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Fatty acid binding protein facilitates sarcolemmal fatty acid transport but not mitochondrial oxidation in rat and human skeletal muscle.
J Physiol 2007; 582(Pt 1):393-405JP

Abstract

The transport of long-chain fatty acids (LCFAs) across mitochondrial membranes is regulated by carnitine palmitoyltransferase I (CPTI) activity. However, it appears that additional fatty acid transport proteins, such as fatty acid translocase (FAT)/CD36, influence not only LCFA transport across the plasma membrane, but also LCFA transport into mitochondria. Plasma membrane-associated fatty acid binding protein (FABPpm) is also known to be involved in sacrolemmal LCFA transport, and it is also present on the mitochondria. At this location, it has been identified as mitochondrial aspartate amino transferase (mAspAT), despite being structurally identical to FABPpm. Whether this protein is also involved in mitochondrial LCFA transport and oxidation remains unknown. Therefore, we have examined the ability of FABPpm/mAspAT to alter mitochondrial fatty acid oxidation. Muscle contraction increased (P < 0.05) the mitochondrial FAT/CD36 content in rat (+22%) and human skeletal muscle (+33%). By contrast, muscle contraction did not alter the content of mitochondrial FABPpm/mAspAT protein in either rat or human muscles. Electrotransfecting rat soleus muscles, in vivo, with FABPpm cDNA increased FABPpm protein in whole muscle (+150%; P < 0.05), at the plasma membrane (+117%; P < 0.05) and in mitochondria (+80%; P < 0.05). In these FABPpm-transfected muscles, palmitate transport into giant vesicles was increased by +73% (P < 0.05), and fatty acid oxidation in intact muscle was increased by +18% (P < 0.05). By contrast, despite the marked increase in mitochondrial FABPpm/mAspAT protein content (+80%), the rate of mitochondrial palmitate oxidation was not altered (P > 0.05). However, electrotransfection increased mAspAT activity by +70% (P < 0.05), and the mitochondrial FABPpm/mAspAT protein content was significantly correlated with mAspAT activity (r = 0.75). It is concluded that FABPpm has two distinct functions depending on its subcellular location: (a) it contributes to increasing sarcolemmal LCFA transport while not contributing directly to LCFA transport into mitochondria; and (b) its primary role at the mitochondria level is to transport reducing equivalents into the matrix.

Authors+Show Affiliations

Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Canada, N1G 2W1. ghollowa@uoguelph.caNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17478525

Citation

Holloway, Graham P., et al. "Fatty Acid Binding Protein Facilitates Sarcolemmal Fatty Acid Transport but Not Mitochondrial Oxidation in Rat and Human Skeletal Muscle." The Journal of Physiology, vol. 582, no. Pt 1, 2007, pp. 393-405.
Holloway GP, Lally J, Nickerson JG, et al. Fatty acid binding protein facilitates sarcolemmal fatty acid transport but not mitochondrial oxidation in rat and human skeletal muscle. J Physiol (Lond). 2007;582(Pt 1):393-405.
Holloway, G. P., Lally, J., Nickerson, J. G., Alkhateeb, H., Snook, L. A., Heigenhauser, G. J., ... Bonen, A. (2007). Fatty acid binding protein facilitates sarcolemmal fatty acid transport but not mitochondrial oxidation in rat and human skeletal muscle. The Journal of Physiology, 582(Pt 1), pp. 393-405.
Holloway GP, et al. Fatty Acid Binding Protein Facilitates Sarcolemmal Fatty Acid Transport but Not Mitochondrial Oxidation in Rat and Human Skeletal Muscle. J Physiol (Lond). 2007 Jul 1;582(Pt 1):393-405. PubMed PMID: 17478525.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Fatty acid binding protein facilitates sarcolemmal fatty acid transport but not mitochondrial oxidation in rat and human skeletal muscle. AU - Holloway,Graham P, AU - Lally,Jamie, AU - Nickerson,James G, AU - Alkhateeb,Hakam, AU - Snook,Laelie A, AU - Heigenhauser,George J F, AU - Calles-Escandon,Jorge, AU - Glatz,Jan F C, AU - Luiken,Joost J F P, AU - Spriet,Lawrence L, AU - Bonen,Arend, Y1 - 2007/05/03/ PY - 2007/5/5/pubmed PY - 2007/8/10/medline PY - 2007/5/5/entrez SP - 393 EP - 405 JF - The Journal of physiology JO - J. Physiol. (Lond.) VL - 582 IS - Pt 1 N2 - The transport of long-chain fatty acids (LCFAs) across mitochondrial membranes is regulated by carnitine palmitoyltransferase I (CPTI) activity. However, it appears that additional fatty acid transport proteins, such as fatty acid translocase (FAT)/CD36, influence not only LCFA transport across the plasma membrane, but also LCFA transport into mitochondria. Plasma membrane-associated fatty acid binding protein (FABPpm) is also known to be involved in sacrolemmal LCFA transport, and it is also present on the mitochondria. At this location, it has been identified as mitochondrial aspartate amino transferase (mAspAT), despite being structurally identical to FABPpm. Whether this protein is also involved in mitochondrial LCFA transport and oxidation remains unknown. Therefore, we have examined the ability of FABPpm/mAspAT to alter mitochondrial fatty acid oxidation. Muscle contraction increased (P < 0.05) the mitochondrial FAT/CD36 content in rat (+22%) and human skeletal muscle (+33%). By contrast, muscle contraction did not alter the content of mitochondrial FABPpm/mAspAT protein in either rat or human muscles. Electrotransfecting rat soleus muscles, in vivo, with FABPpm cDNA increased FABPpm protein in whole muscle (+150%; P < 0.05), at the plasma membrane (+117%; P < 0.05) and in mitochondria (+80%; P < 0.05). In these FABPpm-transfected muscles, palmitate transport into giant vesicles was increased by +73% (P < 0.05), and fatty acid oxidation in intact muscle was increased by +18% (P < 0.05). By contrast, despite the marked increase in mitochondrial FABPpm/mAspAT protein content (+80%), the rate of mitochondrial palmitate oxidation was not altered (P > 0.05). However, electrotransfection increased mAspAT activity by +70% (P < 0.05), and the mitochondrial FABPpm/mAspAT protein content was significantly correlated with mAspAT activity (r = 0.75). It is concluded that FABPpm has two distinct functions depending on its subcellular location: (a) it contributes to increasing sarcolemmal LCFA transport while not contributing directly to LCFA transport into mitochondria; and (b) its primary role at the mitochondria level is to transport reducing equivalents into the matrix. SN - 0022-3751 UR - https://www.unboundmedicine.com/medline/citation/17478525/Fatty_acid_binding_protein_facilitates_sarcolemmal_fatty_acid_transport_but_not_mitochondrial_oxidation_in_rat_and_human_skeletal_muscle_ L2 - https://doi.org/10.1113/jphysiol.2007.135301 DB - PRIME DP - Unbound Medicine ER -