation. To test this hypothesis will (a) analyze how Thapl 1 controls the expression of Suz12 and identify additional target genes of Thapl 1; knowledge of these genes (including Suz12) is critical since they are part of the transcriptional network that controls the undifferentiated state (pluripotency) of hES cells; (b) dissect the relationship between Thapl 1 and DnmtSL; we will study how Thapl 1 interacts with DnmtSL and if this modulates site-specific DMA methylation of genes (Suz12 and others); (c) analyze the NAD+-dependent HDAC activity of Thapl 1. This information will allow us to modulate Thapl 1's HDAC activity, an effect that in turn should help control differentiation of hES cells if our primary Hypothesis is correct. Since Thapl 1 acts as a transcriptional factor and is also involved in at least two epigenetic mechanisms, DNA methylation and histone deacetylation, it may represent an important link between transcriptional control and epigenetics in hES cells. Specific genetic and pharmacologic interventions targeting Thapl1 function may allow control of self-renewal and differentiation of hES cells.