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。它还影响到65岁及以上人群中约35%的人。这一群体中听力丧失的主要原因是毛细胞的丧失。我们感兴趣的是了解决定毛细胞功能的分子事件，以及这些事件是如何控制的。我们预计，这样的理解将允许开发合理的治疗方法来治疗毛细胞丢失。毛细胞是声音的主要传送者，负责将声音的机械能转化为编码的神经元能量。在这项建议中，我们试图了解大电导钾通道的分子基础，因为它影响毛细胞功能。具体地说，我们正在试图阐明这些通道如何带来电调的分子决定因素，这是一种频率歧视的机制。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缺失会导致进行性听力损失。我们建议扩展之前的工作，已经确定了蛋白质一级结构的变化，现在试图确定相互作用的蛋白质如何影响其功能。我们已经使用酵母2杂交技术从耳蜗中分离出了几种与该通道的有限部分相互作用的蛋白质。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钙通道的基侧分类、聚集和共定位。此外，我们将扩展我们成功的酵母2杂交法，以确定与整个BK通道相互作用的其他蛋白质。这些蛋白质也将接受类似的分析。对于这些实验，我们将使用雏鸡作为模型，并将使用我们开发的一套模块化的分析方法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.