Studies on hair cell BK channels

描述（由申请人提供）：听力损失影响大约2500万美国人。它也影响了大约35%的65岁及以上的人。听力损失的主要原因是毛细胞的损失。我们的兴趣是了解决定毛细胞功能的分子事件，以及如何控制这些事件。我们预计，这样的理解将允许合理的治疗方法来治疗毛细胞损失。毛细胞是声音的主要换能器，其作用是将声音的机械能转换成编码的神经元能量。在这个提议中，我们试图了解大电导钾通道的分子基础，因为它影响毛细胞的功能。具体来说，我们正试图阐明这些通道如何带来电调谐，频率歧视的机制的分子决定因素。我们还对确定它们如何与毛细胞基底外侧表面的电压门控Ca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导致进行性听力损失。我们建议扩展以前的工作，已经确定了蛋白质的一级结构的变化，现在试图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几种蛋白质，它们使用酵母2杂交技术与该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该通道的动力学特性。我们还将确定这些蛋白质如何影响它与电压门控Ca通道的基底外侧分选，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，以确定与整个BK通道相互作用的其他蛋白质。这些蛋白质也将进行类似的测定。对于这些实验，我们将使用小鸡作为模型，并将使用我们开发的一组模块化测定来测试它们在影响这些生理过程中的重要性。

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.