Endophilin Rapidly Bends Membranes to Promote Endocytosis

Abstract

Synaptic Vesicle (SV) endocytosis is responsible for generating synaptic vesicles at the presynaptic terminals. To sustain high-frequency brain activities, endocytosis must act rapidly to regenerate SVs, which prevents vesicles from depletion. Endophilin is a synaptic protein that plays critical role in promoting SV endocytosis. Endophilin contains a Bin-Amphiphysin-Rvs (BAR) domain that has been shown to bend flat membranes into highly curved tubules in vitro. Our recent findings demonstrate that the membrane-bending activity is required for endophilin's function in vivo. Here, we perform biophysical analyses to investigate molecular mechanisms for endophilin to generate membrane curvature. Our preliminary results show that the endophilin BAR domain is an active membrane bender instead of a passive sensor. These results will help us to understand how endophilin acts to support SV endocytosis in neurons.