Acylation stimulating protein

Lipid and lipoprotein acylation stimulating protein, lipoprotein lipase. 

K. N. Frayn, Coordinated release of acylation stimulating protein (ASP) and triacylglycerol clearance by human adipose tissue in vivo in the postprandial period, J. Lipid Res., 1998, 39, 884-891. 

Critical review of acylation-stimulating protein physiology in humans and rodents, Biochim. Biophys. Acta, 2003, 7609, 127-143. 

A.D. Sniderman, M. Maslowska, and K. Cianflone, Of mice and men (and women) and the acylation-stimulating protein pathway, Curr. Opin. Lipidol, 2000, 77,... 

K. Cianflone, D.A.K. Roncari, M. Maslowska, A. Baldo, J. FoRDEN,andA. D. Sniderman, Adipsin/acylation stimulating protein system in human adipocytes Regulation of triacylglycerol synthesis. Biochemistry, 1994, 33, 9489-9495. 

M. Maslowska, H. Vu, S. Phelis, A. D. Sniderman, B. Rhodes, D. Blank, and K. Cianflone, Plasma acylation stimulating protein, adipsin and lipids in non-ob-ese and obese populations, Eur. J. Clin. 

M. Maslowska, T. Scantlebury, R. Ger-MiNARio, and K. Cianflone, Acute in vitro production of acylation stimulating protein in differentiated human adipocytes, J. Lipid Res., 1997, 38, 1—11. 

K. Cianflone, M. Maslowska, and A.D. Sniderman, Acylation stimulating protein (ASP), an adipocyte autocrine new directions, Semin. Cell. Dev. Biol., 1999,... 

Z. Yasruel, K. Cianflone, A.D. Sniderman, M. Rosenbloom, M. Walsh, and M.A. Rodriguez, Effect of acylation stimulating protein on the triacylglycerol synthetic pathway of human adipose tissue, Lipids, 1991, 26, 495-499,... 

Y.Z. Tao, K. Cianflone, A.D. Sniderman, S.P. Colby-Germinario, and R.J. Germinario, Acylation-stimulating protein (ASP) regulates glucose transport in the rat L6 muscle cell line, Biochim. Biophys. Acta, 1997, 1344, 221-229. 

R. Germinario, A. D. Sniderman, S. Manuel, S.P. Lefebre, A. Baldo, and K. Cianflone, Coordinate regulation of triacylglycerol synthesis and glucose transport by acylation-stimulating protein, Metabolism, 1993, 42, 574-580. 

A. Baldo, A.D. Sniderman, S. St-Luce, X.J. Zhang, and K. Cianflone, Signal transduction pathway of acylation stimulating protein involvement of protein kinase C, /. Lipid Res., 1995, 36, 1415— 1426. 

Acylation stimulating protein (ASP) Decreased Stimulates triacylglycerol synthesis... 

Matthan, N.R. K. Cianflone A.H. Lichtenstein L.M. Ausman M. Jauhiainen P.J.H. Jones. Hydrogenated fat consumption affects acylation- stimulating protein levels and cholesterol esterifica-... 

There are many studies about the interaction between obesity, inflammation, and immune response components. Adiponectin, angiotensinogen, adipsin acylation stimulating protein, tumor necrosis factor-alpha (TNF-a), interleukin 6 (IL-6), and plasminogen activator inhibitor-1 are proteins secreted by fat cells. These proteins regulate lipid metabolism, inflammation, cardiovascular functions, vascular haemostasis, and immunity [91]. There is growing evidence that low-level inflammation linked to the increased risk of developing cardiovascular disease and associated with... 

Figure 21-6. Regulation of acetyl-CoA carboxylase by phosphorylation/dephosphorylation.The enzyme is inactivated by phosphorylation by AMP-activated protein kinase (AMPK), which in turn is phosphorylated and activated by AMP-activated protein kinase kinase (AMPKK). Glucagon (and epinephrine), after increasing cAMP, activate this latter enzyme via cAMP-dependent protein kinase. The kinase kinase enzyme is also believed to be activated by acyl-CoA. Insulin activates acetyl-CoA carboxylase, probably through an "activator" protein and an insulin-stimulated protein kinase.

