Expanding roles of ABCG1 and sterol transportTarling, Elizabeth J.Current Opinion in Lipidology: April 2013 - Volume 24 - Issue 2 - p 138–146 doi: 10.1097/MOL.0b013e32835da122 GENETICS AND MOLECULAR BIOLOGY: Edited by Robert Hegele Abstract Author Information Purpose of review To offer a comprehensive review on the role of ABCG1 in cellular sterol homeostasis. Recent findings Early studies with Abcg1−/− mice indicated that ABCG1 was crucial for tissue lipid homeostasis, especially in the lung. More recent studies have demonstrated that loss of ABCG1 has wide-ranging consequences and impacts lymphocyte and stem cell proliferation, endothelial cell function, macrophage foam cell formation, as well as insulin secretion from pancreatic β cells. Recent studies have also demonstrated that ABCG1 functions as an intracellular lipid transporter, localizes to intracellular vesicles/endosomes, and that the transmembrane domains are sufficient for localization and transport function. Summary ABCG1 plays a crucial role in maintaining intracellular sterol and lipid homeostasis. Loss of this transporter has significant, cell-type-specific consequences ranging from effects on cellular proliferation, to surfactant production and/or insulin secretion. Elucidation of the mechanisms by which ABCG1 affects intracellular sterol flux/movement should provide important information that may link ABCG1 to diseases of dysregulated tissue lipid homeostasis. Departments of Biological Chemistry and Medicine, David Geffen School of Medicine at UCLA, University of California, Los Angeles, California, USA Correspondence to Elizabeth J. Tarling, UCLA Biological Chemistry, 625 Charles E. Young Dr S., Box 951737 BSRB #337, Los Angeles, CA 90095–1737, USA. Tel: +1 310 206 8383; e-mail: ETarling@mednet.ucla.edu © 2013 Lippincott Williams & Wilkins, Inc.