Intact alpha-subunit is required for membrane-binding of human mitochondrial trifunctional beta-oxidation protein, but is not necessary for conferring 3-ketoacyl-CoA thiolase activity to the beta-subunit.
We have studied the activities of alpha and beta subunit enzymes of the beta-oxidation trifunctional protein complex in a patient who does not process the alpha-subunit. Long-chain 3-ketoacyl-CoA thiolase, the beta-subunit enzyme, was transported into the mitochondrial matrix, where it expressed normal levels of activity, but was not translocated to the membrane. Thus, intact alpha-subunit is required for trifunctional protein membrane translocation, but is not necessary for conferring activity of the beta-subunit.
Weinberger
M J
MJ
Department of Pathology, University of Texas Southwestern Medical Center at Dallas 75235, USA.
Rinaldo
P
P
Strauss
A W
AW
Bennett
M J
MJ
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000172:deficiency / Q000378:metabolism; D000102:Acetyl-CoA C-Acyltransferase / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D007231:Infant, Newborn; D007425:Intracellular Membranes / Q000378:metabolism; D008052:Lipid Metabolism, Inborn Errors / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000201:enzymology; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D063991:Mitochondrial Trifunctional Protein; D009097:Multienzyme Complexes / Q000378:metabolism*; D011485:Protein Binding; D012867:Skin / Q000166:cytology / Q000378:metabolism
D009097:Multienzyme Complexes; D015094:3-Hydroxyacyl CoA Dehydrogenases; D000102:Acetyl-CoA C-Acyltransferase; D063991:Mitochondrial Trifunctional Protein