Endocytic Trafficking of the Notch Receptor.

The endosomal pathway plays an important role in several aspects of Notch signalling ranging from ligand-dependent to independent activation and also degradation of the Notch receptor. Here, we will focus on its role during receptor degradation and describe the endosomal pathway with the components that are important for Notch degradation and the molecular machinery that orchestrates these events. Subsequently, we will describe the journey of Notch through the endosomal system and discuss the role of the genes involved. Mechanisms of the recently discovered ligand-independent activation of the Notch receptor in the endosomal pathway will be described and its contribution in physiologically Notch-dependent processes will be discussed. Last but not least, we will summarize the evidence for endosomal ligand-independent activation of the Notch pathway in vertebrates.