Architecture of the ESCPE-1 membrane coat
Carlos Lopez-Robles, Stefano Scaramuzza, Elsa N. Astorga‐Simón, Morié Ishida, Chad D. Williamson, Soledad Baños-Mateos, David Gil‐Carton, Miguel Romero‐Durana, Ander Vidaurrazaga, Juan Fernández‐Recio, Adriana L. Rojas, Juan S. Bonifacino, Daniel Castaño‐Díez, Aitor Hierro
Abstract
Recycling of membrane proteins enables the reuse of receptors, ion channels and transporters. A key component of the recycling machinery is the endosomal sorting complex for promoting exit 1 (ESCPE-1), which rescues transmembrane proteins from the endolysosomal pathway for transport to the trans-Golgi network and the plasma membrane. This rescue entails the formation of recycling tubules through ESCPE-1 recruitment, cargo capture, coat assembly and membrane sculpting by mechanisms that remain largely unknown. Herein, we show that ESCPE-1 has a single-layer coat organization and suggest how synergistic interactions between ESCPE-1 protomers, phosphoinositides and cargo molecules result in a global arrangement of amphipathic helices to drive tubule formation. Our results thus define a key process of tubule-based endosomal sorting.