Hormone-sensitive lipase of rat adipose tissue correlation of activity with a protein of molecular weight 84 000

Khoo, John C.; Berglund, Lars; Jensen, D.; Steinberg, Daniel

doi:10.1016/0005-2760(80)90096-x

Cited by 17 publications

(3 citation statements)

References 7 publications

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“…This enzyme, partially purified from rat (23,24) and chicken (25) adipose tissue, is phosphorylated/activated by cAMP-dependent protein kinase and dephosphorylated/deactivated by phosphoprotein phosphatases of various origins (34). Hormone-sensitive lipase has not been isolated or characterized from tissues other than adipose tissue [the adrenal is the only exception to date (26,27)] and thus provides a unique marker for this cell type.…”

Section: Discussionmentioning

confidence: 99%

“…The increase in levels ofthese enzymes and receptors, together with the accumulation ofstored triglycerides, strongly supports the conclusion of Green and coworkers that the 3T3-L1 cell can serve as a model for studies ofadipose tissue metabolism. However, thus far there is no evidence for the expression of the most characteristic and functionally important enzyme of adipose tissue-hormone-sensitive lipase, the neutral lipase activated by cyclic AMP (cAMP)-dependent protein kinase that controls rates of lipid mobilization (20)(21)(22)(23)(24)(25). This enzyme appears to be unique to the adipocyte.…”

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confidence: 99%

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Hormone-sensitive lipase in differentiated 3T3-L1 cells and its activation by cyclic AMP-dependent protein kinase.

Kawamura¹,

Jensen²,

Wancewicz³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

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Differentiation of 3T3-L1 fibroblasts to adipo- 3T3-L1 fibroblasts, a subclone of Swiss mouse embryo 3T3 fibroblasts isolated by , are capable of differentiating into adipocyte-like cells engorged with cytoplasmic lipid droplets. The differentiation can be accelerated by treating 3T3-Ll fibroblasts with serum (4), insulin (2), biotin (5), or 1-methyl-3-isobutylxanthine (MIX) (6). Rubin et al. (7) found the combination of MIX and dexamethasone (DEX) to be highly effective. The accumulation oftriglyceride is accompanied by a marked increase in the specific activities of several enzymes involved in fatty acid synthesis and triglyceride synthesis (2, 5, 7-10). There is also an increase in lipoprotein lipase which allows the cells to utilize efficiently the fatty acids from lipoproteins in the medium (11-15). The differentiated 3T3-Ll cells acquire hormone receptors for insulin (7,(16)(17)(18), l3-adrenergic agonists, and adrenocorticotropic hormone (corticotropin) (19). The increase in levels ofthese enzymes and receptors, together with the accumulation ofstored triglycerides, strongly supports the conclusion of Green and coworkers that the 3T3-L1 cell can serve as a model for studies ofadipose tissue metabolism. However, thus far there is no evidence for the expression of the most characteristic and functionally important enzyme of adipose tissue-hormone-sensitive lipase, the neutral lipase activated by cyclic AMP (cAMP)-dependent protein kinase that controls rates of lipid mobilization (20)(21)(22)(23)(24)(25). This enzyme appears to be unique to the adipocyte. The only other tissue in which it has been reported is the adrenal (26, 27). Attempts in this laboratory to demonstrate it in rat heart, skeletal muscle, and liver under various conditions have been negative (unpublished results). Severson (28) reported negative results in rat heart. It has been shown that treatment with dibutyryl cAMP and epinephrine over a period of 2 weeks reduces the accumulation of lipid in 3T3-L1 cells (1), suggesting the presence of a hormone-sensitive lipase. However, the observed reduction in lipid accumulation could be due to inhibition ofthe biosynthesis offatty acid and triglyceride.The studies reported here demonstrate a striking increase (19-fold) in neutral triglyceride lipase during differentiation. Concurrently, basal rate of glycerol release increased by more than 1 order ofmagnitude and glycerol release was further stimulated 3-fold by isoproterenol. Finally, the neutral triglyceride lipase activity in differentiated cells was increased 2-fold by treatment with cAMP-dependent protein kinase. MATERIALS AND METHODSMaterials. Labeled triolein, diolein, and monoolein (containing [1-'4C]oleic acid distributed randomly among the acylated positions) and cholesteryl [1-'4C]oleate were purchased from Rosechem (Los Angeles, CA). Dulbecco's modified Eagle's medium, fetal calf serum, penicillin, and streptomycin were obtained from Irvine Scientific (Santa Ana, CA). MIX was from Aldrich, isoproterenol hydrochloride was from Br...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Hormone-sensitive lipase in differentiated 3T3-L1 cells and its activation by cyclic AMP-dependent protein kinase.

Kawamura¹,

Jensen²,

Wancewicz³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

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“…This is the first report of such regulation for lipid mobilizing systefias in fish. Although activation of adipose tissue lipase has been reported by a number of investigators (Khoo and Steinberg 1974;Belfrage et al 1977;Berglund et al 1980;Fredrikson et al 1981), mammalian hepatic lipase does not appear to be affected by cAMP (Debeer et al 1979).…”

Section: A Ctivationmentioning

confidence: 93%

Purification and characterization of hepatic triacylglycerol lipase isolated from rainbow trout,Oncorhynchus mykiss

Harmon

Michelsen

Sheridan

1991

Fish Physiol Biochem

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Trialcylglycerol (TG) lipase was isolated and partially purified from rainbow trout liver. Triacylglycerol lipase activity was assayed by measuring(14)C-oleic acid release from(14)C-triolein.(14)C-oleic acid release was linear for up to two hours. Optimal activity occurred at pH 7.0 and 15°C. Most of the lipase activity was recovered in the cytosolic fraction. A 27,000-fold purification was achieved after Sepharose (Bio-gel A 0.5 M, 200-400 mesh) chromatography of a resuspended 20% ammonium sulfate fraction. The molecular weight of the trout hepatic lipase as determined by size-exclusion chromatography and by SDS-polyacrylamide gel electrophoresis was 40-43 kD. Lipase-mediated hydrolysis of TG resulted in the production of diacylglycerols, monoacylglycerols, and fatty acids. Kinetic analysis indicated that Vmax=0.016 nmol/h/mg protein and that Km=0.28 mM triolein. Lipolytic activity was enhanced in the presence of cAMP/ATP-Mg(2+). These results suggest that the liver of trout possesses a neutral TG lipase that is responsible for mobilizing stored TG and is catalytically activated by phosphorylation.

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Lipases, Cholesterylesterases and Carboxylesterases in Lymphoid Cell Lines: Substrate Specificity and Relation to Wolman’s, Cholesteryl Ester Storage Diseases and Lipid Storage Myopathy

Salvayre

Nègre

Maret

et al. 1986

Enzymes of Lipid Metabolism II

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Hormone-sensitive lipase of rat adipose tissue correlation of activity with a protein of molecular weight 84 000

Cited by 17 publications

References 7 publications

Hormone-sensitive lipase in differentiated 3T3-L1 cells and its activation by cyclic AMP-dependent protein kinase.

Hormone-sensitive lipase in differentiated 3T3-L1 cells and its activation by cyclic AMP-dependent protein kinase.

Purification and characterization of hepatic triacylglycerol lipase isolated from rainbow trout,Oncorhynchus mykiss

Lipases, Cholesterylesterases and Carboxylesterases in Lymphoid Cell Lines: Substrate Specificity and Relation to Wolman’s, Cholesteryl Ester Storage Diseases and Lipid Storage Myopathy

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