| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
* Department of Molecular Pathology, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Sagamihara, Kanagawa 199-0195, Japan
Department of Biological Chemistry, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
Section of Cardiology, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112
** Department of Molecular Health Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Sagamihara, Kanagawa 199-0195, Japan
Published, JLR Papers in Press, March 22, 2007.
1 Present address of Y. Fujimoto: School of Pharmacy, Iwate Medical University, Yahaba, Iwate 028-3694, Japan (yfujimot{at}iwate-med.ac.jp).
2 To whom correspondence should be addressed. e-mail: t_takano{at}pharm.teikyo-u.ac.jp
Lipid droplets (LDs) function as intracellular storage depots of neutral lipids. Recently, we identified long-chain acyl-coenzyme A synthetase 3 (ACSL3) as a major LD-associated protein in the human hepatocyte cell line HuH7. In this study, we investigated whether droplet-associated ACSL is involved in lipid metabolism in LDs. Addition of oleic acid (OA) to culture medium was shown to enhance the intracellular accumulation of LDs in the cells, which was accompanied by an increase of droplet ACSL3. When LD-enriched cells induced by OA were further incubated without OA for 3 days, 
80% of LDs were retained in the cells. Conversely, cellular LD content was greatly decreased after the addition of an ACSL inhibitor, triacsin C. This was accompanied by a concomitant decrease of the droplet ACSL3. Incubation of isolated LD fractions with 14C-labeled OA or palmitic acid resulted in [14C]acyl-CoA generation in vitro, indicating the presence of ACSL activity in LDs. The droplet ACSL activity varied according to the quantity of LDs in their emergence and disappearance in cells. Incubation of the LD fraction with [14C]oleoyl-CoA resulted in radioactive triacylglycerol and cholesteryl esters. These results suggest that LD ACSL activity is involved in local synthesis of neutral lipids and LD formation.
Supplementary key words triacsin C • triacylglycerol • acyl-coenzyme A
Abbreviations: ACSL, long-chain acyl-coenzyme A synthetase; ADRP, adipose differentiation-related protein; CE, cholesteryl ester; DG, diacylglycerol; DGAT, acyl-coenzyme A:diacylglycerol acyltransferase; ER, endoplasmic reticulum; FC, free cholesterol; LD, lipid droplet; LDH, lactate dehydrogenase; MAM, mitochondria-associated membrane; NSDHL, NAD(P)H steroid dehydrogenase-like protein; OA, oleic acid; PNS, postnuclear supernatant; TG, triacylglycerol
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Bionaz and J. J. Loor ACSL1, AGPAT6, FABP3, LPIN1, and SLC27A6 Are the Most Abundant Isoforms in Bovine Mammary Tissue and Their Expression Is Affected by Stage of Lactation J. Nutr., June 1, 2008; 138(6): 1019 - 1024. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Yao and J. Ye Long Chain Acyl-CoA Synthetase 3-mediated Phosphatidylcholine Synthesis Is Required for Assembly of Very Low Density Lipoproteins in Human Hepatoma Huh7 Cells J. Biol. Chem., January 11, 2008; 283(2): 849 - 854. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |
