The ATP binding cassette transporter, ABCG1, localizes to cortical actin filaments.
The ATP-binding cassette sub-family G member 1 (ABCG1) exports cellular cholesterol to high-density lipoproteins (HDL). However, a number of recent studies have suggested ABCG1 is predominantly localised to intracellular membranes. In this study, we found that ABCG1 was organized into two distinct cellular pools: one at the plasma membrane and the other associated with the endoplasmic reticulum (ER). The plasma membrane fraction was organized into filamentous structures that were associated with cortical actin filaments. Inhibition of actin polymerization resulted in complete disruption of ABCG1 filaments. Cholesterol loading of the cells increased the formation of the filamentous ABCG1, the proximity of filamentous ABCG1 to actin filaments and the diffusion rate of membrane associated ABCG1. Our findings suggest that the actin cytoskeleton plays a critical role in the plasma membrane localization of ABCG1.
Biomedical Imaging Facility, Mark Wainwright Analytical Centre, UNSW Australia, Sydney, Australia.|EMBL Australia Node in Single Molecule Science, School of Medical Sciences, UNSW Australia, Sydney, Australia.
Elvis
E
Pandzic
Faculty of Pharmacy, University of Sydney, Sydney, Australia.
Ingrid C
IC
Gelissen
Biomedical Imaging Facility, Mark Wainwright Analytical Centre, UNSW Australia, Sydney, Australia.
Renee
R
Whan
School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, Australia.|Faculty of Medicine, University of Sydney, Australia.
Philip J
PJ
Barter
Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
Dmitri
D
Sviridov
EMBL Australia Node in Single Molecule Science, School of Medical Sciences, UNSW Australia, Sydney, Australia.|ARC Centre of Excellence in Advanced Molecular Imaging, UNSW Australia, Sydney, Australia.
Katharina
K
Gaus
School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, Australia.|Faculty of Medicine, University of Sydney, Australia.
Kerry-Anne
KA
Rye
School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, Australia.
Blake J
BJ
Cochran
D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1 / Q000378:metabolism* / Q000502:physiology; D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D003412:Cricetulus; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000382:microbiology; D008075:Lipoproteins, HDL / Q000378:metabolism; D014162:Transfection
D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D008075:Lipoproteins, HDL; D002784:Cholesterol