The Role of TULP1 in Photoreceptor Cells

TULP 1是我们发现的一种导致常染色体隐性视网膜色素变性（一种遗传性视网膜色素变性）的基因 全世界有近100万人因变性而失明。RP的遗传病因已知约50% 然而，引起这种疾病的生化途径要少得多。 本研究的目的是探索TULP 1在视网膜中的生理功能， 定义导致与TULP 1突变相关的光感受器变性的病理机制。 TULP家族由四种功能未知的蛋白质组成，其中两种与光感受器有关 退化 本申请的两个特定目的旨在测试中心假设，即TULP 1是 参与感光细胞中蛋白质定向移位的分子机制的组成部分 细胞第一个具体目标是确定TULP 1在光感受器转运途径中的作用。这将 通过使用免疫细胞化学来确定外节蛋白、细胞内 转运蛋白和突触蛋白在Tulpt-/-视网膜中是错误的。免疫电镜将 以确定不正确转运的蛋白质是否是细胞外基质上的货物。 小泡在tulpl-/-视网膜中。第二个具体目标是确定TULP 1/发动蛋白-1的功能 在感光细胞中鉴定的相互作用。这将通过识别功能域来完成， TULP 1和发动蛋白-1之间的相互作用，并确定引起RP的TULP 1突变是否改变了 两种蛋白质之间的结合。实验还提出了产生和表型小鼠缺乏 使用Cre-loxP诱变的感光细胞中的发动蛋白-1。运输途径将在 这些小鼠如目的1所述。 由于对TULP蛋白知之甚少，发现关于TULP蛋白功能的信息 应该提供有关光感受器退化的途径的知识。有可能 这项工作可以为未来的研究奠定基础，旨在评估可能 减缓、停止或逆转视网膜变性的过程。

TULP1 is a gene we identified to cause autosomal recessive retinitis pigmentosa, a hereditary retinal degeneration blinding nearly 1 million people worldwide. The genetic etiology of RP is known for about 50% of cases; however, the biochemical pathways involved in causing the disease much less. The overall objectives of the proposed studies are to explore the physiologic function of TULP1 in the retina and to define the pathologic mechanism leading to photoreceptor degeneration associated with TULP1 mutations. The TULP family consists of four proteins of unknown function, two of which are linked to photoreceptor degeneration. The two specific aims of this application are designed to test the central hypothesis that TULP1 is a component of the molecular machinery involved in the directional translocation of proteins in photoreceptor cells. The first specific aim is to determine the role of TULP1 in photoreceptor transport pathways. This will be accomplished by using immunocytochemistry to determine whether outer segment proteins, intracellular transport proteins and synaptic proteins are mistargeted in tulpt-/- retinas. Immunoelectron microscopy will be performed to determine if the proteins that are incorrectly transported are cargo on the extracellular vesicles in tulpl-/- retinas. The second specific aim is to determine the function of the TULP1/Dynamin-1 interaction identified in photoreceptor cells. This will be done by identifying the functional domains that interact between TULP1 and Dynamin-1 and determining whether TULP1 mutations that cause RP alter the binding between the two proteins. Experiments are also proposed to generate and phenotype mice lacking Dynamin-1 in photoreceptor cells using Cre-loxP mutagenesis. Transport pathways will be evaluated in these mice as described in aim 1. Since little is known about TULP proteins, discovering information regarding the function of TULP proteins should provide knowledge about the pathways involved in photoreceptor degeneration. It is possible that this work could form the foundation for future studies aimed at evaluating therapeutic modalities that might slow, stop, or reverse the course of retinal degeneration.