Phospholipase D in the Golgi apparatus

Abstract

Phospholipase D has long been implicated in vesicle formation and vesicular transport through the secretory pathway. The Golgi apparatus has been shown to exhibit a plethora of mechanisms of vesicle formation at different stages to accommodate a wide variety of cargo. Phospholipase D has been found on the Golgi apparatus and is regulated by ADP-ribosylation factors which are themselves regulators of vesicle trafficking. Moreover, the product of phospholipase D activity, phosphatidic acid, as well as its degradation product diacylglycerol, have been implicated in vesicle fission and fusion events. Here we summarize recent advances in the understanding of the role of phospholipase D at the Golgi apparatus.

Fig. 1

Phosphatidic acid and diacylglycerol can be synthesized through separate routes on the Golgi apparatus. In mammalian cells all pathways are active, allowing for complexity of regulation. Note that diacylglycerol might be derived by additional pathways. PA, phosphatidic acid; PLD, phospholipase D.

Fig. 2

Regulation and effectors of phospholipase D and phosphatidic acid on the Golgi apparatus. See text for details. ARF, ADP-ribosylation factor; BARS, Brefeldin-A ADP-ribosylated substrate; DG, diacylglycerol; PA, phosphatidic acid; PAP, PA phosphatase; PC, phosphatidylcholine; PI, phosphatidylinositol; PIP, PI 4-phosphate; PIP₂, PI 4,5-bisphosphate; PI4KIIIβ, type III PI 4-kinase β; PI4P5K, type I PIP 5-kinase; PKD, protein kinase D; PLD, phospholipase D; SAC1, PIP 4-phosphatase; 5-P’tase, PIP₂ 5-phosphatase.