Roles of protein degradation in the circadian clock

项目摘要/摘要 生物钟几乎影响到哺乳动物生活的方方面面，使我们的体内 生理过程达到一天中的最佳时间。理解分子电路守恒 昼夜节律时间提供了对时钟如何驱动公开节奏的洞察，以及当 昼夜节律被打乱(例如，在倒班工作期间)。昼夜节律时间编码在节奏中 负反馈循环系统中“时钟基因”表达的调控。对这一时机至关重要 系统是节律丰富的时钟蛋白的昼夜节律降解，然而这些 机制仍然难以捉摸。我们已经开始通过以下方式阐明这些机制 开发一种新的功能筛选方法来识别哪些E3泛素 连接酶能降解哪种时钟蛋白。三个发条目标的屏幕数据表明了这一点 方法是敏感和具体的，因此如我们所希望的那样运作。当前的一个主要目标 应用是继续筛选和验证E3连接酶中的其他发条蛋白 以及一些关键的有节奏的昼夜节律输出。我们相信确定这些E3连接酶和它们的 时钟功能的作用将揭示时钟治疗干预的新的潜在靶点- 相关的障碍。 我们找回的第一部银幕热门影片《Siah2》揭示了非凡和意想不到的 对时钟功能和时钟如何调节新陈代谢的新见解。我们发现 缺乏功能性Siah2基因的雌性小鼠失去了一种防止饮食的机制-- 诱导性肥胖。这似乎是由于女性在核心生物钟中扮演的特定角色。 这些结果首次表明，女性特有的发条机制存在，而且 它们直接对女性特有的生物学做出了贡献。不幸的是，绝大多数 昼夜节律数据来自雄性老鼠。因此，我们现在计划重新评估时钟功能和 女性的昼夜节律调节以进一步识别和定义性别特异性的发条 为研究Siah2在雌性生物钟中的作用提供背景的机制。 随着该领域的发展，理解昼夜节律功能的性别差异将是至关重要的 基于昼夜节律的治疗学。 好了！

Project Summary/Abstract Circadian clocks influence nearly all aspects of mammalian life, aligning our internal physiological process to optimal times of day. Understanding the molecular circuitry keeping circadian time provides insight into how the clock drives overt rhythms, and what to fix when the circadian system is disrupted (i.e. during shift work). Circadian time coded in the rhythmic regulation of “clock gene” expression in a negative feedback loop system. Critical to this timing system is the circadian degradation of rhythmically abundant clock proteins, however these mechanisms have remained elusive. We have begun elucidating these mechanisms by developing a novel functional screening approach designed to identify which E3 ubiquitin ligases degrade which clock proteins. Screen data on three clockwork targets indicate this approach is sensitive and specific, thus operating as we hoped. A major goal of the current application is to continue to screen for, and validate, E3 ligases for other clockwork proteins as well as some key rhythmic circadian outputs. We believe identifying these E3 ligases and their roles in clock function will reveals new potential targets for therapeutic intervention of clock- related disorders. The first screen hit we have recovered, Siah2, has revealed remarkable and unexpected new insights into both clock function and how the clock regulates metabolism. We found that female mice lacking a functional Siah2 gene lost a mechanism that “protects” against diet- induced obesity. This appears to be due to a female-specific role in the core circadian clock. These results suggest, for the first time, that female-specific clockwork mechanisms exist, and that they contribute directly to female-specific biology. Unfortunately, the vast majority of circadian data are from male mice. Therefore, we now plan to reassess clock function and circadian rhythm regulation in females to further identify and define the sex-specific clockwork mechanisms to provide a background for examining the role of Siah2 in female clocks. Understanding sex-differences in circadian clock functions will be critical as the field develops circadian-based therapeutics. !