The Role of Cryptochromes in Circadian Regulation of Metabolism

项目摘要/摘要 昼夜节律在生物体中普遍存在，使它们能够预测和适应可预测的 24小时昼夜循环。它们的功能是暂时协调生理过程，例如 在有机体内的新陈代谢。因此，昼夜节律的中断会导致去同步化 体内生物钟和复杂的代谢紊乱，如糖尿病。时钟如何控制的机制 下游代谢途径还不是很成熟。这一关系中的核心参与者之一是 核心时钟基因隐花色素(Cry)。哭声是维持节奏性和确定周期长度所必需的， 但它也与糖尿病和葡萄糖耐量有关。直到最近，哭泣还被认为是起作用的 仅在细胞核内；我们最近出人意料的发现表明，它还抑制细胞质中的糖异生。 通过与Gsα的互动。同时，核哭泣也调节糖异生，尽管是通过一种 完全不同的途径。总而言之，这种双管齐下的方法允许CRY微调其对 葡萄糖动态平衡；然而，它在两个亚细胞位置的存在使得研究其 隔间特定的机制。为了克服这一挑战，我们创造了两种独特的试剂来本地化 向每个地区呐喊。胞质CREY将在原子和细胞水平上进行研究，以确定其结合 以及他们的相互作用如何决定他们的生化功能。核哭声将被调查 基因组规模，以揭示其与其他转录因子在增强子中的相互作用 糖异生基因。染色体构象捕捉技术将使我们能够在整个细胞核范围内模拟 肝细胞特异性增强子体系结构。在治疗方面，我们将描述 从我们的屏幕上识别出的新型时钟调节化合物的作用。这些化合物具有 有可能发现新的时钟基因并调节新陈代谢，为临床翻译铺平道路。 使用这些技术来研究哭泣如何控制糖异生将是对如何 时钟在调节组织特定代谢途径方面实现了精确度。这些研究的成功将 显著提高对生物钟与生理学或疾病之间的串扰的理解 并为应用基于细胞的研究结果改善人类健康提供了概念验证模型。

Project Summary / Abstract Circadian rhythms are pervasive among organisms, allowing them to anticipate and adapt to the predictable 24-hour day-night cycle. Their function is to temporally coordinate physiological processes, such as metabolism, within the organism. Consequently, the disruption of circadian rhythms leads to desynchronized internal clocks and complex metabolic disorders, such as diabetes. The mechanism of how the clock controls downstream metabolic pathways is not well-established. One of the central players in this relationship is the core clock gene Cryptochrome (Cry). CRY is necessary to maintain rhythmicity and determine period length, but it has also been implicated in diabetes and glucose tolerance. Until recently, CRY was thought to function only in the nucleus; our recent unanticipated findings indicate it also inhibits gluconeogenesis in the cytoplasm through its interaction with Gsα. In parallel, nuclear CRY also regulates gluconeogenesis, albeit through a completely different pathway. Together, this two-pronged approach allows CRY to fine-tune its regulation of glucose homeostasis; however, its presence in two subcellular locales has made it difficult to study its compartment-specific mechanisms. To overcome this challenge, we created two unique reagents that localize CRY to each region. Cytosolic CRY will be studied at the atomic and cellular level to identify its binding partners and how their interactions determine their biochemical functions. Nuclear CRY will be investigated on the genomic scale to uncover its interactions with other transcription factors in the enhancers of gluconeogenesis genes. Chromosome conformation capture techniques will enable us to model nucleus-wide hepatocyte-specific enhancer architecture. On the therapeutic front, we will characterize the mechanism of action of novel clock-modifying chemical compounds identified from our screens. These compounds have the potential to identify novel clock genes and to regulate metabolism, paving the way towards clinical translation. The use of these techniques to study how CRY controls gluconeogenesis will be a proof-of-concept for how the clock achieves precision in modulating a tissue-specific metabolic pathway. The success of these studies will significantly improve the understanding of the crosstalk between the biological clock and physiology or disease states, as well as provide a proof-of-concept model for applying cell-based findings in improving human health.