The Fatty Acid Transport Protein (FATP1) Is a Very Long Chain Acyl-CoA Synthetase

• Published in: The Journal of biological chemistry Vol. 274; no. 51; pp. 36300 - 36304
• Main Authors: Coe, N R, Smith, A J, Frohnert, B I, Watkins, P A, Bernlohr, D A
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 17-12-1999
• Subjects: acyl-CoA synthase; Animals; Carrier Proteins - chemistry; Carrier Proteins - genetics; Carrier Proteins - metabolism; Coenzyme A Ligases - chemistry; Coenzyme A Ligases - genetics; Coenzyme A Ligases - metabolism; COS Cells; FATP1 protein; fatty acid transport protein; Fatty Acid Transport Proteins; Fatty Acids - metabolism; Membrane Proteins - chemistry; Membrane Proteins - genetics; Membrane Proteins - metabolism; Membrane Transport Proteins; Myc protein; Sequence Analysis; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.274.51.36300

The primary sequence of the murine fatty acid transport protein (FATP1) is very similar to the multigene family of very long
chain (C20-C26) acyl-CoA synthetases. To determine if FATP1 is a long chain acyl coenzyme A synthetase, FATP1-Myc/His fusion
protein was expressed in COS1 cells, and its enzymatic activity was analyzed. In addition, mutations were generated in two
domains conserved in acyl-CoA synthetases: a 6- amino acid substitution into the putative active site (amino acids 249–254)
generating mutant M1 and a 59-amino acid deletion into a conserved C-terminal domain (amino acids 464–523) generating mutant
M2. Immunolocalization revealed that the FATP1-Myc/His forms were distributed between the COS1 cell plasma membrane and intracellular
membranes. COS1 cells expressing wild type FATP1-Myc/His exhibited a 3-fold increase in the ratio of lignoceroyl-CoA synthetase
activity (C24:0) to palmitoyl-CoA synthetase activity (C16:0), characteristic of very long chain acyl-CoA synthetases, whereas
both mutant M1 and M2 were catalytically inactive. Detergent-solubilized FATP1-Myc/His was partially purified using nickel-based
affinity chromatography and demonstrated a 10-fold increase in very long chain acyl-CoA specific activity (C24:0/C16:0). These
results indicate that FATP1 is a very long chain acyl-CoA synthetase and suggest that a potential mechanism for facilitating
mammalian fatty acid uptake is via esterification coupled influx.