The plasma membrane (PM) houses many proteins required to communicate with the outside world. Clathrin-mediated endocytosis (CME) is an essential process that removes proteins from the PM, thereby providing a way to regulate their activity. In plants, CME is facilitated by 2 protein complexes, the TPLATE complex (TPC) and the AP-2 complex (AP- 2), which have common and distinct roles. Their large subunits have appendages that likely serve as interaction hubs, by analogy to other kingdoms. Through their interactions, TPC and AP-2 can modulate CME. Presently, the interactomes of the TPC and AP-2 appendages are completely unknown in plants. We will initiate various complementary approaches to identify interactors of the TPC and AP-2 appendages. Differences in the appendage interactomes will give insight into the functions of TPC and AP-2. To understand how these interactors contribute to the distinct functions of TPC and AP-2, we will study their role in CME. This will be done by determining subcellular localization and mutant analysis. We will also investigate how the appendages bind their interactors. Lastly, we will generate structural models of the TPC appendages, which will allow comparison with the AP-2 appendages on an atomic level. This will generate insight on how TPC and AP-2 execute their differential function as well as insight on their evolution. Our work will bring us closer to being able to modulate how plant cells communicate with each other and the environment.