Molecular mechanisms and functions of global chromatin control

项目总结/摘要 拟议研究的长期目标是在分子水平上确定机制， 在全球范围内的染色质调控功能。染色质调节深刻地影响着广泛的 各种依赖DNA的过程，包括转录、DNA复制、重组、DNA 修复和DNA损伤反应。因此，阐明染色质调控的机制是一个重要的研究课题。 了解这些基本过程是如何控制的必要前提。之一 染色质领域的主要挑战是阐明染色质是如何在整个过程中重新编程的。 细胞命运决定、发育和细胞周期控制等过程。这是一个特别 这是一个重要的挑战，因为最近确定染色质调节因子中的突变 代表了一类主要的所谓癌症驱动突变，但这些突变如何驱动癌症 仍然未知。因此，阐明染色质调控的机制不仅影响了细胞的功能， 研究DNA依赖过程基本原理的研究人员，以及癌症生物学家。 我们以前已经阐明了染色质调控如何影响转录，DNA复制， 以芽殖酵母为模式生物的S期检查点和重组。与大多数研究一样， 在这个领域，我们在有丝分裂的细胞周期中做了我们的工作。然而，野生酵母细胞，像其他酵母细胞一样， 真核细胞大部分时间处于静止状态。静止与大规模的 染色质重编程以进行整体浓缩。因为绝大多数关于染色质的研究 虽然染色质的调控主要发生在有丝分裂的细胞周期中，但我们对染色质的调控机制知之甚少 在细胞花费大部分时间的时间内。为了了解染色质的全貌 在体内的调控，这是至关重要的，以了解机制和功能的染色质调控过程中， 安静在下一个资助期内，我们将在静止状态下提出以下问题：1） 染色质通过ATP依赖的染色质重塑因子进行全局重编程？2)好吗 染色质结构域和核小体阵列折叠调控？3)基因表达是如何调控的 在全球范围内的转录后水平？我们将结合基因组学，分子遗传学， EM，建模和生物化学，以确定高度保守的染色质 调节子的功能是在全基因组范围内对染色质进行大规模重编程。从长远来看，这些 研究将使我们能够比较和整合整个染色体的染色质调节原则， 有丝分裂细胞周期和静止期，以便我们可以获得染色质调节的全貌。

Project Summary/Abstract The long term goal of the proposed study is to determine, at the molecular level, mechanisms and functions of chromatin regulation at a global level. Chromatin regulation profoundly affects a wide variety of DNA-dependent processes, including transcription, DNA replication, recombination, DNA repair, and DNA damage response. Therefore, elucidating the mechanisms of chromatin regulation is a necessary prerequisite for understanding how these essential processes are controlled. One of the major challenges the chromatin field is to elucidate how chromatin is globally reprogrammed during processes like cell fate determination, development and cell-cycle control. This is a particularly important challenge, because it was recently determined that mutations in chromatin regulators represent one major class of so called cancer driver mutations, yet how these mutations drive cancer remains unknown. Therefore, elucidating the mechanisms of chromatin regulation impacts not only the researchers who study fundamental principles of DNA-dependent processes, but also cancer biologists. We have previously elucidated how chromatin regulation affects transcription, DNA replication, S phase checkpoint and recombination using budding yeast as a model organism. Like most studies in the field, we did our work during the mitotic cell-cycle. However, yeast cells in the wild, like other eukaryotic cells, spend most of their time in quiescence. Quiescence is associated with massive chromatin reprogramming for global condensation. Because the vast majority of work on chromatin regulation has been done during mitotic cell-cycle, we have little idea of how chromatin is regulated during the time cells spend most of their time. In order to understand the whole picture of chromatin regulation in vivo, it is essential to understand mechanisms and functions of chromatin regulation during quiescence. In the next funding period, we will ask the following questions in quiescent state: 1) How is chromatin globally reprogrammed by ATP-dependent chromatin remodeling factors? 2) How are chromatin domains and nucleosome array folding regulated? 3) How is gene expression regulated post-transcriptionally at a global scale? We will use the combination of genomics, molecular genetics, EM, modeling and biochemistry to identify novel mechanisms by which highly conserved chromatin regulators function to massively reprogram chromatin in a genome-wide scale. In the long run, these studies will allow us to compare and integrate the principles of chromatin regulation throughout the mitotic cell-cycle and quiescence, such that we can obtain the full picture of chromatin regulation.