Malonyl-CoA decarboxylase is present in the cytosolic, mitochondrial and peroxisomal compartments of rat hepatocytes.
A role for cytosolic malonyl-CoA decarboxylase (MCD) as a regulator of fatty acid oxidation has been postulated. However, there is no direct evidence that MCD is present in the cytosol. To address this issue, we performed cell fractionation and electron microscopic colloidal gold studies of rat liver to determine the location and activity of MCD. By both methods, substantial amounts of MCD protein and activity were found in the cytosol, mitochondria and peroxisomes, the latter with the highest specific activity. MCD species with different electrophoretic mobility were observed in the three fractions. The data demonstrate that active MCD is present in the cytosol, mitochondria and peroxisomes of rat liver, consistent with the view that MCD participates in the regulation of cytosolic malonyl-CoA levels and of hepatic fatty acid oxidation.
Joly
Erik
E
Molecular Nutrition Unit and the Montreal Diabetes Research Center, Centre de recherche du CHUM, Pavillon de Sève, Y-4603, 1560 Sherbrooke Est, and the Department of Nutrition and Biochemistry, Université de Montréal, Montréal PQ, Canada, H3T 1C5.
Bendayan
Moise
M
Roduit
Raphaël
R
Saha
Asish K
AK
Ruderman
Neil B
NB
Prentki
Marc
M
D000818:Animals; D002262:Carboxy-Lyases / Q000032:analysis* / Q000502:physiology; D002458:Cell Fractionation; D003600:Cytosol / Q000201:enzymology*; D022781:Hepatocytes / Q000166:cytology*; D008297:Male; D008854:Microscopy, Electron; D008930:Mitochondria, Liver / Q000201:enzymology; D020675:Peroxisomes / Q000201:enzymology; D051381:Rats; D017207:Rats, Sprague-Dawley
D002262:Carboxy-Lyases; C021532:malonyl-CoA decarboxylase