DGK在Hedgehog信号通路中的作用

The role of DGK in Hedgehog signaling pathway

目的 :研究甘油二酯激酶(diacylglycerol kinase,DGK)对Hedgehog信号通路的调控机制。方法:蛋白质免疫共沉淀实验分析DGK蛋白与IFT88的结合情况;si RNA敲低DGK后,检测Hedgehog信号通路靶基因Gli1蛋白及m RNA的表达水平;激光共聚焦显微镜分析DGK缺失对原纤毛生长和IFT88蛋白在原纤毛内定位的影响。结果:DGK家族的7个成员都可以和IFT88发生特异性结合;si RNA敲低DGK后,通路靶基因Gli1的转录水平明显下降;DGK蛋白对于通路的调控部位介于Ptch1和Smo之间;DGKδ的缺失会抑制原纤毛的生长以及IFT88在原纤毛中的分布。结论:DGK的敲低影响了IFT88向原纤毛的运输,从而影响了原纤毛的结构和纤毛内转运的正常进行,DGK影响Hedgehog信号通路的正常转导及其活性,可能与其抑制原纤毛的生长有关。

Objective:To investigate the mechanism of regulation of diacylglycerol kinase(DGK) on Hedgehog signaling pathway.Methods: The interaction between DGKs and IFT88 was analyzed through co-immunoprecipitation. The expression levels of Hedgehog signaling target gene Gli1 were detected after si RNA knockdown of DGKs. Ciliogenesis of MEF cells with DGKδ defeciency was observed under confocal microscope. The localization of IFT88 in primary cilia was detected as well in those DGKδ knockout MEFs. Results: The 7 members of DGK family were bound with IFT88 specifically. Si RNA knockdown of DGK decreased the transcriptional level of Gli1. DGKs regulated Hedgehog pathway between Ptch1 and Smo. Knockout of DGKδ inhibited growth of primary cilia and the distribution of IFT88 in cilia. Conclusion: Knockdown of DGK inhibits the activity of the Hedgehog signaling pathway, which is related to defect of ciliogenesis.