Schematic overview of hepatic lipid biosynthetic pathways

Schematic overview of hepatic lipid biosynthetic pathways. There are multiple inter-related pathways for the formation of the major liver phospholipids. The diet is a principal source for Cho and Etn, as well as the fatty acids that are assembled into DAG. Fatty acids may also be derived from de novo fatty acid biosynthesis or transported to the liver from adipose tissue. The major route to PtdCho is the CDP-Cho pathway: Cho kinase (ChoK), CCT, and Cho phosphotransferase (CPT). A major route to PtdEtn is the CDP-Etn pathway: Etn kinase (EtnK), ECT, and Etn phosphotransferase (EPT). Also, PtdCho is converted to PtdEtn by base-exchange with serine to form PtdSer, followed by its conversion to PtdEtn by decarboxylation (PSD) or potentially by another base-exchange enzyme (PSS2) that exchanges Etn for serine. PtdCho is produced from PtdEtn through sequential methylation by PEMT. TG is formed by DAG acyltransferases (DGAT) from the DAG that is not devoted to the synthesis of phospholipids.

Publication

Elimination of the CDP-ethanolamine Pathway Disrupts Hepatic Lipid Homeostasis. (2009) Roberta Leonardi, et al. J Biol Chem. 2009 Oct 2;284(40):27077-27089. Figure: F1. Homo sapiens

Disease mentions