PNPLA4 (patatin-like phospholipase domain-containing protein 4, also known as GS2 and iPLA2(eta)) catalyzes the hydrolysis of TAG (triacylglycerol) to DAG (diacylglycerol) and one molecule of LCFA (long chain fatty acid). The enzyme also has transacylase activity not annotated here (Gao and Simon 2007; Jenkins et al. 2004).
PNPLA4 (patatin-like phospholipase domain-containing protein 4, also known as GS2 and iPLA2(eta)) catalyzes the hydrolysis of atR-PALM (all-trans retinyl palmitate) to atROL (all-trans retinol) and a molecule of PALM (palmitate) (Gao and Simon 2006; Gao and Simon 2007). The reaction is inhibited by cytosolic PLIN3 (perilipin 3). The enzyme may also catalyze transacylation reactions to form retinyl esters or promote the activity of other enzymes that do so (Gao et al. 2009).