Figure 8.

Models comparing Eph/ephrin trogocytosis to apoptotic phagocytosis and classical trogocytosis. Schematic representation of molecular pathways mediating phagocytosis (A), Eph/ephrin-mediated trogocytosis (B), and immune and germ cell trogocytosis (C) showing that Eph/ephrin-mediated trogocytosis shares both similarities (highlighted in green) and distinct properties (blue) with both processes. In all three instances, a Rac-GEF (Tiam2 in the case of Eph/ephrin trogocytosis) activates Rac GTPase to mediate the actin polymerization required for membrane rearrangement essential for internalizing large structures. Furthermore, all three pathways recruit dynamin, required for membrane scission and thereby allowing for internalization. However, in the cases of phagocytosis and Eph/ephrin trogocytosis, the engulfment protein Gulp1 is essential for dynamin recruitment, while it is not required in a classical trogocytosis setting. Moreover, in the case of Eph/ephrin trogocytosis, the stable Gulp1/EphB2 complex requires an active GEF (again using Tiam2) before dynamin recruitment. Dotted lines indicate indirect evidence.