PHOTOCHEMICAL REGULATION OF CALCIUM IN CELL PHYSIOLOGY

描述：(申请人摘要) 细胞内钙离子浓度的变化控制着无数的生理性变化 包括肌肉收缩、分泌、有丝分裂、通道门控、 趋化性和气孔关闭。在过去的15年里，有两种技术 使细胞生理学研究发生了革命性变化：钙离子的测量 使用比率、钙离子特定荧光指示剂的浓度，例如 Fura-2；以及细胞底物浓度的快速增加，如 ATP、cGMP等通过闪光光解从生物惰性或笼状的形式 技巧。这项建议目的是使用快速光化学控制 二价阳离子水平的变化来表征其作用机制和调控 细胞生理过程。钙离子专属的耐光性螯合剂将是 开发并用于操纵细胞内钙离子浓度 独立于其他效应器，如镁离子、三磷酸腺苷、GTP等，因此 这些物种对依赖钙的细胞生理的调节作用可以 被定义。此外，还将合成一种新的、超快的笼式IP3。这 关键的第二信使在许多情况下参与了钙离子浓度的控制 单元类型。这一提议的基础是一种新的钙离子特定的可感光性 一种称为DMNPE-4的螯合剂，它是最近合成的。新的探测器 将被用来研究分泌事件的动力学和调节。 心肌收缩的神经内分泌细胞与钙离子动力学 因为钙离子是细胞内第二关键的物质，所以在小脑中释放。 这些系统中的信使。这些过程中的许多过程在 病态。在对这些疾病状态进行充分描述之前 对非疾病状态的更全面的理解应该是 完成了。拟议的研究将有助于更好地了解 这些过程的正常运作。

DESCRIPTION: (Applicant's Abstract) Changes in intracellular Ca2+ concentration control a myriad of physiological processes including muscle contraction, secretion, mitosis, channel gating, chemotaxis and stomatal pore closure. During the past 15 years two techniques have revolutionised the study of cell physiology: measurement of Ca2+ concentrations using ratiometric, Ca2+-specific fluorescent indicators such as fura-2; and the rapid increase in concentration of cellular substrates such as ATP, cGMP, etc. from a biologically inert or "caged" form by flash-photolysis techniques. The objective of this proposal is use rapid photochemical control of divalent cation levels to characterise the mechanism and regulation of cellular physiological processes. Ca2+ -specific photolabile chelators will be developed and used to manipulate intracellular Ca2+ concentrations independently of other effectors, such as Mg2+, ATP, GTP, etc. so that the regulatory roles that these species have on Ca2+-dependent cell physiology can be defined. Additionally, a new, ultra-fast caged IP3 will be synthesised. This key second messenger is implicated in the control of Ca2+ concentration in many cell types. The basis of this proposal is a new Ca2+-specific photolabile chelator called DMNPE-4, which has been recently synthesized. The new probes will be used to study the kinetics and regulation of secretory events in neuroendocrine cells; of contraction in cardiac muscle and the kinetics of Ca2+ release in the cerrebellum because Ca2+ is the key intracellular second messenger in these systems. Many of these processes are disturbed in pathological states. Before an adequate description of these disease states can be given, a more complete understanding of non-disease states should be accomplished. The proposed studies will contribute to a greater understanding of the normal functioning of these processes.