Signaling at the secretory pathway: implications for trafficking, cell polarity and metastasis

目前，对高尔基体在极性中的作用还没有什么机制性的认识。在我们以前的工作中，我们表明，高尔基体基质蛋白GM 130与RasGRF 2相互作用，我们表明，所有的极性上的GM 130的影响是偶然的与RasGRF 2的相互作用。我们还进行了两个屏幕寻址信号在高尔基体。在RNAi筛选中，我们鉴定PLC γ-1作为内质网（ER）到高尔基体运输的调节剂。在蛋白质组学筛选中，我们发现Rab 8A的磷酸化受到ERK 1/2和p38 MAPK的差异调节。最后，我们还表征了假磷酸酶STYX作为ERK 1/2信号传导、定向细胞迁移、高尔基体结构和细胞命运决定的调节剂。在本申请中，我们将研究以下问题：（I）GM 130在体内极性调节中的作用（II）GM 130在侵袭和转移形成的调节中的作用。这将使用细胞培养模型以及体内模型进行研究（III）探索PLC-γ 1是否是调节中间室（ERGIC）和ER-高尔基体运输的生物发生的自体信号级联的一部分的可能性（IV）Rab 8A的磷酸化在调节细胞后分化中的作用（IV）我们的工作将有助于更好地了解信号如何从内膜调节细胞器的稳态，细胞侵袭和转移性传播。

There is currently little mechanistic insight into the role of the Golgi in polarity. In our previous work we showed that the Golgi matrix protein GM130 interacts with RasGRF2 and we show that all effects of GM130 on polarity were contingent on the interaction with RasGRF2. We also performed two screens addressing signaling at the Golgi. In a RNAi screen we identify PLCgamma-1 as a regulator of endoplasmic reticulum (ER) to Golgi trafficking. In a proteomic screen we found that the phosphorylation of Rab8A is differentially regulated by ERK1/2 and p38 MAPK. Finally, we also characterized the pseudophosphatase STYX as a regulator of ERK1/2 signaling, directional cell migration, Golgi architecture and of cell fate decisions. In the current application we will investigate the following questions:(I) Role of GM130 in the regulation of polarity in vivo(II) Role of GM130 in the regulation of invasion and metastasis formation. This will be studied using cell culture models as well as in-vivo model(III) Explore the possibility whether PLC-gamma1 is part of an autochthonous signaling cascade regulating the biogenesis of the intermediate compartment (ERGIC) and ER-Golgi trafficking(IV) Role of phosphorylation of Rab8A in the regulation of post-Golgi traffickingOur work will contribute to a better understanding of how signaling to and from endomembranes regulates organelle homeostasis, cell invasion and metastatic dissemination.