STRUCTURE AND FUNCTION RELATIONSHIP OF CONE CYCLIC NUCLEOTIDE-GATED CHANNEL

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 光感受器环核苷酸门控（CNG）通道是光信号转导的重要通道。 编码锥CNG通道亚基的基因突变与人类锥细胞疾病高度相关。 视锥细胞CNG通道的突变占全色盲、早发性黄斑变性和进行性视锥细胞营养不良患者的70%。 然而，突变导致锥缺陷的机制是未知的，我们目前对锥CNG通道的结构和功能调节的理解非常有限。 这主要是由于调查视杆细胞占主导地位的哺乳动物视网膜中的视锥系统的困难。 我们已经显示了在转录因子神经视网膜亮氨酸拉链缺陷的小鼠（Nrl敲除小鼠）的视锥优势视网膜中，视锥CNG通道的稳健表达和视杆CNG通道的缺乏。 因此，我们已经证明Nrl敲除小鼠的视网膜是研究哺乳动物中的视锥CNG通道的独特工具。本研究计划是利用这种小鼠模型，通过多种生物化学方法来确定天然锥CNG通道的生物化学成分和性质。 本研究还将通过评估视锥CNG通道与视网膜中钙结合蛋白钙调素和钠-钾-钙交换体NCKX 2的关系来了解其调节。 通过鉴定与CNG通道相互作用的蛋白质，探讨CNG通道的功能调控。 这将通过使用多重亲和纯化和质谱分析来实现。 本研究的长期目标是阐明突变相关的视锥细胞疾病的机制，目的是确定潜在的治疗干预的视锥细胞疾病。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Photoreceptor cyclic nucleotide-gated (CNG) channel is essential to phototransduction. Mutations in genes encoding cone CNG channel subunits are highly linked to human cone diseases. Mutations in cone CNG channel account for 70% of patients with achromatopsia, early-onset macular degeneration, and progressive cone dystrophy. However, the mechanisms by which mutations result in cone defects are unknown and our current understanding of the structure and functional modulation of cone CNG channel is very limited. This is primarily due to the difficulty of investigating the cone system in a rod dominant mammalian retina. We have shown robust expression of the cone CNG channel and lack of the rod CNG channel in the cone-dominant retina of mice deficient in the transcription factor neural retina leucine zipper (Nrl knockout mice). Thus we have demonstrated that the retina of Nrl knockout mice is a unique tool to study cone CNG channel in mammals. This research program is to utilize this mouse model to determine the biochemical components and properties of the native cone CNG channel by using multiple biochemical approaches. The proposed research is also to understand the modulation of cone CNG channel by evaluating its associations with the calcium binding protein calmodulin and the sodium-potassium-calcium exchanger NCKX2 in retina. The functional modulation of cone CNG channel also will be explored by identifying its interacting proteins. This will be achieved by using multiple affinity purification and mass spectrometry analysis. The long-term goal of this research is to elucidate the mechanism of the mutation-associated cone diseases with the objective of identifying potential therapeutic interventions for the cone diseases.