Studies on hair cell BK channels

描述（由申请人提供）：听力损失影响了大约2500万美国人。大约35%的65岁及以上的人也会受到影响。听力损失的主要原因是毛细胞的损失。我们的兴趣在于了解决定毛细胞功能的分子事件，以及这些事件是如何被控制的。我们预计，这样的理解将允许合理的治疗方法开发治疗毛细胞损失。毛细胞是声音的主要换能器，用于将声音的机械能转换为编码的神经元能量。在这个提议中，我们正在寻求理解大电导钾通道的分子基础，因为它影响毛细胞功能。具体来说，我们正试图阐明这些通道如何带来电调谐的分子决定因素，这是一种频率识别机制。我们还对确定它们如何与毛细胞基底侧表面的电压门控钙通道聚集和共定位的分子基础感兴趣。小鼠大电导钾通道的丧失可导致进行性听力丧失。我们建议扩展先前已经确定蛋白质初级结构变化的工作，现在寻求确定相互作用的蛋白质如何影响其功能。我们已经从耳蜗中分离出了几种蛋白质，它们通过酵母杂交技术与这个通道的有限部分相互作用。我们现在将确定这些相互作用的蛋白质如何影响这个通道的动力学性质。我们还将确定这些蛋白质如何影响其与电压门控钙通道的基底侧分选、聚类和共定位。此外，我们将扩展我们成功的酵母2杂交方法，以识别与整个BK通道相互作用的其他蛋白质。这些蛋白质也将接受类似的检测。在这些实验中，我们将使用小鸡作为模型，并使用我们开发的一套模块化分析方法来测试它们对这些生理过程的影响。

DESCRIPTION (provided by applicant): Hearing loss affects approximately 25 Million Americans. It also affects approximately 35% of those 65 and older. The primary cause of hearing loss in this group is a result of a loss of hair cells. Our interest is in understanding the molecular events that determine hair cell function, and how these events are controlled. We anticipate that such an understanding will allow rational therapies to be developed to treat hair cell loss. Hair cells are the primary transducers of sound serving to convert the mechanical energy of sound to a coded a neuronal one. In this proposal we are seeking to understand the molecular basis of the large conductance potassium channel as it affects hair cell function. Specifically, we are trying to elucidate the molecular determinants of how these channels bring about electrical tuning, a mechanism of frequency discrimination. We are also interested in determining the molecular basis of how they are clustered and co-localized with the voltage gated Ca channel at the basolateral surface of hair cells. The loss of the large conductance potassium channel in mice results in progressive hearing loss. We propose to extend previous work that has identified variations in the primary structure of the protein, and now seek to determine how interacting proteins influence its function. We have already isolated several proteins from the cochlea that interact with a limited portion of this channel using the yeast 2 hybrid technique. We will now determine how these interacting proteins affect the kinetic properties of this channel. We will also determine how these proteins affect it basolateral sorting, clustering and co-localization with voltage gated Ca channels. In addition, we will extend our successful yeast 2 hybrid approach to identify other proteins that interact with entire BK channel. These proteins too will be subject to similar assays. For these experiments we wilt use the chick as a model and will use a modular set of assays that we have developed to test their significance in affecting these physiological processes.