Fatty acid synthesis and degradation. Fatty acids are synthesized in the cytosol by the addition of two-carbon units to a growing chain on an acyl carrier protein. Malonyl CoA, the activated intermediate, is formed by the carboxylation of acetyl CoA. Acetyl groups are carried from mitochondria to the cytosol as citrate by the citrate-malate shuttle. In the cytosol, citrate is cleaved to yield acetyl CoA. In addition to transporting acetyl CoA, citrate in the cytosol stimulates acetyl CoA carboxylase, the enzyme catalyzing the committed step. When ATP and acetyl CoA are abundant, the level of citrate increases, which accelerates the rate of fatty acid synthesis (Figure 30.8). 

Decker H, Summers RG, Hutchinson CR, Overproduction of the acyl carrier protein component of a type 11 polyketidc synthase stimulates production of teiracenomycin biosynthetic intermediates in Streptomyces glaucejceru, J Antibiot 1994 47 54-63. 

Schweeke T, Aparicio ]F, Molnar I, Konig A, Khaw LE, Haydock SF, Oliynyk M, Caffrey P, Cortes J, Lester JB, Elohm GA, Staunton J, Leadlay PF. The biosynthesis gene duster for the polyketide immunosuppressant rapamycin. Proc Natl Acad Sci USA 1995 93 7839-7843, Decker H, Summers RG, Hutchinson CR. Overproduction of all of the components of a type II polyketide synthase or only the acyl carrier protein stimulates the production of tetra-cenomycin C biosynthetic intermediates In Streptomyees glaMcescens. J Amibioc 1994 47 54-63. 

A few enzymes, such as the previously mentioned CNP, are believed to be fairly specific for myelin/oligodendro-cytes. There is much more in the CNS than in peripheral nerve, suggesting some function more specialized to the CNS. In addition, a unique pH 7.2 cholesterol ester hydrolase is also enriched in myelin. On the other hand, there are many enzymes that are not myelin-specific but appear to be intrinsic to myelin and not contaminants. These include cAMP-stimulated kinase, calcium/calmodulin-dependent kinase, protein kinase C, a neutral protease activity and phosphoprotein phosphatases. The protein kinase C and phosphatase activities are presumed to be responsible for the rapid turnover of MBP phosphate groups, and the PLP acylation enzyme activity is also intrinsic to myelin. 

The role of protein kinase C in many neutrophil functions is undisputed and has been recognised for some time. For many years it was believed that the source of DAG, the activator of protein kinase C, was derived from the activity of PLC on membrane phosphatidylinositol lipids. Whilst this enzyme undoubtedly does generate some DAG (which may then activate protein kinase C), there are many reasons to indicate that this enzyme activity is insufficient to account for all the DAG generated by activated neutrophils. More recently, experimental evidence has been provided to show that a third phospholipase (PLD) is involved in neutrophil activation, and that this enzyme is probably responsible for the majority of DAG that is formed during cell stimulation. The most important substrate for PLD is phosphatidylcholine, the major phospholipid found in neutrophil plasma membranes, which accounts for over 40% of the phospholipid pool. The sn-1 position of phosphatidylcholine is either acyl linked or alkyl linked, whereas the sn-2 position is invariably acyl linked. In neutrophils, alkyl-phosphatidylcholine (1-0-alky 1-PC) represents about 40% of the phosphatidylcholine pool (and is also the substrate utilised for PAF formation), whereas the remainder is diacyl-phosphatidylcholine. Both of these types of phosphatidylcholine are substrates for PLD and PLA2. 

Fatty acid utilized by muscle may arise from storage triglycerides from either adipose tissue depot or from lipid stores within the muscle itself. Lipolysis of adipose triglyceride in response to hormonal stimulation liberates free fatty acids (see Section 9.6.2) which are transported through the bloodstream to the muscle bound to albumin. Because the enzymes of fatty acid oxidation are located within subcellular organelles (peroxisomes and mitochondria), there is also need for transport of the fatty acid within the muscle cell this is achieved by fatty acid binding proteins (FABPs). Finally, the fatty acid molecules must be translocated across the mitochondrial membranes into the matrix where their catabolism occurs. To achieve this transfer, the fatty acids must first be activated by formation of a coenzyme A derivative, fatty acyl CoA, in a reaction catalysed by acyl CoA synthetase. 

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