Regulation of Ion Channels and Ion Pumps in Yeast

离子通道和离子泵等蛋白质在质膜上的离子运输对细胞的信号转导和体积控制等功能至关重要。尽管通过克隆各自的基因获得了更多关于运输蛋白分子结构的信息，但通道和泵对细胞内离子运输的调节机制尚未被很好地理解。这项研究将集中在模式真核生物酿酒酵母质膜上的机械敏感离子通道和质子泵的调节上。通过膜电容和电导的联合测量，利用膜片钳电生理学对机械敏感通道进行分析，以确定膜变形和特定离子与机械敏感通道激活和适应的关系。这项建议的另一个目标是确定与质子泵功能相互作用的蛋白质的数量和功能，无论是作为调节器还是作为平行离子传输机制，如通道。在分离和鉴定影响泵排出质子的突变体之后，将进行生化、电生理和分子遗传学研究，以确切地确定突变体中泵调节是如何改变的。离子通道和离子泵对细胞的生理学非常重要，因为它们控制着特定离子的跨膜运输。将分子遗传学和复杂的电生理学的强大技术结合起来研究酵母中的离子通道和离子泵，将使我们有可能并行地了解它们的通道分子结构和功能。

Ion transport across the plasma membrane by proteins such as ion channels and ion pumps is vital to cellular functions such as signal transduction and volume control. Despite increased information about the molecular structure of transport proteins from the cloning of the respective genes, mechanisms underlying the cellular regulation of ion transport by channels and pumps are not well understood. This research will focus on the regulation of mechanosensitive ion channels and a proton pump in the plasma membrane of the model eukaryote, Saccharomyces cerevisiae. Mechanosensitive channels will be analyzed using patch-clamp electrophysiology to determine the relationship of membrane deformation and specific ions to the activation and adaptation of mechanosensitive channels by combined measurements of membrane capacitance and conductance. Another goal of this proposal is to determine the number and function of proteins which functionally interact with the proton pump, either as modulators or as parallel ion transport mechanisms such as channels. Isolation and genetic characterization of mutants affecting proton extrusion by the pump will be followed by biochemical, electrophysiological, and molecular genetic studies to determine exactly how pump regulation is altered in the mutants. Ion channels and ion pumps are of great fundamental importance to the physiology of cells since they control the traffic of specific ions across the membrane. The proposed combined application of the powerful techniques of molecular genetics and sophisticated electrophysiology to study ion channels and pumps in yeast will make it possible to develop parallel knowledge of their molecular structure of the channels and their function.