Phospholipase A2 Antagonists Inhibit Constitutive Retrograde Membrane Traffic to the Endoplasmic Reticulum

Traffic (Impact Factor: 4.65). 05/2000; 1(6):504 - 511. DOI: 10.1034/j.1600-0854.2000.010608.x

ABSTRACT Eukaryotic cells contain a variety of cytoplasmic Ca2+-dependent and Ca2+-independent phospholipase A2s (PLA2s; EC However, the physiological roles for many of these ubiquitously-expressed enzymes is unclear or not known. Recently, pharmacological studies have suggested a role for Ca2+-independent PLA2 (iPLA2) enzymes in governing intracellular membrane trafficking events in general and regulating brefeldin A (BFA)-stimulated membrane tubulation and Golgi-to-endoplasmic reticulum (ER) retrograde membrane trafficking, in particular. Here, we extend these studies to show that membrane-permeant iPLA2 antagonists potently inhibit the normal, constitutive retrograde membrane trafficking from the trans-Golgi network (TGN), Golgi complex, and the ERGIC-53-positive ER-Golgi-intermediate compartment (ERGIC), which occurs in the absence of BFA. Taken together, these results suggest that iPLA2 enzymes play a general role in regulating, or directly mediating, multiple mammalian membrane trafficking events.

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