Carnitine O-palmitoyltransferase 1, liver isoform

CPT1A (carnitine O-palmitoyltransferase 1, liver isoform) catalyzes the transfer of long-chain fatty acyl groups onto carnitine, facilitating mitochondrial uptake and β-oxidation of fatty acids (UniProt: P50416). The protein also possesses lysine succinyltransferase activity regulating substrate proteins independent of its classical carnitine palmitoyltransferase function, and contributes to immune regulation and antiviral responses through palmitoylation of MAVS at the mitochondria (UniProt: P50416).

CPT1A is primarily expressed in liver and plays a central role in hepatic triglyceride metabolism and fatty acid oxidation. Mutations in CPT1A cause carnitine palmitoyltransferase 1A deficiency (CPT1AD; MIM 255120), a rare autosomal recessive metabolic disorder characterized by hypoketotic hypoglycemia following fasting or illness in infancy (UniProt: P50416).

CPT1A is upregulated in post-mortem Alzheimer's disease brain tissue relative to age-matched controls (mean log2FC = 0.4775; Chaparral AD proteomics), suggesting altered fatty acid metabolism in AD pathology. This upregulation was detected across 2 of 4 subcellular fractions in TMT-labeled proteomics analysis, indicating potential metabolic remodeling associated with neurodegeneration.