PHOTOCHEMICAL REGULATION OF CALCIUM IN CELL PHYSIOLOGY

描述：（申请人摘要） 细胞内Ca 2+浓度的变化控制着细胞内大量的生理变化， 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，两种技术 彻底改变了细胞生理学的研究：测量钙离子 浓度使用比率，Ca 2+特异性荧光指示剂，如 fura-2;以及细胞底物浓度的快速增加， 通过闪光光解从生物惰性或“笼状”形式去除ATP、cGMP等 技术.本提案的目的是使用快速光化学控制 二价阳离子水平，以阐明机制和调节 细胞生理过程。Ca 2+特异性光不稳定螯合剂将是 开发并用于操纵细胞内Ca 2+浓度 独立于其他效应物，如Mg 2+，ATP，GTP等，使得 这些物种对Ca 2+依赖性细胞生理学的调节作用可以 被定义。此外，还将合成一种新的超快速笼状IP 3。这 关键的第二信使与许多细胞中Ca 2+浓度的控制有关。 细胞类型。该建议的基础是一种新的Ca 2+特异性光不稳定性 螯合剂称为DMNPE-4，最近合成的。新探测器 将被用于研究的动力学和分泌事件的调节， 神经内分泌细胞;心肌收缩和Ca 2+动力学 因为Ca 2+是细胞内的关键第二个 这些系统中的信使。这些过程中有许多受到干扰， 病理状态。在充分描述这些疾病状态之前， 因此，更全面地了解非疾病状态， 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.