CPT1A,B transfers PALM to CAR

Stable Identifier
Reaction [transition]
Homo sapiens
palmitoyl-CoA + carnitine => palmitoylcarnitine + CoASH
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Carnitine palmitoyl transferase 1 (CPT1) associated with the inner mitochondrial membrane, catalyzes the reaction of palmitoyl-CoA (PALM-CoA) from the cytosol with carnitine (CAR) in the mitochondrial intermembrane space to form palmitoylcarnitine (L-PCARN) and CoA-SH. Three CPT1 isoforms exist; CPT1A, B and C. In the body, CPT1A is most abundant in liver while CPT1B is abundant in muscle. CPT1C is mainly expressed in neurons and localises to the ER and not to the mitochondria. It has little or no enzymatic activity in fatty acid oxidation. Both CPT1A and CPT1B are inhibited by malonyl-CoA (Morillas et al. 2002, 2004; Zammit et al. 2001; Zhu et al. 1997). Mutations in CPT1A are associated with defects in fatty acid metabolism and fasting intolerance, consistent with the role assigned to CPT1 from studies in vitro and in animal models (IJlst et al. 1998; Gobin et al. 2003).
In the nucleus, cellular retinoic acid-binding protein 1 or 2 (CRABP1 or 2), bound to all-trans-retinoic acid (atRA), directly binds to the heterodimeric complex of retinoic acid receptor alpha RXRA) and peroxisome proliferator-activated receptor delta (PPARD). When bound to PPARD, atRA can significantly increase the expression of proteins involved in fatty acid oxidation such as CPT1A via its induction of PPARD (Amengual et al. 2012).

Literature References
PubMed ID Title Journal Year
9691089 Molecular basis of hepatic carnitine palmitoyltransferase I deficiency

Mandel, H, IJlst, L, Oostheim, W, Ruiter, JP, Wanders, RJA, Gutman, A

J Clin Invest 1998
14711372 Structural model of carnitine palmitoyltransferase I based on the carnitine acetyltransferase crystal

Morillas, M, Asins, G, Hegardt, FG, Gomez-Puertas, P, Valencia, A, López-Viñas, E, Serra, D

Biochem J 2004
9344464 Functional studies of yeast-expressed human heart muscle carnitine palmitoyltransferase I

Cregg, JM, Woldegiorgis, G, Shi, J, de Vries, Y, Arvidson, DN, Zhu, H

Arch Biochem Biophys 1997
11790793 Structural model of a malonyl-CoA-binding site of carnitine octanoyltransferase and carnitine palmitoyltransferase I: mutational analysis of a malonyl-CoA affinity domain

Morillas, M, Arino, J, Asins, G, Hegardt, FG, Gomez-Puertas, P, Rubi, B, Clotet, J, Valencia, A, Serra, D

J Biol Chem 2002
14517221 Functional and structural basis of carnitine palmitoyltransferase 1A deficiency

Girard, J, Chi, M, Prip-Buus, C, Gobin, S, Jogl, G, Tong, L, Faye, A, Thuillier, L, Bonnefont, JP

J Biol Chem 2003
22871568 Induction of carnitine palmitoyl transferase 1 and fatty acid oxidation by retinoic acid in HepG2 cells

Amengual, J, Ribot, J, Bonet, ML, Petrov, P, Palou, A

Int. J. Biochem. Cell Biol. 2012
11356169 Structure-function relationships of the liver and muscle isoforms of carnitine palmitoyltransferase I

Jackson, VN, Zammit, VA, Fraser, F, Price, NT

Biochem Soc Trans 2001
Catalyst Activity

carnitine O-palmitoyltransferase activity of CPT1A,B [mitochondrial outer membrane]

This event is regulated
Negatively by
Orthologous Events
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