CPT1Cs

CPT1C, or carnitine palmitoyltransferase 1C, is a gene encoding a member of the carnitine palmitoyltransferase 1 (CPT1) family. The CPT1 enzymes catalyze the transfer of long-chain acyl groups from acyl-CoA to carnitine, a key step in channeling fatty acids into mitochondrial beta-oxidation. Of the three mammalian isoforms, CPT1A and CPT1B are widely expressed in liver and muscle, whereas CPT1C is predominantly expressed in the brain, with high levels in certain neuronal populations. In some texts, CPT1C proteins from different species are collectively referred to as CPT1Cs.

Biochemical properties: Unlike CPT1A and CPT1B, CPT1C shows little or no detectable CPT1 catalytic activity in standard assays and is generally regarded as catalytically inactive. It is thought to function primarily as a regulatory protein rather than an enzyme. Localization studies place CPT1C mainly in intracellular membranes of neurons, particularly in the endoplasmic reticulum, rather than in mitochondria.

Physiological roles: In the nervous system, CPT1C appears to influence energy homeostasis and feeding behavior through hypothalamic signaling networks. It may participate in cellular signaling pathways related to energy sensing and endoplasmic reticulum stress responses. The precise mechanisms and downstream partners are active areas of investigation.

Clinical relevance: Variants in CPT1C have been examined for associations with metabolic traits and neurological phenotypes, but evidence remains preliminary and replication is incomplete. Rare mutations have been reported in individual cases, yet causal links to disease require further validation.

See also: CPT1A, CPT1B.