Long-chain acyl-CoA esters and acyl-CoA binding protein are present in the nucleus of rat liver cells.
A detailed analysis of the subcellular distribution of acyl-CoA esters in rat liver revealed that significant amounts of long-chain acyl-CoA esters are present in highly purified nuclei. No contamination of microsomal or mitochondrial marker enzymes was detectable in the nuclear fraction. C16:1 and C18:3-CoA esters were the most abundant species, and thus, the composition of acyl-CoA esters in the nuclear fraction deviates notably from the overall composition of acyl-CoA esters in the cell. After intravenous administration of the non-beta-oxidizable [(14)C]tetradecylthioacetic acid (TTA), the TTA-CoA ester could be recovered from the nuclear fraction. Acyl-CoA esters bind with high affinity to the ubiquitously expressed acyl-CoA binding protein (ACBP), and several lines of evidence suggest that ACBP functions as a pool former and transporter of acyl-CoA esters in the cytoplasm. By using immunohistochemistry, immunofluorescence microscopy, and immunoelectron microscopy we demonstrate that ACBP localizes to the nucleus as well as the cytoplasm of rat liver cell and rat hepatoma cells, suggesting that ACBP may also be involved in regulation of acyl-CoA-dependent processes in the nucleus.
Elholm
M
M
Department of Clinical Chemistry, University of Bergen, N-5021 Bergen, Norway.
Garras
A
A
Neve
S
S
Tornehave
D
D
Lund
T B
TB
Skorve
J
J
Flatmark
T
T
Kristiansen
K
K
Berge
R K
RK
D000214:Acyl Coenzyme A / Q000302:isolation & purification*; D000818:Animals; D000918:Antibody Specificity; D019556:COS Cells; D002352:Carrier Proteins / Q000276:immunology / Q000302:isolation & purification*; D002451:Cell Compartmentation; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000737:chemistry* / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D003593:Cytoplasm / Q000737:chemistry; D026261:Diazepam Binding Inhibitor; D005227:Fatty Acids / Q000302:isolation & purification; D005455:Fluorescent Antibody Technique; D008099:Liver / Q000737:chemistry* / Q000648:ultrastructure; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013440:Sulfides / Q000378:metabolism; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
D000214:Acyl Coenzyme A; D002352:Carrier Proteins; D026261:Diazepam Binding Inhibitor; D005227:Fatty Acids; D013440:Sulfides; C062078:1-(carboxymethylthio)tetradecane