Arf family GTP loading is activated by, and generates, positive membrane curvature

Small G-proteins belonging to the Arf (ADP-ribosylation factor) family serve as regulatory proteins for numerous cellular processes through GTP-dependent recruitment of effector molecules. In the present study we demonstrate that proteins in this family regulate, and are regulated by, membrane curvature. Arf I and Arf6 were shown to load GTP in a membrane-curvature-dependent manner and stabilize, or further facilitate, changes in membrane curvature through the insertion of an amphipathic helix.