Carnitine-acylcarnitine translocase (CACT) (CACT)

The Carnitine-acylcarnitine translocase (CACT), encoded by the SLC25A20 gene, is a vital transport protein located within the inner mitochondrial membrane and serves as a central component of the mitochondrial carnitine shuttle pathway (UniProt: O43772). Its primary biological function is to facilitate the 1:1 exchange of long-chain acylcarnitines for free carnitine, allowing fatty acids to enter the mitochondrial matrix for beta-oxidation (PubMed: 15737918). This pathway is essential for energy production, especially in tissues with high metabolic demands like the heart and skeletal muscle. Genetic defects in the SLC25A20 gene lead to Carnitine-acylcarnitine translocase deficiency, a severe metabolic disorder characterized by life-threatening episodes of hypoketotic hypoglycemia, cardiomyopathy, and liver dysfunction (NCBI: NBK1348). Pharmacologically, the shuttle pathway is targeted by drugs such as Meldonium and Perhexiline to shift cellular metabolism from fatty acid oxidation to glucose oxidation, which can be cardioprotective during ischemia (PubMed: 28215901). Furthermore, emerging research suggests that inhibiting this pathway may have therapeutic potential in treating certain cancers that are metabolically dependent on fatty acid oxidation.

Other names

Solute carrier family 25 member 20Mitochondrial carnitine/acylcarnitine carrierCACSLC25A20

Inhibition of the carnitine shuttle pathway reduces the transport of long-chain fatty acids into the mitochondria, thereby decreasing fatty acid oxidation and promoting glucose utilization, which can be cardioprotective in ischemic conditions (PubMed: 28215901).