PalmitoylCoA

Palmitoyl-CoA is the CoA thioester of palmitic acid (a 16-carbon saturated fatty acid). It is a long-chain fatty acyl-CoA that functions as a central intermediate in lipid metabolism. It is formed in cells by ATP-dependent activation of palmitate catalyzed by acyl-CoA synthetases, yielding palmitoyl-CoA, AMP, and pyrophosphate.

In cellular metabolism, palmitoyl-CoA participates in beta-oxidation for energy production in mitochondria and, for some substrates, peroxisomes. Long-chain acyl-CoAs are transported into mitochondria via the carnitine shuttle, where CPT1 converts palmitoyl-CoA to palmitoyl-carnitine for import, and CPT2 regenerates palmitoyl-CoA for oxidation. Palmitoyl-CoA can also be elongated to longer-chain acyl-CoAs by fatty acid elongases (ELOVL enzymes) in the endoplasmic reticulum.

Palmitoyl-CoA serves as a substrate in lipid biosynthesis. It donates palmitoyl groups for the formation of glycerophospholipids and triacylglycerols through acyltransferase enzymes. It also participates in desaturation and further elongation processes that shape membrane lipid composition and lipid-derived signaling molecules.

Protein palmitoylation is another important role for palmitoyl-CoA. In this post-translational modification, a palmitoyl group is covalently attached to cysteine, serine, or threonine residues of proteins by DHHC family palmitoyltransferases, influencing membrane association, trafficking, stability, and signaling.

Dysregulation of palmitoyl-CoA metabolism can affect energy balance and lipid signaling, with potential links to metabolic disorders. Palmitoyl-CoA levels are modulated by enzymes that synthesize and hydrolyze acyl-CoA thioesters, and by intracellular transport mechanisms.