Investigating the Role of Ribeye in Retinal Ribbon Function

 描述(由申请人提供)：视网膜的光感受器和双极细胞以及听觉和前庭系统的毛细胞将感觉刺激信号传递给神经递质释放的分级变化。为了做到这一点，这些细胞进化出突触带，这是一种蛋白质结构，将释放部位附近的大量突触小泡捆绑在一起。突触带功能的分子机制还知之甚少。少数蛋白质被定位在突触带上，这些单个分子的重要性以及它们如何对突触带的独特功能做出贡献仍然是个谜。在这些蛋白质中，含量最丰富的是Ribeye，这是一种突触带特有的蛋白质，被认为构成了突触带的大部分，并假设形成突触带的核心。Ribeye起源于转录辅阻遏子CtBP2的另一个起始点。Ribeye的确切作用尚不清楚，该提议的长期目标是确定Ribeye在突触带中的功能作用。为了研究Ribeye的功能，我们将结合分子生物学、遗传学和电生理学，主要以斑马鱼为主要模型系统。在目标1中，我们培育了斑马鱼，并对其进行了鉴定，斑马鱼的两个核眼基因都发生了定向突变。在目标2中，我们观察了Ribeye基因产物中的一种或两种对光感受器和毛细胞带结构的影响。在目标3中，我们将观察Ribey去除对其他突触带蛋白的分布和定位的影响。在目标4中，我们将研究Ribeye丢失对神经肥大毛细胞胞吐和钙电流的影响。在分子水平上了解突触带功能最终将有助于理解视觉和听觉信息是如何处理和交流的。此外，它还可能提供线索，帮助理解专门影响视力和听力的疾病。此外，对这些特殊神经元突触前过程的基本了解将对神经元的总体交流产生更广泛的影响，从而可能有助于我们对心理健康和神经疾病的各个方面的理解。

 DESCRIPTION (provided by applicant): Photoreceptors and bipolar cells of the retina and hair cells of the auditory and vestibular systems signal sensory stimuli as graded changes in neurotransmitter release. To do so, these cells have evolved synaptic ribbons, proteinaceous structures that tether large numbers of synaptic vesicles near release sites. The molecular machinery underlying synaptic ribbon function is poorly understood. A handful of proteins have been localized to the synaptic ribbon and the importance of these individual molecules as well as how they contribute to the unique functions of the synaptic ribbon remains elusive. Of these proteins, the most abundant is Ribeye, a protein unique to the synaptic ribbon and thought to constitute most of the synaptic ribbon and hypothesized to form the core of the synaptic ribbon. Ribeye arises from an alternative start site of the transcriptional corepressor CtBP2. The precise role of Ribeye remains unknown and the long-term goal of this proposal is to determine the functional role of Ribeye in the synaptic ribbon. To study Ribeye function, we will employ a combination of molecular biology, genetic and electrophysiology primarily using zebrafish as a primary model system. In Aim 1 we generated and characterize zebrafish with targeted mutations in both ribeye genes. In Aim 2, we the effect of one or both Ribeye gene products on the structure of photoreceptor and hair cell ribbons. In Aim 3, we will look at the effect of Ribey removal on the distribution and localization of other synaptic ribbon proteins. In Aim 4, we will investigate the effects of Ribeye loss on exocytosis and calcium current in neuromast hair cells. Understanding synaptic ribbon function at the molecular level will ultimately aid in understanding how visual and auditory information is processed and communicated. In addition, it may provide clues to help understand diseases that specifically affect vision and hearing. In addition, the fundamental understanding of presynaptic processes in these specialized neurons will have broader implications for neuronal communication in general and thus, may contribute to our understanding of various aspects of mental health and neurological disorders.