The role of nuclear architecture in cardiac development

 描述(由申请人提供)：这项提案概述了心脏发育的表观遗传学调控的新理论，该理论基于强大的初步数据和与细胞内染色质组织相关的不断发展的概念。致密和沉默的异染色质区域位于细胞核的外围，与内核层相关。这些“层蛋白相关结构域”或“LAD”是动态的，并随着细胞分化而改变。在这项提案中，我建议测试从核周释放LAD是否会导致心脏前体细胞心脏分化的改变，以及LAD是否与核层捆绑在一起会导致相反的效果。我们的初步数据表明，HDAC3通过与LAP2？(一种完整的核膜蛋白)和cKrox(一种DNA结合转录因子)共同发挥作用，在连接LAD中发挥非催化作用。此外，我们的工作表明，HDAC3的拴系功能的丧失可以调节LADS并加速心脏分化。我们将探讨LADS在心脏谱系承诺中的作用以及LAD连接复合体的作用。我们将鉴定LAD系留染色质特有的表观遗传标记，并测试这些标记的功能。最后，我们将表征组成LAD系链的蛋白质复合体。如果成功，这项工作将打开一个新的研究领域，涉及调节心血管系统中复杂基因程序的协调激活的信号转导级联和发育信号。这一发现可能会阐明心脏疾病，包括与核板异常相关的心肌病(“板层病”)，并将为操作和评估心血管发育提供新的途径。

 DESCRIPTION (provided by applicant): This proposal outlines a novel theory for the epigenetic regulation of cardiac development that is based upon strong preliminary data and evolving concepts related to the organization of chromatin within cells. Regions of compacted and silenced heterochromatin reside at the periphery of the cell nucleus in association with the inner nuclear lamina. These "lamin associated domains" or "LADs" are dynamic, and change with cellular differentiation. In this proposal, I propose to test whether releasing LADs from the nuclear periphery can result in changes in cardiac differentiation of cardiac precursor cells, and whether tethering of LADs to the nuclear lamina can result in opposing effects. Our preliminary data indicate that Hdac3 plays a non-catalytic role in tethering LADs by functioning in association with Lap2ß (an integral nuclear membrane protein) and cKrox (a DNA-binding transcription factor). Further, our work shows that loss of the tethering function of Hdac3 can modulate LADs and accelerate cardiac differentiation. We will explore the function of LADs in the cardiac lineage commitment and the role of LAD tethering complexes. We will identify specific epigenetic marks characteristic of LAD-tethered chromatin and test the function of these marks. Finally, we will characterize the protein complexes that compose LAD tethers. If successful, this work will open a new field of investigation relating to signal transduction cascades and developmental signals that regulate the orchestrated activation of complex gene programs in the cardiovascular system. The findings may elucidate cardiac disorders including cardiomyopathies related to abnormalities of the nuclear lamina (the "laminopathies") and will provide new avenues for manipulating and evaluating cardiovascular development.