long-chain-fatty-acid-CoA ligase 5; long-chain acyl-CoA synthetase 5; LACS 5 (ACSL5, ACS5, FACL5, UNQ633/PRO1250)

Function

• acyl-CoA synthetases (ACSL) activate long-chain fatty acids for both synthesis of cellular lipids, & degradation via beta-oxidation
• ACSL5 may activate fatty acids from exogenous sources for synthesis of triacylglycerol destined for intracellular storage (putative)
• utilizes a wide range of saturated fatty acids with a preference for C16-C18 unsaturated fatty acids (putative)
• may also stimulate fatty acid oxidation (putative)
• at the villus tip of the crypt-villus axis of the small intestine, may sensitize epithelial cells to apoptosis specifically triggered by the death ligand TRAIL
• may have a role in the survival of glioma cells

ATP + a long-chain carboxylic acid + CoA = AMP + diphosphate + an acyl-CoA

Cofactor: Mg+2 (putative)

Kinetic parameters:

• KM=0.11 uM for palmitic acid (isoform 1 at pH 7.5)
• KM=0.38 uM for palmitic acid (isoform 1 at pH 9.5)
• KM=0.04 uM for palmitic acid (isoform 3 at pH 7.5)
• KM=0.15 uM for palmitic acid (isoform 3 at pH 8.5)
• pH dependence:
  • optimum pH is
    • 9.5 (isoform 1)
    • 7.5-8.5 (isoform 3)

Structure

• belongs to the ATP-dependent AMP-binding enzyme family

Compartment

• mitochondrion outer membrane
• endoplasmic reticulum
• single-pass type 3 membrane protein (putative)

Alternative splicing

named isoforms=3

More general terms

• fatty-acid CoA ligase
• mitochondrial protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=51703
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:51703
• OMIM: https://mirror.omim.org/entry/605677
• UniProt: http://www.uniprot.org/uniprot/Q9ULC5.html