The MAP1-LC3 conjugation system is involved in lipid droplet formation
Section snippets
Materials and methods
Antibodies. Antibodies to rat full-length LC3 [12] were prepared by immunizing the recombinant rat full-length LC3 protein. Antibodies were purified from anti-sera with affinity chromatography coupled with antigens. Anti-perilipin, anti-ApoB, and anti-GAPDH antibodies were purchased from Progen and Ambion.
Measurement of total triacylglycerol. Cells or tissues were lysed in 0.02% of SDS and total lipids were extracted using the method of Bligh and Dyer [13]. Triacylglycerol contents in the
LD formation is suppressed in hepatocytes by an Atg7 deficiency
LDs accumulate abundantly in the cytoplasm of hepatocytes when mice are starved for 12 to 48 h. We first examined whether LDs are normally formed in the liver of conditional Atg7-deficient mice (Atg7flox/flox: Albumin-Cre) at 22 days of age after weaning. LDs stained with 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY), an indicator for neutral lipids like TAG [18], were sparsely detected in hepatocytes of Atg7-deficient mouse livers under starvation conditions for 12 h,
Acknowledgments
The authors thank K. Ikeue, K. Ohta, A. Koseki and K. Isahara for technical assistance. This work was supported by a grant-in-aid for Creative Scientifc Research (to Y.U., M.K., M.S. and T.U.) from the Japan Society for the Promotion of Science.
References (24)
Lipid droplet accumulation in the heart during fasting
Acta Histochem.
(1987)- et al.
Participation of autophagy in storage of lysosomes in neurons from mouse models of neuronal ceroid-lipofuscinoses (Batten disease)
Am. J. Pathol.
(2005) - et al.
A method for the isolation of lipid droplet fractions from decapsulated rat adrenals
Steroids
(1981) - et al.
Regulated localization of Rab18 to lipid droplets: effects of lipolytic stimulation and inhibition of lipid droplet catabolism
J. Biol. Chem.
(2005) - et al.
Perilipins, ADRP, and other proteins that associate with intracellular neutral lipid droplets in animal cells
Semin. Cell Dev. Biol.
(1999) The biogenesis and functions of lipid bodies in animals, plants and microorganisms
Prog. Lipid Res.
(2001)- et al.
Mobilisation of triacylglycerol stores
Biochim. Biophys. Acta
(2000) - et al.
Atg8, a ubiquitin-like protein required for autophagosome formation, mediates membrane tethering and hemifusion
Cell
(2007) - et al.
Intracellular protein catabolism and its control during nutrient deprivation and supply
Annu. Rev. Nutr.
(1987) - et al.
Loss of autophagy in the central nervous system causes neurodegeneration in mice
Nature
(2006)
Suppression of basal autophagy in neural cells causes neurodegenerative disease in mice
Nature
The role of autophagy during the early neonatal starvation period
Nature
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These authors equally contributed to this work.