Regulatory Roles of Zinc Fluxes in Metalloprotein Occupancy and Cell Cycle Progression

项目摘要 本计画主要探讨金属蛋白质的结构、光谱、功能及调控细胞的机制 细胞内锌浓度的程序性波动。锌熔剂具有 最近被发现是人类生理学中的关键调节事件，包括皮层神经元功能， 免疫反应受精和胰岛素分泌尽管它在这些深刻的生理学中扮演着明显的角色， 锌作用的生物化学尚不清楚。关于无机化学的知之甚少， 参与介导细胞对锌通量的反应的指导性机制的金属蛋白，锌 运输途径，或特定金属蛋白受体在信号事件中的作用。解释和 最终干预由这些通路中断引起的疾病，我们必须首先阐明 锌依赖开关事件的分子机制。 虽然锌传统上被视为参与蛋白质结构和酶催化的静态辅因子， 最近的研究支持了这样的观点，即调节蛋白中的锌结合位点响应于蛋白质的瞬时波动。 锌的可用性，并以调节关键细胞事件的方式打开和关闭。我们将检验这个假设 调节性锌通量通过特定的受体- 中介过程。这一假设基于多条证据，包括：（1）数据显示 单个细胞在细胞周期中不同时间点锌分布的波动;（2）活细胞成像显示 锌波的运动;（3）物理化学方法显示锌与特定的 因素该提案的总体目标是使用生物化学和光谱方法， 了解锌的流入和流出如何控制细胞周期。探测和控制化学品的工具 将产生锌的浓度以进一步我们对锌生理学的理解。此外，我们将 利用X射线吸收和发射光谱、NMR和质谱等新兴技术， 了解锌的化学环境，并探测含锌蛋白质的锌占有率， 调节细胞周期进程。总之，这些研究的结果将阐明锌的强大作用 细胞周期中的信号流。

PROJECT SUMMARY This project examimes the structure, spectroscopy, function, and mechanism of metallproteins that regulate cell cycle progresion in response to programmatic fluctuations in intracellular zinc concentration. Zinc fluxes have recently been discovered to be key regulatory events in human physiology, including cortical neuron function, immune response, fertilization, and insulin secretion. Despite its apparent roles in these profound physiologies, the biochemistry of zinc action is not well understood. Little is known regarding the inorganic chemistry of metalloproteins involved in the instructive mechanisms that mediate cellular responses to zinc fluxes, zinc trafficking pathways, or the role of specific metalloprotein receptors in signaling events. To interpret and eventually intervene in diseases caused by disruption of such pathways, we must first elucidate the fundamental molecular mechanisms of zinc-dependent switching events. While zinc has traditionally been viewed as a static cofactor involved in protein structure and enzyme catalysis, recent studies support the idea that zinc binding sites in regulatory proteins respond to transient fluctuations in zinc availability and are switched on and off in ways that regulate key cellular events. We will test the hypothesis that regulatory zinc fluxes exert instructive control over the mammalian cell cycle through specific, receptor- mediated processes. This hypothesis is based on multiple lines of evidence, including: (1) data showing fluctuations zinc distribution at various points in the cell cycle for single cells; (2) live cell imaging demonstrating the movement of waves of zinc; and (3) physicochemical approaches showing colocalization of zinc with specific factors. The overarching objective of this proposal is to use biochemical and spectroscopic approaches to understand how the influx and efflux of zinc exert control over the cell cycle. Chemicals tools to probe and control the concentration of zinc will be created to further our understanding of zinc physiology. In addition, we will leverage emerging techniques in X-ray absorption and emission spectroscopy, NMR, and mass spectrometry to understand the chemical environment of zinc and probe the zinc occupancy of zinc-containing proteins that regulate cell cycle progression. Taken together, the results from these studies will elucidate a robust role for zinc signaling fluxes during the cell cycle.