Defining the mechanisms of epigenetic information flow

染色质是蛋白质、DNA和RNA的集合体， 真核生物基因组的形式，强加了一个百万倍的长度规模压缩，以适应 细胞核中的DNA染色质结构不仅仅是静态的包装， 作为潜在DNA功能的动态调节器。局部染色质结构可能 数十年来保持稳定，但仍具有足够的动态性以响应信号通路， 增强发育、疾病和 环境变化。事实上，细胞身份及其变化与细胞的功能密切相关。 连接到染色质状态--保持神经元是神经元而不是肝细胞。除了 从DNA序列特异性转录因子，信息载体负责 这种结构变异是对基因组本身的化学修饰， 参与包装的组蛋白（通常称为“表观遗传”标记），以及 作为非编码RNA作用于染色质界面。虽然对这些知之甚少 表观遗传信息载体，很明显，他们在发展中发挥着至关重要的作用， 认知与疾病阐明了表观遗传的分子机制 信息载体影响染色质的结构和功能，特别是在背景下， 是鲁登堡实验室的统一主题。未来四 年，我们将发现和表征新的表观遗传的详细机制， 信息载体，关注核小体水平变异和孤儿组蛋白 修饰，为最近认识到的DNA修饰定义结合伴侣， 他们的功能，并进行详细的机械特性的一类 我们发现的分子--富含染色质的非编码RNA， 转录激活因子。此外，我们将从生物化学的角度来定义RNA在细胞中的功能。 MLL/SET 1家族组蛋白修饰复合物及其功能 在细胞环境中的后果。我们在这些领域的跨学科工作将需要 新工具和实验方法的开发-我们的杰出曲目 在NIGMS的资助下，开创性的工具开发记录表明，未来 这些努力将取得类似的成功。的基本机械理解 我们将通过这些途径开发的表观遗传信息系统将影响我们的 了解核功能及其在疾病中的失调。

Chromatin, the assemblage of protein, DNA and RNA that represents the physiologic form of the eukaryotic genome, imposes a million-fold length-scale compaction to fit DNA in the nucleus. Rather than serving as mere static packaging, chromatin structure acts as a dynamic regulator of underlying DNA function. Local chromatin structure may be stable for decades, yet is sufficiently dynamic to respond to signaling pathways, potentiating transcriptional program changes in development, disease, and environmental changes. Indeed, cellular identity and changes thereof are intimately connected to chromatin states-- keeping a neuron a neuron and not a liver cell. Apart from DNA sequence-specific transcription factors, the information carriers responsible for this structural variation are chemical modifications to the genome itself and attendant histone proteins involved in packaging (often referred to as “epigenetic” marks), as well as noncoding RNA acting at the chromatin interface. Although little known about these epigenetic information carriers, it is clear that they play crucial roles in development, cognition and disease. Elucidation of the molecular mechanisms by which epigenetic information carriers impact chromatin structure and function, particularly in the context of transcriptional activation is the unifying theme of the Ruthenburg lab. In the next four years, we will discover and characterize the detailed mechanisms of new epigenetic information carriers, focusing on nucleosome-level variation and orphaned histone modifications, defining binding partners for recently appreciated DNA modifications and their function, and performing detailed mechanistic characterization of a class of molecules we discovered--chromatin-enriched noncoding RNA that act as local transcriptional activators. In addition, we will biochemically define the function of RNA in the MLL/SET1 family of histone modification complexes and its functional consequences in cellular contexts. Our interdisciplinary work in these areas will require the development of new tools and experimental approaches—our outstanding track record of pioneering tool development with NIGMS funding makes the case that future efforts will meet with similar success. The fundamental mechanistic understanding of epigenetic information systems we will develop through these avenues will impact our understanding of nuclear function and its dysregulation in disease.