Regulation of the Hedgehog Pathway by new cilium proteins in Development and Disease

项目总结 Hedgehog(HH)信号的缺陷广泛地与各种出生缺陷和癌症有关。这个 HH信号的转导依赖于初级纤毛，这是一种被称为 细胞的天线。为了激活HH信号，几乎所有的蛋白质转导都需要通过 纤毛。然而，这些蛋白质转运的分子机制还不完全清楚。 理解；纤毛内的信号级联在野外也尚不清楚。我们的目标是 通过对纤毛蛋白在体外和体外调节HH信号的机制研究来填补这一空白 在活体内。在初步研究中，我们利用了一种新的邻近标记工具，并建立了一个实验性的 为利用定量蛋白质组学在纤毛中发现新的信号蛋白奠定基础。我们发现 神经过程中参与受体内化的分子令人惊讶的纤毛定位 发展。在这项研究中，我们的目标是1)破译新纤毛分子是如何控制蛋白质的 HH信号激活过程中纤毛的转运；2)确定其在HH控制神经中的作用 在发育中的大脑中的祖细胞增殖；以及3)应用邻近生物素化方法来 确定在HH激活过程中参与Smo运输和信号转导的新蛋白质。 我们的方法是创新的，因为它将揭示纤毛中一种旧蛋白质的新功能 HH转导，并使用新开发的生物素化工具来获得系统的观点 HH信号激活过程中的信号蛋白。完成后，我们的研究将揭示Long HH途径中存在的问题，并可能突出HH相关干预的新方法 发育障碍。

PROJECT SUMMARY Defects in Hedgehog (Hh) signaling is widely implicated in various birth defects and cancers. The transduction of Hh signaling relies on the primary cilium, a miniature cell surface organelle known as the antenna of the cell. To activate Hh signaling, almost all protein transducers need to transit through the cilium. However, the molecular mechanisms of these protein transportation are not completely understood; and the signaling cascade within the cilium also remains unclear in the field. Our goal is to fill this gap with mechanistic studies of novel cilium proteins in the regulation of Hh signaling in vitro and in vivo. In preliminary studies, we have leveraged a new proximity-labeling tool and built an experimental platform to discovery new signaling proteins in the cilium with quantitative proteomics. We discovered surprising cilium localization of a molecule involved in receptor internalization during neural development. In this proposal, we aim to 1) decipher how the new cilium molecule control protein transport in the cilium during Hh signal activation; 2) determine its role in the Hh-controlled neural progenitor proliferation in the developing brain; and 3) apply the proximity biotinylation approach to identify new proteins involved in Smo trafficking and signaling during the time course of Hh activation. Our approach is innovative because it will reveal a new function of an old protein in the cilium during Hh transduction, and it employs a newly developed biotinylation tool to gain the systematic view of signaling proteins during Hh signaling activation. Upon completion, our study will shed light on long standing questions in the Hh pathway and may highlight new methods for the intervention of Hh related developmental disorders.