TY - JOUR
T1 - Regulation of the long-chain carnitine acyltransferases
AU - Brady, Paul S.
AU - Ramsay, Rona R.
AU - Brady, Linda J.
PY - 1993
Y1 - 1993
N2 - Long-chain carnitine acyltransferases are a family of enzymes found in mitochondria, peroxisomes, and endoplasmic reticulum that catalyze the exchange of carnitine for coenzyme A in the fatty acyl-CoA. Conversion of the fatty acyl-CoA to fatty acylcarnitine renders the fatty acid more permeable to the various cellular membranes. The mitochondrial carnitine palmitoyltransferases are considered important in the regulation of mitochondrial β-oxidation of long-chain fatty acids. However, palmitoylcarnitine produced by peroxisomal carnitine octanoyltransferase or by microsomal carnitine palmitoyltransferase is not different from that produced by the mitochondrial enzyme. Therefore, for there to be control of fatty acid oxidation by the long-chain carnitine acyltransferases, there would have to be some mechanism to coordinately regulate these varied enzymes. The first system of regulation involves inhibition by malonyl-CoA, an intermediate in the synthesis of fatty acids. Malonyl-CoA inhibits long- chain carnitine acyltransferase activity by all three enzymes at similar concentrations in the physiological range. In addition, the mitochondrial and peroxisomal enzymes are known to be regulated at the level of mRNA transcription by a number of shared factors. Although the microsomal enzyme is less well studied, there does, indeed, appear to be a pattern of coordinate regulation for this system.
AB - Long-chain carnitine acyltransferases are a family of enzymes found in mitochondria, peroxisomes, and endoplasmic reticulum that catalyze the exchange of carnitine for coenzyme A in the fatty acyl-CoA. Conversion of the fatty acyl-CoA to fatty acylcarnitine renders the fatty acid more permeable to the various cellular membranes. The mitochondrial carnitine palmitoyltransferases are considered important in the regulation of mitochondrial β-oxidation of long-chain fatty acids. However, palmitoylcarnitine produced by peroxisomal carnitine octanoyltransferase or by microsomal carnitine palmitoyltransferase is not different from that produced by the mitochondrial enzyme. Therefore, for there to be control of fatty acid oxidation by the long-chain carnitine acyltransferases, there would have to be some mechanism to coordinately regulate these varied enzymes. The first system of regulation involves inhibition by malonyl-CoA, an intermediate in the synthesis of fatty acids. Malonyl-CoA inhibits long- chain carnitine acyltransferase activity by all three enzymes at similar concentrations in the physiological range. In addition, the mitochondrial and peroxisomal enzymes are known to be regulated at the level of mRNA transcription by a number of shared factors. Although the microsomal enzyme is less well studied, there does, indeed, appear to be a pattern of coordinate regulation for this system.
KW - carnitine octanoyltransferase
KW - carnitine palmitoyltransferase
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U2 - 10.1096/fasebj.7.11.8370473
DO - 10.1096/fasebj.7.11.8370473
M3 - Review article
C2 - 8370473
AN - SCOPUS:0027160660
VL - 7
SP - 1039
EP - 1044
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 11
ER -