Premium
Incorporation of Arachidonic and Stearic Acids Bound to L‐FABP into Nuclear and Endonuclear Lipids from Rat Liver Cells
Author(s) -
Maté Sabina M.,
Layerenza Juan P.,
VesLosada Ana
Publication year - 2007
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-007-3063-3
Subject(s) - biochemistry , fatty acid , arachidonic acid , chemistry , stearic acid , clinical chemistry , free fatty acid receptor , polyunsaturated fatty acid , enzyme , organic chemistry
The incorporation of exogenous fatty acids bound to L‐FABP into nuclei was studied. Rat liver cell nuclei and nuclear matrices (membrane depleted nuclei) were incubated in vitro with [1‐ 14 C]18:0 and 20:4n‐6 either free or bound to L‐FABP, ATP and CoA. FA esterification in whole nuclei and endonuclear lipids was ATP‐CoA‐dependent, and with specificity regarding fatty acid type and lipid class. 18:0 and 20:4n‐6, free or L‐FABP bound, showed the same incorporation and esterification pattern in lipids of whole nuclei. Only 20:4n‐6 L‐FABP bound was less incorporated into TAG with respect to free 20:4n‐6. In the nuclear matrix, 18:0 free or L‐FABP bound was esterified with a higher specific activity (SA) into: PtdEtn > PtdIns, PtdSer > PtdCho. 20:4n‐6 free or L‐FABP bound was esterified into: PtdIns > PtdEtn > PtdCho. 20:4n‐6:L‐FABP was esterified in endonuclear total‐PL and PtdIns with a greater SA with respect to free 20:4n‐6 and with a minor one as FFA. To summarize, trafficking of FA to nuclei includes esterification of 18:0 and 20:4n‐6 either free or L‐FABP‐bound, into nuclear and endonuclear lipids by an ATP‐CoA‐dependent pathway. Endonuclear fatty acid esterification was more active than that in whole nuclei, and independent of the nuclear membrane. Esterification patterns of fatty acids L‐FABP‐bound or free into whole nuclear lipids were the same whereas in the nuclear matrix, L‐FABP could play an important role in the mobilization of 20:4n‐6 into specific sites of utilization such as the PtdIns pools.