Catalytic subunit of the alternative triglyceride biosynthesis pathway, which mediates formation of triacylglycerol from diacylglycerol and membrane phospholipids . Synthesizes triacylglycerol at the expense of membrane phospholipids, such as phosphatidylcholine (PC) and its ether-linked form (ePC), thereby altering the composition of membranes . The alternative triglyceride biosynthesis pathway is probably required to provide the energy required for rapid growth when fuel sources are limiting . It maintains mitochondrial function during periods of extracellular lipid starvation . Can also use acyl-CoA as donor: acts as a acyl-CoA:monoacylglycerol acyltransferase (MGAT), but also shows acyl-CoA:diacylglycerol acyltransferase (DGAT) activity (By similarity).
Subcellular locations: Endoplasmic reticulum membrane