Protocol for monitoring the endosomal trafficking of membrane proteins in mammalian cells

Here, we present a protocol to study epidermal growth factor (EGF) receptor (EGFR) or transferrin trafficking in mammalian cells. We describe steps for using fluorescent ligands or antibodies, confocal imaging, and quantitative analysis to track their movement. We detail procedures for cell culture preparation, labeling membrane proteins, optimizing imaging, and isolating cell lysates for the biochemical analysis of EGFR degradation after EGF treatment. This protocol is adaptable to various cell types and for assessing genetic or pharmacological impacts on endosomal trafficking. For complete details on the use and execution of this protocol, please refer to Ye et al.,¹ Ye et al.,² and Wang et al.³.