Phosphatidylcholine (PC) synthesis by the CDP-choline pathway in mammalian cells regulates lipid droplet size and triacylglycerol storage. Mechanistically this involves increased CCTα expression and translocation to the nuclear envelope. CCTα regulates the PC synthesis required for lipid droplet biogenesis without associating with the surface of the particle.

Phosphatidylcholine (PtdCho), a zwitterionic glycerophospholipid that comprises 40-60% of eukaryotic membrane mass, is an essential component of lung surfactant, bile, and lipoproteins, and a source for signaling molecules such as diacylglycerol (DAG) and phosphatidic acid