Abstract:
Endocytosis and recycling pathways regulate the display of receptors on the plasma membrane. Cells regulate recycling of membrane receptors by sorting them to tubular recycling endosomes. The ATP-binding protein, EHD1 (EPS 15 homology domain-containing protein 1) is known to localize to recycling endosomes. Cells depleted of EHD1 show defective recycling. Our work describes the membrane-active functions of this protein. We show that ATP-binding is necessary for membrane recruitment and modulates its distribution in cells. EHD1 displays preferential binding to highly curved membranes tubes, and bulges the underlying membrane. ATP hydrolysis promotes self-assembly of the polymer which triggers extensive membrane remodeling of membrane tube, leading to fission. Deletion of N-terminal residues of EHD1 causes a defect in bulge expansion and membrane fission. Comparing EHD1 to a closely related paralog, EHD2, we show at that EHD2 has a slower ATPase activity and is less effective in membrane remodeling
