Functional Analysis of Cilia in Hedgehog Signaling and Gli Activity Regulation

在动物发育过程中，Hedgehog （Hh）家族的分泌蛋白对细胞增殖和细胞命运的决定至关重要。PI最近发现，大多数哺乳动物细胞顶部的纤毛是细胞对Hh做出反应所必需的。在这项提议中，PI将研究纤毛是否以及如何影响Gli蛋白的能力，Gli蛋白是一组参与基因表达调节的三种蛋白，介导细胞对Hh的反应。首先，PI将对纤毛对所有三种Gli蛋白的激活至关重要的假设进行基因测试。随后，PI将使用细胞生物学和生化方法研究这些Gli蛋白转运到纤毛的机制。最后，PI将测试Gli蛋白不进入纤毛就不能被激活的假设，通过基因工程使Gli蛋白不再进入纤毛。这里提出的研究计划不仅将阐明纤毛调节Gli蛋白活性的机制，而且还将提供更多关于基本细胞机制如何调节信息流以确保动物正常发育的一般见解。通过将研究材料应用于本科教学，鼓励本科生参与实验室研究，并为研究生提供参与教学活动的机会，实现科研与教育的结合。女性和少数族裔学生将通过NASA赞助的项目被招募参加这个项目。最后，PI将积极参与外联活动，例如接待高中生和参加旨在向当地社区传播科学知识的系列讲座。

Hedgehog (Hh) family of secreted proteins is critical for cell proliferation and cell fate determination in animal development. The PI recently showed cilia, tiny 'hairs' on top of most mammalian cells, are needed for cells to respond to Hh. In this proposal, the PI will investigate whether and how cilia influence the ability of Gli proteins, a group of three proteins involved in gene expression regulation, to mediate the cell's response to Hh. First, the PI will genetically test the hypothesis that cilia are essential for the activation of all three Gli proteins. Subsequently, the PI will investigate the mechanisms by which these Gli proteins are transported into the cilia, using cell biological and biochemical approaches. Finally, the PI will test the hypothesis that Gli proteins cannot be activated without getting into cilia by genetically engineering Gli proteins such that they are no longer transported into the cilia. The research program proposed here will not only elucidate the mechanism by which cilia regulate the activities of Gli proteins, but also provide more general insight into how basic cellular machinery regulates information flow to ensure normal development of an animal. The integration of research and education will be achieved by applying the research material to undergraduate teaching, encouraging undergraduate students to participate in lab research and providing opportunities for graduate students to be involved in teaching activities. Female and minority students will be recruited to participate in this project through NASA sponsored programs. Finally, the PI will be actively involved in outreach activities such as hosting high school students and participating in lecture series aimed at disseminating scientific knowledge to the local community.