CILIA IN EYE DEVELOPMENT AND DISEASE

描述（由申请人提供）：本研究计划侧重于纤毛在感光细胞形态发生中的作用。纤毛对许多组织的发育、分化和功能至关重要。在脊椎动物的眼睛中，感光细胞的感光部分，即所谓的外节，形成高度分化的纤毛。在睫状体轴丝缺失的情况下，外节不形成，光感受器不起作用，并且其退化。轻度纤毛缺陷经常导致视色素在感光细胞中的错误定位。这是一个严重的缺陷，已知会导致感光细胞死亡。人类失明的许多形式都与纤毛功能障碍有关。肾病综合征（NPHP）和Meckel-Gruber综合征（MKS）是睫状体疾病，除了其他异常外，还涉及感光细胞变性和失明。虽然已经鉴定了几个NPHP和MKS基因，但对其蛋白产物在细胞中的功能知之甚少。我们推测，NPHP和MKS蛋白有助于视色素的光感受器外节的运输。因此，它们的缺陷导致视色素错误定位和感光细胞死亡。利用生物化学和遗传学的方法，我们确定了MKS以及NPHP蛋白和参与纤毛蛋白运输的分子复合物之间的结合相互作用。在这里，我们建议进一步研究这些相互作用，并测试如何MKS和NPHP蛋白质有助于视蛋白在光感受器外段的运输。对人类NPHP和MKS缺陷携带者的研究发现了许多导致感光细胞死亡的分子损伤。然而，这些病变如何影响蛋白质功能仍然是未知的。我们将测试人类突变如何影响NPHP和MKS蛋白定位于纤毛并结合其伴侣的能力。结合上述实验，这些研究将揭示光感受器形态发生、功能和存活所必需的基本机制。他们还将提供一种方法来测试人类突变对感光细胞中蛋白质功能特定方面的影响。 公共卫生相关性：纤毛是感光细胞分化和存活所必需的。它们的故障经常导致失明。几种形式的综合征性遗传性失明，包括肾病综合征（NPHP），Meckel-Grueber综合征（MKS）和Bardet-Biedl综合征（BBS）与纤毛功能障碍有关。该项目将促进对这些疾病中涉及的基因如何在感光细胞中发挥作用的理解。

DESCRIPTION (provided by applicant): This research proposal focuses on the role of cilia in photoreceptor morphogenesis. Cilia are essential for development, differentiation, and function of many tissues. In the vertebrate eye, the photosensitive part of the photoreceptor cell, the so-called outer segment, forms as a highly differentiated cilium. In the absence of ciliary axoneme, the outer segment does not form, the photoreceptor is not functional, and it degenerates. Milder cilia defects frequently cause the visual pigment mislocalization in the photoreceptor cell. This is a serious defect, known to cause photoreceptor death. Many forms of human blindness involve cilia malfunction. Nephronophthisis (NPHP) and Meckel-Gruber syndrome (MKS) are ciliary disorders that in addition to other abnormalities involve photoreceptor degeneration and blindness. Although several NPHP and MKS genes have been identified, the function of their protein products in the cell is poorly understood, if at all. We hypothesize that NPHP and MKS proteins contribute to the transport of the visual pigment to the photoreceptor outer segment. Accordingly, their defects lead to visual pigment mislocalization and photoreceptor death. Using biochemical and genetic approaches, we identified binding interactions between MKS as well as NPHP proteins and molecular complexes involved in ciliary protein transport. Here we propose to study these interactions further, and to test how MKS and NPHP proteins contribute to opsin transport in the photoreceptor outer segment. The studies of human carries of NPHP and MKS defects identified many molecular liesions that cause photoreceptor death. How do these lesions affect protein function remains, however, unknown. We will test how human mutations impact the ability of NPHP and MKS proteins to localize to cilia and to bind their partners. Together with experiments outlined above, these studies will reveal fundamental mechanisms, necessary for photoreceptor morphogenesis, function, and survival. They will also offer a way to test the impact of human mutations on specific aspects of protein function in the photoreceptor cell. PUBLIC HEALTH RELEVANCE: Cilia are necessary for photoreceptor differentiation and survival. Their malfunction frequently results in blindness. Several forms of syndromic hereditary blindness, including Nephronopthisis (NPHP), Meckel-Grueber Syndromethe (MKS), and Bardet-Biedl Syndrome (BBS) are associated with cilia malfunction. This project will advance the understanding of how genes involved in these diseases function in the photoreceptor cell.