CILIA IN EYE DEVELOPMENT AND DISEASE

描述(由申请人提供)：这项研究计划集中在纤毛在光感受器形态发生中的作用。纤毛是许多组织发育、分化和功能所必需的。在脊椎动物的眼睛中，感光细胞的感光部分，即所谓的外节，形成了高度分化的纤毛。在没有睫状轴丝的情况下，外节不形成，光感受器不起作用，退化。较轻的纤毛缺陷经常导致视觉色素在感光细胞中的错误定位。这是一种严重的缺陷，已知会导致光感受器死亡。许多形式的人类失明都与纤毛功能障碍有关。肾病综合征(NPHP)和Meckel-Gruber综合征(MKS)是一种纤毛疾病，除了其他异常外，还涉及光感受器退化和失明。尽管已经确定了几个NPHP和MKS基因，但它们的蛋白产物在细胞中的功能即使有的话，也是知之甚少。我们假设NPHP和MKS蛋白有助于将视觉色素运输到光感受器外段。相应地，它们的缺陷导致视觉色素错误定位和感光细胞死亡。利用生化和遗传学方法，我们确定了MKS和NPHP蛋白与纤毛蛋白运输相关的分子复合体之间的结合作用。在这里，我们建议进一步研究这些相互作用，并测试MKS和NPHP蛋白如何促进光感受器外段的视素运输。对携带NPHP和MKS缺陷的人的研究发现了许多导致光感受器死亡的分子水平。然而，这些损伤是如何影响蛋白质功能的尚不清楚。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。结合上面概述的实验，这些研究将揭示光感受器形态发生、功能和生存所必需的基本机制。他们还将提供一种方法来测试人类突变对光感受器细胞中蛋白质功能的特定方面的影响。 公共卫生相关性：纤毛是光感受器分化和存活所必需的。它们的故障经常导致失明。几种形式的综合征遗传性失明，包括肾病(NPHP)、Meckel-Grueber综合征(MKS)和Bardet-Biedl综合征(BBS)与纤毛功能障碍有关。该项目将促进对参与这些疾病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.