title: The perilipin-2 (adipophilin) coat of cytosolic lipid droplets is regulated by an Arf1-dependent mechanism in HC11 mouse mammary epithelial cells.
abstract: The cytosolic lipid droplets (cLDs) store excess intracellular lipids, and perilipin-2 is believed to protect cLDs from degradation. Here, we investigated the role of the small G-protein Arf1 and the proteasome in the fates of perilipin-2 and cLDs. In oleate-loaded cells, upon brefeldin A (BFA) treatment, perilipin-2 remained associated with cLDs for at least 30 min before significant release, and proteasomal degradation-mediated decrease was observed. Interestingly, the cLD population did not mimic the decline in perilipin-2. We tested several chemical modulators of regulators of Arf1 activity on the association of perilipin-2 with cLDs. QS11 and Exo2 accelerated the reduction in perilipin-2, although less than BFA. In contrast, Exo1 unexpectedly slowed down its degradation. Correlatively, BFA, QS11, and Exo2 enhanced the dissociation of perilipin-2 from cLDs, whereas Exo1 inhibited it. There was a synergistic effect of BFA with Exo2 and QS11, and of Exo2 with QS11, whereas Exo1 antagonized the effect of BFA without affecting that of Exo2 or QS11. We concluded that the Arf1 complex regulates the association of perilipin-2 with cLDs. Additionally, MG132 and BFA modified the number of cLDs over a relatively short period.
authors.affiliation: INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Pauloin
authors.affiliation: INRA-CRJ MIMA2 Platform, Domaine de Vilvert, UMR1198 Biologie du Développement et Reproduction, Domaine de Vilvert, F-78352 Jouy-en-Josas, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Adenot
authors.affiliation: INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Hue-Beauvais
authors.affiliation: INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Chanat
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D066292:Lipid Droplets / Q000378:metabolism; D050356:Lipid Metabolism; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D019301:Oleic Acid; D000070778:Perilipin-1; D000070780:Perilipin-2; D010750:Phosphoproteins / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D000070778:Perilipin-1; D000070780:Perilipin-2; D010750:Phosphoproteins; C000602983:Plin2 protein, mouse; D019301:Oleic Acid; D046988:Proteasome Endopeptidase Complex; D020823:ADP-Ribosylation Factor 1
keywords: Arf1; HC11; brefeldin A; epithelial cell; lipid droplet; mammary gland; perilipin