Multi-functional protein that contributes to the endocytic process, but also to events that occur at the neck during cytokinesis. Plays a role as an endocytic adapters with membrane-tubulation activity that associates with transmembrane cargo proteins and initiates the formation of endocytic sites. Contributes to the stabilization of the nascent clathrin-coated pit. Also plays a role in late endocytosis by mediating vesiculation. Involved in the regulation of cell cycle-dependent dynamics of the septin cytoskeleton by promoting septin turnover in different cell cycle stages (By similarity). Interacts with dil1. Belongs to the SYP1 family.