Endocytosis in the Spatial Control of Polarised Cell Functions

Endocytosis, originally thought of as a device to transport nutrients and membrane-associated molecules across the plasma membrane through vesicles, is emerging as a connectivity infrastructure (which we have called the endocytic matrix) of different cellular networks necessary for the execution of various cellular programmes. A primary role of the endocytic matrix is the delivery of space- and time-resolved signals to the cell, and it is thus essential for the execution of polarised functions. Here, by discussing paradigmatic cases, we intend to outline emerging concepts of how the endocytic wiring system functions as a highly interconnected intracellular highway that mobilises membrane and signalling molecules, ensuring polarised compartmentalisation of signals. We will specifically focus on two exemplar cases: the impact of the endocytic matrix on cell migration and on asymmetric cell division. In each of these cases, endocytosis and recycling have been shown to ensure the asymmetric distribution of biological molecules, which, in turn, is crucial for proper polarised cellular functions