CDPCholinPfad

CDPCholinPfad (often referred to in English as the CDP‑choline pathway or Kennedy pathway) is a conserved biochemical route for the de novo synthesis of phosphatidylcholine, a major phospholipid of eukaryotic cell membranes. The pathway converts free choline into phosphatidylcholine through three enzymatic steps: phosphorylation of choline to phosphocholine by choline kinase; activation of phosphocholine to cytidine diphosphate‑choline (CDP‑choline) by CTP:phosphocholine cytidylyltransferase (CCT); and transfer of the phosphocholine moiety to diacylglycerol by choline phosphotransferase (CPT or CEPT) to form phosphatidylcholine.

The CDPCholinPfad operates primarily at the endoplasmic reticulum and nuclear envelope and is central to membrane biogenesis, lipid remodeling and cellular signaling. CCT is usually the rate‑limiting enzyme and is regulated by membrane lipid composition, phosphorylation state and interactions with amphipathic domains, allowing coordinated responses to changes in demand for membrane synthesis. In hepatocytes an alternative route, the PEMT pathway, partially complements CDP‑choline activity by methylating phosphatidylethanolamine to phosphatidylcholine.

Dysfunction of the CDPCholinPfad has been implicated in liver disease, neurodegeneration and altered lipid metabolism. CDP‑choline (citicoline) is also used as a pharmacological compound and nutritional supplement in some therapeutic contexts to support membrane repair and cognitive recovery. The pathway is evolutionarily conserved across eukaryotes and many prokaryotes, reflecting its fundamental role in cell physiology.