果蝇泛素连接酶Hyd (Hyperplastic discs)对Wingless信号通路的调控机理

The Wnt/Wingless (Wg) signaling pathway is evolutionarily conserved and is involved in numerous developmental processes. Abnormal Wnt signaling has been associated with many human diseases, ranging from cancers to degenerative diseases. Our preliminary data have shown that HECT-type E3 ubiquitin ligase Hyd (Hyperplastic discs) is a nuclear protein acting downstream or in parallel with Arm to positively regulate Wg signaling in the wing disc of Drosophila. In this proposal, we will utilize a combination of genetic, cell biology and molecular approaches in Drosophila to further define the role(s) of Hyd in Wg signaling. Firstly, we will determine whether hyd is involved in Wg signaling in various developmental contexts. Secondly, we will dissect the Hyd domains required for Wg signaling. Thirdly, we will define the mechanism(s) by which hyd regulates Arm-TCF transcription complex in Wg signaling. Finally, we will employ proteomics and yeast two-hybrid system to screen for Hyd binding partners, and perform functional analysis both in vitro and in vivo to verify that the identified candidates are indeed important for Hyd’s activity in Wg signaling. This proposal will elucidate the mechanism of Hyd in Wg signaling pathway, providing new insights into the mechanisms of Wnt-related human diseases.

Wnt/Wingless (Wg)信号通路在进化过程中非常保守，广泛参与高等动物多种发育过程。该信号通路的异常与很多人类疾病的发生相关，如癌症和机体退行性疾病。我们的前期研究结果表明，果蝇E3泛素连接酶Hyd (Hyperplastic discs)对Wg信号通路具有正调控作用。本项目将通过果蝇遗传学手段，结合细胞生物学及生物化学的方法，进一步阐明Hyd对Wg信号通路的分子调控机制。首先，验证Hyd对Wg信号的调控是否具有组织特异性。其次，确定Hyd调控Wg信号所必需的功能结构域。随后，研究Hyd如何通过影响Arm-TCF转录复合物的功能活性来调控Wg信号转导。最后，通过酵母双杂交和质谱分析，筛选与Hyd相互作用的蛋白，并通过一系列体内和体外实验对其进行功能验证。鉴于Wnt信号通路在进化上的高度保守性，本项目的实施将为人类Wnt信号相关疾病的防治提供重要的理论依据。