高原低氧适应性因子Epas1对哺乳动物生物钟的影响及调控机制

生物钟与低氧信号通路有紧密的互作关系，然而高原慢性低氧与哺乳动物生物钟的相互调控鲜有报道。针对高原世居哺乳动物的全基因组水平分析揭示Epas1基因可能在高原适应性中起着重要作用，但其对生物钟的影响及调控机制未知。前期预实验发现高原鼠兔昼夜节律异常，且高原鼠兔Epas1（简称pEpas1）蛋白稳定性增强。据此推测：高原低氧适应性因子Epas1可能参与哺乳动物生物钟的调控。本项目拟1）通过qRT-PCR、荧光素酶报告系统和小鼠行为学实验等方法在分子、细胞、动物水平上检测pEpas1过表达细胞及小鼠的生物节律，探究pEpas1对哺乳动物生物节律的影响；2）通过蛋白质互作、ChIP-seq和转录组学分析等方法检测pEpas1与生物钟核心基因的相互作用，探究pEpas1调控哺乳动物生物钟的分子机制。本项目将有助于理解高原极端环境下生物钟调控机制和高原适应因子Epas1的进化意义。

The circadian clock interacts with hypoxia signaling pathway closely. However, the regulatory mechanisms of circadian clock under highland chronic hypoxia condition in mammals are rarely reported. Genome-wide analysis of plateau dwelling mammals has revealed that Epas1 may play an important role in high-altitude hypoxia adaptation. However, the impact and mechanism of Epas1 regulating mammalian circadian clock are still unknown. Our previous study found that the circadian rhythm was disrupted in plateau pika. In addition, the protein stability of Epas1 from plateau pika (call pEpas1 for short) is increased. We hypothesized that the highland-adaptation mutation for Epas1 may be involved in regulating mammalian circadian clock. This project intends to 1) detect the circadian rhythm of mammalian cells and mouse with pEpas1 overexpressed at the molecular, cellular, and animal levels, through qRT-PCR, luciferase reporter assay, mouse behavioral experiments and other methods, to explore the impact of pEpas1 on mammalian circadian clock; 2) detect the relationship between pEpas1 and core clock genes via protein-protein interaction, ChIP-seq, transcriptomic analysis and other methods to clarify the mechanism of pEpas1 regulating mammalian circadian clock. Finally, we propose that this project will help to understand regulatory mechanisms of circadian clock under chronic exposure to high altitude, as well as the evolutionary sense of Epas1.