Figure 2

Models of ABCA1-mediated lipidation of apoA-I. (A) ABCA1 moves FC and PL from the inner to outer leaflet of the plasma membrane, and then loads FC and PL onto apoA-I to generate HDL. (B) ApoA-I binds to ABCA1, C-terminal domain of apoA-I inserts into the region of the perturbed PL bilayer created by ABCA1 and then is lipidated. (C) The binding between apoA-I and ABCA1 generates FC and PL-rich membrane domains. ApoA-I then interacts with lipid domains to promote their solubilization and release from the cells. (D) ABCA1- and apoA-I-containing vesicles endocytose in cytoplasm, ABCA1 pumps lipids into the vesicle lumen and then apoA-I is lipidated. HDL is released through exocytosis.