scholarly journals Unsaturated Fatty Acids Repress the Expression of Adipose Fatty Acid Binding Protein (aP2) in RAW 264.7 Macrophages

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Sara Lynn Coleman ◽  
Young‐Ki Park ◽  
Chai Siah Ku ◽  
Ji‐Young Lee
1998 ◽  
Vol 76 (4) ◽  
pp. 593-599 ◽  
Author(s):  
J M Stewart ◽  
T E English ◽  
K B Storey

Hibernating mammals rely heavily on lipid metabolism to supply energy during hibernation. We wondered if the fatty acid binding protein from a hibernator responded to temperature differently than that from a nonhibernator. We found that the Kd for oleate of the liver fatty acid binding protein (1.5 micromolar) isolated from ground squirrel (Spermophilus richardsonii) was temperature insensitive over 5-37°C, while the rat liver fatty acid binding protein was affected with the Kd at 37°C being about half (0.8 micromolar) that found at lower temperatures. This same trend was observed when comparing the specificity of various fatty acids of differing chain length and degree of unsaturation for the two proteins at 5 and 37°C. At the lower temperature, ground squirrel protein bound long-chain unsaturated fatty acids, particularly linoleate and linolenate, at least as well as at the higher temperature and matched requirements for these fatty acids in the diet. The most common long-chain fatty acid, palmitate, was a more effective ligand for ground squirrel liver fatty acid binding protein at 5°C than at 37°C, with the opposite occurring in the eutherm. Rat protein was clearly not adapted to function optimally at temperatures lower than the animal's body temperature.Key words: fatty acid binding protein, temperature, hibernation.


1987 ◽  
Vol 247 (2) ◽  
pp. 485-488 ◽  
Author(s):  
T C Wilkinson ◽  
D C Wilton

1. The fluorescent fatty acid probe 11-(dansylamino)undecanoic acid binds to rat liver fatty acid-binding protein with a 1:1 stoichiometry. 2. The binding of the fluorescent probe is competitive with long-chain fatty acids. 3. Binding displacement studies were performed with a wide range of fatty acids and other ligands and identified C16 and C18 fatty acids as the preferred fatty acids for rat liver fatty acid-binding protein. No preference was observed for unsaturated fatty acids within this group. 4. Fatty acyl-CoA binds less well than the corresponding fatty acid.


1996 ◽  
Vol 271 (1) ◽  
pp. G113-G120 ◽  
Author(s):  
B. A. Luxon

Male livers, containing lesser amounts of fatty acid binding protein (FABP), utilize fatty acids more slowly than female livers. Conventional wisdom dictates that FABP stimulates fatty acid use by increasing cytoplasmic transport rates. Previously, we showed that the cytoplasmic diffusion of a fatty acid analogue [12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (NBD-stearate)] is faster in female hepatocytes, paralleling the larger amounts of FABP. Sex differences in other cytoplasmic factors could also lead to faster diffusion, independent of FABP levels. The aim of this study was to determine the effect of inhibition of fatty acid binding to FABP on the directly measured intracellular transport rate of NBD-stearate. The binding of NBD-stearate to FABP was reduced by incubating hepatocytes isolated from male and female rats with alpha-bromo-palmitate (0-1,500 microM), a modified long-chain fatty acid that binds to FABP. The inhibition by alpha-bromo-palmitate on NBD-stearate binding to FABP was measured with the use of centrifugation to separate cytosol from cytoplasmic membranes. Laser photobleaching (fluorescence recovery after photobleaching) was used to measure the cytoplasmic diffusion of NBD-stearate in hepatocytes. Alpha-Bromo-palmitate incubation reduced NBD-stearate binding to FABP in a dose-dependent manner. The measured diffusion rate was also reduced in proportion to the degree of binding inhibition. We conclude that cytoplasmic transport of NBD-stearate is modulated by binding to soluble proteins like FABP. FABP enhances diffusive transport by reducing binding to immobile cytosolic membranes.


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